Industrial Training Report
111
UNIVERSITY OF MORATUWA Faculty of Engineering Non-GPA Module 3992: Industrial Training TRAINING REPORT R.M. Azoor 100860K Earth Resources Engineering Holcim Lanka Ltd. 11-11-2013 to 02-05-2014 13-06-2014
Transcript of Industrial Training Report
UNIVERSITY OF MORATUWA
Faculty of Engineering
Non-GPA Module 3992: Industrial Training
TRAINING REPORT
R.M. Azoor
100860K
Earth Resources Engineering
Holcim Lanka Ltd.
11-11-2013 to 02-05-2014
13-06-2014
i
PREFACE
I received the opportunity of undergoing my 6-month Industrial Training at Holcim Lanka
Ltd. I was placed along with three other colleagues at the Aruawakkalu Limestone mine
situated in Eluwankulam Puttalam Sri Lanka. The training period spanned a total of 24
weeks, from 18th of November 2013 to the 2nd of May 2014. In this report I have attempted
to provide a brief but thorough description of the knowledge gathered, skills acquired and
mastered and, and situations experienced. The content to follow in this report are based on
my experiences and were compiled by myself.
This report is organized in three chapters. The first chapter gives a brief introduction about
the training establishment. Holcim being a multinational company, the chapter begins with
some background information about the global Holcim group. Next, information regarding
Holcim Lanka Ltd is presented along with the vision and mission statements, organizational
structures and product portfolio. This information has been structured starting from the
corporate level, to the Palavi processing plant and finally to the Limestone Quarry where we
were placed at. The first chapter ends with a SWOT analysis of Holcim Lanka Ltd.
The second Chapter emphasizes on the training experiences I received. The chapter begins
with our induction to the organization. Information we gathered and learnt during the first
few days at the Aruwakkalu mine such as the geology of the area, the summary of the
quarrying process and the office practices and administration activities are included here. The
rest of the chapter is organized into subsections according to the principal operations carried
out during limestone mining. Each subsection contains a brief introduction to the processes
and highlights activities carried by us relating to each of the quarrying processes. Summaries
of findings made have been included where possible and other relevant information has been
annexed. This chapter also highlights learning opportunities we received.
The third and final chapter of this report presents the conclusion of the training program by
highlighting the knowledge and experiences gained, competencies developed, weakness
identified in myself and the overall personal growth experienced during the training period. .
I have also included comments on the entire training program. Suggestions have also been
included where applicable. In writing this report I have tried my level best to give a complete
picture of the content and value of the training program that I underwent as part of the BSc
Engineering Hons Degree program. and also believe that it meets this objective.
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ACKNOWLEDGEMENT
It is widely accepted that the 6 month Industrial training is the most important aspect of the
BSc Engineering Degree. It enables undergraduates to get hands on experience in the industry
and helps to gather practical knowledge which could only be acquired through working. I was
fortunate to undergo this valuable training at Holcim Lanka Ltd, one of the most prestigious
establishments in the industry. This opportunity would not have been a reality if not for the
effort and commitment put in by many individuals, at the University of Moratuwa, NAITA
and Holcim Lanka Ltd, into ensuring a solid and valuable training experience.
Firstly, my thanks goes to Mr. N.A. Wijeyewickrema, Director of the Industrial Training
Division and all other Personnel at the Training Division for facilitating the training program.
I also wish to acknowledge the officials at NAITA for arranging our training program. I wish
to thank the Head of the department of Earth Resources Engineering, Dr A.M.K.B.
Abeysinghe and other officials at the department for the support given in this regard. My
special thanks go to Mr. S. Weerawarnakula for arranging out training placements and for the
valuable insight given regarding our training program and also for the guidance given to us.
I wish to thank all personnel at Holcim Lanka Ltd for providing such a valuable training
program for us. I wish to thank Quarry Manager, Mr. W.N. Wedage for guiding us
throughout the program and for highlighting the outcomes of training and ways of achieving
them during our training period. I also wish to thank Quarry Engineer, Mr. Gayan Silva for
enabling a smooth induction to the organization and for the guidance given to us. My special
thanks go to the Junior Mining Engineers, Mr. P. Kumarage and Mr. A. Batagalla for taking
us under their wing and for providing us with the required knowledge and for giving us hands
on experience in all mining activities.
I also wish to thank Human Resources Officer at the Quarry, Mr. R.K.S. Marasinghe for the
support given to us with our lodging and other facilities and also Maintenance Superintendant
Mr. R.P.S. Dhanuka, Laboratory officers, Mr. R.P.W. Kariyawsam, Mr. J.M.W. Jayasundara,
Mr. A.H.M. Premaratne, Mr. R.M.S. Jayaratne and Mr. K.K.J. Darmasiri for further
enhancing our training experience. I am also thankful to all operators at the quarry for sharing
their knowledge and also the security officers and all other employees for the support
provided. I also wish to specially thank my fellow trainees with whom I had a pleasant
training experience.
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CONTENTS
Preface ..................................................................................................................................................... i
Acknowledgement .................................................................................................................................. ii
Contents ................................................................................................................................................. iii
List of Figures ......................................................................................................................................... vi
List of Tables ........................................................................................................................................ viii
List of Equations ................................................................................................................................... viii
1 Introduction to the Training Establishment .................................................................................... 1
1.1 Holcim Group .......................................................................................................................... 1
1.2 Holcim Lanka Ltd ..................................................................................................................... 1
1.2.1 Organizational Structure ................................................................................................. 2
1.2.1.1 Corporate Structure .................................................................................................... 2
1.2.1.2 Palavi Processing Plant Structure ................................................................................ 3
1.2.1.3 Aruwakkalu Quarry Structure ..................................................................................... 3
1.2.2 History of the Aruwakkalu Mine ..................................................................................... 3
1.2.3 Vision and Mission Statements ....................................................................................... 4
1.2.3.1 Vision ........................................................................................................................... 4
1.2.3.2 Mission ........................................................................................................................ 4
1.2.4 Product Portfolio ............................................................................................................. 4
1.2.4.1 Holcim Sanstha Supiri ................................................................................................. 4
1.2.4.2 Holcim Ready Flow ...................................................................................................... 5
1.2.4.3 Holcim Extra ................................................................................................................ 5
1.2.4.4 Ambuja Cement .......................................................................................................... 5
1.3 SWOT Analysis of Holcim Lanka Ltd ........................................................................................ 6
2 Training Experiences ....................................................................................................................... 9
2.1 Induction to the Organization ................................................................................................. 9
2.1.1 Safety Induction .............................................................................................................. 9
2.1.2 Familiarization with the Quarry Site ............................................................................... 9
2.1.2.1 The mining land extent ............................................................................................. 10
2.1.2.2 Geology of the Area .................................................................................................. 11
2.1.3 The quarrying process ................................................................................................... 12
2.1.4 Administration and Office Activities ............................................................................. 14
2.1.4.1 Engineering and Maintenance division ..................................................................... 14
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2.1.4.2 Quarry Lab ................................................................................................................. 14
2.1.4.3 Human Resources Division ........................................................................................ 14
2.1.4.4 Security Division ........................................................................................................ 14
2.2 Bed Cleaning, Drilling and Blasting ....................................................................................... 15
2.2.1 Bed Cleaning ................................................................................................................. 15
2.2.1.1 Machines Used .......................................................................................................... 15
2.2.1.2 Activities Carried Out ................................................................................................ 16
2.2.2 Drilling ........................................................................................................................... 18
2.2.2.1 The Drilling Process ................................................................................................... 18
2.2.2.2 Machines Used .......................................................................................................... 19
2.2.2.3 Drill Patterns ............................................................................................................. 20
2.2.2.4 Hazards encountered in Drilling and their mitigation .............................................. 22
2.2.3 Blasting .......................................................................................................................... 24
2.2.3.1 Explosives .................................................................................................................. 24
2.2.3.2 Explosive Handling and Storage ................................................................................ 28
2.2.3.3 Charging .................................................................................................................... 29
2.2.3.4 Blast Wiring and Detonation ..................................................................................... 32
2.2.3.5 Specific Charge .......................................................................................................... 34
2.2.3.6 Other types of Blasting.............................................................................................. 35
2.2.3.7 Problems Encountered in Blasting ............................................................................ 37
2.2.3.8 Hazard Management in Blasting ............................................................................... 38
2.2.4 Activities Carried Out by Us .......................................................................................... 39
2.3 Loading, Hauling and Dispatching ......................................................................................... 43
2.3.1 Loading and Hauling Machine Fleet .............................................................................. 43
2.3.1.1 Komatsu WA600 Front End Wheel Loader ............................................................... 43
2.3.1.2 Komatsu HD 325A Dump Trucks ............................................................................... 45
2.3.1.3 3rd Party 10-Wheel Haul Trucks ............................................................................... 53
2.3.2 Hauling roads ................................................................................................................ 55
2.3.2.1 Road Maintenance .................................................................................................... 55
2.3.2.2 Planning and Design .................................................................................................. 57
2.3.3 Dispatching .................................................................................................................... 60
2.3.3.1 The Dispatching Process ........................................................................................... 60
2.3.3.2 Locomotive Transport ............................................................................................... 60
2.3.4 Activities and Projects ................................................................................................... 62
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2.3.4.1 Hauling Fleet Optimization ....................................................................................... 62
2.3.4.2 Hauling road level survey and road slope analysis ................................................... 64
2.4 Quality Control and Planning ................................................................................................ 69
2.4.1 Lab Activities ................................................................................................................. 69
2.4.1.1 Sampling .................................................................................................................... 69
2.4.1.2 Quality Parameters ................................................................................................... 73
2.4.1.3 Laboratory Testing .................................................................................................... 74
2.4.2 QSO and Quarry Master ................................................................................................ 75
2.4.2.1 Quarry Scheduling and Optimization (QSO) ............................................................. 75
2.4.2.2 QuarryMaster ............................................................................................................ 77
2.4.3 Mix Bed Preparation ..................................................................................................... 79
2.4.4 Activities at Palavi Processing Plant .............................................................................. 79
2.4.5 Activities carried out ..................................................................................................... 80
2.4.5.1 Alumina mapping of the Quarry ............................................................................... 80
2.4.5.2 Preparing Cross Sections of the Quarry Pit ............................................................... 80
2.4.5.3 Fill Volume Calculation of Old Road .......................................................................... 81
2.5 Overburden Removal and Rehabilitation ............................................................................. 82
2.5.1 Overburden Removal .................................................................................................... 82
2.5.1.1 cycle times ................................................................................................................. 82
2.5.1.2 Bench face and slope analysis ................................................................................... 83
2.5.2 Rehabilitation of the Quarry ......................................................................................... 87
2.5.2.1 Activities with IUCN................................................................................................... 87
2.5.2.2 Seedling bed Preparation .......................................................................................... 87
2.6 Machine maintenance and Workshop Activities .................................................................. 88
2.6.1 Daily maintenance operations ...................................................................................... 88
2.6.1.1 Tyre Maintenance .................................................................................................... 89
2.6.1.2 Welding Grinding ...................................................................................................... 89
2.6.2 Machine Safety Survey .................................................................................................. 89
2.7 Workshops and Other Learning Opportunities ..................................................................... 90
2.7.1 Lubricant Workshop at CETRAC .................................................................................... 90
2.7.2 Workshop on Maintenance of Construction Equipment ............................................. 91
2.7.3 Tire maintenance lecture by Triangle tire corporation ................................................. 91
3 Conclusion ..................................................................................................................................... 92
Annexes .................................................................................................................................................. ix
vi
Cement Production Chart .................................................................................................................. ix
Fill Volume Report .............................................................................................................................. x
List of Abbreviations ............................................................................................................................. xv
References ............................................................................................................................................xvi
LIST OF FIGURES
Figure 1.1: Corporate Organization Structure ........................................................................................ 2
Figure 1.2 : Organization Structure of Palavi Processing Plant ............................................................... 3
Figure 1.3 : Organization Structure of Quarry ........................................................................................ 3
Figure 1.4: Summary of SWOT Analysis .................................................................................................. 8
Figure 2.1 : Land Extent belonging to Quarry and the Quarry Pit ........................................................ 10
Figure 2.2 : A quarry face showing each type of material .................................................................... 12
Figure 2.3 : The Entire Quarrying Process ............................................................................................. 13
Figure 2.4 : The Entire Quarrying Process ............................................................................................. 13
2.5: Bed Cleaning using Komatsu D375 A ............................................................................................. 15
Figure 2.6: The CAT 374D Excavator being used for loading ................................................................ 16
Figure 2.7 : A covered Drill Hole ........................................................................................................... 19
Figure 2.8 : Parts of a track Drill ............................................................................................................ 20
Figure 2.9 : A typical Staggered Drill Pattern ........................................................................................ 21
Figure 2.10 : Burden, Spacing and Hole Depth of a Bed ....................................................................... 22
Figure 2.11 : Drilling at Night ................................................................................................................ 24
Figure 2.12 : Dynamite Cartridges ........................................................................................................ 25
Figure 2.13 : Water gel Cartridges ........................................................................................................ 26
Figure 2.14: A bag of Ammonium Nitrate ............................................................................................ 27
Figure 2.15 : Schematic and an image of an Electric Detonator ........................................................... 28
Figure 2.16: A primed water gel cartridge couple ................................................................................ 29
Figure 2.17 : Connecting an extra wire to an ED .................................................................................. 30
Figure 2.18 : Normal and Deck Charging .............................................................................................. 31
Figure 2.19 : A Series Parallel Circuit with 4 Loops .............................................................................. 32
Figure 2.20 : Circuit Diagram for Wiring Pattern .................................................................................. 33
Figure 2.21 : Charging a Drill Hole in Boulder Blasting ......................................................................... 35
Figure 2.22 : Fragmentation after Boulder Blasting.............................................................................. 35
Figure 2.23 : Methods of Boulder Blasting ........................................................................................... 36
Figure 2.24 : Testing Circuit .................................................................................................................. 38
Figure 2.25 : Yellow Fumes when Blasting ............................................................................................ 38
Figure 2.26 : Signboards for the Explosive Magazine ........................................................................... 40
Figure 2.27 : Stacking Line .................................................................................................................... 40
Figure 2.28 : The refurbished Explosive Magazine ............................................................................... 41
Figure 2.29 : Plan of Proposed Ammonia Hut ....................................................................................... 42
Figure 2.30 : Komatsu WA 600 Loader ................................................................................................. 43
Figure 2.31 : Komatsu HD 325 A Dump Truck ....................................................................................... 45
Figure 2.32 : Tyre Positions ................................................................................................................... 50
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Figure 2.33 : Road Watering Plan ......................................................................................................... 57
Figure 2.34 : The Planned New Ramp Area .......................................................................................... 58
Figure 2.35: Current and Future Cycle Distances .................................................................................. 59
Figure 2.36 : Locomotive Transport ...................................................................................................... 60
Figure 2.37 : Queue at the Loading Point ............................................................................................. 64
Figure 2.38 : 3D Model of road created using Surfer ........................................................................... 65
Figure 2.39 : Two methods of road filling ............................................................................................. 66
Figure 2.40 : Refilled Area of the New Road ......................................................................................... 68
Figure 2.41 : A typical test hole............................................................................................................. 69
Figure 2.42: 3D models of upper and lower layers ............................................................................... 71
Figure 2.43 : Coning and Quartering ..................................................................................................... 72
Figure 2.44 : The QSO Layout ................................................................................................................ 76
Figure 2.45 : QSO prediction for 4 quarters of 2014 ............................................................................ 77
Figure 2.46 : The 3 Dimensional Model of the Quarry in QuarryMaster .............................................. 78
Figure 2.47 : Short Term Mine Planning with QuarryMaster ............................................................... 78
Figure 2.48 : Preparing of Mixed Heaps ................................................................................................ 79
Figure 2.49 : Layered appearance of a Mixed Heap ............................................................................. 79
Figure 2.50: Contour Map of Alumina Variation ................................................................................... 80
Figure 2.51 : Cross Sections of the Quarry Pit ...................................................................................... 81
Figure 2.52 : The Existing Surface and the Proposed Surface ............................................................... 81
Figure 2.53 : Overburden Removal ....................................................................................................... 82
Figure 2.54 : Risk Assessment Matrix ................................................................................................... 86
Figure 2.55: Seedling Bed Locations ..................................................................................................... 87
Figure 2.56 : Daily Machine Checks ...................................................................................................... 88
Figure 2.57 : Welding Operations ......................................................................................................... 89
Figure 2.58 : The Excel data Entry Form Used for the Machine Survey ............................................... 90
Figure A.3.1 : The Cement Production Process ...................................................................................... ix
Figure A.3.2: Elevation Grid .................................................................................................................. xii
FigureA.3.3: Surfer 3D model of Existing Surface ................................................................................ xiii
FigureA.3.4:Surfer 3D model of Proposed Surface ...............................................................................xiv
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LIST OF TABLES
Table 2.1 : Fuel Consumption of D375A during bed cleaning ............................................................... 17
Table 2.2 : Advantages and Disadvantages of Dynamite ...................................................................... 25
Table 2.3 : Advantages and Disadvantages of Water gel ...................................................................... 26
Table 2.4: Quantities of Explosives Used .............................................................................................. 31
Table 2.5 : Fuel Consumption of WA 600 Wheel Loader ...................................................................... 44
Table 2.6 : Dump Truck Cycle Times ..................................................................................................... 46
Table 2.7 : Tyre Records ........................................................................................................................ 48
Table 2.8 : Fuel Consumption of Dump Trucks ..................................................................................... 52
Table 2.9 : Summary of Dump Truck Cost ............................................................................................. 53
Table 2.10 : Comparison of Hauling Trucks........................................................................................... 54
Table 2.11 : Effective Distance in Road watering.................................................................................. 56
Table 2.12 : Loading Process times of Sump Trucks and 10-Wheel Trucks .......................................... 63
Table 2.13 : Calculated fill Heights in the two Methods ....................................................................... 67
Table 2.14 : Coordinates extracted from Test Hole Data ..................................................................... 70
Table 2.15: Quality Targets of the Quarry ............................................................................................ 74
Table 2.16 : Overburden Removal Cycle Time Summary ...................................................................... 83
Table 2.17: Summary of Bench Face Risk Assessment ......................................................................... 84
LIST OF EQUATIONS
Equation 2.1: Drilling Cycle Time .......................................................................................................... 18
Equation 2.2 : Calculating Blast tonnage .............................................................................................. 21
Equation 2.3 : Resistance in a Series Circuit ......................................................................................... 33
Equation 2.4 : Resistance in a Parallel Circuit ....................................................................................... 33
Equation 2.5 : Specific Charge............................................................................................................... 34
Equation 2.6 : Formula for LSF .............................................................................................................. 73
Equation 2.7 : Alumina Ratio ................................................................................................................ 73
Equation 2.8: Silica Module .................................................................................................................. 73
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1 INTRODUCTION TO THE TRAINING ESTABLISHMENT
1.1 Holcim Group
Holcim is a Swiss based company specializing in the production of cements and aggregate. It
was founded in 1912 in Jona Switzerland and was known as Holderbank until the company
changed its name to "Holcim in 2001. As of 2014, Holcim operates in more than 70 countries
worldwide and has a workforce of 71000 employees. The current production capacity of
Holcim is, 215 million tons per year. In addition to cement and aggregate products Holcim
also provides consultancy services and energy and waste management solutions. Holcim is
one of the two largest cement manufactures in the world with the other being Lafarge. In
April 2014, it was announced that the two companies have agreed to a merger. This new
company, LafargeHolcim, would be the world leader in the industry by far with a
manufacturing capacity of over 427 million tons per year.
1.2 Holcim Lanka Ltd
Holcim Lanka Ltd is a part of the global Holcim group and is the market leader in cement and
related building materials in Sri Lanka. Like Holcim global, Holcim Lanka Ltd also provides
technical and consultation services in the fields of construction and waste management in
addition to manufacturing cement. While being the leader in the industry, Holcim Lanka Ltd
is also Sri Lanka's only integrated cement manufacturer. This means that cement is produced
from raw materials sourced from Sri Lanka itself, unlike most other processes where clinker
used for manufacturing cement is imported. This integrated cement manufacturing process
used by Holcim Lanka Ltd is often described as a "Quarry to Lorry Operation".
Holcim Lanka Ltd operates a limestone mine in Aruwakkalu where the main component of
cement, limestone is sourced, a processing plant in Palavi where the cement is produced and
packed, and a grinding plant in Galle. Another packing plant is planned to be constructed in
Tricomalee. In addition to these, Holcim Lanka Ltd also operates the Galle Import terminal
where Ambuja cement is imported. The head office of Holcim Lanka Ltd is located at 413,
Duplication Road Colombo 3. Finance, Human Resources, Business planning and other
management processes are performed here.
Limestone mined from the Aruwakkalu Quarry site, is transported to the processing plant at
Palavi via railway where limestone and other additives also sourced from various locations in
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Sri Lanka are processed to produce cement. The cement is packed and distributed through an
extensive distribution network spanning all 9 provinces of Sri Lanka.
Holcim Lanka Ltd has a production capacity of about 1.6 million tons of cement per year and
has a workforce of about 15,000 employees (both direct and indirect). Holcim Lanka Ltd
generated annual revenues of Rupees 20.1 billion (157 million USD ) in the year 2012. Along
with its improved financial performance Holcim Lanka Ltd has also strived to give value
back to the society with its many CSR Projects. Holcim Lanka Ltd is also a trendsetter in
sustainable development in the industry.
1.2.1 Organizational Structure
Holcim Lanka Ltd, has a functional organizational structure where the organization is divided
into segments according to the functions performed. The structure follows a hierarchical
arrangement with clear lines of reporting. Starting from the corporate level, the structure
leading to that of the Aruwaakalu Quarry has been shown below.
1.2.1.1 Corporate Structure
In the corporate structure shown below, the Quarry and the Plant comes under the
Manufacturing department.
Figure 1.1: Corporate Organization Structure
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1.2.1.2 Palavi Processing Plant Structure
The Palavi Processing Plant is headed by the plant manager .
Figure 1.2 : Organization Structure of Palavi Processing Plant
1.2.1.3 Aruwakkalu Quarry Structure
All staff at the quarry report to the Quarry Manager as shown below.
Figure 1.3 : Organization Structure of Quarry
1.2.2 History of the Aruwakkalu Mine
The Integrated cement plant consisting of the Aruwwakalu limestone mine and the
Processing plant at Palavi was previously known as the Cement Corporation and was a fully
government owned entity. It began operations in 1970 and functioned under the Ministry of
Industrial Development. In 1993, the cement corporation was privatized and taken over by a
Pakistani cement company named "Thawakkal". In 1996, the company ownership was
transferred to "Holderbank", the company which eventually changed its name to "Holcim" in
the year 2001.
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1.2.3 Vision and Mission Statements
Sustainable Development is the core value of all business activities of Holcim Lanka Ltd. It
Strives to create value by strengthening the communities it serves. To achieve its goal of
sustainable development, Holcim Lanka Ltd takes a "Triple bottom line" approach, where
economic, social and environmental impacts, are integrated into all day to day business
activities and core operations. The vision and mission statements of the company are as
follows.
1.2.3.1 Vision
"To be the leading and the preferred supplier of cement and related building materials to
build foundations for Sri Lanka's future. "
1.2.3.2 Mission
"To be Sri Lanka's most respected and attractive company - creating value to all our stake
holders."
1.2.4 Product Portfolio
In essence, cement is manufactured by grinding clinker to a fine powder. Cement acts as a
binding agent when mixed with water, sand and gravel to produce concrete. the properties of
cement and the resulting concrete can be varied with different ratios of the ingredients and
also with various additives.
To meet the requirements of the current construction industry, Holcim Lanka Ltd produces a
range of cements each with its own characteristic properties. The Current product portfolio of
Holcim Lanka Ltd is given below.
In addition to the products mentioned below , Holcim Lanka also produces customized blends
of cement with tailor made properties for special applications and projects.
1.2.4.1 Holcim Sanstha Supiri
Holcim Sanstha Supiri is the most popular product of Holcim Lanka Ltd and has rooted
deeply into the Sri Lankan society as a consistent and dependable cement. It is a Portland
Limestone cement manufactured in compliance with Sri Lankan and British standards. The
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characteristic property of this cement is it's high workability. High workability reduces
bleeding and honeycomb effects. This results in a high long term strength in the concrete.
Recommended Applications: Structural elements in normal concrete (foundations, slabs and
beams )
Packaging and Delivery : Can be purchased in 50kg bags
1.2.4.2 Holcim Ready Flow
Holcim Ready Flow is an ordinary portland cement manufactured in compliance with Sri
Lankan and British standards. By optimizing the cement content, it helps the concrete achieve
high strength and durability. Also in using this cement the cost for admixtures can be
lowered.
Recommended Applications: Ready mix and structural concrete applications such as
infrastructure projects where early strength and durability is required.
Packaging and Delivery : Has to be purchased in bulk form
1.2.4.3 Holcim Extra
This is a relatively new addition to the Holcim product lineup and is a portland pozzolana
cement manufactured in compliance with Sri Lankan standards. It is a high performance
cement produced to withstand severe environments and to last longer. Concrete made using
Holcim Extra is resisitant to acids, sulfates, and chlorides.
Recommended Applications: Long term Concrete structures exposed to sea water such as
harbours, jetties, sea walls, bulkheads. Infrastructure in wastewater and hazardous material
handling projects.
Packaging and Delivery : Has to be purchased in bulk form
1.2.4.4 Ambuja Cement
It is an ordinary portland cement imported by Holcim Lanka ltd also manufactured
incompliance to British and Sri Lankan standards. It has a high early strength and a quicker
setting time.
Recommended applications : Pre cast work where quick setting is required.
Packaging and Delivery : Can be purchased in 50kg bags
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1.3 SWOT Analysis of Holcim Lanka Ltd
A SWOT Analysis, examining the Strengths, Weaknesses, Opportunities and Threats to
Holcim Lanka Ltd., was performed as follows.
Strengths
Sri Lanka's only Integrated cement manufacturer
- Holcim Lanka Ltd, operates Sri Lanka's only integrated cement
manufacturing process. This reduces the cost by a significant amount.
Lots of past experiences
- Having had over 50 years of experience in the industry as, Lanka Cement
Corporation and also with experience from Holcim Global, Holcim Lanka Ltd,
has a lot of accessible knowledge on cement production.
Well known brand in Sri Lanka
- Formerly "Sanstha" and now "Holcim Sanstha" brand is well known in the
Sri Lankan Society and is often associated with higher standards in the cement
industry.
Solid Quality Control
- With extensive measures for quality control such as the state of the art X-Ray
Fluorescence spectroscopy method employed at the plant, high quality cement
can be produced with consistency.
Safety Standards
- Being a company highly commited to safety it occupies a high place in the
minds of potential employees.
Extensive distribution network
- Holcim Lanka Ltd possesses an extensive distribution network making its
brand well known in even the remotest corners of the country.
International Support
- Holcim being a multinational company, it receives continuous technical
support and expertise which help elevate the standards of cement
manufacturing and other related activities such as quarrying.
Sustainability
- Being a trend setter in sustainability, Holcim Lanka Ltd. has a solid
foundation in the cement industry of Sri Lanka.
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Weaknesses
Higher Price
- Being a premium cement brand in Sri Lanka, the price of Holcim cement is
markedly higher than other brands. This causes a demand shift towards the
other cheaper brands in the market.
Long distance between quarry and plant
- The Limestone quarry and the processing plant being situated over 30
kilometers apart increases the transportation cost and also the overall
production cost.
Lesser marketing of Specialty Cements
- Holcim Lanka Ltd. Produces specialty cements suitable for unique
applications such as irrigation projects, and high performance and abrasion
resistive cements. However, due to the lack of proper marketing, many are not
aware of this fact.
Opportunities
Expanding Manufacturing processes
- Sri Lanka has extensive limestone deposits in the Northern part of country.
Also, infrastructure such as the KKS cement plant already being available ,
presents the opportunity to Holcim to expand its integrated cement
manufacturing process further.
Rapid infrastructure development
- Due to the rapid development of Sri Lanka, the construction industry is
booming and the demand for cement is increasing rapidly. This creates a lot of
opportunities in marketing Holcim Cements in mass scale.
Global Merger
- The planned merger between Holcim Global and Lafarge, the two largest
cement manufacturers in the world would also enable Holcim Lank to attain
new heights in the Sri Lankan Industry as well.
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Threats
Low price imported alternatives
- Several new lower priced cement brands have and continue to enter the
market and poses the threat of lowering the market share of Holcim Cement.
High Energy Cost
- Cement manufacturing is highly energy intensive process and the recent
increase in fuel prices have increased the overall production cost of cement.
World Cement demand decreasing
- Although the Sri Lankan construction industry is booming, the global
demand for cement is declining and with it the research and development into
the area. This reduces the international support received by Holcim Lanka.
Environmental protests for quarrying process
- Despite the extensive rehabilitation and the environmentally friendly
methods employed, the limestone quarrying process is still opposed by several
environmental activists.
Figure 1.4: Summary of SWOT Analysis
Strengths
•Sri Lanka's only Integrated cement manufacturer
•Lots of past experiences
•Well known brand in Sri Lanka
•Solid Quality Control
•Safety Standards
•Extensive distribution network
•International Support
•Sustainability
Weaknesses
•Higher Price
•Long distance between quarry and plant
•Lesser marketing of Specialty Cements
Opportunities
•Expanding Manufacturing processes
•Rapid infrastructure development
•Global Merger
Threats
•Low price imported alternatives
•High Energy Cost
•World Cement demand decreasing
•Environmental protests for quarrying process
Holcim Lanka Ltd.
9
2 TRAINING EXPERIENCES
2.1 Induction to the Organization
Upon arriving at the Palavi Cement plant and signing the training contracts, we were given a
safety induction by the safety officer. Then we arrived at the Aruwakkalu Quarry Site where
our entire training program took place. During the first day at the Aruwakkalu site, we were
given a tour of the quarry site and office premises and also another safety induction.
2.1.1 Safety Induction
Holcim Lanka Ltd considers safety to be of paramount importance and strives hard to
maintain a workplace with zero harm or injury. While safety procedures are implemented in
all operations, the safety regulations at Holcim are distilled down to 5 "Cardinal Rules".
These cardinal rules are,
1. Do not override or interfere with any safety provision, nor allow anyone else to override or
interfere with them, regardless of their relative seniority to yourself.
2. Personnel protective equipment (PPE), Rules applicable to a given task, must be adhered to
at all times.
3. Isolation and lockout procedures must always be followed.
4. No person may work if under the influence of alcohol or drugs.
5. All injuries and incidents must be reported.
We were given a thorough safety induction and all necessary Personnel Protection Equipment
including Safety Shoes, Hard hats and Safety Goggles. We were also given uniforms with a
high visibility reflective band. All employees at Holcim Lanka Ltd, all third party contractors
and even trainees are expected to be well versed in the above cardinal rules and to strictly
adhere to them.
2.1.2 Familiarization with the Quarry Site
After the Safety Induction and the tour of the quarry premises we were given a brief
introduction about the quarry site and the geology of the limestone basin.
10
2.1.2.1 The mining land extent
The land extent available for mining is bordered by the Dutch Bay from the east and Kala
Oya from the West. Beyond the Kala Oya lies the Wilpattu National Wildlife Reserve. The
boundary of this land extent is outlined in light green in Figure 2.1. This large land has been
divided into 3 blocks namely A, B, and C. Only Block A has been mined up to now. The
entire land extent has been explored and prospected during the 1950s for limestone, by means
of core drilling operations. The data gathered from these core drill data has been fed into the
QSO (Quarry Scheduling and Optimization) software which is used for long term planning of
quarry operations.
The present quarry pit occupies only a small area of this land with dimensions of 600m in E-
W direction and 400m in the N-S direction, and has a the total excavated area is about 140Ha.
The quarry pit is maintained at this size in order to ease operations and refilling is done as the
quarry advances forward. According to the optimization data and physical quality data, the
current quarry advancement trend is in the N-E direction.
Figure 2.1 : Land Extent belonging to Quarry and the Quarry Pit
11
2.1.2.2 Geology of the Area
The entire area consists of Miocene limestone lying on a Precambrian basement. The
basement consists mainly of sandstone formations. The limestone layer also shows variations
in quality indicating different periods and conditions of sedimentation. At certain areas a clay
layer has also been sandwiched between limestone layers. The overall effect of this formation
is seen as an increase of quality of the limestone with depth of excavation. This gives rise to
two layers of Limestone. A low grade layer on top and a high grade layer at the bottom which
are excavated separately.
The topmost limestone layer has a higher content of silica and is known as siliceous
limestone. The reason for this high silica content is that the layer has undergone differential
weathering which is also evident by the irregular and wavy "finger like" formation of the
layer.
Atop this layer lies an overburden layer consisting of red soil. This red soil has intruded into
the irregular limestone layer which lies beneath it. For this reason and also due to the high
silica content of the first limestone layer it is not used for production and is discarded, For
this reason, this layer is called the "Reject layer".
The top most portion of the overburden consists of a fertile soil layer. This layer can be
identified by the high content of humus and other organic matter. This layer is excavated
separately and piled separately to be used as the top most fill layer in the rehabilitation
process. The following layers of overburden soil are not fertile and are primarily used for
refilling purposes.
High quality limestone can be found below the ground level of the quarry as well. If not
diluted by clay this layer is also extracted by base excavations.
The above mentioned limestone and overburden layers are depicted in the section of the
quarry face in Figure 2.2 below.
12
Figure 2.2 : A quarry face showing each type of material
2.1.3 The quarrying process
After the tour of the quarry site and office premises, we were introduced to the individual
quarry operations. We acquainted ourselves with these activities and the operators and
personnel involved in them.
The unit processes in the quarry operation are as follows
Overburden Removing
Bed Cleaning
Drilling
Blasting
Quality Assurance
Hauling
Mix bed preparation
Wagon loading and Dispatching
Rehabilitation
13
The above operations are listed in the order in which limestone production has to be carried
out. However some of these operations are carried out simultaneously for practical reasons.
For example, overburden removal and rehabilitation are usually carried out together as the
overburden excavated is used in refilling the excavated pits in the rehabilitation process. The
entire quarry process can be represented by the following flow chart
Figure 2.3 : The Entire Quarrying Process
Figure 2.4 : The Entire Quarrying Process
14
2.1.4 Administration and Office Activities
The quarry office premises consists of four main sections to manage and oversee the entire
quarrying process. These sections are, The Engineering and Machine maintenance division,
The Quarry Lab, Human Resources Division and the Security Division. All division heads
report to the Quarry Manager.
2.1.4.1 Engineering and Maintenance division
The engineering division consists of a Quarry Engineer and two Junior Mining Engineers. All
planning activities, scheduling, and handling of all quarry operations are performed by them.
Computerized records of all activities such as performance parameters, production and output
are maintained and daily, monthly and annual scheduling and planning is conducted. In
addition to this, long term quarry planning, quarry infrastructure building and overall quality
improvement is also performed. We were exposed to these areas during our period of
training. The machine maintenance is headed by the Maintenance Superintendant. All
activities of the workshop and handling breakdowns of machines comes under his
responsibilities.
2.1.4.2 Quarry Lab
The lab is headed by the Quarry Chemist and conducts tests for the quality of the material
excavated. Sampling is done during drilling, after blasting and also during mix bed
preparation. Quality tests are performed regularly and also samples are sent to the plant at
Palavi for XRF analysis. Using this data, the mix bed preparation is coordinated.
2.1.4.3 Human Resources Division
The Human Resources division concerns itself with the welfare of employees and performs
all typical HR related activities such as HR planning, recruitment, grievance handling, etc. It
organizes welfare related activities for the employees and also coordinates with the store
keeper to provide goods and services that are entitled to the employees.
2.1.4.4 Security Division
The security division maintains the overall security of the quarry site as well as the land
extent controlled by the company. Safety related activities are also performed by this
division. The handling of explosives and their safe storage is one of the main responsibilities
of this department.
15
2.2 Bed Cleaning, Drilling and Blasting
Bed Cleaning, Drilling and Blasting are in order, three unit operations performed in order to
break and loosen the consolidated limestone or reject beds. Bed cleaning is performed to
facilitate drilling, while drilling is performed to charge explosives when blasting. Blasting
can be regarded as the first stage of comminution.
All three of these operations are performed in order, when preparing reject beds for reject
blasts and in preparing Limestone beds for production blasting.
2.2.1 Bed Cleaning
The main purpose of bed cleaning is to clean the surface of the bed and to flatten the surface
to enable drilling. Generally, a Bulldozer is used to rip the outcrops and uneven surfaces
while the blade of the dozer is used to shove the ripped debris away from the bed. Several
passes over the bed with the dozer blade grounded flattens the bed and also smoothes it to a
certain extent and enables easy drilling. A well prepared bed also makes it easy for the track
mounted drills to travel over the bed.
2.2.1.1 Machines Used
2.2.1.1.1 Komatsu D375A Dozer
The Komatsu D375A Dozer is
the largest dozer in Sri Lanka
and is the main machine used for
bed cleaning at Holcim Lanka
Ltd. It has a Blade diameter of
about 4metres and is equipped
with ripper attachment at the
rear side. Both the ripper
attachment and the dozer blade
are used in the preparation of
beds. It is possible to rip and
separate material of hard
consolidated limestone even 2.5: Bed Cleaning using Komatsu D375 A
16
without blasting. For this reason, ripping by the dozer is also considered a mode of
production at times.
Sometimes depending on availability constraints and practical reasons, Hired dozers are also
used for bed cleaning.
2.2.1.1.2 CAT 374D Excavator
This machine is also the largest
of its kind found in Sri Lanka.
It is maintained by United
Tractors and Equipment (UTE)
Ltd., under a full maintenance
contract with Holcim Lanka
Ltd. It has bucket capacity of
over 3 cubic metres and has a
boom specifically designed to
suit the limestone bed
dimensions of the Aruwakkalu
Quarry. In addition to
performing bed cleaning
operations, owing to its high
bucket capacity, the CAT 374D Excavator is also used for loading.
Preparing access roads to the bed is also a vital component of bed cleaning. In doing so, care
should be taken not to interfere with other activities such as hauling. For this reason bed
cleaning has to be performed with careful planning.
2.2.1.2 Activities Carried Out
Bed cleaning is the most fuel consuming jobs when considering dozers. When cleaning reject
beds, the dozer has to break and level strong siliceous limestone formations. Also the dozer
has to maneuver a lot in small spaces when cleaning limestone beds. These reasons result in a
very high energy consumption by the dozer. To assess the diesel consumption of the Holcim
owned Komatsu D375A Dozer, we were assigned to conduct an analysis.
To perform this analysis, we gathered data from the FMC (Full Machine Contract) data
Sheets where the daily performance of each operator and job is recorded. We gathered the
Figure 2.6: The CAT 374D Excavator being used for
loading
17
data and filtered them by job and working hours to obtain information about the hours spent
cleaning beds and also the fuel consumption for each day. Fuel consumption is calculated by
monitoring the volume of fuel pumped into the machine at each instance. By summing up all
the daily values the corresponding totals for each month were arrived at. Using this data the
average fuel consumption was calculated. Table 2.1 shows the summary of each month's fuel
usage and the final average fuel consumption at the end of the year 2013.
Table 2.1 : Fuel Consumption of D375A during bed cleaning
Shift A Shift B
Month Working Hrs Diesel(l) Working Hrs Diesel(l)
Jan 134.8 10691 109.4 9848
Feb 105.8 8918 121.7 9921
Mar 97.3 7987 73 5564
Apr 89.6 7262 90 7990
May 40.2 3246 28.6 2282
Jun 115.5 11423 76 6036
Jul 97.8 7478 42.7 3209
Aug 132 11308 82.5 6821
Sep 128.9 9741 96.3 7679
Oct 117.7 8029 94.1 7490
Nov 87.4 7052 68 5656
Dec 19.1 854 68.7 5968
Total 1166.1 93989 951 78464
Average Diesel
Consumption(l/hr) 80.60 82.51
18
2.2.2 Drilling
The purpose of drilling is to open holes in the limestone bed in order to load explosive
charges into them. Drill holes with diameter 64mm are drilled to a depth ranging from 10 to
40 feet (3-12 m). The drill hole depth depends on the type of bed and its vertical extent. For
example, Most reject and low grade limestone beds are drilled to 30feet (3 rods) while some
high grade beds are only drilled up to 20feet (2 rods). The required drilling depth can vary
from place to place in the quarry due to the spatial variation of depth and quality of the
limestone bed. These variations are determined with core drilling data and drilling activities
are planned and directed accordingly.
These drill holes are drilled in patterns on the bed to facilitate better energy distribution
which leads to a more uniform breakage of the rock and helps minimize adverse effects such
as fly rocks. Crawler mounted pneumatic track drills are used for drilling.
2.2.2.1 The Drilling Process
Once the bed has been cleaned, the Drill Operator and the helper takes the drill on to the bed
via the access roads and starts drilling according the instructions provided by the engineer.
According to the data gathered by us, The average cycle time for drilling is 15 minutes with
the time taken only to drill one hole is 12 minutes.
Drilling Cycle Time = Time taken to travel to the hole + time taken to drill the hole
Equation 2.1: Drilling Cycle Time
While drilling is performed, the drill dust and powder that is flushed out of the hole is
gathered into a dustpan. This dust is packed and sent for sampling. These samples provide
data about the bed that is being drilled and is useful for planning activities.
Once the drilling is completed, the drill hole is covered with a piece of tarpaulin, a large rock
laid on top of it and covered with surrounding soil/quarry dust to create a mound. This serves
two purposes. Firstly it protects the drill hole from rain and prevents the hole form being
flooded by water or filled with soil. Secondly it helps to easily identify the locations of the
drill holes when charging the blast. A picture of a covered drill hole without soil mound over
it, is shown in Figure 2.7.
19
Figure 2.7 : A covered Drill Hole
2.2.2.2 Machines Used
For drilling purposes, a Holcim owned track drill with a Hired compressor and another track
mounted drill and compressor system which is hired from NEM construction Ltd. are used.
Both drills operate with compressed air. These drills operate at a nominal operating pressure
of 0.7 MPa.
The main components of the drill are as follows
Hammer
Drill Rod
Drill Bit - 64 mm button bit
The Hammer is the power source of the drill and provided both rotary and percussive forces.
Thus this is a rotary percussive type drill. The Hammer moves vertically across the boom of
the drill by means of a gear and chain arrangement. The Hammer pushes down the drill rod as
drilling progresses. When the rod has gone down the hole, the drill rod is detached, the
hammer raised and another drill rod is attached to the previous drill rod and coupled with the
hammer. Then the drilling cycle begins again. At the Aruwakkalu mine, the drill hole depth
varies between 1rod and 4 rods.
The Drill Rod transmits the energy from the hammer to the Drill Bit. The rods are made from
hardened steel and each rod is 10feet (3m) long. While in the drills currently used at the
mine, the drill rods have to be manually changed, other composite drills can change the rods
automatically.
Tarpaulin Piece
Rock
20
The Drill Bit is the component that comes into contact with the rock and where all the shear
forces act. For this reason, the Drill Bit have to made of a highly tough material. The Bits
used at the mine are Button Bits made of Tungsten Carbide. A button bit (shown in Figure
2.8), there are air vents located between the buttons. These vents serve the purpose of
flushing out the drilled material. The flushing medium is air. While drilling is performed, air
is pumped through the drill steel into the bit where the bit - rock interaction takes place. The
air pressure cause the rock powder to be flushed out from the drill hole opening.
Figure 2.8 : Parts of a track Drill
In a discussion we had with Quarry Engineer we discussed the possibility of using a down the
hole hammer drill for drilling as it would eliminate the need to change drill rods as drilling
progresses and thus would save time. While this would save time, most down the hole
hammers have a larger drill bit diameter and wouldn't suit our requirements very well. Also
the possibility of the hammer getting stuck down the drill hole is higher in limestone
formations. Therefore down the hole hammers are not suitable for the Aruwakkalu Quarry.
2.2.2.3 Drill Patterns
The beds at the Aruwakkalu Quarry are always prepared in rectangular sections. Therefore
the most appropriate patterns are the rectangular pattern or the staggered pattern. However,
21
the staggered pattern enables a better blast energy distribution through the bed and results in
more uniform and consistent rock breakage. Therefore the staggered pattern is used most
often.
The parameters associated with drill patterns are Burden and Spacing. Burden is the distance
to the drill hole from the face of the bench while spacing is the distance between adjacent
holes of the same row. At the Aruwakkalu Mine ,
Burden = 2.5 metres
Spacing = 2.8 metres
The above burden and spacing with the staggered hole pattern has been proven to be the most
suitable configuration in terms of fragmentation and explosive utilization.
Figure 2.9 : A typical Staggered Drill Pattern
The Burden, Spacing, Depth of Hole and the no of holes in drilled in the bed can be used to
calculate the production volume of a blast. Since the volume of a bench can be calculated by
multiplying the three spatial dimensions, length, breadth and depth, by multiplying the result
with the density of the rock gives the production tonnage. This calculation can be illustrated
in the formula below.
T = S ∗ B ∗ H ∗ N ∗ ρ
Equation 2.2 : Calculating Blast tonnage
S - Spacing : Distance
between adjacent drill
holes in a row
B - Burden : The distance
from the free face
(between rows)
22
Where,
S - Spacing (m)
B - Burden (m)
H - Depth of Drill Hole (m)
N - Number of Drill Holes
ρ - Density of material (MT/m3)
and, T - Blast Tonnage (MT)
The densities of material encountered at the Aruwakkalu Quarry are as follows,
Reject material-2.0MT/m3
Low grade Limestone - 2.2 MT/m3
High grade Limestone - 2.4 MT/m3
In addition to the staggered drill pattern, during special circumstances a radial drill pattern is
used. The radial pattern is used when performing base blasting where there is no bench face
for the rock to break into. In this case a cut hole is drilled in the middle and the other holes
are drilled radially. The cut hole provides the space for the blast to break into. The delays are
arranged so that they increase radially outward. This ensures that the blast will collapse
towards the centre of the cut hole.
2.2.2.4 Hazards encountered in Drilling and their mitigation
1. Lightning
Lightning poses an extreme danger. The climate of the Puttalam area gives rise to
sudden weather changes and can result in sudden stormy conditions and thunder and
lightning. Being situated beside the lagoon, the quarry is also affected by micro
climatic conditions which can aggravate the said weather conditions. Since the
vertical drill boom is the highest part of the open quarry, that becomes more
Figure 2.10 : Burden, Spacing and Hole
Depth of a Bed
23
susceptible for a lightning strike. This is an extremely hazardous situation for the
drillers.
To avoid such dangerous situations, at the slightest indication of a drastic weather
change, the drillers are instructed to immediately stop drilling and to take safety
precautions.
2. Unstable Benches
Pure limestone being a soft material, the strength of limestone beds is not uniform,
and can lead to bench failures especially if a drill goes towards the edge of the bed.
Such situations can cause falls from high benches and lead to equipment and
personnel damage. Therefore Drillers are advised to be vigilant when drilling on
benches. In addition to this, when drilling the row closest to the face, a safety
clearance is kept. However, we observed drilling taking in place in precarious areas in
unavoidable circumstances.
3. dust generation
Drilling creates a lot of dust, Since the flushing medium is also air, the fine dust from
the drill steel spreads everywhere. The drillers are equipped with dust masks to
protect them from dust inhalation.
4. loud noise
The loud noise cause by the Drilling machinery over a long time of exposure can
cause hearing damage to personnel. While ear plugs and muffs are available, only a
handful of operators use them. This safety provision can be improved further by
distributing and emphasizing the value of sound protective gear.
5. Drilling during the Night
During certain circumstances, such as when a higher production is required in a short
amount of time, Drilling is done during the night shift. When drilling at night, a small
lamp is lit at the site for illumination. However, this lamp only illuminates the
immediate vicinity and low visibility in areas beyond can cause accidents.
To avoid these situations, night drilling can be avoided as much as possible. But if
there is no choice, a better set of lights to illuminate the area better would increase
safety of the drillers
24
Figure 2.11 : Drilling at Night
2.2.3 Blasting
The main purpose of blasting is to crack, fragment an loosen the limestone beds. Explosives
are charged into the drill holes and detonated electrically. The quantity of explosives to be
used for each blast are calculated to comply with requirements. Planning and stock control of
explosives are performed with computerized applications and matters related to explosives
and blasting are carried out with Army and Navy supervision.
2.2.3.1 Explosives
Two main types of explosives are used. A cartridged secondary explosive is used to crack and
fragment the rock and an blasting agent is used to provide the heaving power to separate the
cracked rock. The electric detonator (ED) contains a primary explosive which is used to
initiate the secondary explosive cartridges.
The cartridged explosive used at the quarry is Dynamite or Water gel. During the first half of
our training period we used dynamite, while during the latter stages of our training period
new stocks of water gel arrived and we received experience on handling water gel as well.
The blasting agent used at the quarry is ANFO
25
2.2.3.1.1 Dynamite
Dynamite is a nitroglycerine based explosive that is
commonly used for rock blasting operations. It comes in
cartridge from which consists of a mixture of Nitroglycerine,
Sodium and Ammonium Nitrate, Wood meal and other
additives formed into a cylindrical shape with 25mm
diameter and 200mm length and wrapped with paper. It has
a higher detonation pressure than water gel and this results
in a lesser quantity of required for blasting. (Refer Table 2.4 ). The dynamite used at the
Aruwakkalu Quarry were imported from India through the Sri Lanka Navy.
The advantages and Disadvantages of Dynamite are summarized below.
Table 2.2 : Advantages and Disadvantages of Dynamite
Advantages Disadvantages
Higher detonation pressure
Produces better fragmentation
No residue remains after blasting
It's a "Headache explosive" (generates
headache inducing fumes).
Expensive
Over time, Nitroglycerine leaches away from
the cartridge reducing its effectiveness.
Figure 2.12 : Dynamite
Cartridges
26
2.2.3.1.2 Water Gel
Water gels, also known as "Slurries" are 3rd generation explosives and were developed as a
safer alternative to Nitroglycerine based explosives such as dynamite. A typical water gel or
slurry, is a mixture of oxidizing salts such as Ammonium or Sodium Nitrate, a fuel sensitizer,
aluminum powder, gelatins such as Guar-gums and cross linking agents dispersed in water.
This mixture has a silvery colour and a gelatinous texture and is cap sensitive. It is filled into
a plastic casing and covered with a cap to prevent spillages. Water gel used at the
Aruwakkalu Quarry is manufactured in Sri Lanka.
The Advantages and Disadvantages of water gel are listed below
Table 2.3 : Advantages and Disadvantages of Water gel
Advantages Disadvantages
Cheaper than Dynamite
It is a "Non headache explosive"
The plastic casing prevents from explosive
components leaking
Has a lower detonation pressure than
dynamite
Lesser fragmentation compared to an equal
quantity of dynamite
Residual pieces of the plastic casing may
Figure 2.13 : Water gel Cartridges
27
Easier to handle and charge
Resistant to water
remain after blasting
Explosive can deteriorate over time due to
separation of ingredients in mixture
2.2.3.1.3 ANFO
ANFO is a widely used blasting agent and is
prepared by mixing Ammonium Nitrate and
fuel oil to a ratio of 95:5 by weight. Hence its
name (Ammonium Nitrate + Fuel Oil)). At the
Aruwakkalu Quarry, 2 litres of diesel is
poured into a 25kg bag of prilled Ammonium
Nitrate and is mixed well. It is not cap
sensitive and requires to be primed by a high
explosive such as dynamite or water gel.
Ammonium Nitrate provides high borehole
pressures and helps to further propagate
cracks formed by the dynamite and also
provides heaving power to separate the
fragmented rocks. Ammonium Nitrate is most
effective when it is used in the right quantity and in the absence of water. For this reason it
must be ensured that the drill holes are dry when using ANFO. This is further discussed in
section 2.2.3.7.
2.2.3.1.4 Electric Detonators (ED s)
Electric Detonators contain a primary explosive at their base and is ignited by a electrical
fuse. The sudden detonation of the small quantity of primary explosive sets off the detonation
in the attached secondary explosive attached as the primer (water gel or dynamite). Most
electrical detonators contain a delay element before the priming charge. The ED is given a
Figure 2.14: A bag of Ammonium
Nitrate
28
Delay Number depending on its delay. These delay numbers represent gradually increasing
delays with steps of 25 milliseconds. Delay numbers of EDs are required to time the blast and
to control the way the muck pile is formed.
Figure 2.15 : Schematic and an image of an Electric Detonator
2.2.3.2 Explosive Handling and Storage
When a blast is to take place, firstly the number of holes and the hole pattern is observed and
recorded. Then the amount of each type of explosive is calculated and details are filled into a
"Goods Issue/Goods Return form" commonly abbreviated as "GI from". Details about the
delay pattern, ED delay breakdown and also the wiring pattern are also included into the GI
from. A later revamping of the GI from format made fields for including the specific charge
as well.
Once the GI form is filled it is authorized by the Mining Engineer or Quarry engineer and
sent to the security officer. The Security Officer notes down the explosive requirements from
the GI form and heads over to the quarry police along with either Navy or Army personnel to
obtain keys to the explosive magazine.
The explosive magazines are situated away from the quarry office and quarry pit, and in
direct proximity to the Quarry Police where police officers guard the magazines at all times.
Two storage buildings, one for Dynamite/Water gel and another for Ammonium Nitrate
which is the primary component of ANFO constitutes the explosive storage. Electric
29
detonators are housed in a separate compartment in the Dynamite storage building. Both
buildings belonging to the explosive magazine are heavily secured with locks and the
dynamite and ED containing building has a protective fence around it. In addition to this
other safety measures such as lightning conductors, fire retardants and fire extinguishers and
warning signs have been installed.
After accessing the explosive magazine, the required amount of explosive material is taken
out and transported separately. Ammonium Nitrate bags are transported by tractor to the fuel
tanks to be mixed with Diesel and produce ANFO. Dynamite and Electric detonators are also
transported to the bed to the blasted in two different vehicles, both under supervision of Army
or Navy personnel.
2.2.3.3 Charging
Once the explosives arrive at the blasting bed, charging begins. The steps involved in
charging a blast are as follows.
1. The explosives and the electric detonators are distributed among the drill holes
according to their proper quantities (refer Table 2.4).
2. An electric detonator (ED)is inserted into one cartridge - in water gel, the plastic cap
is removed, the ED pushed is pushed into the gelatinous mass and the cap secured
again. In the case of dynamite, the ED can be directly pushed into the cartridge
through the paper folding at the end of it. (refer Figure 2.16)
Figure 2.16: A primed water gel cartridge couple
30
3. The primed cartridge (the one with the ED in it) is coupled with another cartridge and
is tied with the wire accompanying the ED, and slowly lowered into the hole. If the
depth of the hole is more than 9m(3 rod) then another wire has to be attached to the
ED wires. When attaching an extra length of wire it should be connected at different
points vertically as shown in Figure 2.17, so that it wouldn't cause a short circuit.
Figure 2.17 : Connecting an extra wire to an ED
4. The remaining cartridges assigned to the hole are also dropped into the hole and, the
correct amount of ANFO is also put into the hole and tamping is performed.
5. The remaining portion of the hole is filled by quarry dust or surrounding soil as
stemming.
6. In this arrangement, the primed and other cartridges are at the bottom of the hole with
ANFO on top of it finally covered by stemming. This arrangement is known as the
indirect initiation. For holes up to 9m this method suits well. However, in the case of
deeper holes, the primer being at the bottom of the hole can lead to insufficient crack
development at the top portion of the bed. Therefore, in these cases a method called
"Deck Charging" is used. In this method two primers are used, one at the bottom of
the hole and one at the middle. (shown in the right hand side of Figure 2.18). These
two EDs are connected in series.
31
Figure 2.18 : Normal and Deck Charging
7. This leaves only the two ends of the wires protruding from each covered hole and the
bed is now ready for wiring.
The typical quantities of each explosive used in the different types of blast are listed below.
Table 2.4: Quantities of Explosives Used
Typeof Blast
Type of Explosive
3m hole blast
(1 rod)
/per hole
6m hole blast
(2 rod)
/per hole
9m hole blast
(3rod)
/per hole
12m hole blast
(4 rod)
/per hole
Dynamite 250g
(2 cartridges)
750g
(6 cartridges)
1000g
(8 cartridges)
1250g
(10 cartridges)
Water gel 500g
(4 cartridges)
1000g
(8 cartridges)
1300g
(10 cartridges)
1500g
(12 cartridges)
ANFO 5kg
12.5kg 20kg 25kg
Electric Detonator 1 1 1 2( deck charging
32
*cartridge weight of dynamite = 125g, cartridge weight of water gel = 130g, weight of ANFO
bag = 25kg
2.2.3.4 Blast Wiring and Detonation
Once charging has been completed wiring has to be done. The Quarry is equipped with a
generator and a battery operated exploding machine. The generator is a diesel powered AC
(alternating current) generator capable of voltage output of 240V. The exploding machine
produces a very high voltage via capacity discharge, but a significantly lower current. Due to
inconsistencies in the generator, most often the exploding machine is used for detonation.
Therefore, for the entire blast to be properly set off, the resistances should be balanced so that
an appropriate amount of current and voltage reaches all EDs.
The way of achieving this in the Aruawakkalu Quarry is, by using a "series parallel circuit" in
blast wiring. To do this, the EDs are connected n separate loops with each loop having about
8 EDs. These loops are connected to a main wire drawn across the bed in parallel. Figure 2.19
shows a typical series parallel arrangement of 32 hole blast with 4 loops with 8 ED's
connected in series in each.
Once the loops are made, before connecting them to the main wires, the loop resistances are
checked with a blast Ohm-meter. the resistance of the loop should be equal to the resistance
of on ED multiplied by the number of EDs in the loop since they are in series. The resistance
of an ED with its connecting wire is about 12. If all the resistances are correct, the loops are
attached to the main wires as shown in Figure 2.19
Figure 2.19 : A Series Parallel Circuit with 4 Loops
33
In this arrangement, two loops are connected to a single node point in the set of main wires.
This does not alter the circuit and lesser node points reduces the likelihood of connection
errors as well. The circuit diagram for the above wiring pattern is as follows
Figure 2.20 : Circuit Diagram for Wiring Pattern
Once the circuit is completed, the total resistance of the circuit is once again measured using
the blast Ohm-meter.
The calculation of the total resistance for the above example is done as follows.
𝑅 = 𝑅1 + 𝑅2 + 𝑅3 + ⋯+ 𝑅𝑛
Equation 2.3 : Resistance in a Series Circuit
1
𝑅=
1
𝑅1+
1
𝑅2+
1
𝑅3+ ⋯+
1
𝑅𝑛
Equation 2.4 : Resistance in a Parallel Circuit
Resistance of a loop, given resistance of a single ED = 12.
Rloop = 12 * 8 = 96
Let. R be the total resistance. Then,
1
𝑅=
1
96+
1
96+
1
96+
1
96
34
1
𝑅 =
4
96
𝑅 = 96/4 = 24
If the number of holes does is not easily divisible to equal loops, looping is done by
connecting lesser number of EDs to the loops at the far end of the blasting bed, where the
main wire starts (the side farthest from the exploding machine). This is done to compensate
for the increase in resistance by the length of wire drawn to the far side of the bed. This
procedure is followed especially when large beds are blasted.
Once the circuit is connected, the main wire is drawn to a distance exceeding 200m away
from the bed. It should be ensured that the blast circuit along with the main wire drawn to a
distance of 200m should not give a resistance more than 70. This is checked by using the
blast Ohm-meter. By this time, all vehicles and personnel in the quarry are informed and
evacuated from the quarry. After another final safety inspection and a setting off a loud siren,
the blaster uses the exploder to detonate the blast. The blaster detonates with a shelter nearby
to take cover in the case of fly rocks.
Once the blast has occurred and dust has settled, an inspection of the bed is carried out to
assess the level of fragmentation and also to check for any charged holes that did not fire. If
intact explosives are found they are gathered and handed over to the security officer to be
stored in the explosive magazine separately until they can be disposed of during the next
blast.
2.2.3.5 Specific Charge
Specific Charge refers to the quantity of explosives required to blast unit volume of rock. At
the Aruawakkalu quarry, specific charge is calculated for each blast and is monitored and
maintained. It is expressed in units kilogram per metric tonne (kg/MT). At Aruwakkalu, the
stipulated limit of specific charge is 0.15.
𝑆𝑝𝑒𝑐𝑖𝑓𝑖𝑐 𝐶𝑎𝑟𝑔𝑒 = 𝑊𝑒𝑖𝑔𝑡 𝑜𝑓 𝐸𝑥𝑝𝑙𝑜𝑠𝑖𝑣𝑒𝑠 (𝑘𝑔)
𝐵𝑙𝑎𝑠𝑡 𝑇𝑜𝑛𝑎𝑔𝑒 (𝑀𝑇)
Equation 2.5 : Specific Charge
Weight of explosives is the total weight of Dynamite/Water gel and ANFO utilized for the
blast. The blast tonnage is calculated using Equation 2.2.
35
We calculated the specific charge for all the blasts we were involved in. The specific charge
serves as a check for the amount of explosives used and is also required for keeping records.
In the reformatting of the Goods Issue/Return form (GI form) a field for specific charge was
also included indicating that specific charge be calculated before the blast and not afterwards.
The limit of 0.15 for the specific charge at the Aruwakkalu Quarry has been selected to keep
in accordance with the explosive usage stipulated by the Geological Survey and Mines
Bureau (GSMB) and also to avoid negative impacts of blasting such as excessive ground
vibration and fly rocks.
2.2.3.6 Other types of Blasting
In addition to the main bench blasting at the quarry we experienced other types of blasting as
well.
2.2.3.6.1 Boulder Blasting
Sometimes, bench blasting produces very large boulders
that are unable to be hauled and are difficult to handle.
These boulders are therefore left in the quarry. While
rock breakers can be used to break these rocks, due to the
large size and the time taken to fragment them using a
rock breaker, it is a very uneconomical process. Using a
rock breaker is also not an option if isolated boulders
have to be broken.
For this reason, boulder blasting is preferred to fragment
these rocks and also add them into production. Boulder
blasting requires relatively a lesser amount of explosives
and also is quicker. Therefore it is cost effective
Most large boulders which are separated from the beds
contain undisturbed, remaining portions of drill holes in
them. This makes the blasting process easier because the
explosives can be charged into the drill hole itself. This is
illustrated in the left hand image of Figure 2.23. In this situation the primed explosive
cartridge is dropped into the middle of the drill holes and confined tightly with clay.
Figure 2.21 : Charging a Drill
Hole in Boulder Blasting
Figure 2.22 : Fragmentation
after Boulder Blasting
36
If there are no drill holes present in the boulder, a confined space such as a crevice or a corner
is used to keep the cartridge and it is covered very well with clay as seen in the right hand
side of Figure 2.23. Once the cartridges are set up a wire is draw to a safe distance and
detonated using the exploder.
It should be noted that ANFO is not used in boulder blasting since only fragmentation of the
rock is required. Therefore a detonator and explosive cartridges would suffice. Boulder
blasting could give rise to fly rocks therefore necessary precautions should be taken.
Figure 2.23 : Methods of Boulder Blasting
Once the boulder has been fragmented, the pieces can be collected with a wheel loader and
can be hauled along with the other material.
2.2.3.6.2 Base Blasting
Most high quality material is located at the bottom most layers of the limestone formations.
For this reason, at times the necessity to excavate material below the base of the quarry
arises. In these situations, sometimes the excavator is used to excavate the base. However if
large areas of the base needs to be extracted, base blasting is used.
There are two main challenges in base blasting. Firstly, since the water table lies below the
base, the drill holes get filled with water. Since ANFO does not detonate with water, this
leads to problems. Secondly, unlike in bench blasting and boulder blasting, there is no space
37
for the material to break into in the case of base blasting, and can lead to insufficient
fragmentation.
To overcome the first problem of water in the drill holes, the ANFO is loaded into polythene
liners and sealed to make watertight ANFO cartridges. These cartridges are lowered into the
holes with water. Priming with water gel is done in the usual manner.
The second problem is overcome by drilling a cut hole round of a radial drill pattern. The
centre cut hole round provides the space required for the surrounding rock to break into. The
delays of the detonators in the radial drill pattern are arranged with the lowest delay at the
centre and the delay numbers increasing radially outward.
2.2.3.7 Problems Encountered in Blasting
We encountered several problems related to blasting and we experienced the ways to avoid
them and also to correct them.
2.2.3.7.1 Blast Circuit Problems
Often in large blasts involving lots of wiring and connections, circuit problems such as
disconnections short circuiting can occur. To avoid these problems, the circuit is checked
stage by stage using the blast Ohm-meter. However, occasionally after the circuit has been
completed and while checking, faults can appear. Handling this problem has to be done
systematically in order to save time and to avoid disturbing the rest of the circuit.
If a faulty loop is found after connecting them to the main bus wire (this is indicated by an
anomalous Ohm-meter reading) first the loop has to be disconnected from the main wire and
connected to a separate testing circuit. In the testing circuit, as shown in Figure 2.24, each ED
is tested systematically until the faulty ED or connection is found. If there is no fault, as the
connector wire (indicated in blue in the diagram) is connected to the indicated nodes, the
Ohm-meter reading should increase each time by a factor equal to that of the resistance of a
single ED (12 ). Once the faulty ED or the faulty connection node is located, it is adjusted
or in extreme cases, removed and the circuit is reconnected.
38
Figure 2.24 : Testing Circuit
2.2.3.7.2 Water in Drill Holes
When water is present in drill holes ANFO does not detonate.
This degrades the quality of the blast and reduces its power.
Blasts which have been degraded by water in this manner
emanates characteristic yellow fumes during the blast.
To avoid this, ANFO is loaded into plastic liners and
charging is done as explained under Base Blasting. To avoid
rain water seeping into drill holes, the holes are properly
covered with a tarpaulin.
2.2.3.8 Hazard Management in Blasting
1. Fly rocks : Fly rocks presents the most immediate danger of blasting. While there are
no permanent residents around the quarry area it poses a danger to the blaster and
other personnel present at the time of blasting.
To avoid Fly rocks the quantity of explosives used must be controlled. By checking
the specific charge before each blast and optimizing the amount of explosives used,
Figure 2.25 : Yellow
Fumes when Blasting
39
this is taken care of to a major extent. Proper stemming and tamping also helps to
minimize fly rocks.
2. Air Blast and Ground Vibrations: This too causes the greatest discomfort and
potential danger to the personnel of the quarry, since there are no permanent residents
around the quarry area.
To minimize the impact of air blast over pressure and ground vibrations, proper
charging practices must be employed. By using appropriate delays in the detonators
and by employing a suitable hole pattern also these negative impacts can be
minimized.
3. Dust and Fumes : Blasting produces lots of dust. Also if water is mixed with ANFO at
the time of blasting, Sulfur is produced and it gets dispersed as yellow fumes. While
dust cannot be prevented, avoiding drill holes filed with water will not produce the
toxic yellow fumes.
Most of the above situations are alleviated if the personnel stay at a safe distance from the
blast. This is practiced at the quarry by always maintaining a safe distance of more than
200m. However we observed that tamping is not performed properly in charging.
Improvement on this front could help further reduce the risk of fly rocks and to reduce the air
blast over pressure.
2.2.4 Activities Carried Out by Us
Out of the many activities and projects assigned to us we carried out several projects related
to Drilling and Blasting. Given below is short summary of such activities.
2.2.4.1.1 Explosive Magazine Refurbishment
The explosive magazine at the Aruwakkalu Quarry is well maintained. However, in order to
improve its standard and also in preparation for an audit, a refurbishment was carried out.
While the main building itself remained unchanged, a protective wall, a fence with a lockable
gate, and a concrete base in front of the magazine building doors were constructed.
40
We were assigned to prepare a checklist to identify other possible improvements and to
implement those improvements. The areas we identified and that needed attention are,
Inadequate safety sign boards
Stacking of explosives too high, No Stacking line
Fire risk in the surrounding area (dried bushes etc)
No Proper labeling
Multilingual Signboards were prepared to prohibit smoking and fire hazards in the vicinity of
the explosive magazine. These signboards were hung on the newly prepared gate. Signboards
warning that rock blasting is taking place were also prepared to be erected near the quarry.
Figure 2.26 : Signboards for the Explosive Magazine
Boxes containing explosive
cartridges such as dynamite or
water gel should be handled
carefully and should not be piled
into stacks that are very high. This
makes the boxes susceptible to
toppling and also creates a risk of
pressure initiation. The explosive
magazine does not have a stacking
line to indicate the maximum
stacking height of boxes. Therefore,
we marked a stacking line along the inside walls of the magazine.
Figure 2.27 : Stacking Line
41
This stacking line corresponds to the height of six boxes kept on top of each other, an
accepted safe height of stacking. Once the stacking
line was in place we also made sure that only boxes
that have not been opened remained in stacks as
partly empty boxes increases the risk of toppling.
The loose cartridges were transferred to one box and
was labeled properly with the number of loose
cartridges in it. This system if arranging and labeling
ensures that there are no partly empty boxes lying
around while all loose cartridges are kept at one
place. This system saves time in sorting out and
counting explosives.
The area surrounding the explosive magazine had a lot of dried plants and shrubs. Since this
increases the risk of fire propagating, the entire area was cleared.
2.2.4.1.2 Explosive Stock Control Application
After every blast the GI form is sent to the store keeper to update stock records. This data is
then entered into an excel spreadsheet to maintain proper records. Periodically these record
are matched by physical checks at the explosive magazine. The system used so far had some
inconsistencies and some data had to be entered separately. We prepared a new system where
these inconsistencies were sorted out and so that all data can be entered and reviewed in one
document.
This excel sheet had columns for inputting data about daily usage of explosives and
detonators along with their delay numbers. and it would deduct them from the existing stocks
and display the remaining stocks. we checked with data of several physical checks to remove
any inconsistencies.
2.2.4.1.3 Plan for a New Ammonia Hut
The current ammonia hut at the Aruwakkalu quarry is situated near the quarry police and the
dynamite storage building. This hut is made from a lockable container box and is well
secured. However, the space in the container and around is limited and Ammonia has to be
re-stocked quite often. It also lacks the facility to mix ammonia with diesel to prepare ANFO.
Figure 2.28 : The refurbished
Explosive Magazine
42
To overcome these difficulties, a plan for the new Ammonia Hut was drawn by us. This new
design has double the storage capacity of the existing one, and also has the facility and space
for mixing ANFO. It was also designed so that it can be accessed by the tractor so that ANFO
bags can be loaded easily. The stage of the ammonia hut designed to be elevated to the height
of the tractor trailer so that loading can be more streamlined.
However construction work of this ammonia hut did not begin during our period of training.
Figure 2.29 : Plan of Proposed Ammonia Hut
43
2.3 Loading, Hauling and Dispatching
The loading, hauling and dispatching operations of the Aruwakkalu quarry are performed by
Holcim itself. Once the limestone beds are blasted, the dozer shoves them and creates
material piles. A wheel loader loads this material into the a fleet of dump trucks which then
haul them to mix beds. From the mix beds, the material is loaded into railway wagons and
dispatched.
2.3.1 Loading and Hauling Machine Fleet
Holcim owns and operates a primary fleet of loading and hauling machines. This fleet
consists of the following machines.
2.3.1.1 Komatsu WA600 Front End Wheel Loader
This is the largest machine of its kind in Sri Lanka. It has a bucket capacity of about 6 cubic
metres. This means that it can handle about 10 metric tonnes at a time. This enables the
loader to load the 32 tonne dump truck in just six passes. The machine is maintained under a
maintenance contract by DIMO with the undercarriage maintenance done by Holcim.
Figure 2.30 : Komatsu WA 600 Loader
2.3.1.1.1 Fuel Consumption of loader
We carried out a project to assess the performance of the wheel loader. Wheel loaders are
equipped with a torque converter based transmission system and constantly changes gears
between forward and reverse. Therefore, a lot of power in consumed, leading to a higher fuel
consumption. The high torques involved in loading also leads to a high fuel consumption.
44
Therefore we used the daily records kept by the management to isolate performance related
data. Using this data and correlating it with the diesel quantities pumped into these machines
we obtained the average fuel consumption rate.
Given below is a summary of the analysis conducted with data gathered over 11 months in
the year 2013. We grouped the data according to the two shifts as a way of comparing the
performance. The working hours indicated in the table below were obtained by using the start
and end meter readings of the machine at the end of each shift of work. We also extended this
analysis for each operator in order to determine a parameter to measure performance of the
operator in the wheel loader. However to truly measure performance, other data would also
have to be included.
Table 2.5 : Fuel Consumption of WA 600 Wheel Loader
WA 600 Loader
Shift A Shift B
Month Working Hrs Diesel Working Hrs Diesel
Jan 16.8 884.25 66.2 3809
Feb 41.9 2834.9 83.2 5070
Mar 24.6 1276.4 81 3612
Apr 22.2 1431.8 54.7 3786
May 3.5 335 53.5 3016
Jun 42.3 4294.2 70.4 5296
Jul 52 2373.8 68.6 3225
Aug 16.8 972 67.8 3736
Sep 29.1 1640.2 98.3 6345
Oct 58.9 3075.9 99.3 6060
Nov 60.5 4323.3 45.3 3664
45
Total 368.6 23442 788.3 47619
Fuel Consumption 63.5964831 60.40720538
From the above table it can be seen that the wheel loader approximately consumes 60 litres
per hour. This makes it necessary to refuel the machine every day.
2.3.1.2 Komatsu HD 325A Dump Trucks
There are three of these dump trucks employed for hauling purposes. They are also managed
by DIMO with the undercarriage maintenance done by Holcim. The three dump trucks are
named KD 7, KD 8 and KD 9 with the KD 9 being the latest addition to the fleet and also in
the best condition. Several projects and activities relating to dump trucks were carried out by
us. They are described below.
Figure 2.31 : Komatsu HD 325 A Dump Truck
2.3.1.2.1 Hauling Cycle Times
The first activity we were given was to measure cycle times of the dump trucks. For this we
got into the truck during a shift and travelled in it with the operator while gathering data.
While gathering data, we also learnt the key operations and the safety features of the truck.
Since we travelled in different trucks during each time, we did not conduct a cycle time
analysis for each truck. Instead we gathered all the data and prepared an average set of data
with them.
46
Table 2.6 : Dump Truck Cycle Times
Loading
Time
Hauling
Time
Dumping
Time
Travel Back
time
Cycle
Time
1 6 1 4 12
1 5 1 5 12
1 6 2 5 14
2 6 1 4 13
2 6 2 6 16
1 4 2 6 13
2 5 1 6 14
1 4 2 4 11
2 6 2 4 14
2 4 2 6 14
1 5 2 4 12
2 4 1 4 11
1 6 2 4 13
1 6 1 5 13
2 5 1 6 14
2 6 1 4 13
Average Cycle Time 13.0625
*Values are to the nearest Minute
47
The above table summarizes only a handful of data gathered by us. According to the above
data, the cycle time of a typical truck is about 13 minutes. However, for calculation purposes
the cycle time is taken as 15 minutes.
Cycle time such as the above we collected is an important factor in determining the
performance and output of a quarry. Since the cycle time is directly correlated to the amount
of material hauled, it can be used to prepare models regarding quarry output.
Also, when designing new quarry roadways, ramps and other infrastructure, the cycle time
has to be considered because with an increase in road distance, the cycle time increases and
the hauling tonnage per unit time drops. Therefore they should be designed by taking the
cycle time into consideration.
Cycle time is also a useful tool in optimization of the quarry. A very high hauling cycle time
would mean the loader and the mix bed preparing dozers would idle. This is a fuel wastage.
A low cycle time would mean that there would be queues at the hauling or dumping point
which in turn leads to the idling of the dump trucks which again results in a fuel wastage.
2.3.1.2.2 Tyre Analysis
The performance of machinery and their availability plays a major role in the productivity
and output of a mine. For this reason, every aspect of the machines should be properly
maintained. The tyres of these machines are what keeps the machine in contact with the
ground and bears the weight of the machine. While tyres for mining machinery are designed
to withstand a beating, incorrect maintenance can reduce lifetime of the tyres, or ultimately
lead to catastrophic accidents.
Therefore proper record keeping of tyres is essential for a mine. Such tyre records assists in
large way to the maintenance of tyres and also helps to measure performance of the tyres.
Since these tyres of heavy machines are expensive, proper record keeping is essential to make
the maximum use of the tyres.
Detailed tyre record are available at the Aruwakkalu quarry and these record are updated and
maintained by the maintenance division. We analyzed these tyre records and extracted vital
information regarding them. Information about tyre wear and lifetime of tyres were obtained
by using data about tread depth of tyres over time.
48
We also measured tread depth periodically and updated these tyre records.
Table 2.7 : Tyre Records
Tire
Brand
Tire Serial
No
Type Position Date of
Installatio
n
Tread
remainin
g (mm)
amount
of Wear
Current
Status
Triangl
e
1201051350
1
Radial NA NA 22 29 Not running
Triangl
e
1201083350
1
Radial NA NA 21 30 Not running
Triangl
e
1112261350
2
Radial NA NA 9 42 Not running
Triangl
e
1201092350
2
Radial NA NA 19 32 Not running
Triangl
e
1112292350
1
Radial NA NA 33 18 Not running
Triangl
e
2211192340
1
Radial RRI 14/1/2013 9 42 Running
Triangl
e
2211152350
2
Radial RRO 3/1/2013 10 41 Running
Triangl
e
2211191340
2
Radial RLI 3/1/2013 33 18 Not running
Triangl
e
2211173350
1
Radial RRO 30/5/2013 20 31 Not running
Triangl
e
2211173350
2
Radial RRI 30/5/2013 11 40 Not running
Triangl 2211133340 Radial RLO 30/5/2013 15 36 Running
49
e 1
Triangl
e
2211191350
1
Radial FL NA NA #VALUE
!
Not running
Triangl
e
2211183340
1
Radial FR 11/1/2013 24 27 Not running
Triangl
e
2304222360
2
Radial FR 6/6/2013 45 6 Not running
Triangl
e
2304222360
1
Radial FL 6/6/2013 20 31 Running
Triangl
e
2304211360
2
Radial FR 6/9/2013 7 44 Running
Triangl
e
2304193360
1
Radial FL 6/9/2013 43 8 Not running
Triangl
e
2304133360
1
Radial RRO 6/6/2013 28 23 Running
Triangl
e
2304162360
1
Radial RRI 6/6/2013 24 27 Running
Triangl
e
2307053360
1
Radial RRI 30/10/201
3
39 12 Running
Triangl
e
2307061360
2
Radial RRO 30/10/201
3
39 12 Running
Triangl
e
2307052360
1
Radial RLI 30/10/201
3
40 11 Running
Triangl
e
2307042360
2
Radial RLO 30/10/201
3
39 12 Running
Triangl 2307171360 Radial FR 30/10/201 39 12 Running
50
e 1 3
Triangl
e
2307051360
2
Radial FL 6/10/2013 39 12 Running
Triangl
e
2307041360
1
Radial FL 6/11/2013 39 12 Running
Triangl
e
2307182360
2
Radial RLI 15/01/201
4
48 3 Running
The above table shows some tyre records. Some fields have been removed for brevity. The
position indicated abbreviations are as follows
Figure 2.32 : Tyre Positions
Using these tyre records we were able to extract information about its rate of wear and thus,
by calculating the time it takes a new tyre to wear to such a rate that it has to be discarded, we
calculated the predicted lifetime of a new tyre as follows.
"Discarded" Tires
Average Lifetime = 1880.625
FL - Front Left
FR - Front Right
RLO - Rear Left Out
RLI - Rear Left In
RRO - Rear Right Out
RRI - Rear Right In
51
Some of the tires encountered at the Quarry had performance problems due to faults such as
peeling off of the tread, swelling of sidewall and cracking of the rubber. These faults
significantly degraded the tyre and resulted in shorter running times.
To rectify this situation, an official from the Triangle Tyre cooperation came to inspect the
conditions and also educated us about general tyre handling. We gathered a lot of information
about the subject during this visit.
Unit Cost (Rs) = 430763.00
Cost per Hour (Rs) = 229.0531
Tire cost per tonne hauled= 11.45266
average amount of wear
when discontinued(mm) = = 30
average wear = 25.54545
average lifetime = 1750.818
wear rate(mm/hr) = 0.014591
predicted lifetime of new
tire (Hours) = 2056.121
52
2.3.1.2.3 Fuel consumption of Dump Trucks
To calculate the fuel consumption of dump trucks the daily record were used in a similar
manner as was done for the WA 600 loader. Here too, the working hours were obtained by
the start and end meter readings of the machine. This analysis was carried out separately for
the three trucks KD7, KD8 and KD9. The summary of the analysis is given below. The
analysis spans the entire year 2013.
Table 2.8 : Fuel Consumption of Dump Trucks
KD 7 KD 8 KD 9
Month
Working
Hrs Diesel
Working
Hrs Diesel
Working
Hrs Diesel
Jan 56.5 1751.03 0.90 28.29 5.20 180.76
Feb 57.9 1794.42 56.50 1519.89 11.00 324.05
Mar 65.6 2033.06 83.00 2008.05 6.00 160.65
Apr 58.8 1822.31 85.90 2748.28 26.40 1079.28
May 90 2789.26 88.20 2161.66 36.10 1312.46
Jun 109.7 3399.79 39.70 983.92 19.80 527.40
Jul 51.9 1608.47 14.90 393.47 0.00 1052.86
Aug 20.5 635.33 5.30 181.48 23.50 745.92
Sep 67.6 2095.04 25.20 1396.04 17.80 568.83
Oct 88.8 2752.07 13.30 321.28 23.50 668.44
Nov 73.1 2265.50 4.60 125.58 12.70 396.62
Dec 61.7 1912.19 21.90 510.29 24.30 816.00
Total 802.100 24858.471 439.400 12378.236 206.300 7833.257
Average 30.992 28.171 37.970
53
From this analysis it can be seen that the average fuel consumption of the dump trucks at the
Aruwakkalu Quarry is 30 litres per hour. This is significantly lower than that of the loader.
This is because while the dump truck travels a larger distance, it does not exert the engine as
much as the loader does.
2.3.1.3 3rd Party 10-Wheel Haul Trucks
To keep up with higher production needs and to ensure a higher hauling rate, in addition to
the Komatsu Hauling fleet belonging to Holcim, a 3rd party fleet of 10-wheel haul trucks is
also employed at the quarry for hauling purposes. These trucks do not have the capacity of a
dump truck, but by employing several of these trucks along with one or two large dump
trucks, the hauling rate can be increased. These 10-wheel trucks have a capacity of 12 metric
tonnes.
To identify the performance difference between large dump trucks and the smaller 10-wheel
haul trucks we gathered data about each truck and compared them. Data regarding, cycle time
and hauling capacity and fuel consumption were considered.
Later, as an expansion of this project, we also calculated the cost involved in operating each
truck. For the dump truck, the main cost components were, Maintenance fee paid to DIMO,
Undercarriage maintenance including tires, Fuel cost, Operator salaries. The summary of this
calculation is given below.
Table 2.9 : Summary of Dump Truck Cost
Type of cost rate per hour
Diesel 3769.211532
DIMO Maintenance 5265
Undercarriage maintenance 1608
operator salaries 520.8333333
Total (Rs) 11,163.04
54
However, in the case of the 3rd part trucks, a fixed hourly rate of Rs 250 has to be paid per
truck. Therefore since there is a large difference in cost for the two types of hauling trucks,
we compared the hauling capacity and overall performance of the two types of trucks. This
was done to check whether the performance of the dump trucks will compensate for its high
cost.
The summary of the comparison is given below.
Table 2.10 : Comparison of Hauling Trucks
Type of Machine HD-325 Dump Truck 10 wheel truck
Hauling rate (loads per hour) 4 3.5
Maximum Trucks possible 4 7
Tonnes per truck 30 12
Tonnage per Hour 480 294
Cost per Hour (Rs) 44800 10500
Cost per tonne hauled (Rs) 93.33 35.71
While the cost per tonne of the dump truck is higher than that of the 10-wheel trucks, the
tonnage per hour is significantly higher. Since the key factor in meeting daily production
targets is the tonnage per hour, the dump truck compensates on that front.
We took this analysis further and furnished a fully fledged report about the optimization of
Dump Truck Feet. This is explained under Section 2.3.4.1.
55
2.3.2 Hauling roads
Hauling roads are very important in the hauling process. The road distance and road
conditions dictate the rate of hauling and the production rate. The road conditions are also
directly correlated to the machine conditions and dictate how often the machines have to be
repaired. Therefore, the it is important that the roads are well maintained and that careful
planning and design is done in their construction.
2.3.2.1 Road Maintenance
Haul roads have to be periodically maintained. This includes road surface clearing,
smoothening, refilling and cutting operations. The main machine used in road maintenance is
the Komatsu Motor Grader belonging to Holcim. However occasionally, the wheel loader and
the dozer is also used for road work relatively large and complex in nature.
While road surface smoothening and filling is done when required, an activity that has to be
performed continuously on a daily basis is road watering. The reason for road watering is to
minimize dust on the roadways. Excessive amounts of dust reduces visibility and also poses a
health risk.
The road watering at the Aruwakkalu quarry was divided among the companies doing
overburden removing for the quarry. However, concerns were raised about this arrangement
stating that the current arrangement is not fair for all parties involved. Due to this reason, we
decided to prepare a new road watering plan which was fair to all parties.
The basis, for this new arrangement was the "Effective Distance" to be watered. Here,
effective distance means, the distance coupled with the number of passes required to cover
the road. For example, a wide road will have a greater effective distance than a narrower road
of the same length because a higher number of passes are required to cover the road. The
main hauling road required four passes under these arrangement and the other roads required
lower.
Once the effective distance was measured, we measured the lengths of all roadways
belonging to the quarry, including the roadways inside the quarry pit. Next we divided the
effective distance of the entire roadways according to the overburden removal volumes of the
three companies involved, EDC, TML and ISURU. The overburden removal volumes are
also the basis of payment for these companies. Therefore, the dividing the road distances in
this way was deemed fair to all.
56
Next the corresponding GPS points were established which would demarcate the areas of
watering. The respective areas were marked on a map and handed over to the supervisors of
the three companies.
Table 2.11 : Effective Distance in Road watering
Section Distance (m) No. of required
passes
Effective distance
(m)
Inside Quarry 750 2 1500
Main Hauling road 800 4 3200
Quarry entrance
road
500 3 1500
Total 6200
The calculation was done as follows.
Total Effective Distance = 6200 m
Overburden BCM ratio = EDC :TML :ISURU = 6:5:3
Allotted Distances
EDC = 6200*6/14 = 2700m
TML = 6200*5/14 = 2300m
ISURU = 6200*3/14 = 1200m
(Values are rounded to the nearest 100m )
57
Figure 2.33 : Road Watering Plan
2.3.2.2 Planning and Design
Planning and design of the quarry roadways is done both on the short term and long term. To
a great extent planning and design helps to optimize all current operations and also helps the
quarry progress smoothly into the future. Therefore planning vital structures such as
roadways has to be done in anticipation of the changes in the future to avoid costly re-
structuring activities. We were involved in several planning and design activities related to
roadways.
58
2.3.2.2.1 Re-Structuring of the Ramp Area
The ramp area situated near the office and is a place where both heavy vehicles and light
vehicles move about. For safety reasons, efficiency and also aesthetics, it was decided to re-
structure the ramp area.
Under this, the first activity was to isolate the ramp area so that only heavy vehicles can enter
it. We conducted a GPS survey of the new ramp area and then using the data gathered, drew
plans for this new ramp area on AutoCAD and reviewed them. Later this plan was put into
action.
Figure 2.34 : The Planned New Ramp Area
In order to isolate the ramp area, soil bunds were put up. These soil bunds serve two
purposes. It acts as a buffer and provides safety in case of an accidental vehicle slippage and
it also helps to keep out rain water from lowing into the roads. An area was separately created
for parking dump trucks during meal times. Under this arrangement, Light vehicles stay away
from the heavy vehicles and thus safety is ensured.
Dump Truck Parking Area
Isolated Heaps
Area for light vehicles
59
2.3.2.2.2 Hauling Distance Planning
The current quarry is situated at a distance of about 1.5km and the main hauling road
measures close to 3km. As the quarry progresses forward, the cycle distance also increases.
Eventually, the cycle distance will be too much and the machines will start idling and also,
the fuel consumption will also increase. Therefore, it is necessary to keep the cycle distances
in check.
Once the cycle distances reaches an impractical level, a decision has to be made to restructure
the dumping area and if possible move the ramp closer to the quarry pit. In order to do
planning of this kind, the current cycle distances and the rate of quarry progress needs to be
considered. Based on these data, it is possible to estimate the cycle distances of the future.
To conduct this analysis, first we gathered distance data from the dump trucks while
travelling in them and mapped the current haul roads, and their respective cycle distances on
a map. Next using the QSO optimization software, we calculated how far the quarry will
progress and its layout. Then we mapped the future roadways into the new quarry pit, and
calculated the cycle distances accordingly.
The current cycle distances and the cycle distance as projected 10 years into the future are as
follows. According to it, in 10 years, the cycle distance becomes impractically long.
Figure 2.35:
Current and
Future
Cycle
Distances
Current Cycle
Distances
Cycle Distances in 10
years
Projected
future quarry
60
2.3.3 Dispatching
After the quarried limestone is hauled to the ramp and mix beds are prepared (see section
2.4.3: Mix Bed Preparation), The dispatching process begins. According to the limestone
requirements of Palavi, either high grade, low grade or finished grinding material is
dispatched to Palavi via railway.
2.3.3.1 The Dispatching Process
We spent two days studying the dispatching process when the other quarry operations were
ceased due to the Staff Annual Trip of the quarry. The dispatching cycle begins when a train
with an empty set of wagons arrive at the ramp of the quarry. Each train has an average of 25
wagons and each wagon can accommodate 23 tonnes of material. There are two sets of
wagons operating such that while one set of wagons are being transported by the train the
another set of wagons is being filled and prepared at the quarry.
Once the train arrives the shunting operation is performed and the train changes to the track
closest to the loading platform. Then the train attaches itself to the set of filled and prepared
wagons and leaves. This transfer process takes about half an hour to complete.
Once the train leaves, the loading to the empty wagons brought by the train begins. Loading
is done by wheel loaders and loading is done by two loaders at a time and by breaking the
heap and mixing it to ensure homogeneity. Once the wagons are filled, an excavator
compacts the material in the wagons. The machinery used at the ramp are hired machinery
from EDC Ltd. Once compaction is done, the wagons are covered by a tarpaulin to avoid
spillage and to protect from moisture. Once the train arrives again this set wagons is
dispatched.
2.3.3.2 Locomotive Transport
The railway lines from the quarry to the Palavi processing plant is used exclusively for
Figure 2.36
:
Locomotive
Transport
61
limestone transportation and is managed by Holcim with the involvement of the Ceylon
Railways. Two locomotive engines owned by Holcim were used to transport the wagons filed
with limestone during our period of training.
During our study of the dispatching process we observed the train movements and gathered
related data. During our study a derailment of the train and the resulting repairs during the
following days caused delays in train movement. However, on average 7 haul trips are made
per day.
The summary of data we gathered during these one of the three days is given below
Dispatch Details
26-Dec-13
Trai
n No. LSF SR
Mixed
Heap
Arrival
of Train
Departure
of Train
Preparation
Time
Load
Weight(tonnes)
111 131 3.24 MHF 2:35 3:15 0:40 724
112 79 4.17 MLC 7:10 7:55 0:45 656
113 131 3.06 MHF 10:35 11:05 0:30 659
114 221 2.24 FG 16:05 16:45 0:40 624
Total Load for the Day(tonnes) = 2663
Derailment of the train near the 12th mile post and repairing the transfer point for faulty
wagons caused a delay.
62
2.3.4 Activities and Projects
In addition to the activities mentioned above, we also carried out some extensive projects.
They are described briefly in this section.
2.3.4.1 Hauling Fleet Optimization
Hauling activities in the quarry are carried out by a fleet of 3 Komatsu HD 325 dump trucks
and a separate 3rd party fleet of 10-wheel trucks. As discussed in section 2.3.1.3, While the
costs associated with operating the HD 325 fleet are significantly higher than that of the 10-
wheel truck fleet, the dump trucks have a very high capacity and carry almost thrice the
volume of a 10-wheel truck. Thus the other factor that has to be considered is, the fleet size.
Although, dump trucks can haul at a higher rate, technically a fleet with a sufficiently high
number of 10-wheel trucks should be able to haul at the same rate. However, practically the
fleet size is limited by many constraints such as cycle distance, cycle time and hauling
conditions. Therefore we attempted to identify the maximum fleet size in each arrangement.
For continuous hauling to take place, there should not be any trucks waiting in line at the
loading point. This means that the cycle time of one truck should be equal to the time it takes
to load all the trucks in the fleet.
Therefore, by dividing the cycle time by the loading process time, the maximum no. of trucks
that can haul material without interruption can be obtained.
Here, the "loading process" time indicates the total time taken from the entry to the loading
point until the exit. This includes the time taken to maneuver the truck as well.
Costing and hauling rates were computed from data extracted from FMC and Quarry
Performance sheets.
From the data gathered,
Cycle time of Dump Trucks = 15 minutes
Cycle time of 20- wheel Trucks = 17.143 minutes
63
Table 2.12 : Loading Process times of Sump Trucks and 10-Wheel Trucks
Dump Trucks 10 Wheel Trucks
Loading Process
time (hr:min:sec)
Loading Process
time (minutes)
Loading Process
time (hr:min:sec)
Loading Process
time (minutes)
0:02:51 2.85 0:01:55 1.9167
0:04:03 4.05 0:02:20 2.3333
0:04:44 4.7333 0:02:40 2.6667
0:03:51 3.85 0:02:25 2.4167
0:03:53 3.8833 0:02:19 2.3167
0:04:20 4.3333 0:02:31 2.5167
Average Time 3.9500 Average Time 2.3611
Therefore,
Maximum Number of Dump Trucks = 15/3.95 = 3.7975 ≈ 4
Maximum Number of 10 -Wheel Trucks= 17.143/2.3611 = 7.2606 ≈ 7
Also,
Limestone Requirement of quarry = 4500 tonnes
Hours taken to haul by Dump Trucks = 4500/480 = 9.375
Hours taken to haul by 10-wheel trucks = 4500/294 = 15.306
According to Table 2.10 : Comparison of Hauling Trucks, it was seen that the cost per tonne
hauled is significantly higher in the case of dump trucks. However, the above data shows that,
to meet the daily requirement of 4500 tonnes, Dump trucks need to haul for a period of about
9 hours while 10-wheel trucks need to operate for about 15 hours. Therefore the daily
64
limestone target cannot be achieved during a day's work (12 hours effective)by using a fleet
of 10-wheel trucks.
Furthermore this analysis is important because, it highlights the importance of having the
right number of hauling trucks. Smooth hauling operations without any interruptions can only
be carried out with the right number of trucks in the field. Insufficient trucks will result in the
loader idling while too many trucks will result in queues at the loading point and will lead to
trucks idling.
We notices several instances in the quarry where too many trucks caused queues at the
loading point. Therefore this analysis would help to rectify this problem.
Figure 2.37 : Queue at the Loading Point
2.3.4.2 Hauling road level survey and road slope analysis
With the overburden removal process and the filling of the old road, all haulage operations
are expected to be carried out via the new quarry road. Although it had been cleared
previously its gradient and centre line elevations have not been found. In order to find out
these details, We performed a level survey at the new quarry road.
65
The objective of this survey was to calculate the reduced levels along the road, and to find
the gradient variation of the road.
Upon visual inspection it can be seen that the new haul road has quite a steep gradient
especially towards the
latter part of the road,
at the entrance to the
quarry pit. This can be
seen by the 3D model
we created using the
"Surfer" Software by
using the survey data.
This model does not
show the deviation
and curves of the road
but can be used to
visualize the gradient.
Although mine
machinery and dump trucks are able to ascend steep gradients, the gradient of main haulage
roads are limited to less than 7:100. This is because at steep gradients, the automatic
transmission systems found in most of these machines shift to a lower gear which in turn
results in a higher fuel consumption. By maintaining a gentle gradient, the machines will be
able to travel on the road in higher gears thus lowering fuel consumption. Therefore, limiting
the road gradient helps in optimizing machine performance.
The limiting value of the gradient, 7:100 has been arrived at by studying machine operation
over various gradients and conditions and by considering the optimum performance of
machines. This value is an accepted standard and is also specified in the Quarry Process
Manual of Holcim Lanka Ltd. Therefore we also calculated the required fill heights in order
to maintain the gradient of the road below 7:100 while minimizing the volume that would
need to be cut for this purpose.
We adopted the standard leveling procedure and the collimation method was used to book the
readings. For the flat part of the road, we used a station interval of 30m, while for the latter
part where steep slopes are present, we chose an interval of 20m.
Figure 2.38 : 3D Model of road created using Surfer
66
After carrying out the survey and booking the readings, we entered all data into an MS Excel
sheet and calculated the gradient variation of the road. Using this gradients we calculated the
fill volumes required to bring the overall gradient to a manageable level. We used two
approaches to calculate the fill volume.
In method 1, since the road starts inclining steeply downwards starting at the 1080 m point,
Filling heights were calculated from the 1080 m point. Thus the proposed road surface begins
at the 1080 m point. This method neglects the small local variations before the 1080 m level.
In method 2, in order to eliminate the local gradient variations as well, filling heights were
calculated starting from the 960 m point. In this method, filling had to be done in two places.
Figure 2.39 : Two methods of road filling
We constructed proposed surfaces for both methods and calculated the fill heights in both
cases. The results are summarized below in Table 2.13.
In method 1, the local gradient variation at 960 m point is left as it is, and only the latter part
of the road is filled. The road had to be extended by 25.35 m to accommodate the new
gradient
67
In method 2, the local gradient variation is also eliminated. Filling has to be done in two
sections with a negligible cut section. The road had to be extended by 30.0 m.
The section highlighted in yellow indicates the extra lengths the road had to be extended in
method 2. While method 1 is the easier to implement, method 2 takes care of the local
gradient variation found at the 960 m and gives an overall smoother road.
The filling work on this portion of the road began while we were still at training. The road
was extended as was decided in both methods. At the end the filling was carried out
according to a combination of the two proposed methods.
Table 2.13 : Calculated fill Heights in the two Methods
Survey Station Fill Height Method 1 Fill Height Method 2
960 0
980 0.3145
1000 0.3676
1020 0.1948
1040 0.1625
1060 0.1002
1080 -0.0526 0
1100 0.0508 0.1379
1120 0.1391 0.1932
1140 0.4033 0.4805
1160 0.8788 0.9987
1180 1.2586 1.3157
1200 2.1066 2.3221
68
1220 2.3256 2.2668
1240 2.3737 2.2326
1257 2.0331 1.7544
1267 1.3555
1277 0.6779
1287 0.0003
At the end of the project we were able to propose a solution to the steep roads of the new
hauling road without performing any time consuming and expensive cut operations. Filling
work beginning immediately after is a testament to its effectiveness. The picture below shows
the refilled area of the road.
Figure 2.40 : Refilled Area of the New Road
69
2.4 Quality Control and Planning
In the manufacturing of cement it is important to maintain the physical properties and
consistency. This means that the raw material used for cement production should be of
consistent quality. Therefore, quality control of the limestone reproduces is a vital component
of the quarrying process.
Limestone naturally occurring does not have a consistent composition. Therefore, through
extensive sampling, coordinated quarrying, and proper mixing, the desired quality of
limestone is obtained. To achieve this, The personnel at the quarry lab works alongside the
quarry Engineers and the Chemists at the Palavi processing plant to ensure that the required
quality product in the right quantities are produced.
2.4.1 Lab Activities
The lab occupies the central position in the quality assurance process coordinating with the
engineering division of the quarry and also the chemical department at the Palavi Processing
plant.
2.4.1.1 Sampling
Sampling in the main activity carried out by the lab. sampling is performed throughout the
day and every day. samples gathered are tested at the quarry lab itself and some samples
collected are sent to Palavi via train
dispatch to be analyzed more accurately.
Results received from such tests are
updated daily into records.
The types of sampling performed at the
quarry are as follows.
2.4.1.1.1 Test Hole Sampling
Test holes are holes drilled to for the
purpose of sampling itself. They are drilled
on the reject bed soon after the overburden
is removed. Holes are drilled up to a depth
of 60 feet (6 rod holes ). Samples are taken
from the drill dust that is flushed out from Figure 2.41 : A typical test hole
70
the drill steel. While the approximate quality of the area is known by QSO , Test holes are
drilled as means for conformation and also to accurately record the quality of the particular
area. To this end, GPS coordinates of the test holes are taken and the they are recorded in MS
Excel Sheets. A typical test hole and type of material found are shown in Figure 2.41 : A
typical test hole.
We observed the test hole sampling and we gathered samples and GPS location data and also
entered them into records. We also formatted some of the older records and restructured and
organized them so that they can be used for further analyses.
We organized some test hole data into a table shown in annex ,and extracted the elevations
along with their GPS coordinates to create a set of 3D Cartesian coordinates.
Table 2.14 : Coordinates extracted from Test Hole Data
Top Layer Bottom Layer
x y z x' y' z'
94743 338990 5 94743 338990 1.5
94698 338999 4.5 94698 338999 -1.5
94702 338985 7.5 94702 338985 1.5
94687 339010 0.5 94687 339010 -0.5
94689 338990 0.5 94689 338990 -0.5
94755 339071 5 94755 339071 1.5
94970 338465 1.5 94970 338465 -1
95078 339206 15.5 95078 339206 9.5
95112 339191 11.5 95112 339191 3
95102 339186 13.5 95102 339186 2.5
95124 339157 7 95124 339157 -4
95078 338800 -15 95078 338800 -16
71
These coordinate data was fed into the "Surfer" software and a 3D model of the layer was
created. Using this 3D model and by calculating the volume between the surfaces, the volume
of the layer was calculated.
Figure 2.42: 3D models of upper and lower layers
however it must be noted that the area is a rectangular area spanning the extreme corners of
sampling.
The volume calculation is as follows.
Total Volumes by:
Trapezoidal Rule: 1034419.365
Simpson's Rule: 1034551.84
Simpson's 3/8
Rule: 1034536.013
2.4.1.1.2 Drill Hole Sampling
Drill hole sampling is just like test hole sampling except that the main purpose of drill holes
is to drill holes for charging explosives. Since Drilling is performed every day, Drill hole
samples are collected daily. The samples are collected by means of a dust collecting pan.
These collected samples are put into sample bags and are sent to the quarry lab for testing.
In drill hole sampling one major problem is that most high quality material gets carried away
by the wind and the dust collected at the pan is composed majorly of the heavier sand
72
component. For this reason, the drill hole sample results are of lower quality, which is why
other methods of sampling are required for a proper assessment.
2.4.1.1.3 Mix Heap Sampling
Just as the name suggests, mixed heap sampling is taken from the mixed heaps at various
times of the day. This method of sampling paints a more accurate picture of the quality of the
material hauled form the quarry, The main purpose of this type of sampling is to monitor and
optimize heaps so that they are maintained at the required quality levels consistently.
2.4.1.1.4 Wagon Sampling
Wagon sampling is the final stage of sampling and in done once the material is loaded into
the wagons before dispatching. It gives a final measure of the type of material that is sent to
the Palavi processing plant. Samples are taken from every third wagon of every train
departure.
When collecting samples, at least 5kg of material is taken and it is reduced to 200g by means
of coning and quartering. Coning and quartering is standard laboratory process of obtaining
an unbiased sample.
Figure 2.43 : Coning and Quartering
If the samples contain rocks and pebbles, before coning and quartering is performed, it is
crushed by means of a jaw crusher to produce a sample with particles of manageable size.
Once coning and quartering has been done, the contents are heated to remove moisture
transferred into Disk Mill for grinding into a powder. After grinding into a powder they are
transferred into packets and sealed. These sealed packets are sent to Palavi for testing.
73
2.4.1.2 Quality Parameters
The main quality parameters involved in the manufacturing of cement are given below.
While the chemical parameters listed below are governed by the requirements of the
production of cement, the moisture content and physical parameters are governed by the
processing conditions and the requirements of the machines used for processing.
1. Lime Saturation Factor (LSF)
This is the most important and often widely quoted parameter concerned with cement
production. It is the first parameter that is tested and the main factor considered in mix bed
preparation and dispatching. The grouping of quarried limestone into high quality and low
quality is done on the basis of LSF. An LSF above 120 is generally termed high quality. It
combines ratios of several chemical components and is calculated as follows.
𝐿𝑆𝐹 = 𝐶𝑎𝑂
2.8𝑆𝑖𝑂2 + 1.18𝐴𝑙2𝑂3 + 0.65𝐹𝑒2𝑂3∗ 100%
Equation 2.6 : Formula for LSF
2. Alumina Ratio
Alumina Ration is the secondary quality parameter and gives a measure of the limestone's
clay content.
𝐴𝑙𝑢𝑚𝑖𝑛𝑎 𝑅𝑎𝑡𝑖𝑜 = 𝐴𝑙2𝑂3
𝐹𝑒2𝑂3
Equation 2.7 : Alumina Ratio
3. Silica Module
𝑆𝑖𝑙𝑖𝑐𝑎 𝑀𝑜𝑑𝑢𝑙𝑒 = 𝑆𝑖𝑂2
𝐴𝑙2𝑂3 + 𝐹𝑒2𝑂3
Equation 2.8: Silica Module
4. Chlorine Content
5. Magnesium Oxide (MgO) Content
6. Moisture Content
74
The Chlorine Content and MgO content is not very important in the quarrying level. However
they are used for record keeping as it can be used to create a comprehensive chemical
analysis of the quarried material.
The main purpose of measuring moisture content is to avoid Crusher jamming at the
processing plant. For this reason, during the dry season, a moisture content of 7% is
maintained while during the wet season a level of 8% is maintained. Moisture content can be
reduced by adding boulders (less than 1.5m) with the limestone, as boulders do not contain
water.
2.4.1.3 Laboratory Testing
The quarry lab is equipped with apparatus and reagents to carry out all necessary chemical
tests. We observed several of these chemical tests being performed. The procedures in the
testing of limestone are quite different to the standard laboratory practice we are familiar
with, especially in the use of indicators and titrations.
Although the lab is equipped with the facilities, the accuracy in the testing performed is not
up to the level required. Also sometimes results are required in a short period of time. For
these reasons, samples are sent to Palavi for testing via XRF (X-Ray Fluorescence
Spectroscopy). This yields highly accurate results in a short time.
The quality targets expected to be produced by the Quarry in terms of chemical parameters
are as follows.
Table 2.15: Quality Targets of the Quarry
LSF SM Cl-
Quarried
Limestone
HGL Min 110 Max 3.5 Max 0.6% Moisture Content
LGL Min 50 Max 5.5 Dry
Season
Wet
Season
Mixed
Heap
HGM 150±20 Max 3.5 Max 0.03% Max 7.0% Max 8.0%
LGM 85±15 Max 4.5 Max 0.035
%
75
Where,
HGL-High Grade limestone LGL-low grade lime stone
HGM- High LSF mix bed LGM-low LSF mix bed
2.4.2 QSO and Quarry Master
QSO and QuarryMaster are two software packages designed by Holcim Global Technical
Services for the exclusive use in their limestone quarries around the world. The Aruawakkalu
Quarry also has these software installed and they are used for planning and optimization of
the quarry.
2.4.2.1 Quarry Scheduling and Optimization (QSO)
As the name suggests the QSO software is designed for the purpose of scheduling and
optimizing the quarry output. It is a software primarily used for long term planning of the
quarry. The basic idea of QSO is to model the quarry in a 3 dimensional space with blocks of
manageable size. This model contains data about the quantity, of material the distribution of
quality and also the spatial layout and extent. With this data fed into the software, it
calculates the optimum way that quarrying should be performed.
The main input data for the QSO software are core drilling data. Although we did not
experience the core drilling process, we got the opportunity to study several core drilling data
sets. We studied these data sets and compiled and formatted some of them for ease of
analysis. A typical core drilling dataset contains
GPS / Grid location
Elevation of Surface
Depth of each reject and Limestone Layer
Quality of Each layer
Using this data, the QSO software creates a 3-dimensional layout arranged in blocks of
50mx50m and also in layers for each quality. The right side of Figure 2.44 shown below
shows the blocks arranged in layer for each quality, while the left portion of the image shows
on such layer isolated for analysis. The blocks shown in red are the blocks available for
mining..
76
Depending on the required quality and also other restrictions such as quarry boundaries and
environmental considerations, it is possible to "run" the software into the future. Then the
software considers the blocks available for mining and also the current quarry advancement
rate to predict the future of the mine.
This gives us a graphical plan of the long term quarry progress. We were given the
opportunity to use this software. We used the software to predict the layout of the quarry in
the year 2014 during each quarter. Figure 2.45 shows the layouts produces by QSO for the 4
quarters of 2014. The dark blue blocks indicates overburden removal, the light blue blocks
indicate low grade limestone while the green blocks indicate high grade limestone.
In the figure above it can be seen that the high grade limestone that is to be extracted during
the 1st quarter has depleted by the 2nd quarter while the low grade limestone areas in the first
quarter has become high grade limestone in the 2nd quarter. This reflects the fact that the
high grade limestone lies at the bottom strata of the deposit.
The figure also shows that overburden removal will, to major extent complete by the first
half of the year while during the latter half, only limestone extraction will take place. In
addition to the graphical layout, QSO also provides the quantity and quality data numerically.
Figure 2.44 : The QSO Layout
77
Figure 2.45 : QSO prediction for 4 quarters of 2014
2.4.2.2 QuarryMaster
QuarryMaster is the other software used at the quarry. It provides ways to optimize day to
day operations in the quarry and is mainly used for short term planning. The software has a 3
dimensional, spatially referenced model of the quarry and daily changes and sampling data
can be inserted into it on a daily basis. Blasting performed at the quarry are marked and
virtually blasted in the software also.
Quarter 1 Quarter 2
Quarter 3 Quarter 4
78
Figure 2.46 : The 3 Dimensional Model of the Quarry in QuarryMaster
We performed a lot of activities relating to QuarryMaster. We gathered GPS points
periodically around the quarry boundary in order to update QuarryMaster. We performed a
GPS survey and mapped current
overburden removal areas. Since
these areas will be the areas
which will be mined in the
immediate future, we inserted
the GPS survey data into
QuarryMaster and mapped the
quarry pit and calculated the
extra area which will be mined
during the next couple of
months.
Figure 2.47 shows a map prepared
in this manner highlighting the
areas to be mined from December 2013 and September 2104 and also the quarry boundaries
after that period.
Once the sampling data from the lab is also inserted into the software along with their
location data, the software build up a model of the locations of available material and their
qualities like in QSO, but in a more short term way and also as isolated and local data. Using
this, the optimum system of hauling can be determined. This also helps in mix bed
preparation.
Figure 2.47 : Short Term Mine Planning with
QuarryMaster
79
2.4.3 Mix Bed Preparation
Mix bed preparation is the name given to the pre-blending process employed quite recently at
the quarry. Mix beds are prepared at the ramp
area and is done to mix the hauled material
before dispatching them to Palavi.
Under this method, heaps are built by using
layers of alternating quality material. Once the
dump trucks dump the material at the ramp, a set
of small dozers, shove these material and
create heaps.
Dumping id performed in quality of
alternating material which the gives the heaps
a layered appearance. The qualities and
frequencies of material hauling is decided by
using the QuarryMaster software. The heap is broken perpendicular to the prismatic section,
so that all the layers mix when it is broken thus giving a mixed material with consistent
quality. Only after a heap has been depleted completely it is rebuilt again. Complete heaps
are covered to protect them from the rain
2.4.4 Activities at Palavi Processing Plant
The material sent from the quarry to Palavi is first crushed by means of two Hammer
Crushers. Since there had been some problems with the performance of these crushers. We
were assigned to analyze this situation. For this purpose we received crusher performance
data from Palavi in the form of daily record sheets. We tabulated these data into a MS Excel
sheet and analyzed them. Upon initial analysis it was difficult to come to a conclusion
because, Crusher 1 did not have enough data due to a break down. However, upon further
analysis it was found that Crusher 2 was performing better
Figure 2.48 : Preparing of Mixed
Heaps
Figure 2.49 : Layered appearance of a
Mixed Heap
80
2.4.5 Activities carried out
In addition to the above activities we carried out several other projects. They are described in
this section.
2.4.5.1 Alumina mapping of the Quarry
After LSF the next most significant quality
parameter is the Alumina Ratio. To assess the
Alumina variation in the quarry it was
decided to analyze available data and to check
whether any inferences could be made. For
this we utilized the test hole and drill hole
sampling data and extracted the Alumina
Ratio data from the sampling results. We
coupled this data with its location data as well
and created a 3D Cartesian coordinate data
set.
These coordinates were inserted into the
Surfer software and the a contour map of the
Alumina variation was obtained.
In this contour map it can be seen that a very
high variation of Alumina has occurred at the
north east portion of the map. This turned out to be an anomaly caused by a high
concentration of sampling points in that area. Therefore since the sampling points were not
well distributed, the accuracy of this map is questionable.
2.4.5.2 Preparing Cross Sections of the Quarry Pit
Part of the long term planning of the quarry is the quarry pit rehabilitation plan. For this it is
required to fill the quarry pit appropriately so that there are no excessive slopes. This has to
be ensured for the safety of wildlife as well as to avoid devastating results from erosion.
As a part of this we were assigned to draw cross section of the quarry to determine the current
steepness of the slopes. Once the current shape is known the most appropriate filling plan can
Figure 2.50: Contour Map of Alumina
Variation
81
be adopted. To do this we gathered elevation data of the quarry and used the surfer software
to draw up cross sections.
Figure 2.51 : Cross Sections of the Quarry Pit
2.4.5.3 Fill Volume Calculation of Old Road
This is one of the major projects carried out by us. Although slightly similar to the above
project, this was far more complex and extensive. We had to calculate the volume of soil
which would be required to fill the old hauling road as it is no longer used. Since overburden
soil was going to be used for this, knowing the exact volume required will help in planning
the overburden dumping strategy.
We gathered over 500 points of elevation along with their northing and easting coordinates.
We processed this data and created a 3D model of the existing topography of the area of the
road. Then we also modeled a smooth proposed surface using Surfer. We used these two
surfaces to calculate the volume of soil required. The full report is included in the Annex.
Figure 2.52 : The Existing Surface and the
Proposed Surface
Existing Proposed
82
2.5 Overburden Removal and Rehabilitation
Overburden removal and rehabilitation lies at two different ends of the quarry operations
spectrum. However both of these operations are often carried out simultaneously. This is
because the top side excavated during overburden removal is used for rehabilitation.
2.5.1 Overburden Removal
Overburden removal at the Aruwakkalu quarry carried out by 3 Companies. Namely, EDC
(Eric Dharmasena Construction (Pvt) Ltd. , TML (Tokyo Machine Leasing) , and ISURU
Engineering. EDC has the largest
machine fleet overall and also
performs activities in the ramp.
TML has the largest machine fleet
for overburden removal. These
three companies are assigned
separate areas for overburden
removal and they are paid
according to the bank cubic meters
(BCM) of overburden soil
excavated.
During the overburden removal process, the fertile topsoil layer is first excavated and piled
separately. This soil consists of organic matter and is suitable for plant growth. The
subsequent layers of excavated overburden soil is not fertile and therefore is used primarily to
fill abandoned pits.
2.5.1.1 cycle times
The excavation of overburden is done by excavators and the soil is loaded into 10-wheel haul
trucks and hauled into the dumping points. We conducted a cycle time analysis for the 3
companies. The results are summarized below.
Figure 2.53 : Overburden Removal
83
Table 2.16 : Overburden Removal Cycle Time Summary
Company Average Cycle Time Cycle Distance Average Cycle per
Day
EDC 8.77 minutes 2.2 km 48
TML 10.1 ,minutes 2.3 km 55
ISURU 15.03 minutes 2.4 km 45
2.5.1.2 Bench face and slope analysis
In the excavation of overburden, benches are left for stability purposes The stipulated
dimensions of the benches are 5m X 5m. However, in some areas these dimensions have
not been adhered to and it has posed a risk with also several collapsed benches.
We were assigned to conduct an analysis of this situation. The first step was to monitor and
assess the current bench conditions. We recorded several locations around the quarry and
measured the bench dimensions and also recorded GPS location data. Using these data we
calculated the slope angles of different areas of the quarry.
Although according to the stipulated dimensions, the slope angle should be approximately 45ͦ.
However, from our measurements we found out that most bench slopes exceeded this
amount.
The next step was to carry out a Risk assessment of the above areas. We photographed the
areas and assessed the potential risk involved by consulting a risk matrix. The risks that we
considered are as follows:
Plane failure:- failure of a bench face as a plane
Wedge failure :- Wedge like failure caused by erosion
Rock falls:- caused by instability of benches
A summary of the findings of the slope analysis and the risk assessment are given below.
84
Table 2.17: Summary of Bench Face Risk Assessment
Location
Grid
No.
GPS
identification
Potential
For
Potential
Consequences
Risk
Rating
Mitigation
Measures
ISURU 1 95209,338838 Rock falls
personnel and
equipment
damage
C3
(13)
scaling of
loose rocks
ISURU 2 95222,338838
Rock
Falls
personnel and
equipment
damage
D3
(17)
scaling of
loose rocks
ISURU 3 95253,338873
Wedge
failure
personnel and
equipment
damage D2(12)
removal of
loose
material
ISURU 4 95301,338865 rock falls
personnel and
equipment
damage D3(17)
scaling of
rocks
ISURU/TML 5 95341,338884
Wedge
failure
collapsing of
benches D4(21)
proper
benching
TML 6 95344,338933 rock falls
personnel and
equipment
damage D3(17)
scaling of
rocks
TML 7 95348,338983 rock falls
personnel and
equipment
damage D3(17)
scaling of
rocks
TML 8 95357,339027
Wedge
failure
personnel and
equipment
damage D2(12)
removal of
loose
material
TML 9 95356,339079 Rock falls personnel and
equipment
C3
(13)
scaling of
loose rocks
85
damage
TML 10 95364,339131 Rock falls
personnel and
equipment
damage
C3
(13)
scaling of
loose rocks
TML 11 95375,339177 Rock falls
personnel and
equipment
damage
C3
(13)
scaling of
loose rocks
EDC/TML 12 95369,339238 Rock falls
personnel and
equipment
damage
C3
(13)
scaling of
loose rocks
EDC 13 95334,339260 Rock falls
personnel and
equipment
damage C2(6)
scaling of
loose rocks
EDC 14 95302,339262
Wedge
failure
personnel and
equipment
damage D2(12)
removal of
loose
material
EDC A 95070,339207
Wedge
failure
personnel and
equipment
damage, road
blockage D4(21)
proper
benching
EDC B 95150,339259
plane
failure road blockage B2(5)
proper
benching
EDC C 95216,339271
plane
failure road blockage B2(5)
proper
benching
EDC D 95268,339308
wedge
failure road blockage C3(13)
proper
benching
EDC E 95330,339346
plane
failure bench collapse B3(9)
proper bench
heights
86
EDC F 95494,339286
wedge
failure,
plane
failure bench collapse C3(13)
maintaining
proper bench
dimensions
TML G 95532,339210
plane
failure banch collapse D4(21)
maintain
bench heights
TML H 95469,339108
bench
failure bench colapse E5(25)
proper
benching
TML I 95467,339041
plane
failure road blockage C4(18)
maintain
proper bench
heights
TML J 95422,338969
wedge
failure bench collapse c3(13)
proper bench
dimensions
ISURU K 95285,338806
plane
failure bench collapse C4(18)
maintain
bench
dimensions
Figure 2.54 : Risk Assessment Matrix
87
2.5.2 Rehabilitation of the Quarry
The rehabilitation process at the Aruwakkalu mine is done with the involvement of IUCN (
International Union for Conversation of Nature) . Once the quarrying is over the pits are
filled with overburden soil eliminating all steep slopes. Then the area is filled with fertile
soil and plant species typically found in that area are replanted. The rehabilitated areas are
constantly monitored and improvements are made to preserve the flora and fauna of the area.
2.5.2.1 Activities with IUCN
IUCN is the organization responsible for providing recommendation and monitoring the
rehabilitation of the quarry. They provide recommendations for the type of plant species to be
replanted. For this they visit and record the flora and fauna of the surrounding areas .Another
important activity performed by IUCN is the animal rescue programme, in which animal
species are taken out of the quarry site where overburden removal is scheduled to begin. This
activity is carried out with the help
of the Villagers. These rescued
animals are released into fully
rehabilitated areas.
2.5.2.2 Seedling bed Preparation
The plants that are required for
rehabilitation are usually purchased.
However under a new initiative it
was decided to cultivate seedlings
taken from the surrounding forest s
in seedling beds constructed in the
rehabilitated area itself. We were
assigned to plan and prepare the
seedling beds required for this
purpose.
We selected areas which were not
exposed to direct sunlight and
which were not prone to surface
runoff. Once the suitable areas
Figure 2.55: Seedling Bed Locations
88
were selected fertile soil from the overburden removal process was used to construct seedling
beds. The idea was to plant saplings in these seedling beds until they could be relocated to
the rehabilitated areas. This initiative saves the cost involved in purchasing plants. We also
recorded the locations of these seedling beds in a map for future reference. The map is given
above.
2.6 Machine maintenance and Workshop Activities
The Aruwakkalu Quarry has its own workshop and maintenance division to maintain the
machinery belonging to Holcim. The workshop performs undercarriage maintenance of the
Komatsu Machine fleet and complete maintenance in other machines. The workshop is also
equipped and responsible for all electrical work in the quarry and surrounding premises.
The maintenance division maintains extensive records of performance, maintenance and
breakdown in all machines.
2.6.1 Daily maintenance operations
Daily maintenance occupies a significant role in all workshop operations. Machines are
checked daily according to specific check lists for each machine to ensure that all machines
are in good condition. Engine maintenance is performed by the DIMO maintenance crew and
is overseen by the Holcim operators.
Figure 2.56 : Daily Machine Checks
89
2.6.1.1 Tyre Maintenance
An important part of daily maintenance is the checking of tyres. Tyre pressures are checked
daily and inflated to the correct amount before operations begin. We gathered tyre pressure
data over a period of time both before and after operations. We found out that the tyre
pressure increases by about 20% after operations.
We also periodically measured the tread depths of tyres and tabulated them in order to find
the wear rate of tyres. The tabulated data and resulting calculations is given in section Table
2.7.
2.6.1.2 Welding Grinding
We also performed welding and grinding operations at the workshop and experienced the
methods involved and precautions taken. In constructing sign boards for the explosive
magazines we performed some of the welding and grinding operations.
Figure 2.57 : Welding Operations
2.6.2 Machine Safety Survey
In order to assess the safety levels of the entire machine fleet operating at Holcim (including
3rd party machines as well) We performed a safety survey. The main purpose of this survey
was to assess whether the machines are prone to theft and to identify areas which could be
improved in this regard.
90
We visited all supervisors and gathered data about their machines and tabulated them. Since
this activity involved a lot of machines and lot of criteria a large amount of data had to be
entered. To overcome this situation we prepared a data entry form using Macros in Excel.
Once tabulated this data was used to identify weaknesses present in machines and steps were
taken to rectify them.
Figure 2.58 : The Excel data Entry Form Used for the Machine Survey
2.7 Workshops and Other Learning Opportunities
In addition to the learning opportunities at the Quarry Site we also received the opportunity to
participate in two workshops organized by CETRAC (Construction Equipment Training
Centre) We were sent along with an employee of Holcim to this full day programme
consisting of the two sessions. We learnt lot of new things about the proper use of lubricants
and also the basics of machine maintenance at these workshops.
2.7.1 Lubricant Workshop at CETRAC
In this workshop we learnt the defining characteristics of lubricants and their performance
under different conditions . After a basic introduction to the types of lubricants we were
taught the proper usage of each type. We were also given the knowledge to understand the
naming system of lubricants and each of their properties.
An important fact that we gathered was the difference between mono-grade and multi-grade
oils and the pros and cons of each type. We also learnt the importance of changing engine
91
and transmission oil periodically to avoid carburization of the lubricant oil and resulting
engine damage.
Back at the quarry we were able to apply the new knowledge gained and further cemented
our knowledge with discussions with personnel and the workshop.
2.7.2 Workshop on Maintenance of Construction Equipment
In this workshop we learnt the basic parameters of measuring equipment performance.
Terms such as,
availability
meantime to failure
equipment down time
cost per unit time
overall equipment effectiveness (OEE)
were discussed. We also learnt methods of measuring performance and effectiveness of
machines. However, almost all these methods discussed were already implemented at
Holcim.
The FMC daily record sheets maintained at Hoclim includes all the necessary details
required to calculate the key performance indicators taught to us at the workshop. With the
knowledge gained at this workshop we were able to use the FMC record sheets in much more
complicated analysis and were able to produce information about operator performance as
well.
2.7.3 Tire maintenance lecture by Triangle tire corporation
Due to problems with heavy machinery tyres at the quarry, a consultant from the Triangle
Tyre Corporation visited the premises to assess the tyre conditions. At the end of his visit, he
presented a lecture about the proper usage of tyres.
We learned the importance of the daily maintenance of tyres and the proper machine handling
practices such as symmetrical loading, avoiding tyre spinning etc to extend the lifetime of
tyres. The road conditions and the frequency if road maintenance has on the performance of
tyres was also discussed. A special attention was given to controlling the road watering
system as excessively wet roads damage tyres more frequently.
92
3 CONCLUSION
The Industrial Training programme is undoubtedly is the most important aspect of the 4 year
degree in Engineering. After 3 years of university study, gathering knowledge and learning
theories, industrial training period cements all the knowledge gathered and helps us to
understand the theories we learnt. In the real world application of things we learnt at the
university during our training period we experienced aspects that we never thought would be
important when we learnt them. For example, although we knew the theories and procedures
with respect to activities like blasting, hauling, only during our training period did we learn
the actual process practically such as the proper quantities of explosives and the application
of specific charge to control explosive usage. We also received hands on experience in most
quarry activities and learnt the minute details and intricacies in each of them. To conduct
We received such an extensive training programme at Holcim Lanka Ltd. that at the end of it
we were confident that we could manage a quarry of that capacity by ourselves. In an
industry where securing a position for training let alone a highly exceptional place such
Holcim Lanka Ltd. is a difficult task, we are thankful to NAITA , the University of Moratuwa
and Holcim Lanka Ltd. for facilitating this programme.
Upon starting our training programme at Aruvakkalu Quarry, we were welcomed graciously
by Quarry Manager, Eng. W. N Wedage , Quarry Engineer Eng. G. Silva, and the Junior
Mining Engineers, P Kumarage, and A Batagalla. We were explained the outcomes of this
training and were told to make the maximum of this opportunity. To this end, we were
assigned to the two shifts under the two junior mining Engineers in order to experience all
aspects of the quarry operations and to experience the full responsibility of an Engineering
job in the field of mining. We worked hard for extensive hours under the constant guidance
of our immediate superiors who treated us like their own brothers. We were encouraged to
ask questions and allowed to perform most operations related to the quarry without
hesitation. We were assigned several projects and often given the full responsibility to carry
them out on our own. We were provided with assistance whenever we required, and we
were able to perform these projects to the satisfaction of our superiors. These projects were
mostly practically oriented and we had to gather real data sometimes over a period of several
months. This sort of activity was not possible to be conducted at the university. At the end
of each project, we were instructed to furnish full reports highlighting the findings and our
recommendations. We were happy to see that some of our findings from our projects being
applied at the quarry. One major opportunity we received during our training programme was
93
to learn and work with several new software programmes. While learning to use software
programmes exclusive to Holcim such as QSO and QuarryMaster, we also learnt several
other widely used programmes. We learnt to operate 3D terrain modeling software "Surfer"
and used it extensively in many of our projects. We also sharpened our skills in handling
software we already learnt at university such as AutoCAD.
During this training period I found out that communicating with personnel at the quarry and
maintaining a proper network was a difficult task for me. After realizing this I made a
conscious effort to move around more with the people in order to develop my people skills.
At the end of the six months training, I experienced a massive improvement on this front.
However, I still have improvements to be made in this regard, and I plan to work on my
communication skills during the final year by engaging more with social activities at the
university. Overall the training period helped me to identify this weakness of mine and
equipped me with the tools to overcome this and to turn my weakness into strength.
Holcim Lanka Ltd. is equipped very well to provide industrial trailing. We were considered
as employees of the Company during our stay and were provided meals, accommodation
transport and also given an allowance. Being a Company highly focused on safety and
proper operational procedures, we were given all personal safety equipment including hard
hats, safety shoes, safety goggles and also a uniform with high visibility bands. To carry out
our project work, we were also given office space complete with all facilities. The effort put
in by the Company for our training programme made our training a pleasant experience.
At the end of the training programme, all our expectations were met and also we achieved all
the outcomes explained to us by the quarry officers at the beginning of our training. We
received hands on experience and became very proficient in all the activities we performed.
We also improved our analytical skills and learnt to perform multiple activities efficiently by
using software packages we learnt. We also developed our report writing skills. However,
due to the extensive nature of our training programme, we were short of time to get some
other experiences. For example, we were not able to spend enough time at the Palavi
Processing Plant in order to fully understand the cement production operation. While we got
a basic understanding of this, spending some more time at the plant would have enabled us to
experience the finer details of the process and to better understand what happens to the
material which is quarried at Aruwakkalu. We also felt that we did not receive enough
experience on the management side of operations. We feel that as a budding Engineer it is
important to experience the management side of a company. In order to solve this problem it
94
would be useful for future trainees if a training schedule with placements at different sections
of the organization for different periods along with the main training at Aruvakkalu quarry
was prepared prior to training.
As a suggestion to improve overall training experience it would be easier for trainees if a
system is implemented by the university which enables trainees to submit their monthly
reports through an online portal. This would reduce the hassle of having to post or
physically deliver the reports each month.
Considering the overall training experience, I consider myself lucky to be placed at Holcim
Lanka Ltd. and am extremely happy with the outcome of the programme. I was able to learn
new things as well as improve on my personal goals and also helped indentify my strengths,
and also correct my weaknesses. I am extremely thankful to the University of Moratuwa and
NAITA and also all personnel at the Aruwakkalu Quarry of Holcim Lanka Ltd. for providing
us with such a valuable and useful industrial training programme.
ix
ANNEXES
Cement Production Chart
Figure A.3.1 : The Cement Production Process
x
Fill Volume Report
Introduction
This study was conducted with the objective of calculating the volume of overburden soil that
can be accommodated by refilling of the old quarry road. Filling of the old quarry road is
expected to begin as hauling operations are carried out on the new road and once the
overburden removing process has started. The filling of the old quarry road will reduce
unsuitable slope profiles and help in landscaping and rehabilitation of the area.
Methodology
The volume was calculated by modeling the existing profile and the required final profile 3
dimensionally using Surfer9 software and by calculating the fill volume between the two
surfaces by the same.
The primary data required for the project was obtained from the 2013 year end topographic
map of the Aruwakkalu Quarry Site.
Software Packages
the software packages used for the project are,
AutoCAD 2012
Surfer 9
Microsoft Office Excel 2007
Procedure
The procedure followed in the volume calculation is as follows.
A 20mx20m grid was constructed on the topographic map covering the entire extent of the
area to be filled. (The grid used for finding elevation)
using the contours of the topographic map, the elevations a the grid points were found. In
areas where there was a higher terrain variation, additional points were taken in the middle of
the existing grid.
The elevations of the grid pints along with their spatial coordinates (Easting and Northing)
were entered to an Excel spreadsheet.
This Excel data was imported into Surfer, converted into a grid file and the surface was
plotted in 3D.(Existing Surface)
xi
In the Surfer environment a new grid file corresponding to the final filled surface was created
by interpolating several spatial coordinate data in the expected final surface.(Proposed Final
Surface)
Using the two grid files the fill volume between the existing surface and the proposed fill
surface was calculated.
Results
The volumes calculated from Surfer 9 are as follows
Volume Calculation Method Calculated Volume
Trapezoidal Rule 893,309.18782507
Simpson's Rule 893,656.21780539
Simpson's 3/8 Rule 893,584.35438327
Cut & Fill Volumes
Cut Volume : 6,210.1710087063
Fill Volume : 899,519.35883357
Net Volume : 893,309.18782486
4.0 Conclusion
From the above set of results obtained from Surfer it is evident that approximately 900,000
m3
of overburden sol is required to fill the old quarry road.
Although both cut and fill volumes have been calculated by Surfer, due to economic reasons
only the fill volume is considered.
Discussion
The economic reasons cited under Conclusion for leaving out the cut volumes, are the
additional time and costs which will be incurred in cutting and moving soil which was
already cut and hauled when the old quarry road was being constructed. Furthermore, since
the filled area is to be used for rehabilitation process, as long as the slope profiles are not
excessive, further cutting is not required.
This volume calculation was performed with limited data and the grid constructed has a
resolution of 20x20m. Despite additional points within this grid, this causes a slight error in
xii
the final calculated volume. Also, differences in contours in the topographic map and sudden
variations in the actual ground could also cause deviations from the calculated result.
An approximate fill volume of 900000m3 is a manageable volume of soil which can be
hauled using dump trucks. In order to economically haul the removed overburden to the
filling location, a study can be carried out taking the hauling cycle distance and cycle times
and loading and dumping points into consideration.
The grid used for finding elevation
Figure A.3.2: Elevation Grid
xiii
Existing Surface
FigureA.3.3: Surfer 3D model of Existing Surface
xiv
Proposed Final Surface
FigureA.3.4:Surfer 3D model of Proposed Surface
xv
LIST OF ABBREVIATIONS
FMC - Full Maintenance Contract
QSO - Quarry Scheduling and Optimization
ED - Electric Detonator
EDC - Eric Dharmasena Construction
TML - Tokyo Machine Leasing
SOP - Safe Operational Procedures
GPS - Global Positioning System
LSF - Lime Saturation Factor
AR - Alumina Ratio
SM - Silica Modulus
XRF - X-Ray Fluorescence Spectroscopy
HGL - High Grade Limestone
LGL - Low Grade Limestone
HGM - High LSF mix bed
LGM - Low LSF mix bed
IUCN - International Union for the Conservation of Nature
GI Form - Goods Issue/Return Form
xvi
REFERENCES
Quarry Safety Operating Procedure (SOP)
Holcim Organizational Policy
Holcim Lanka Sustainability Review 2012
Parts and operating Manuals of Machines
Quarry Rehabilitation Guidlines
Inspections and recommendation report on quarry rehabilitation by IUCN
Holcim Global Company Profile [http://www.holcim.com/about-us/company-
profile.html] - Date Accessed - 02-05-2014
Holcim Lanka Cements [http://www.holcim.lk/product-services/cement.html] - Date
Accessed - 02-05-2014
