Post on 21-Jan-2023
Chapter 1 Introductiona. Historical Background of Dundee Precious Metal Tsumeb
The Tsumeb Complex was built between 1961 – 1962 and
commissioned in 1963 by Tsumeb Corparation Limited (TCL)
under mining giant Newmont Mining. It featured an
integrated copper and lead section, and smaller plants
that produced cadmium and arsenic trioxide as by-
products. Production officially started on March 3, 1964.
At that stage, the Smelter produced more than 3,500 tons
of copper and 6,000 tons of lead per month. By 1986 the
smelter was also producing sodium antimonite for export.
In 1988, TCL was taken over by the Gold Fields South
Africa and administered by Gold Fields Namibia (“GFN”).
Approximately six years later, the lead Smelter was
closed permanently. In July – August 1996, TCL’s mining
and smelting operations came to a standstill due to a
prolonged labour strike. This ultimately led to the
closure and liquidation of GFN in 1998.
Ongopolo Mining and Processing Limited (“OMPL”) gave
Namibia High Court an offer to take over the GFN’s mines
at Tsumeb, Kombat, Otjihase and Khusib Springs, as well
as the Smelter Complex in Tsumeb and it was accepted in
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March 2000. From 2000 – 2008, only the Copper section was
operational, the Arsenic plant was run on a small scale.
In July 2006 Weatherly Mining International acquired
OMPL, in December 2008 Weatherly suspended all the mining
operations because of a major decline in the world copper
price and only kept the Tsumeb Smelter going. The Smelter
was converted to a toll smelter at the beginning of 2009.
In March 2010, Weatherly sold the smelter to Dundee
Precious Metal Inc and shares with Weatherly retaining
all the mining assets.
Currently, half of the concentrates comes from Dundee’s
Chelopech mine in Bulgurial and the additional
concentrate is solicited from Peru, Greece, Russia,
Poland, Botswana and Democratic Republic of Congo.
Top-Submerged Lance (‘TSL”) furnace is at full
production. A new Oxygen plant, commissioned in February
2010 to increase the efficiency of the TSL, delivers 170
tons of Oxygen per day and increased the capacity of the
smelter dramatically from 120 000 tons of concentrates
per year to about 240 000 tons of concentrates per year.
At a moment, the Smelter Complex consists of five main
plants, Ausmelt plant, Copper plant, Oxygen plant,
Arsenic plant and Power plant that are all running at
their full potential, each with a specific purpose but
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working together to achieve a common goal, smelting
copper concentrates.
Electrical power for some of the smelters operations are
supplied by an on-site power plant. The plant has the
capacity to produce 2.5 MW of power. The power plant
uses the steam produced from the hot off-gases from the
reverb furnace in two waste heat boilers. The steam is
used to drive turbines in the power plant and generate
electricity. Additional electrical power is drawn from
the national grid as required.
b. Dundee Precious Metal Tsumeb Visionand Mission
Our vision
A precious metal focused mining company that grows
through responsibly developing great assets and people.
Mission Statement
We acquire structure and finance, explore, develop and
operate our mining and processing assets. Our commitment
is to deliver excellence in sustainability and creating
value of all stakeholders
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Core Values
Our core values are fundamental to defining who we are as
a company and how we behave. Values guide our actions.
Everyone at Dundee is expected to support and and
demonstrate these values in our work.
Dignity and Respect
We are about people – their well-being, their careers and
development, and their day-to-day work experience. We
treat all colleagues fairly, listen to their input and
work with them to create solutions that respect both
individual needs and corporate interests.
Continuous Improvement
We are passionate about continuous improvement. We seek
out and execute operational practices that drive
innovation, speed to market, cost efficiency, technical
and professional excellence.
Transparency
We set and uphold the highest ethical standards and
business practices. Our dealings with employees,
governments, stakeholders and communities are open,
honest and transparent. We do what we say we will do and
fulfill our commitments. We hold each other accountable
for delivering results.
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Environmental Responsibility
We are leaders in promoting sustainable growth and
environment responsibility. We go beyond legislative
compliance to promote pragmatic environmental solutions
and practices in all of our operations
Safety
The health and safety of our employees and local
communities are paramount and enable us to be in
business. Safety can never be compromised.
Community Investment
We are about the quality of the communities in which we
operate. Our legacy will be to ensure we have helped
residents make the community a better place than before
we arrive on the scene. We have a strong corporate and
social responsibility to the communities in which we
invest.
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c. Dundee Organogram and location
Rick Howes
President and Chief Executive Officer
Adrian Goldstone
Executive Vice President
The geographically of Dundee Precious Metal Tsumeb is
situated about 4 km north of Tsumeb town and Tsumeb is about
430 km north of capital city Windhoek in Namibia.
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Hume Kyle
Executive Vice
Lori E Beak
Senior Vice
Michael Dorfman
Richard Gosse
Senior Vice President
Paul Proulx
Senior Vice President
David Rae
Senior Vice PresidentJeremy
CooperSimon Meik, PhD
Reuben Mills
Vice
Hans Nolte
Vice
Adrian Goldstone
Executive Vice
Dundee Precious Metals Tsumeb
P.O. Box 936
Smelter Road, Tsumeb, Namibia
www.dundeeprecious.com
d. ObjectivesThe aims of this report is to outline the importance of
the industrial attachment, the skills acquired during the
attachment period, activities carried out, challenges and
the engineering solutions to all the problems
encountered. Compare the theory learned at school and the
hand on experience at the industrial attachment. Outline
tools and equipments mainly used at the attachment. All
that will be enclosed in this report.
e. Challenges and how I overcome themLike in any work place, challenges will always manifest
themselves in many ways, ranging from the work you do,
the people you work with, knowing the work place and
adopting to the work place.
At the beginning I had a lot of challenges, firstly
getting to know the place. There are mainly five Plants
around, thus excluding different offices in the premises.
I started working at the power plant, than copper plant,
after that I went to Ausmelt and lastly went back to the
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power plant. However , the daily works were not only
restricted to the same plant. One cane visits more than
one plant a day. Some plants are too big and have a lot
of places within them. That has been a problem find a
specific place the plant. This problem was not overcame
over one day all two, but as I started moving around I
got to know most of the places, however even after a
month there are still places I haven’t been too and some
I still have to.
In addition to that is getting used to the technical
words used at work, however this was not such of a big
problem because I learn to ask as soon as I hear a word
that I wasn’t familiar with.
The most challenging thing and of course the most
important of all was about the machines and tools we work
with to repair and to be repaired. One need to understand
how the machine work and this has been a challenge to me
through out. There was only one out to this problem, by
asking from the artisan I am working with and if I don’t
understand I than go to my supervisor and do the research
on that machine. Most of the time, I have to read about
the machines after work in order to get thoroughly
understanding of the machines. As a result, I got more
depth of most machines and the passion of my work.
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The hard thing of all is when my supervisor assumes I
know when it is even the first time for me to be exposed
to the situation. Even if I have to apply my engineering
skills it was still impossible for me to get it right,
let alone within the time interval. This just showed me
how much of things I need to know.
Other than that, it was a great experience. My horizons have been expanded.
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Chapter 2 The core activities of thecompanyThe core activity of this company is to smelt copper. The
copper concentrates are received by rail and off loaded at
the receiving bay. During the preparation of a charge for
the reverberatory or ausmelt furnaces the
necessary concentrates, fluxes and fuels are blended for
introduction into the furnaces.
Concentrates are blended with crushed reverts and various
fluxes to produce a furnace charge material. The charge is
fed into the furnace which is fuelled by pulverised coal.
The charge mix is smelted at approximately 1200 ºC to form a
slag and a matte (metal sulfides) phase. The molten slag,
which has a lower density and floats on top of the matte, is
removed from the furnace by skimming and granulated in
water. The slag is further processed at the slag mill if the
copper content is more than 0.6%. The matte phase is tapped
from the reverb furnace into ladles and transported to the
converters for further processing.
Hot off-gases pass through a waste heat boiler, which
recovers heat from the off-gases for steam generation. The
steam is used at the power plant to generate electricity
while the hot air from the air heaters is introduced to the
Reverb furnace to aide in combustion. The off-gas is
further cooled in a spray cooling or conditioning tower to
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120oC before the cooled gas enters the baghouse where solids
(baghouse dust) and gas are separated when passing through
the glass fibre bags. Final cleaned off-gases are released
to the atmosphere via a high stack. Dust from the baghouse
is either processed at the arsenic plant or dumped at
the waste disposal site which is under construction.
Off-gases from the Ausmelt pass through a spray cooling
system to cool it down to 120ºC before entering the baghouse
where dust is separated from gas before the cleaned gas
is released to the atmosphere via a second stack. Dust
recovered at the baghouse is taken to the arsenic plant for
processing.
Off-gases from the converter are cooled in a water spray
cooling tower to 120ºC and pass through the converter
baghouse before being released to the atmosphere via the
same stack used for the reverberatory furnace. Dust
collected in the baghouse is treated at the arsenic plant or
dumped into the waste disposal site.
Concentrates and other secondary material processed at NCS
are traditionally relatively high in arsenic. The arsenic
passes through the smelter and is captured from the off-
gases in the baghouses. Baghouse dusts with high arsenic
levels are used as feedstock into the arsenic plant.
Baghouse dusts that cannot be processed in the arsenic plant
will be disposed of in the waste disposal site.
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The arsenic plant is used to produce arsenic trioxide from
dusts recovered during the smelting process. This is sold to
the third party.
That is mainly the processes that are taking place at the
company on a day to day basis.
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Chapter 3 Fault finding on Blower no
3 in the power plant.
There are 4 blowers at the
power plant. A blower is an
electrical device more like
a fan but it is designed to
produce a flow of gas at
higher pressure and with
larger gas volume flow.
This blowers are installed
to drive the hot gas
produced during the casting
process of copper. This gas
is used to generate
electricity. The Fig 1 and
Fig 2 show a blower no 3.
It is not working. In Fig
1, are the electrical
terminals, we were
measuring the lines voltage
and lines current to see if
there is imbalance. And see
if that is the reason why
the blower is not working.
This was the first time I
was exposed to three phase
system. I learned how to
measure the line voltage
and line current as well as
the phase voltage and
current.
U1V1 = 284V =U2V2 U1W1 =
275V=U1W1
V1W1 = 281V = V2W2
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Fig 1 Three phase terminals
Fig 2 Blower no 3 beingrepaired, at this stagewe are finding the
The results were correct and there
was no unbalanced voltage and
current.
We than went to inspect the
blower no 3 control panel. All the
wiring was good and we couldn’t
find any fault. As a last resort,
we tried to find the manufacture
circuit drawing of the machine. I
didn’t understand much of the
things for the first few
days. Eventual I learned how
the controls work. We found
out there was a conduct that
was not coming and that’s how
I came learn the use of
relays.
A relay is an electrically
operated switch. It comprises
a coil (of wire), a plunger,
and contacts, all housed together
within a case or body. Energizing
the coil creates a magnetic field
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Fig3
Fig
which moves the plunger. The
movement of the plunger causes a
moving contact to move toward (or
away from) a non moving contact. It
is the coming together of these
contacts ( making) or separation of
them (breaking) that has the effect
of switching. Wires or electrical connections internally
link the coil to the external connections to which the
operating supply will be connected Similarly internal
contact connections go to other terminals for connection to
the circuit being switched. The connections to a relay are
usually in the form of pins or blades in the base, which may
plug into a matching socket to which external wiring is
connected conventionally. Many smaller relays are soldered
directly into circuits, but for this machine they are
plugged in the circuit.
Through out, I learned how to service the blower and the
control panel. Finally a team from South Africa specialised
in control system came. I was than working with them. I
learned how to use a Sub-station Tester to dedect faults .
Using a Sub-station Tester, we dedected the faulty relays
and servesed the working relays. Fig 3, Fig 4 and Fig 5
shows the
relays we took from the control panels for all blowers.
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Fig5 Circuit drawing for blower control
Most of the time we install and fix light bulbs. Most
foroulecent bulb have ignators. I learned how to correctly
install light bulbs, suprisingly is the work of the ignitors
and how they work. Within the ignitor there is a coil that
make up small transformer. It transform 230V up to 400V,
that actually energize the electrons in the tube as the
current passes through the fillament starter. The fillament
starter is has a thermal switch that open when it got hot.
The tube contains Mercury gas, which is a good conduct of
electricity. As the mercury electrons get energized they
start to move around inside the tube and hence acting as a
conduct inside the tube, when that happen the thermoster
open and light is given out. White powder in side the tube
give it that foroulecent light. Fig 7 shows the inginator
circuit and fig 8 shows me and my colleaque replacing the
ignitor of the light bulb.
We also did installed and programmed the softstarter for
2.2kW motor. A softstarter is a programmable divice that
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Fig
help start the motor with low corrent drawn. If a motor is
started without a softstarter, it drows out a lot of current
and bigger motors may not even start. A softstarter allow
the motor to dradually start rotating until it reaches its
maximum speed, by so doing less current is drown as the
motor start.
In general, we have been dealing with electrical cables,
during the process I learn there are different cable sizes
and their categorised by the current and voltage they do
carry. The inslutor depends on the voltage that will go
through, high voltage means more inslution and high current
means thick cable.
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Chapter 4a.Skills and attitudes acquired
Professionalism and time management, this is the most attitudes I acquired. In engineering, time iscritical. The company can make a great lose if delivery was not on time.
Servicing electrical machines, motors, generators,
geysers and cranes.
Changing the direction of motors. Inspection of electrical machines, lights and
electrical connections. Awareness of the hazardous around and correct
measures to be taken in case of emergency. Using electrical equipment’s to test. Eg Multi
mater, sub-station tester etc. Analyzing problems and sequence reasoning to come
to a correct solution to a problem. Team work and communication within the staffs Wiring DPs
b.Conclusion
This was a great experience for me. I got the exposure
to most of the electrical machines and drives. I was
exposed to three phase system and learn how to measure
current and voltage in the three phase system. Most of
the systems are already in place and hence I didn’t get
exposed to designing of new project. The systems are
old and most of the drawing has been modified that make
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it hard to read and follow, more special when you have
to find a fault.
The company operates under harsh condition and most of the time we are exposed to hazards of different kind. However there are measures in place so that the safeties of workers are not compromised. As a policy, each one of us has to do a HIRA and get permission fromthe plant manager before you start working.
c.Recommendations
Engineering trainees at this company are not allowed towork on their own and most of the time I watch andobserve what others are doing. I recommend if at leastI can be given a project that I can run on my own withonly supervision. Most of the time I work with theartisans and they do not do the engineering work. Thistime around it was great because I have to learn howthings work, but I need to be involved in designing.
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