Charcoal Technology - SAIMM

2010/11/12

1

Improved Production

of CS2

Patrick Dicks

Charcoal Technology

In this technology charcoal is used asa source of carbon as supplied by afarmer.

C + 2S ↔ CS2

2010/11/12

2

Charcoal based CS2 Plant

Methane Technology Carbon disulphide (CS2) is formed by the endothermic

reaction of methane and sulphur:

CH4 + 4S ↔ CS2 + 2H2S

The reaction takes place in the gas phase at elevatedtemperature and pressure.

Sulphur is recovered from the by-product H2S making useof Claus technology:

2H2S + O2 → 2S + steam

2010/11/12

3

Advantages

Raw Materials Charcoal supply insecure Methane composition stable

Capacity Maximum capacity of old plant 7,200mt/a vs.

20,000mt/a Availability of electricity

Much smaller environmental footprint: 140 kWh versus 1,600 kWh per ton CS2 Generate steam from exothermic Claus reaction

September 2008

2010/11/12

4

September 2009

September 2009

2010/11/12

5

SAIMM

Copper belt Zambia15th September 2010

Dr Stephen Foster SENMIN

2010/11/12

6

POLYACRYLAMIDES INSOUTH AFRICA

Three stages in the production Fermentation and separation of a biocatalyst Bio-conversion of acrylonitrile to acrylamide Reaction of acrylamide with acrylic acid to

produce polymers (flocculant) - products ofvarious molecular weight and charge from Non-ionic to anionic Specific to ores in Southern Africa

Main raw materials acrylic acid and acrylonitrilesourced in South Africa and secure

Lead time to market short

Polyacrylamides

The Bioacrylamide process has four keystages: Biofermentation, the large scale cultivation of the

catalytic bacteria. Harvesting of the biocatalyst from the

fermentation broth. Bioconversion, utilising the biocatalyst to convert

Acrylonitrile to Acrylamide. Separation of the biocatalyst from the ACM

product.

2010/11/12

7

Biofermentation

2L4 Days 25L

4 Days

1200L4 Days

60m3

4 Days

Bioconversion Enzyme catalysed hydrolysis of

ACN to ACM Bacteria is Rhodococcus.

rhodochrous Occurs naturally in soil Aerobic, gram positive, pleomorphic BSL-1, classified non-hazardous to

humans Nitrile Hydratase is the enzymatic

catalyst This is a whole cell conversion as

the enzyme is not separated fromthe bacterial cells.

2010/11/12

8

Bioconversion

Bioconversion

Green chemistry Low power input Virtually no effluent compared to traditional

catalytic processes Pure final product – no side reactions

High purity final products with controlledmolecular weight distribution

2010/11/12

9

PRODUCTION PLANTSasolburg, RSA

WHAT’SNEW IN POLYMERS ?RHEOMAX TECHNOLOGIES

2010/11/12

10

Thickener underflow issues

• Underflow densities• Rake torque limitations• Pumping limitations• Plant throughput• Conventional flocculant chemistry• Variations in slurry feed properties

• Water / Reagent Recovery• Limited water resources• Water / Reagent costs

• Expansion of existing operations• Bottleneck at thickening process

• High reagent consumption

• Management of tailings disposal.

RHEOMAX DR

Ciba® RHEOMAX™ DR products show superiorflocculating properties over conventional flocculants,offering a significant reduction in overallconsumption.

Developed by Ciba by chemically manipulating thepolymer structure backbone

Ciba® RHEOMAX™ DR products produce lower yieldstress underflows, at higher densities, which are moretolerant to process fluctuations and allow a widerdynamic operational range.

2010/11/12

11

Underflow Solids

Yie

ld S

tres

s, P

aRHEOMAXTM Performance Benefits

RHEOMAX™ Conventional

YS = the stress at which a

Material begins to deform

Flocculant Dose

Sett

lem

ent R

ate

RHEOMAXTM Performance Benefits


2010/11/12

12

Settlement Rate

Und

erfl

ow S

olid

sRHEOMAXTM Performance Benefits


0.0-20.0 20.0-40.0 40.0-60.0 60.0-80.0

80.0-100.0 100.0-120.0 120.0-140.0 140.0-160.0

Increasing Underflow Solids

Incr

easin

g Sh

ear

Conventional Flocculant - Mud Yield Stress Profile

Yield Stress Pa

2010/11/12

13

51 52 53 54 55 56 57 58 59 60 61 62 63 64 650

2.5

5

7.5

10

12.5

15

Incr

easi

ng S

hear

0.0-20.0 20.0-40.0 40.0-60.0 60.0-80.0

80.0-100.0 100.0-120.0 120.0-140.0 140.0-160.0

Increasing Underflow Solids, g/ l

RHEOMAXTM Flocculant - Mud YieldStress Profile

0.0-20.0 20.0-40.0 40.0-60.0 60.0-80.0

80.0-100.0 100.0-120.0 120.0-140.0 140.0-160.0

Increasing Underflow Solids

Incr

easin

g Sh

ear

Conventional Flocculant - Mud Yield Stress Profile

RHEOMAXRHEOMAXTMTM DRDRProduce lower yield stressunderflows, they are more

tolerant to fluctuations in solidscontent and applied shear,allowing a wider dynamic

operational range and consistentperformance

2010/11/12

14

Summary:RHEOMAX DR vs. Conventional Flocculant

Lower dose to achieve a given settlement rate

Higher underflow solids for a given settlement rate

Lower yield stress for a given underflow solids

Robust performance to plant fluctuations•Less shear sensitive•More tolerant to solids variations

RHEOMAX™ Performance Benefits

CASE STUDY - GOLD

50

52

54

56

58

60

62

64

66

68

70

Unde

rflow

Den

sity (

%) RHEOMAXTM 1040

MAGNAFLOC 800HP

Sedimentation of

Tailings Thickener

2010/11/12

15

Averaged Trial DataPolymer Dose 13g/t

7 g/t

46% Reduction in Polymer RequirementUnderflow Density 57%

67%

10% Increase in Underflow SolidsWater Recovery 50%

64%

14% Increase in Water Recovery

Case Study – Gold

MAGNAFLOC 800HP

RHEOMAXTM 1040

MAGNAFLOC 800HP

MAGNAFLOC 800HP

RHEOMAXTM 1040

RHEOMAXTM 1040

Conclusions

RHEOMAXDR offers advantages over conventionalflocculants in:-

Dose requirement Tolerance to feed solids fluctuations Tolerance to shear (feed flow rate) fluctuations Underflow density Underflow yield stress Water / Reagent recovery Increased plant throughput

2010/11/12

16

RHEOMAX ETD (Enhanced TailingsDisposal)

Ciba® RHEOMAX™ ETD patented technology is aCiba application utilising Rheology modifyingproducts to deliver enhanced tailings characteristicsat the point of disposal.

Ciba® RHEOMAX™ ETD Rheology modifiers offerthe end user a number of opportunities to enhancethe operation of their tailings management process.

Introduced after many years of R&D manipulatingpolymers

Tailings problems and issues

• Capital required for increased tailings disposal

• Extension of mining operations

• Requirement for large areas of land

• Water / reagent recovery

• Contaminated returned water / reagents

• Rehabilitation

• Protracted environmental liability

• Segregation of coarse and fine solids

• Slow rate of compaction

• Little or no control of slurry rheology

2010/11/12

17

ConsolidatedSolids

Free Water

RHEOMAXTM ETD – The Process

Rheomax

Co-disposal of Mineral SandsThe Problems

Pumping Tailings slurry to the Disposal Compoundadversely impacts on it’s yield stress.

Tailings revert to low viscosity fluid.

Fine clays and water wash out from the coarsesolids

Recovered water is contaminated with fines

Slow rate of solids compaction.

RHEOMAX™ ETD – Mineral Sands

2010/11/12

18

Co-disposal of Mineral Sands

The Solution

RHEOMAX™ ETD treatment is applied to the slurry within thepipeline and works in-situ

Mineral slurry develops a discrete shear resistant solids structureprior to deposition.

Water drains quickly away leaving stacked solids

Homogeneous co-disposal of course and fines

Above-surface bed height promotes compaction and further waterrelease.


Untreated Material – Slump Angle: 0%


2010/11/12

19

RHEOMAX™ 9025: Slump Angle: 53%



Rapid Clean water recovery

2010/11/12

20

RHEOMAX™ ETD – Mineral SandsDemonstrating Excellent Consolidation Of

Co-Disposal Material


0

0.5

1

1.5

2

2.5

0.1 1 10 100 1000Particle Size (um)

Volu

me

(%)

TopSection

BottomSection

0

0.5

1

1.5

2

2.5

0.1 1 10 100 1000Particle Size (um)

Vol

ume

(%)

Top SectionBottom Section RHEOMAXTM 9025

TREATED SLURRY

UNTREATED

SLURRY

2010/11/12

21

Co-disposal of Mineral SandsThe ResultFinal stacking angle of between 8 and 10 degrees

Clean water quickly and effectively recovered

Co-disposal ratio met the local environmental requirements

No reworking or double handling of segregated material

Faster trafficable surface.


RHEOMAXRHEOMAXTMTM

ETDETD –– Mineral SandsMineral Sands

Rheomax ETD – LOW DOSELOW DOSE Rheomax ETD – HIGH DOSEHIGH DOSE

• Slurry stacks higher and with a smaller footprintas dose is increased

• Water release volume and quality improves withincreasing dose

2010/11/12

22

Untreated Slurry

RHEOMAXTM ETD - Laboratory EvaluationsCoal

Treated Slurry62% of the available

water was readilyreleased

Cell preparation

2010/11/12

23

Stacking starts at one end ofcell, and moves forward as cellheight reached

Large volumes of clean water released andpumped back to plant

Deposition and water release

Excavation Can StartWithin 24 Hours

Of Stacking

Partial Excavation

RheomaxTM ETD – Coal W Australia

2010/11/12

24

RheomaxTM ETD : red mud W Australia

Non segregated co-disposal alumina site40 % incoming feed; final 80% solids

THANK YOU

THANK YOU

2010/11/12

25

SAIMM 2010-ChingolaPhillip Viviers – New Business

Development

History of Senmin

1963 – SRC (Synthetic Rubber Company)

1965 – Latex

1968 – Orchem (Rubber Chemicals)

1970 – Karbochem Mining Chemicals

2010/11/12

26

History of Senmin

1978 – NCP& Karbochem

1978 – Senmin

1996 – Dow Chemicals

2003 – Chemserve

History of Senmin

2005 – Pelichem and Senmin

2006 – Chemserve Zambia - Senmin

2010 – AECI

2010/11/12

27

Customer Base

Anglo Platinum – VM De Beers – VM Impala – VM Junior Platinum miners Lonmin – VM Northam PMC – VM

Customer Base

DRC Namibia - Rosh Pinah, Rossing & Langer Heinrich Malawi, Tanzania, Ghana, Ivory Coast, Sierra

Leone, Uganda, Mali, Morocco, Mauritania Zambia Zimbabwe – Mimosa, Unki & Zimplats

2010/11/12

28

Product Range

Depressants – Guar 6 000 t/a– CMC 8 000 t/a

Dithiophospates – 5 000t/annum

Dithiocarbamates – 4 000t/annum

Flocculants – 20 000 t/a

Product Range

Frothers – 1 800 t/a

Xanthate powder – 7 000 t/a

Xanthate pellets – 12 000 t/a

Xanthate in solution – 60 000 t/a

2010/11/12

29

Product Range

Agricultural Chemicals – 2 600 t/a

Fuel Additives - 1 200 t/a

Rubber Chemicals

Water Treatment Chemicals

What is next ?

Diluent for SX

Production of solvent extractants?

NaSH – BFS

Techcentre – Sasolburg

2010/11/12

30

QUESTIONS ?

Charcoal Technology - SAIMM

Documents

Transcript of Charcoal Technology - SAIMM