Pyrite Roasting an alternative to Sulphur CombustionSulphuric 2009, Runkel / Sturm

2 AgendaAgenda

Introduction

Description of the Fluid Bed Technologyand References

Comparing Acid Production via Pyrite Roasting and Sulfure-Burning

Conclusion

3 Introduction Introduction -- SOSO22--Source for AcidSource for Acid

Metal-Sulfate

DecompositionMeSO4 MexOy+SOz

Roasting,Smelting,Sintering

SulphureCombustion

4 AgendaAgenda

Introduction

Description of the Fluid Bed Technology and References

Comparing Acid Production via Pyrite Roasting and Sulfure-Burning

Conclusion

5 Different Fluidized Bed SystemsDifferent Fluidized Bed Systems

Stationary Fluidized Bed characterised by:

Low gas velocities (Pyrite : 0,4 – 1,5 m/s)Grain Size: 70 µm – 6 mmBubbling bed with defined bed surfaceLimited solids carry overLow slip velocityNumber of plants: 264

Circulating Fluidized Bed is characterised by:

Higher gas velocity(Pyrite: 3 – 6 m/s)Grain Size: 55% minus 38 µm (gold)Increased solids entrainmentIntensive internal and externalrecycle of solidsMaximum slip velocityVery intensive mixingExcellent heat and mass transfer ratesNumber of plants: 172

Transport Reactor characterised by:

Very high gas velocitiesMinimum slip velocity

Gas

Velo

city

SolidsIncreasingsolids density

Bubbling Fludized Bed Circulating Fluidized Bed Flash Reactor

Increasing Expansion

6 Example of Pyrite roasting plantsExample of Pyrite roasting plants

Gidji (Gold)

ETI(Pyrite)

Tongling (Pyrite/Pyrrhotite)

Location Kalgoorlie/Australia Bandirma/TurkeyTongling/ChinaRoaster Type CFB SFB SFBRoaster Grate Area m² 8.5 100 138

Raw Material flot. Pyrite flot. Pyrite flot. Pyrite/Pyrrothite

Feed slurry dry (9% H2O) dry (6% H2O)S content in feed wt% 33 48 37Capacity t/d 575 650 1130Roast Temperature °C 640 850 900Steam Production t/h no steam 43 82Steam Parameters MPa/C no steam 4.2/400 3.82/450Cinder t/h 20 20 41Offgas Roaster Nm³/h 58,000 60,000 100,000Acid Production t/d no acid 750 1200Power Consumption RoastingkW 1000 1250 1400

7 GidjiGidji/W.A. KGCM/W.A. KGCM

8 ETIBANKETIBANK--BandirmaBandirma –– TurkeyTurkey

9 TonglingTongling -- ChinaChina

10 Roasting technology for Roasting technology for pyrite concentrate, latest plants installedpyrite concentrate, latest plants installed

Year Location Number & Plant Type Concentrate2009 Syama, Mali 1 x 590 t/d CFB Pyrite (Gold)2007 Tongling, China 1 x 1130 t/d SFB Pyrite / Pyrrohtite2004 ETI, Turkey 1 x 630 t/d SFB Pyrite 1996 Wengfu, China 2 x 600 t/d SFB Coarse Pyrite 1991 KCGM/Gidji W.A. 2 x 575 t/d CFB Pyrite (Gold)1984 Almagrera, Spain 1 x 725 t/d SFB Pyrite 1983 Siilinjärvi, Finland 1 x 420 t/d SFB Pyrite

11

Concentrate Feed

Fluid Bed Roaster

Calcine Storage

Heat Recovery

Hot Gas Cleaning

Wet Gas Cleaning Sulphuric

Acid Plant

Steps after RoastingSteps after Roasting

12 AgendaAgenda

Introduction

Description of the Fluid Bed Technology and References

Comparing Acid Production via Pyrite Roasting and Sulfure-Burning

Conclusion

13 Example and Comparison of Process Example and Comparison of Process Parameters of recently designed Acid Parameters of recently designed Acid PlantsPlants

Pyrite RoastingSFB CFB

Sulphur Burning

Capacity sulphuric acid t/d 1200 1500 1500 5000Feed Rate t/d 1130 1800 490 1630Furnace Offgas volume Nm³/h 105000 130000 120000 260000SO2 in process gas vol% ~ 11 11.5 18High pressure steam t/mt Mh 1.35 - 1.6 1.25 - 1.4Power Consumption kWh/mt Mh ~ 70 ~ 50By-Product - Cinder no by - productEffluents / Waste - Weak acid Filter Cake

14 Types of pyrite concentrate

Type Composition Grain Size

Pyrite Concentrate (flotation) S 47-48 wt%; Fe 42–43 wt% fine particles 55% < 45µm Coarse Pyrite S 47-48 wt%; Fe 42–43 wt% coarse particles 0 – 6 mm Pyrrhotite Concentrate (flot.) S 34-38 wt%; Fe 50–54 wt% fine particles 55% < 45µm Coarse Pyrrhotite S 28-29 wt%; Fe 47–50 wt% coarse particles 0 – 4 mm

15Assumption and InfluenceAssumption and Influence--FactorsFactors

Any influence of the location of the plant is excluded.Transportation Cost for Sulfure is excluded.Extracost for Calcine Deposit is excluded.Assuming an average S-content in Pyrite without As (FeAsO4).Revenues for valuable Metals in Calcine like Au, Ni, Cu etc. are excluded.Consumption figures such as fuel, water andlabour are not significant different.

16 ComparisonComparison

1.000 t/d Acid (LSTK)Capacity for Comparing

74 US$/t acid41US$/t acidOperating Cost (estimation)

150 US$/t35 US$/tRawmaterial Price (04/2009)

40 Mio. €80 Mio. €(one line SFB)

Investmentcost

max. 5.000 t/dSFB: max. 1.200 t/dCFB: max. 1.500 t/d

CapacityS-BurningPyrite Roaster

17

Pyrite Roasting

Fluid Bed Reactor

Heat Recovery

Hot Gas Dedusting

Wet Gas Cleaning

Sulphuric Acid Plant

Roasting

Pyrite

Air

Cinder Effluents

Water

Acid

Sulphur Combustion

Sulphur Burner

Heat Recovery

Sulphuric Acid Plant

Sulphur BurningAir

Sulphur Sulphur Melting

Water

AcidSulphur Filtration

Filter Cake

ComparisonComparison

18

Pyrite RoastingOutotec´s roots in Fluid Bed Technology

Fluid Bed Reactor

Heat Recovery

Hot Gas Dedusting

Wet Gas Cleaning

Sulphuric Acid Plant

Roasting

Pyrite

Air

Cinder Effluents

Water

Acid

Sulphur Combustion

Sulphur Burner

Heat Recovery

Sulphuric Acid Plant

Sulphur BurningAir

Sulphur Sulphur Melting

Water

AcidSulphur Filtration

Filter Cake

19

‐100

‐50

0

50

100

150

200

1 2 3 4 5 6 7 8 9 10

Years

Inco

me

in M

io U

SD$

Pyrite Roasting

Sulphur Burning

After 5 years pyrite roasting has higher returns

Breakeven (example 1000 t/d Acid)

Capital cost for the sulphur burning plant is lower than pyrite roastingBreaks even earlier than the pyrite roasting plant at three years. However, the operating cost for pyrite roasting is so lower, Pyrite roasting break even a mere 12 months after the sulphur burning plant,Pyrite Roasting also gains equal returns by the fifth year and Exceeds the returns of sulphur burning by the sixth.

20 AgendaAgenda

Introduction

Description of the Fluid Bed Technology and References

Comparing Acid Production via Pyrite Roasting and Sulfure-Burning

Conclusion

21 Conclusion

Throughputs in a single roasting line for stationary fluid beds of up to 1.130 t/d Circulating fluid beds of up to 1.800 t/d based on pyrite concentrate and depending on chemical composition.At the capacity range described, the pyrite roasting process can be the favourite process route especially when looking at long-term revenues. The economic benefit of a roasting plant as an alternative to the sulphur burning can be significant after an operation of approximately five years.

22

Pyrite Roasting an alternative to Sulphur CombustionSulphuric 2009, Runkel / Sturm

24

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25Circulating Fluid Bed Roasting (CFB)Circulating Fluid Bed Roasting (CFB)

Gidji – Gold RoasterPyrite with Gold ContentGrain size: 55% minus 38 µmHigher gas velocities in the range of 3 – 6 m/sTemperature 650°C (ore very temperature sensitive)Solid Residence Time: 30 Minutes

26 Stationary Fluid Bed Roaster (FB)Stationary Fluid Bed Roaster (FB)

First developed for dry pyrite feedingFor Acid Production + Steam Production. Pyrite grain size 70 µm (flotated) - 6 mmGas velocity in the fluid bed: 0.4 (70 µm) - 1.5 m/s (6 mm)Temperature 850°C

air

feed

overflow

calcine +offgas

bed