Planning and Design of a Process for PGM Ore Dressing

1. Planning and Design of a Process for PGM Ore Dressing

2. Presentation topicsPresented by IntroductionA.Chandan Process Units • Size reductionRamakrishna • Froth flotationPadala • Pyrometallurgy Tariq • HydrometallurgyKumar Water TreatmentSelva Plant LayoutB.Ravikumar Environmental Regulation and SafetyYozi Bastian Cost EstimationAmar Planning and Design of a Process for PGM ore Dressing

3. PGM Concentrate PROCESS PGM Ore Planning and Design of a Process for PGM ore Dressing Merensky-Reef 600 t/h TASK PGMs 5.5 g/t PGMs 50-90 %

4. Planning and Design of a Process for PGM ore Dressing

5. PGMs Applications Individual process selection Process block diagram Process description PFD Process block diagram 3D-layout Fixed capital investments Individual unit layout Working capital (p.a) Breakeven point Planning and Design of a Process for PGM ore Dressing TOPICS INTRODUCTION INDIVIDUAL UNITS PLANT LAYOUT COST CONCLUSION

6. PERIODIC TABLE Planning and Design of a Process for PGM ore Dressing Platinum Group Metals • Pt Platinum • Pd Palladium • Rh Rhodium • Ir Iridium • Ru Ruthenium • Os Osmium INTRODUCTION By: A.CHANDAN

7. Platinum coated computer hard drive disks. Platinum-based drugs can be used to treat a number of cancers. Palladium salts are used in electroplating and in the manufacture of process catalysts. Platinumjewellery Rhodium foils are used in equipment for detecting cancer. PGM Ore Planning and Design of a Process for PGM ore Dressing APPLICATIONS

8. PROCESS BLOCK DIAGRAM U’flow Planning and Design of a Process for PGM ore Dressing Off gas treatment (Fe, Cu, Ni) sulphates for recovery Crushing and Grinding Froth Flotation Roasting and Smelting Atmospheric and Pressure Leaching PROCESS BLOCK DIAGRAM Water treatment PGMs to refinery Block diagram of the PGM ore concentration process

9. Planning and Design of a Process for PGM ore Dressing Size Reduction By Ramakrishna

10. U’flow Planning and Design of a Process for PGM ore Dressing (Fe, Cu, Ni) sulphates for recovery Off gas treatment Crushing and Grinding Froth Flotation Roasting and Smelting Atmospheric and Pressure leaching Water treatment PGMs to refinarey Block diagram of the PGM ore concentration process

11. Planning and Design of a Process for PGM ore Dressing Contents • Process Options and Selection • Equipment Selection • Crushing • Grinding • Solid-Liquid Separator • Process Flow Diagram • Design Parameters

12. Options • Run of mine to AG/SAG • Tube mill without any preliminary crushing • SIngle stage run of mine grinding Planning and Design of a Process for PGM ore Dressing Process Options and Selection Purpose of size reduction • To liberate individual minerals trapped in rock crystals (ores) and thereby open up for a subsequent enrichment in the form of separation • To produce fines from mineral fractions by increasing specific surface

13. Planning and Design of a Process for PGM ore Dressing Process Steps Process steps • Stationary Screening • Primary Crushing • Secondary Crushing • Tertiary Crushing • Screening • Grinding (wet grinding) • Solid-Liquid Seperation Selection Parameters • Particle size • Reduction ratio • Power requirement • Hardness of the ore

14. Planning and Design of a Process for PGM ore Dressing Equipment Selection Selection of crushers & grinding equipment depends on • Hardness of the ore • Throughput • Operating conditions • Feed size • Capacity • Cost effective alternative • Capital & maintainance • Power

15. Crushing stage Crusher type Primary crusher Jaw crusher Secondary crusher Cone crusher Tertiary crusher Cone crusher Planning and Design of a Process for PGM ore Dressing Equipment Selection Selection of Crushers • Roll, hammer, Impact crushers are suitable for soft ore and for low capacities • For harder feed there is a choice between a gyratory and a jaw crusher Compared to other crushers the cone crusher has some advantages • Making them very suitable for size reduction and shaping downstream a crushing circuit. • Possibilities to change feed and discharge openings during operation

16. Planning and Design of a Process for PGM ore Dressing Equipment Selection Selection of Grinding Equipment • Rod mills usually run open circuit • The selection is in between AG/SAG and ball mill. Advantages of Ball mill • It can be used for wet or dry, wet grinding facilitates the removal of the product • Installation and power costs are low and the grinding medium is cheap and suitable for hard materials • It can be used for batch or continuous operation and also in open or closed circuit grinding

17. Planning and Design of a Process for PGM ore Dressing Equipment Selection Selection of Solid-Liquid seperator Advantages of hydrocyclones over centrifuges • Simple construction & cheaper than centrifuge • Low maintenance • Less space required • Control of speed is easier • Low energy consumption • Higher efficiency with low cost can be obtained • Higher capacity can be handled by operating multiple hydrocyclones (hydrocyclone battery)

18. Planning and Design of a Process for PGM ore Dressing Process Flow Diagram

19. Crushing stage Crusher type Particle size (mm) Power (kW) Inlet Outlet Primary crusher Jaw crusher 400 134 364 Secondary crusher Cone crusher 134 32 597 Tertiary crusher Cone crusher (2) 32 9 373 Planning and Design of a Process for PGM ore Dressing Design Results • Crushers Results

20. Ball mill L/d Ratio 2 L 11.48 m D 5.74 m Nc 17.64rpm N 11.47rpm N/Nc 0.65 Power required 7.0MW Planning and Design of a Process for PGM ore Dressing Results • Hydrocyclone • Number of hydrocyclones = 11 • Cone angle = 20° • D50C = 92.5µ

21. Froth FlotationbyPadala Subrahmanyeswara Reddy

22. U’flow Planning and Design of a Process for PGM ore Dressing (Fe, Cu, Ni) sulphates for recovery Off gas treatment Crushing and Grinding Froth Flotation Roasting and Smelting Atmospheric and Pressure leaching Water treatment PGMs to refinarey Block diagram of the PGM ore concentration process

23. Planning and Design of a Process for PGM ore Dressing Froth Flotation • Process Selection • Purpose • Flotation Reagents And Amounts • Flotation Machines - Selection • Flotation Circuit • Flotation Process Flow Sheet • Results

24. Planning and Design of a Process for PGM ore Dressing Froth Flotation Processes • Gravity Separation or Flotation Selection • Froth Flotation Purpose • Minerals – 3% • Metal Oxides – 2% • Gangue(Sand) – 95% • Concentrating minerals

25. Reagent Name Amount Collector Sodium Ethyl Xanthate 1 kg/ton of feed Frother Pine Oil 1 kg/ton of feed Activator Copper Sulfate 1kg/ton of feed Planning and Design of a Process for PGM ore Dressing Froth Flotation Flotation Reagents And Amounts

26. Planning and Design of a Process for PGM ore Dressing Froth Flotation Flotation Machines Outokumpu Flotation Machines • Basic Inventory is 20% lower than in a conventional plant • Low space requirements • A simple design with low maintenance cost • Low power requirements • Easy performance control • Fast froth removal

27. Planning and Design of a Process for PGM ore Dressing Froth Flotation Flotation Circuit

28. Equipment Time Required (min) Percentage Recovery No. of cells Rougher 15 76 5 Scavenger-1 25 50 7 Scavenger-2 25 30 7 Scavenger-3 25 15 7 Cleaner 10 66 4 Planning and Design of a Process for PGM ore Dressing Froth Flotation Flotation Tanks Details

29. Planning and Design of a Process for PGM ore Dressing Froth Flotation Process Flow Sheet

30. Planning and Design of a Process for PGM ore Dressing Froth Flotation Results PGMs in feed = 3.28 kg/hr PGMs in Concentrate = 2.94 kg/hr PGMs in Tailings = 0.34 kg/hr Percentage of Extraction = 89.5 Percentage Purity = 90

31. Pyrometallurgy By Tariq Anwar

32. U’flow Planning and Design of a Process for PGM ore Dressing (Fe, Cu, Ni) sulphates for recovery Off gas treatment Crushing and Grinding Froth Flotation Roasting and Smelting Atmospheric and Pressure leaching Waste water treatment PGMs to refinarey Block diagram of the PGM ore concentration process

33. Planning and Design of a Process for PGM ore Dressing Pyrometallurgy Contents • Roasting • Smelting • Atomization • Process flow diagram • Results 33

34. Roasting Roasting Converts sulphides to oxides or sulphates Why ? • Ore is rich in sulphides • Eliminates fugitive SO2 emissions from smelter • Produces SO2 of high concentration for Sulphuric acid production • Reduced energy consumption for smelting • Roasting eliminates drying Planning and Design of a Process for PGM ore Dressing

35. Planning and Design of a Process for PGM ore Dressing Roasting Reactions   2FeS2 + 11 O2 Fe2O3 + 4SO2 2FeS + 3O2 2FeO + 2SO2 2CuFeS2 + 13/2O2 2CuO + 4SO2 + Fe2O3 Feed size ~ 74 microns Operating temperature & pressure ~ 1000 °C & 1bar Considerations • Involves gas-solid reactions • Reactions begin at the outer layer of the solid particle • Outer layers are converted into new compounds • “Ash layer” diffusion controls reaction

36. Planning and Design of a Process for PGM ore Dressing Roasting Options • Multiple hearth roaster • Fluidized bed roaster Fluidized bed advantages • Easy handling and transport of solids •  Large throughput possible         • Uniform temperature distribution • Large solid gas exchange area • Suitable for handling smaller particles

37. Planning and Design of a Process for PGM ore Dressing Smelting • Reduction with carbon, forming, two layers – metallic layer & slag layer Reductant & fluxes are added to reduce metal oxides to metals Why ? • PGM‘s are conveniently “collected” in iron based alloy • PGM losses are very low • Base metals of high purity are formed • High reaction rates • Well established process ·

38. Planning and Design of a Process for PGM ore Dressing Smelting Options • A.C. (alternating current) arc furnace • D.C. (direct current) plasma arc furnace D.C. Plasma arc furnace advantages • Can handle fines • Dc arc is more stable than ac arc • Simple construction (single electrode) - easy gas sealing • Very high temperatures can be attained • Little off gas volume - less losses • Can process chromite bearing PGM ore(UG2 ore)

39. Planning and Design of a Process for PGM ore Dressing Smelting Temperatures • Off gases ~ 1100 °C • Metal & slag ~ 1600 °C • Plasma column ~ 20000 °C • Arc attachment zone ~ 2500°C Roof & walls are water cooled! Reactions FeO + C Fe + CO NiO + C Ni + CO CuO + C Cu + CO Fe2O3 + C 2Fe + 3CO

40. Planning and Design of a Process for PGM ore Dressing Atomization Convert the hot molten metal coming from DC arc furnace into solid particles of appropriate size for subsequent leaching step Options • Water atomizer • Gas atomizer Water atomizer advantages • Widely used for powders of Au, Pd, Pt, Co, Cu, Ni, & Fe • Particle size from 10 microns to few millimeters • The particles are irregular in shape • Cost effective as compared to granulation & milling

41. Planning and Design of a Process for PGM ore Dressing Process flow diagram

42. Planning and Design of a Process for PGM ore Dressing Results Roaster Height ~ 12.6 m Diameter ~ 8.2 m Fluidization velocity ~ 0.8 m/s Smelter Power consumption ~ 15.2 MW Operating current ~ 33.6 kA Electrode diameter ~ 473 mm Capacity ~ 45 tonnes

43. Roasting and Smelting Planning and Design of a Process for PGM ore Dressing Results Atomizer Height ~ 3 m Diameter ~ 1.2 m Water flow rate ~ 16.6 Kg/s Product size ~ 14 microns 0.016 % PGM’s 0.03 % PGM’s

44. Planning and Design of a Process for PGM ore Dressing Hydrometallurgy by Kumar

45. U’flow Planning and Design of a Process for PGM ore Dressing (Fe, Cu, Ni) sulphates for recovery Off gas treatment Crushing and Grinding Froth Flotation Roasting and Smelting Atmospheric and Pressure leaching Waste water treatment PGMs to refinarey Block diagram of the PGM ore concentration process

46. Planning and Design of a Process for PGM ore Dressing Contents Leaching Process classification Selection of process Block diagram Considerations Reactions Equipment selection Process flow diagram Design parameters

47. Planning and Design of a Process for PGM ore Dressing Leaching Two main steps are involved is Contact of liquid solvent with the solid to effect transfer of solute from the solid to the solvent. Separation of resulting solution from the residual solid.

48. Planning and Design of a Process for PGM ore Dressing Process Classification • Insoluble PGM residue The base metal is dissolved leaving the PGMs in a highly concentrated residue suitable for refining • Dissolved PGM The base metal and PGMs are dissolved together, and then subsequent separation of each metals in a sequence of hydrometallurgical operations

49. Planning and Design of a Process for PGM ore Dressing Selection of process Atmospheric leach • simpler to operate • cheaper • most reliable to leach the bulk Pressure leach • To speed the dissolution of all values into the leach solution • improve the solubility rate of solids that are at best only slowly soluble at atmospheric leach. • Atmospheric leach - Iron and Nickel • Pressure oxidative leach - Copper

50. Planning and Design of a Process for PGM ore Dressing Considerations Physical characterstics of the solids Process and operating conditions Choice of solvent Temperature Leaching cycle and contact method Type of reactor