ROTARY LEAD RECYCLING VESSELS APRIL 2013

SCRAP LEAD ACID BATTERIES PROCESSING COKE ADDITION REDUCES LEAD SULPHATE TO PbS AVOIDING EXCESSIVE SO2 POLLUTION ADDITION OF CAST IRON (TURNINGS AND BORINGS) REDUCES LEAD SULPHIDE TO METALLIC LEAD AND IRON SULPHIDE. SODA ASH ADDITION ALSO TO DESULPHURIZE AND TO FLUIDIZE SLAG/MATTE BY-PRODUCT (REFRACTORY LINING SENSITIVE TO EXCESS SODA)

Lead Sulphate reduced to Lead Sulphide with Coke PbSO4 + 2C > PbS + 2CO2 Iron Sulphide produced by reaction with Iron PbS + Fe > Pb + FeS Sodium Sulphide created by reduction of soda ash C + 2PbS + 2 Na2CO3 > 2 Pb + 2 Na2S + 3CO2

SEPARATORS (40 – 60% SILICA) LEAD RESOURCE RECOVERY BREAK-DOWN LEAD PASTE (1.5 - 5% SULFUR) POSTS AND GRIDS SEPARATORS (40 – 60% SILICA)

Desulfurisation of Lead Sulfate PbSO4 + Na2CO3 PbCO3 + Na2SO4 BATTERY PASTE CONTENTS PASTE CAN CONTAIN: 50-60% PbSO4 30-35% PbO2 10-15% PbO 0.2-0.7% Sb (Antimony) Desulfurisation of Lead Sulfate PbSO4 + Na2CO3 PbCO3 + Na2SO4

Precipitated silica: Morphology SEPARATORS Precipitated silica: Morphology REACTION STAGE DRYING STAGE Strong bonding Weak bonding Very weak bonding 5 - 30 nm 30 - 300 nm 1-50 µm 150-300 µm Agglomerate Primary particle Aggregate Agglomerate (in slurry) PULVERIZING Bonding energy got during drying stage can be adjusted. According the shear rate of the application there is no need to pulverize micropearls to get targeted particles size in the polymer matrix. 15-20 µm Agglomerate (Powder)

PROCESSING AND VESSEL LINING DESIGN ISSUES IMPACTING REFRACTORY WEAR RATE 1. OXYGEN ENRICHED FUEL BURNERS 2. SODIUM LEVELS IN THE FEED 3. SILICA CONTENT OF THE FEED 4. MORTAR COMPOSITION 5. IRON CONTENT OF BRICK LINING 6. OPTIMIZATION OF HEAT FLUX THRU LINING

Magnesia: Production Process Steps MgCl2+Ca(OH)2 --> Mg(OH)2+CaCl2 Mg(OH)2-->MgO+H2O (app. 1000 °C) MgO (caustic) MgCl2 (from sea water or brines) agglomeration MgO calcined and briquetted sintering (1700 up to 2100 °C) MgO sintered briquette

Chrome Ore (main component: chromite) Chromite/ Serpentine (intergrown) Chromite Turkey Groups (composition): ores rich in Cr2O3 Türkey; Pakistan Cr2O3 55 % Fe2O3 16,4 % Al2O3 10,0 % SiO2 2,4 % Chromite crystals ores rich in iron South Africa typisch Cr2O3 44,6 % Fe2O3 28,2 % Al2O3 14,7 % SiO2 0,6 % South Africa ores rich in Al2O3 Kuba Cr2O3 32,2 % Fe2O3 14,8 % Al2O3 26,2 % SiO2 5,63 % Grain size: lump – fine concentrate

Fused Magnesia-Chrome: Production Process The raw material magnesia/chrome is fused in an electric arc furnace at high temperatures (> 2800°). material feed 3 independent moveable electrodes Electric arc Water cooled steel shell molten material furnace car

Fused Magnesia-Chrome: Production Process cooling of steel shell after fusion process electric arc furnace crushing, grading and classing further cooling after taking off the shell

10mm. NARMAG 60DB

10mm. SUPER NARMAG 145

10mm. SUPER NARMAG FG

TYPICAL ANALYSIS OF SRF “SLAG”

JCI GARCIA SLAG ANALYSIS

SODA ASH,COKE AND IRON METALLICS REACT WITH LEAD SULPHATE/OXIDE TO REDUCTION OF LEAD SULPHATE TO ELEMENTAL LEAD AND SODIUM/IRON SULPHIDE EUTECTIC SODA ASH,COKE AND IRON METALLICS REACT WITH LEAD SULPHATE/OXIDE TO PRODUCE SODIUM AND FERROUS SULPHIDE C + PbO + PbSO4 > Pb + PbS + CO2 PbS + Fe > Pb + FeS C + 2PbS + 2 Na2CO3 > 2 Pb + 2 Na2S + 3CO2

A.P. Green, Harbison-Walker, NARCO