4.2 Process Flow Diagrams Below are Process Flow Diagrams (PFDs) illustrating the recovery of arsenic following the pyrometallurgical treatment of ore. The PFDs demonstrate that arsenic can be recovered in several forms. Arsenic may be recovered as a solid using a dust collector, as shown in Figure 2; it may be recovered as a slurry with a wet electrostatic precipitator, as shown in Figure 3; or it may be recovered dissolved in an acidic liquid within a scrubber, as shown in Figure 4. Subsequently, arsenic recovered as either a solid or a slurry is directly conveyed to the GlassLock process to produce an inert, non-leachable glass, as depicted in Figure 5. FLUIDIZING AIR OFF GAS FLUIDIZED BED PYROLYSIS POST-COMBUSTION CHAMBER AIR SO2 (g) As2O3 (s) As2S2 (g) ARSENIC-FREE CONCENTRATE COOLING SCREW As2O3 (s) O/F U/F 2 3 TO MARKET / LEACHING PROCESS 5.3 % As CONCENTRATE CYCLONE ARSENIC BAG HOUSE 1 TO VITRIFICATION PLANT COOLING WATER 4 TO ATMOSPHERE GYPSUM TO LANDFILL LIME SLURRY TANK LIME SILO OFFLOAD TRUCK SO2 SCRUBBER GYPSUM RETENTION TANK TO EFFLUENTS PROCESS WATER WATER WASTE HEAT BOILER OFF GAS OFF GAS CYCLONE CYCLONE QUENCH TO BAGHOUSE WATER GAS SPRAY COOLER As2O3 (s) STEAM SO2 (g) As2O3 (g) SO2 (g) As2O3 (g) Dust Trap Dust Trap Figure 2 – Integrated flowsheet: pyrolysis + arsenic recovery with dust collector
RkJQdWJsaXNoZXIy MTM0Mzk2