Abatement of SOx emissions in relation with basic metal sulfides processing
Abstract
About forty percent of the SOx emissions are generated during the processing of metal sulfides of Cu, Ph, Zn, Ni, etc. Although new technologies for metal sulfide's smelting allow the production of H2SO4 with a reasonable cost and decrease the emissions of sulfur oxides, the generated quantity of SOx is considered as a serious threat to environment.
This paper suggests alternatives for low temperature processing of complex sulfide ores or concentrates 'CSO or CSC' under neutral, reducing and chlorinating atmospheres or their combination.
At T > 400 degrees C, The neutral and reducing treatments allow the decomposition of pyrite and the partial recovery of sulfur as S degrees and H2S, At 300 degrees C, the chlorinating treatment of CSC is fast, exothermic and allows the separation of FeCl3 from the valuable elements' chlorides. It also generates SyClx that can be either reduced by H2 or hydrolyzed in presence of sodium sulfide. The recovery rate of elemental sulfur with respect to the sulfur input exceeds 90 %.