Production of ZnS from flue gas SO₂ through the combined processes of microbial transformation and chemical precipitation

With a view of SO₂ resources-making treatment to producing ZnS with microbial transformation and chemical precipitation; the influence of carbon-source type, acetic-acid concentration, ZnCl₂ dosage and reaction time on SO₃^2- removal and ZnS generation were investigated; and the generated ZnS applying XPS and XRD was analyzed. Addition of ZnCl₂, inducing SRB transformation, S^2- generated ZnS precipitation very quickly, and other attached reaction was inhibited. The SO₃^2- removal and ZnS generation were the greatest when the molecular concentration ratio of acetic-acid C atom/SO₃^2- was 1. ZnS generating amount increases with increase of ZnCl₂ dosage; but ZnCl₂ overdose resulted in lowering of Zn utilizing rate and increase of Zn(OH)₂ foreign substances in ZnS. The SO₃^2- removal and ZnS generation tended to be complete after 14 day incubation. The structure analysis showed that generated ZnS was hexagonal system α-ZnS.