Fluidized roasting synthetic reclaiming of complex silver copper concentrate

The treatment of Gacun complex silver copper concentrate with high Pb,Zn,Ag and Sb by a fluidized roasting synthetic reclaiming process was studied.The process consists of desulfurization by roasting,two-stage countercurrent leaching of copper and zinc with sulfuric acid,leaching of antimony and silver with chloride,leaching of gold with sodium chlorate,and transformation of lead with ammonia bicarbonate,and it can reclaim synthetically valuable elements well.Agglomerating of the concentrate can be avoided through controlling air surplus coefficient to be only 1.1,linear velocity in the hearth to be 0.25 to 0.35 m·s^-1 and roasting temperature to be 600 to 630℃.The desulfurization ratio was 49.68% and the concentration of SO₂ in smoke reached 5.5%,which meet the requirement of producing sulfuric acid in commercial production at these operating parameters.