Abstract:Sulfation roasting of copper sulfide concentrates mixed with ammonium sulfate can not only promote leaching of copper, but also realize cyclic utilization of ammonium sulfate by neutralization treatment of waste acid solution from extraction process of copper with decomposed ammonia. The results show that the best copper sulfation effect is realized under conditions including ammonium sulfate dosage of 1.5n (molar ratio of ammonium sulfate and chalcopyrite), roasting temperature of 420 ℃, and roasting duration of 180 min. Ammonium sulfate is almost completely decomposed and about 97% ammonia produced can be absorbed with dilute sulfuric acid liquor. Copper leaching rate of calcined cinder is 89.96% after leached at 80 ℃ for 90 min with ratio of liquid to solid of 4.