Abstract:The process of wet copper smelting is mainly used to extract copper from copper concentrate in Democratic Republic of the Congo (DRC). After roasting and two-stage acid leaching of copper sulfide concentrate containing 55%~65% copper, the acid leaching residue contains 3%~10% copper. Based on the process mineralogy analysis of calcine acid leaching residue of a copper concentrate in the DRC, pressure leaching method was used to recover copper from the acid leaching residue. The results show that copper in the acid leaching residue of calcine of copper concentrate mainly exists in the form of chrysocollite, chalcanthite and copper ferrite. The copper content of these three minerals accounts for 96.87% of the total copper content, and copper ferrite is the main difficult to leach mineral. During acid leaching, the amount of acid used has the greatest impact on copper leaching rate. The copper leaching rate is 94.52% and copper content in the residue can be reduced from 7.66% before treatment to 0.52% under the optimum leaching conditions including liquid-solid ratio of 4 mL/g, acid-ore ratio (the mass ratio of sulfuric acid dosage to acid leaching residue) of 65%, a leaching time of two hours, and leaching temperature of 180 ℃.