Abstract: The copper smelting slag contains Cu 1.13 % . Process mineralogy research shows that copper mainly exists in the form of similar chalcopyrite,similar bornite,similar covellite and copper. In order to recover copper efficiently,flotation tests were carried out. The results show that,at the fineness of grinding is 0.045 mm and the following is 85 %,using Ester-105 as the collector and sodium sulfide as activator addition,copper concentrate would be discovered with copper grade of 18.10 % and recovery of 87.48 % through the process of two roughing-three cleaning-two scavenging.