A comprehensive review on the recovery of copper values from copper slag

Abstract

Copper slags are a by-product generated from copper extraction. Rich in iron oxide, silica, calcium oxide, and alumina, copper slags are mostly stockpiled or used in landfill applications. These slags consist of a substantial amount of valuable metals in an entrained metallic, sulphide or dissolved oxidized form, copper being one of them. The loss of such metallic values and the disposal issues of the enormous quantum of discarded slags have urged reprocessing. These metallurgical wastes, nowadays, represent a promising secondary source of copper. The recovery of copper from these slags can be the right solution to meet the increased demand for copper. The present article attempts to review important research carried out in this direction. The beneficiation of copper slag employing gravity concentration and froth flotation, with particular emphasis on different collector systems, has been reviewed thoroughly. Further, the reported pyro-and hydro-metallurgical processing routes have been deliberated. The present article also broadly summarizes the challenges in slag processing and provides the roadmap for further investigations and large-scale studies.