Metallurgical Process for Total Recovery of All Constituent Metals from Copper Anode Slimes: A Review of Established Technologies and Current Progress

Abstract

Copper anode slimes, the by-product of the copper electrorefining process, have been the subject of extensive investigation for recovering precious metals viz., Au, Ag, Pt and Pd, in addition to being the main source of rare/energy-critical elements such as Se and Te. There have been various approaches aiming at the development of extraction processes involving thermal and aqueous approaches and their combination. In this paper, the literature relating to the treatments of copper anode slime is compiled to present the underlying concept for the total recovery of all valuable metals from anode slimes. The industrial and proposed scenarios gathered from various sources show that the basis of applying different streams essentially depends on the concentration of copper and selenium in the slimes. Copper anode slime processing has a history of being in a development period, though at times showing overlaps. The discussion of each metallurgical process is basically explained by thermodynamic analysis using suitable software as well as fundamentals of the chemistry. Recent progress is highlighted and compared to the established technologies with regard to environmental impact and economic consideration/feasibility. This discussion is followed by the construction of a conceptual flowsheet on the progress currently made. It is expected that further work regarding metal recovery from copper anode slimes would objectively shorten the number of stages for the pretreatment as well as metal separation from leach solutions.