Mineralogical Characterization of Anode Slimes: Part 7—Copper Anodes and Anode Slimes From the Chuquicamata Division of Codelco–Chile

Abstract

Listen

Translate article

Copper anodes and anode slimes from the Chuquicamata Division of Codelco-Chile were examined mineralogically. The copper matrix of the anodes contains most of the Ag and much of the As and Sb in solid solution. Numerous inclusions are present at the copper grain boundaries, and these consist mostly of Cu2O although grains of Cu2O–Cu2Se and Cu2O–Cu2 Se–(Cu–Sb–As oxide) also are present. The Cu2Se has a significant solid solution Te and S content. The anode slimes consist principally of an oxidate matrix phase which agglomerates or cements the finer slimes particles. The oxidate matrix phase is a complex Cu–Ag arsenate-antimonate-selenite (or selenate)-sulphate--ehloride although many of the particles approximate copper arsenate in composition. Silver is present in the oxidate matrix phase, and seems to substitute for Cu in some grains of CuSO4·5H2O. Metallic silver is present as sponge-like masses and as <0.5 μm spheroidal grains which are commonly embedded in CuSO4·5H2O. Silver chloride occurs on masses of the oxidate matrix phase and as tiny isolated particles. Much of the silver, however, occurs as Ag2Se or (Ag, Cu) 2Se. Gold is readily detected as a <1 μm film of Au or Au-rich Au–Ag selenide on fragments of Ag2Se or as <1 μm inclusions in some of the selenide particles. Surprising is the presence of trace amounts of Cu sulphides, Cu–Ag sulphides and porous masses of Ag–Cu telluride–sulphide. Résumé Une analyse minéralogique des boues anodiques et des anodes de cuivre provenant de la Division Chuquicamata de Codelco–Chile a été effectuée. L'anode de cuivre contient la majeure partie de l'argent et beaucoup d'arsenic et d'étain en solution solide. Plusieurs inclusions sont situées le long des joints de grains du cuivre. Elles sont principalement composees de CuO, bien que Cu2O–Cu2Se et Cu2O–Cu2Se–(Cu–Sb–As oxyde) soient aussi presents. Le Cu2Se a une teneur importante en Te et S en solution solide. Les boues anodiques sont principalement composées d'une matrice d'oxydate liant les particules les plus fines. La matrice d'oxydate est un complexe Cu–Ag.