GB1218167A - Recovery of copper - Google Patents

Abstract

1,218,167. Extracting metals. INTERNATIONAL NICKEL CO. OF CANANDA Ltd. May 2, 1969 [May 2, 1968], No.22632/69. Heading C7D. Cu is recovered from cupriferous material by forming the material into a turbulent molten bath containing Cu sulphide and having a Cu: Ni ratio of more than 7: 3 by weight (preferably at least 10:1); volatizing more than half of one or more of the impurities Bi, Pb, Sn and Zn (and preferably also As) from the bath without forming a metal phase in the bath; surface-blowing the bath with a free-O 2 - containing gas to convert a minor portion of the Cu sulphide to an immiscible metal phase in which one or more of Sb, As, Bi, Pb, Sn and the precious metals is concentrated; removing the immiscible metal phase; surfaceblowing the remaining turbulent bath of Cu sulphide witha free-O 2 - containing a gas to convert Cu sulphide to liquid Cu, to saturate the liquid Cu with O 2 and to oxidize and volatilize one or more of the impurities As, Pb, Se, S, Te and Sn; and then lowering the O 2 content of the liquid Cu to less than 0À1% by reduction with an atmosphere reducing to Cu 2 O. When the cupriferous material contains too much Ni, the material is first converted to a S- deficient matte e. g. by surface-blowing with free-O 2 - containing gas, the matte is slowly cooled to produce crystals of Ni sulphide and Cu sulphide having a Cu: Ni ratio greater than 10:1 with or without a magnetic fraction containing precious metals, the Ni sulphide, Cu sulphide and magnetic fraction are separated (e. g. the magnetic fraction magnetically, the sulphides by flotation) and treated individually to recover the Ni, Cu and precious metals. Cu sulphide is treated as described above; the magnetic fraction is melted, surface-blown with free-O 2 - containing gas, granulated by quenching, treated with CO to remove Ni as Ni carbonyl, and the remainder treated by leaching to remove Cu and S from the precious metals; and the Ni sulphide is either blown to Ni metal as described in Specification 960, 698, or treated to produce Ni carbonyl. When the cupriferous material contains substantial amounts of Fe as Fe sulphide, the Fe is initially oxidized to Fe oxide which is removed before purification of the bath. Before, after, or at the same time as the final step of treating with reducing gas, the bath may be subjected to sabatmospheric pressure treatment, e.g. at less than 10<SP>-3</SP> atmosphere. The bath may be kept in a turbulent state penumatically, electromagnetically or, preferably, by using a top blown rotary converter.