Patent ID: 6245125
Filing Date: 2001-06-12
Classification: C22B,Y02P,Y10S

Abstract:
A process for the recovery of at least copper, nickel and cobalt from a concentrate containing copper, nickel and cobalt minerals which includes the following steps:(a) biologically oxidising the mineral concentrate in slurry form to dissolve copper as soluble copper sulphate and nickel as nickel sulphate;(b) subjecting the slurry to solid/liquid separation to produce a solution with a high copper and nickel concentration;(c) treating the solution with a solvent extraction reagent so that copper ions are exchanged by the reagent for hydrogen ions to produce a raffinate which is high in sulphuric acid and low in copper sulphate;(d) stripping the solvent extraction reagent with a sulphuric acid solution;(e) electrowinning copper from the sulphuric acid solution;(e1) recovering cobalt from excess raffinate of step (c) using a reagent which is specific for cobalt over nickel,(f) recycling a portion of the raffinate from step e1 to step (a); and(g) recovering nickel as nickel sulphate from the raffinate which remains after step (f).