Recovery of copper from zinc leaching liquor using ACORGA M5640

Abstract

The present paper describes the solvent extraction and separation of Cu(II) from a leaching liquor obtained by the direct atmospheric leaching of a zinc concentrate with an oxidative mixture of Fe 2(SO 4) 3 (0.4 M) and H 2SO 4 (0.5 M) in the presence of O 2 at 353 K. The obtained solution, containing 1.35 g L −1 Cu(II), 5 mg L −1 In(III), 41 g L −1 Fe {20% Fe(III), 80% Fe(II)}, and 34 g L −1 Zn(II), was extracted with 25% (v/v) solution of ACORGA M5640 (modified with 12.5% (v/v) isodecanol). Quantitative (>98%) and selective transfer of Cu(II) in to the organic phase was achieved in pH range of 1.3–1.5 (A/O = 1). The presence of isodecanol in the extractant solution helped in obtaining complete stripping of copper. Three stages of extraction at an A/O ratio of 5 concentrated the initial metal content {Cu(II) initial-aqueous = 1.35 g L −1} in the organic phase {Cu(II) after extraction, in LO = 6.6 g L −1}. This extraction was selective over Zn(II), Fe(II), Fe(III), and In(III). The loaded organic phase was scrubbed with 20 g L −1 H 2SO 4 followed by the stripping of Cu(II) with 25 g L −1 of Cu 2+ in 180 g L −1 of H 2SO 4 (A/O = 1, two stages).