Recovery of copper from zinc leaching liquor using ACORGA M5640

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 Fe2(SO4)3 (0.4 M) and H2SO4 (0.5 M) in the presence of O2 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 H2SO4 followed by the stripping of Cu(II) with 25 g L−1 of Cu2+ in 180 g L−1 of H2SO4 (A/O = 1, two stages).

Figure optionsDownload as PowerPoint slideResearch highlights▶ Almost quantitative extraction of copper from the dilute metallurgical processing solution. ▶ Selective separation of copper from other associated metals from zinc leaching liquor. ▶ Complete stripping of copper from the extractant phase such as to use the recovered solution in electrowinning baths. ▶ Regeneration of the extractant.