Application of short bed reciprocating flow ion exchange to copper/zinc separation from concentrated leach solutions

Abstract

Significant improvements to conventional fixed bed ion exchange have previously been demonstrated using counter-current reciprocating flow ion exchange (RFIX) in short bed columns. Applications have generally involved the separation and recovery of metals from relatively dilute solutions, typically 1–10 g/l. These techniques have now been expanded to the treatment of more concentrated solutions. The present study was made using solutions produced by the sulphuric acid leaching of copper smelter flue dust.Solutions containing 32 g/l copper and 73 g/l zinc were treated in a 30 cm×3.8 cm diameter column containing Dow FXS 43084 chelating resin. A copper-rich product stream containing 18–20 g/l copper and 3–4 g/l zinc was produced using 1.5 molar sulphuric acid eluant. The zinc-rich raffinate stream contained 62–64 g/l zinc and 6–7 g/l copper. Some process implications of incorporating RFIX in the treatment of concentrated solutions are discussed.