The Recovery of Gallium(III) from Acid Leach Liquors of Zinc Ores Using Selective Ion Exchange Resins

Synopsis

The extraction of gallium(III) from acid leach liquors of zinc ores using two types of ion exchange resins, namely Duolite ES 467 and an experimental resin denoted HDP is reported. Duolite ES 467, a commercially available chelating resin containing aminophosphonic acid groups can selectively extract gallium(III) from zinc liquors at high acidity. This extraction however is extremely slow, even at 50°C. The HDP resin which contains both carboxylic acid and hydroxidiphosphonic acid groups is more attractive. In fact, the extraction of metal cations occurs mainly by reaction with the hydroxydiphosphonic acid groups when operating at high acidity. Below pH 0.5, gallium (III) is selectively extracted by HDP, except against iron(III) which should be reduced into iron(II) prior to treatment of the solution by ion exchange. After extraction, gallium(III) can be easily eluted from HDP by 2 mol.L^-1 aqueous sodium hydroxide.