Solvent extraction of indium(III) from HCl solutions by the ionic liquid (A324H+)(Cl−) dissolved in Solvesso 100

Indium(III) is extracted from HCl solutions (0.1–6 M HCl) by the ionic liquid (A324H)(Cl). The ionic liquid was generated in a previous reaction of the tertiary amine Hostarex A324 (triisooctyl amine) dissolved in Solvesso 100 with 1 M HCl solution. The metal extraction was investigated under various experimentalconditions: equilibration time, temperature, metal and HClconcentrations in the aqueous solution and ionic liquid concentration in the organic solution. Experimental results suggested that the indium extraction is due to an anionic exchange reaction between the chloride ion of the ionic liquid and the InCl of the aqueous solution. The performance of the system was compared against the extraction of other metals in binary solution (indium and accompanying metal) and against other ionic liquids. Indium(III) was stripped from metal-loaded organic solutions by the use of diluted hydrochloric acid solutions, and the precipitation of zero valent indium is possible by a further addition of sodium borohydride to the In-bearing strip solution.