Enrichment of Indium From Leaching Solution of Zinc Slag

The enrichment of indium from leaching solution of zinc slag was studied. The effects of solution initial pH, composition of organic phase, the volume proportion between aqueous phase and oil phase(Va/Vo),agitation speed and time on extraction of indium, and in reverse extraction, the effects of hydrochloric acid concentration and volume proportion between aqueous phase and oil phase on reextraction ratio of indium were examined. The results show that the extraction rate of indium can reach around 98% by four-stages counter-current extraction under the optimal conditions of the leaching solution pH of 0.5,the organic phase composition of 20% P204+80% sulfonated kerosene, agitation speed of 1 000 r/min and the agitation time of 2 min. In reextraction process,the one-stage re-extraction rate of indium is over 92% when using hydrochloric acid of 4 mol/L as re-extraction age nt. By extraction and re-extraction, the indium in low concentration solution can be enriched by the high efficiencv,energy saving and short proeess.