Recovery of indium from scrap TFT-LCDs by solvent extraction

摘要

Recovery of indium from scrap LCDs,which contain indium in the form of indium tin oxide (1TO) films,is becoming economically and environmentally justified.Indium is a precious metal and the present study was aimed to recover indium from scrap TFT-LCDs by solvent extraction which was based upon H2SO4 acid leaching-D2EHPA extraction-HCl back extraction.The results showed that indium could be better leached in H2SO4 (1∶1,v/v) acid solution in the optimal liquid/solid ratio of 1∶1 while other metals' leaching concentrations were relatively low.Indium could be selectively extracted from its H2SO4 solutions by 30％ D2EHPA with O/A ratio of 1∶5 within 5 min,and be completely stripped by 4M HCl from D2EHPA with A/O ratio of 1∶5,the final extraction efficiency achieved more than 97％.