Acid Leaching of Indium-Lead-Tin Alloy Wire Scrap

摘要

Acid leaching of indium-Iead-tin alloy wire scrap has been studied. An experimental study was excuted to produce leaching liquor for subsequent separation of the concerned metals from the scrap material. Two leaching solutions were investigated; hydrochloric acid and hydrochloric-nitric acid oxidationleaching. Parameters affecting leaching processes such as time, temperature, acid concentration and acid: scrap stoichiometric ratio have been evaluated. Results obtained revealed that hydrochloric acid failed toextract metals completely, the maximum extraction efficiency was in the orderof indium 97.1, lead 94.1 and tin 89.2% by using 5M HCI for 6 hours at 95°C,HCI: scrap ratio was 5. Addition of nitric acid as oxidizing agent resulted incomplete extraction for metals, the optimum leaching conditions were conductedby addition of 0.6 ml of 1 : 1 HN03 / g scrap to the leachate of 5M HCI for 1.45 hours at 80°C with HCI : scrap ratio of 2.5. Another advantage for using of HCI-HN03 leaching was that about 71% of the lead content was separated as pure crystals of PbCI, on cooling the resulting solution.