Indium extraction from a lead-tin alloy - using lead chloride and zinc chloride in presence of a sulphur-contg. agent

摘要

In is extracted from a Pb-Sn alloy with Zn and Pb chloride in the presence of an S-contg. reagent in an amt. 0.1-5 pts S per part In. Extn. is conducted at 300 degrees - 380 degrees C and the resulting In-contg. slag is recovered and leached with aq. acid. In is deposited from the acid leach soln. onto Zn plates immersed in the soln. and recovered as a metal sponge. Zn(OH)2 is pptd. from the remaining soln. and recycled to the extn. stage. The In sponge is electrolytically refined in a melt of Zn and In chloride in the presence of 3-10% NH4Cl and then further electrolytically refined in an aq. electrolyte which is continuously recycled through a sorbent. The presence of the S-contg. reagent in the initial extn. stage the yield and purity of the final prod.