Mechanism and application of gold extraction with triphenylarsine oxide and trioctylamine oxide
Gong Yuqiu and Xia Shihua (Department of Chemistry, Hangzhou University, Hangzhou)
By using chemical extraction methods (including slope, isothemal and JOB's method),the compositions of the extracted species of Au(Ⅲ)with triphenylarsine oxide (TPAsO) and trioctylamine oxide (TONO) were determined respectively to be [TPAsOH]AuCl4 and [(TONO)2H] AuCl4. H NMR and IR spectra indicated that H ion is bonded to oxygen in TPAsO and TOPO. The reaction mechanism of extraction is formed in the course of Ion-association, and the structure of the two extracted, species is given.Both TOPO and TPAsO are very efficient extractants of gold (Ⅲ) and have been used to extract Au(Ⅲ) from technological solution for refining.