Role of oxygen and ammonium ions in silver leaching with thiosulfate–ammonia–cupric ions

作     者：Valentin Ibarra-Galvan Alejandro López-Valdivieso Xiong Tong Yi-Qi Cui 

作者机构：Faculty of Chemistry Colima University Minerals Engineering Area Institute of Metallurgy Autonomous University of San Luis Potosi Faculty of Land and Resource Engineering Kunming University of Science and Technology 

出 版 物：《Rare Metals》 (稀有金属（英文版）)

年 卷 期：2014年第33卷第2期

页      面：225-229页

核心收录：

学科分类：080603[工学-有色金属冶金] 08[工学] 0806[工学-冶金工程] 

基　　金：Research and Technology Development Center  Administrative Services of Pennoles for the financial support of this Research Project 

主　　题：Silver Thiosulfate leaching Non cyanide silver leaching Cupric tetraamine Oxygen 

摘      要：The dissolution of silver with thiosulfate and copper ions was studied in a batch-stirred reactor at 25 °C in the absence and presence of various ammonium ions and oxygen concentrations in the aqueous solution. Leaching silver with 4 mg L-1oxygen in the aqueous solution requires high concentration of ammonium and thiosulfate ions. High silver dissolution is achieved at pH of high cupric tetraamine concentration, around pH 9.8, but a high degradation of thiosulfate ions is resulted from their oxidation by the presence of oxygen. When the oxygen concentration is below 1 mg L-1, dissolved silver thiosulfate species are fairly stable and the degradation of thiosulfate ions in the aqueous solution is low. Under these conditions,high silver dissolution is attained using low thiosulfate concentration. At the oxygen concentration of 4 mg L-1,dissolved silver thiosulfate species precipitate out of the aqueous solution significantly affecting silver *** of dissolved silver thiosulfate species occurs because of oxidation of the thiosulfate bonding to the silver.