Pretreatment of arsenic-bearing gold ore with microwave-assisted alkaline leaching

Abstract

In this paper, the removal of arsenic from arsenic-bearing gold ore through air oxidation and sodium hydroxide leaching with microwave irradiation was studied. Firstly, single-factor experiments were carried out. The results indicated that the removal rate of arsenic was influenced by the sodium hydroxide concentration, ratio of liquid to solid, microwave power, and reaction time. Then, orthogonal experiments were done to determine the main influencing factors. The results obtained from the experiments of orthogonal arrays showed that reaction time and microwave power were the important influencing factors, and the optimum conditions of sodium hydroxide concentration, reaction time, microwave power, and ratio of liquid to solid were 18 wt.%, 60 min, 700 W, and 5, respectively. Under the optimal conditions, the removal of arsenic could reach approximately 81.46 wt.% and, at the same conditions, the sulfur removal rate was about 55.56 wt.%. The results of X-ray diffraction analysis revealed that AsS and FeAsS were decomposed during the leaching process, while FeS

An electrochemical method to investigate the effects of compound composition on gold dissolution in thiosulfate solution

“…Gold extraction has always been a highly polluting and toxic process due to the use of cyanide [1]. The leaching of gold in the thiosulfate solution is a promising noncyanide gold leaching method that is widely implemented [2][3][4][5].…”