The comparison of gold extraction methods from the rock using thiourea and thiosulfate

Abstract

Gold extraction from the rock is generally carried out using mercury. However, the high toxicity of mercury has a very dangerous impact on the environment and health. Various efforts have been made to reduce the use of mercury in gold extraction, one of which is the leaching method using thiosulphate and thiourea solution because they have low toxicity and are environmentally friendly. This study aimed to determine the results of gold extraction with thiosulphate and thiourea solution and determined the optimum concentration and time of extraction. The yield of the gold extract with thiosulphate solution was greater than that of thiourea solution. The thiosulphate solution had an optimum concentration of 0.3 M and an optimum time of 2 h. While the thiourea solution had an optimum concentration of 0.2 M and an optimum time of 3 h. The results of the Friedman test on the leaching time and concentration parameters show that leaching time has a significant effect on the Au leaching process, and the concentration parameter does not affect the Au leaching process from solid samples.