The prospects for an alternative gold leach reagent: Thiourea

Orgul, S
Atalay, U
Gold has been traditionally extracted from ores by leaching with an alkaline cyanide solution. However, certain characteristics and drawbacks of cyanidation process have stimulated research into alternative processes. A number of non-cyanide reagents have been tried for the dissolution of gold. Among them, thiourea leaching seems to be a promising process. This study was carried out on a finely disseminated Kaymaz gold ore (4 g/t Au). The effect of various leaching parameters such as concentration of thiourea, concentration of ferric sulphate, molar ratio of ferric sulphate/ thiourea, leaching duration, temperature and pulp density are studied. The investigations indicated that at room temperature with 16.04 kg/ton consumption of thiourea at pH of 1.35, it was possible to obtain a gold extraction of 85.8 % for the particle size of 80 % passing 53 micron feed in 6 hours. Staged addition of chemical reagents, pretreatment of ore by acid washing and microwave heating were also tested in accordance with lowering the thiourea consumption.
Citation Formats
S. Orgul and U. Atalay, “The prospects for an alternative gold leach reagent: Thiourea,” ANTALYA, TURKEY, 2000, p. 505, Accessed: 00, 2020. [Online]. Available: