Thiosulfate Leaching In Carbonaceous Gold-Bearing Ores

Abstract

Gold leaching in metallurgical process is one of the major unit operations in processing plant designs. Conventional cyanidation method had been adopted and is being used widely. However, alternative lixiviants over cyanide are being sought by the mining industries. Environmental impacts by cyanide have posed a problem to human life and other biotic species. Research to replace this chemical is being conducted. At this point in time, thiosulfate is claimed to be a better alternative to cyanide. This study presents the performance of thiosulfate as a leaching agent over cyanide in carbonaceous gold-bearing ores. The technical, environmental and economic aspects of using thiosulfate over cyanide have been investigated. A laboratory experiment was conducted to see the leaching effect of both lixiviants on carbonaceous gold-bearing ores taken from Legadembi Open Pit Mine. And it was found that thiosulfate has a better and faster recovery of 91.54% over 61.70% of cyanide recovery in 48 hours of leaching time. Graphs and tables are presented to show the technical superiority of thiosulfate over cyanide. Therefore, this work gives indications for the amenability of thiosulfate leaching on carbonaceous gold-bearing ores. A further research perspective is sought for thiosulfate leaching in other refractory ores as well.