Leaching of a carbonaceous gold concentrate in copper-tartrate-thiosulfate solutions

•The thermodynamics and mechanism of gold leaching in copper-tartrate-thiosulfate solutions is systematically investigated.•Leaching behavior of a carbonaceous gold concentrate using copper-tartrate-thiosulfate solutions is studied.•The capability of leaching gold by copper-tartrate-thiosulfate solutions is comparable to that in cyanidation or traditional copper-ammonia-thiosulfate systems.•The consumption of thiosulfate can be significantly reduced in the presence of tartrate.