LEACHING OF GOLD FROM FINE-GRAINED FLOTATION TAILINGS

Abstract

This study focuses on leaching of gold from fine-grained waste materials from flotation. The input raw material is the waste product after flotation containing about 1–2.5 g/t of Au. This paper makes part of wider research to identify all available methods and select the most appropriate technology to obtain residual gold from fine-grained waste materials. An alternative method to conventional cyanide methods, which have negative environmental impacts [1], has been tested under laboratory conditions, namely thiourea leaching. We observed the effect of the grain size of input raw materials with concentration of thiourea and Fe3+ ions in dependence on temperature and pH during research. The pH values were maintained low during all experiments to avoid dissociation of the leaching solution. In optimal condition of leaching we achieved 85% success rate of gold recovery. The data may be useful to improve the processes of recovery of useful constituents from unused wastes with the content of gold.

Keywords

• flotation; gold; leaching; thiourea