Lime use in gold processing - A review

The gold processing industry is a large consumer of lime reagents in various forms. Its role in gold processing is mainly as a pH control agent for optimal cyanidation leaching of gold, as well as a neutralization agent in refractory gold processing via acidic oxidation routes. There are, however, a range of conditions upstream of cyanidation that influence lime consumption and its functionality in the overall process. Lime also positively impacts gold absorption onto carbon in CIP/CIL circuits compared to other pH modifiers. The quantity of lime consumed depends upon several factors, including (1) lime reagent properties, (2) methods of preparation, (3) gold ore type, and (4) processing flow sheet. This article provides a comprehensive review of lime functionality in gold processing and process features that influence its consumption.