The Gold Electrowinning/Replate Circuits at Gold Fields' Ortiz and Mesquite Operations

The pursuit of effective gold recovery from cyanide solutions has presented a longstanding challenge in metallurgy, particularly since the inception of the cyanidation process. This study aims to present a viable method developed by Gold Fields that demonstrates efficiency and cost-effectiveness in producing a refinery-ready gold product, distinct from traditional electroplating techniques. The methodology encompasses a unique replating system utilized at the Ortiz and Mesquite operations, where gold is electroplated onto stainless steel wool rather than mild steel wool, subsequently reversed onto stainless steel plates for extraction. This innovative approach facilitates multiple reuses of the steel wool, allows for quick and clean removal of gold from the plates, significantly cuts operating costs, and minimizes slag production. The Ortiz operation, situated in Central New Mexico, yields approximately 1250 kg of gold annually through a heap leach process, while the Mesquite operation, commenced in early 1986, processes 2.7 million tonnes yearly, with effective leaching techniques described in detail. Overall, the findings emphasize the advancements brought by Gold Fields in the field of gold extraction and their potential implications for industry practices.