Principles and Research Progress of Non−cyanide Leaching of Refractory Gold Ores

Cyanide leaching is currently the most commonly used method for extracting gold from difficult−to−treat ore, due to its high leaching efficiency and low cost. However, the use of cyanide is associated with significant environmental and human health risks due to its high toxicity, and further treatment of waste water. As a result, there has been a significant amount of research into non−cyanide leaching processes. Non−cyanide leaching of gold is a low−toxicity process that offers numerous environmental and other benefits. It has become an important area of research in the development and exploitation of gold ore. In this regard, the principle and research progress of eight non−cyanide leaching methods are reviewed, such as the thiosulfate method, the amino acid method, the thiocyanate method, the rock sulfide synthesis method, the thiourea method, the halogen leaching method, the bioleaching method, and the polysulfide method, and their advantages and disadvantages are summarized. Finally, The development direction of non−cyanide gold leaching technology is also prospected.