非氰提金技术研究进展

随着难处理金矿的占比不断增加以及人们对环保问题的日益重视，氰化法受到了技术和环保两方面的制约，非氰方法成为金、银提取的必然趋势。非氰方法包括湿法工艺和火法工艺两大类。系统介绍了湿法非氰方法中卤素法、硫脲法、硫代硫酸盐法、硫氰酸盐法和环保提金剂的原理及发展状况；火法非氰方法主要介绍了具代表性的高温氯化焙烧工艺和造锍捕金工艺，其适用对象分别为铁含量高的含金物料和含砷、硫、碳等难处理金精矿。通过综合分析得出贵金属提取的重要趋势是火法—湿法工艺结合，即先通过火法充分富集贵金属，再利用湿法工艺高效回收。

Advances in Non-cyanide Process for Gold Smelting

With the increasing of proportion of refractory gold ore and public’s attention to environmental issues，the cyanide process has been severely constrained by both technology and environmental protection.The use of non-cyanide process for the extraction of gold and silver is an inevitable trend.Over the past decades，there were series of approaches developed for the gold extraction from ore by using non-cyanide process.Compared to cyanidation，these approaches seemed more environmentally friendly.However，the non-cyanide processes are often restricted by their high reagent consumption and relatively low gold extraction rate.To fully understand the development of non-cyanide processes，this paper presented an extensive overview of non-cyanide processes.By a summary of the numerous literatures concerned about non-cyanide process and results of the experiments conducted by the author's research group，this paper reviews two kinds of non-cyanide processes，pyrometallurgy and hydrometallurgy.It then reviews the mechanism and development of some typical non-cyanide hydrometallurgy processes，including halogen，thiocyanate，thiourea，thiosulphate and the so-called environmental friendly lixiviant.Characterization of the environmental friendly lixiviant showed the presence of sodium cyanide and sodium cyanate，indicating that the in situ generation of sodium cyanide with the lixiviant probably occurred in leaching process.The non-cyanide pyrometallurgy process includes high-temperature chlorination and matte smelting enriching gold，which were applied to the treatment of high iron containing gold bearing materials and refractory gold ore containing arsenic，sulfur，carbon，respectively.High-temperature chlorination is a promising method especially for the treatment of pyrite cinder whose gold is commonly wrapped by the iron oxide and silicate.In recent years，great progress have been made for the settlement of the problems in this process，including pulverization，scaffolding，the corrosion and adhesion of refractory.In China，some gold smelter has successfully adopted this process for gold extraction from pyrite cinder.The meaningful non-cyanide lixiviant should possess three characteristics：Firstly，it should be able to form stable complex ion with gold ions；It should show good coordination selectivity for gold ions，which can greatly decrease the toxicity of the lixiviant；Thirdly，it should cooperate with some oxide.The authors also think that the combination of hydrometallurgy and pyrometallurgy process for the recovery of precious metal is an important tendency in gold industry，that is，the precious metal will firstly be enriched by pyrometallurgy，following the hydrometallurgy process to efficiently recover precious metal.