Predicting Cyanide Consumption in Gold Leaching: A Kinetic and Thermodynamic Modeling Approach

Minerals

Glenn Hefter¹  Lubomir Hnedkovsky¹  Gamini Senanayake¹  Ahmad Khodadadi Darban²  Mohammad Reza Khalesi²  Yaser Kianinia²  Mahmoud Abdollahy²  Marjan Shahbazi³ 

[1] Department of Chemical & Metallurgical Engineering & Chemistry, Murdoch University, Murdoch, WA 6150, Australia;Department of Mining Engineering, Tarbiat Modares University, Tehran 1411713116, Iran;Department of Mining Engineering, Yazd University, Yazd 8915818411, Iran;

关键词: leaching;    gold ores;    cyanide;    modelling;    consumption;    kinetics;    speciation;   

DOI  :  10.3390/min8030110

来源: DOAJ

【 摘 要 】

The consumption of cyanide during processing operations is a major economic cost in the extraction of gold from its ores, while the discharge of cyanide wastes may result in significant environmental pollution. Many factors influence the levels of consumption and discharge of cyanide, including ore mineralogy and lixiviant solution chemistry. This paper proposes a robust methodology to estimate leaching cyanide consumption due to oxidation and reactions with gold, chalcopyrite and pyrite minerals forming various cyanide complexes, cyanate, thiocyanate and hydroxide precipitates of copper and iron. The method involves concurrent modelling of both the oxidation and leaching kinetics of minerals and the chemical speciation of the lixiviant solutions. The model was calibrated by conducting cyanide leaching experiments on pyrite, chalcopyrite, pyrite + chalcopyrite, pyrite + chalcopyrite + gold and pyrite + chalcopyrite + gold + quartz systems and determining the total Cu, Fe, Au and CN− concentrations in solution. We show that this model can successfully estimate the formation of cyanide complexes and, hence, the consumption of cyanide.

【 授权许可】

Unknown