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http://dx.doi.org/10.9719/EEG.2020.53.2.159

Improvement of Au Leaching from Gold Concentrates Using a Microwave and Thiourea-mixed Solvent  

Kim, Bong-Ju (Korea Atomic Energy Research Institute)
Kwon, Jang-Soon (Korea Atomic Energy Research Institute)
Koh, Yong-Kwon (Korea Atomic Energy Research Institute)
Park, Cheon-Young (Dept. of Energy and Resource Engineering, Chosun University)
Publication Information
Economic and Environmental Geology / v.53, no.2, 2020 , pp. 159-166 More about this Journal
Abstract
In this research, we investigate the effect of microwave pretreatment on the recovery of gold from the gold concentrates by thiourea leaching. The changes in mineral phases by decomposition of pyrites in the gold concentrates using microwave were observed, and the result of microwave irradiation showed that the temperature of the irradiated sample increases with increasing irradiation time. With the reaction of temperature increases, Sulfur (S) in pyrites was converted to sulfur dioxide (SO2), and then the content of S in the sample was reduced. The analytical results of XRD and SEM-EDS showed that pyrites are converted to magnetite and hematite, and its surfaces are changed to a porous shape where micro-cracks are developed. The Au leaching efficiency from the irradiated gold concentrates using thiourea-mixed solvent increased with the increases of irradiation time and solvent concentration. The experimental results considering leaching parameters indicate that the mechanism of microwave irradiation increases the maximum leaching efficiency and leaching rate of the gold concentrates, and the solvent does a role for the increasing of leaching rate constant.
Keywords
microwave; invisible gold; pyrite; leaching; thiourea;
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