National Mineral Resources University, Saint Petersburg, Russia:

F. D. Zolotarev, Post-Graduate Student (Mineral Concentration Chair), e-mail: fzolot@mail.ru
T. N. Aleksandrova, Head of Mineral Concentration Chair
I. T. Zhadovskiy, Assistant (Chair of General and Physical Chemistry

JSC “Irgiredmet”, Irkutsk, Russia:
A. V. Bogorodskiy, Senior Researcher

Gold recovery from technological refractory raw materials can be considered as one of the most urgent problems of modern gold mining industry. A pressure oxidation technology (which exploitation is rather expensive) is used for the processing of refractory sulfide gold-bearing ores. Intensification and increasing of this method efficiency are the urgent tasks for the researchers from the whole world. Using the halide-ion containing noble metal solvents in pressure oxidation process is one of prospective ways of hydrometallurgical processing of refractory sulfide gold-bearing raw materials. Researches were carried out using sulfide flotation concentrate of one of Amur Oblast deposits. Basically, sulfide minerals of researched flotation concentrate are shown by pyrite and arsenopyrite. Gold content is 38.6 g/t, while silver content is 61.2 g/t. NaCl was used in one of two experiment sets as a halide source, while oxidated material was cyanated. Leaching time of pressure leaching cake with addition of halide-ion was reduced from 25 to 2 hours. Reagent consumption was also reduced by almost 2 times. These factors make a significant influence on capital and exploitation costs during the processing of refractory gold-bearing materials with similar chemical and mineral composition. Experimental data were processed by mathematical statistics methods. Regression analysis was carried out with obtaining of equations of cyanation kinetics of pressure oxidation cakes, which can be used for further forecasting of leaching process.
This work was carried out within the State Task No.5.1284.2014/К.

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