Khabarovsk Federal Research Center, Far East Branch, Russian Academy of Sciences, Khabarovsk, Russia:

Rasskazova A. V., Senior Researcher, Candidate of Engineering Sciences
Sekisov A. G., Acting Director, Doctor of Engineering Sciences, sekisovag@mail.ru
Kirilchuk A. G., Post-Graduate Student

Far Eastern Federal University, Vladivostok, Russia:

Vasyanovich Yu. A., Professor, Doctor of Engineering Sciences

The article emphasizes the urgent need of heap leaching in the current geotechnical conditions. The application prospects for heap leaching are connected with preliminary oxidation of refractory ore. Another important requirement is geo-engineering typification of ore through geotechnical mapping. An alternative of cyanide in gold leaching is chlorine compounds. The article describes the theory of formation of active chlorine–oxygen complexes using electrochemical and photochemical effects. Iron acts as a catalyst of gold complexing by means of change in the oxidation rate +3/+2. The tests of agitation leaching are carried out on oxidized copper–porphyry–gold ore from the Malmyzh deposit. Efficiency of the best reagent scheme is proved by the results of percolation leaching. The laboratory experiment included primary processing of ore in peroxide–sulfuric solution prepared by electrochemical and photochemical treatment. After diffusion oxidation during ageing of treated samples for three days, the samples were irrigated with active hypochlorite–chloride solution for 15 days. The experiment proved recoverability of gold at a rate of 92–93% and copper at a rate of 55–60% without capital input and at minimized operating cost. The new-developed circuit of heap leaching includes layer-by-layer stockpiling. Selectivity of heap leaching is ensured by treatment of layers of qualitatively different ore types and grades by solutions of different reagents, at certain concentrations and in certain hydrodynamic modes of irrigation.

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