Amur Scientific Center of Far East Division of Russian Academy of Sciences, Blagoveshchensk, Russia:

O. A. Ageev, Head of Department of Complex Use of Mineral Raw Materials and Innovation Developments, e-mail: vip.ageev2014@mail.ru

Institute of Chemistry of Far East Division of Russian Academy of Sciences, Vladivostok, Russia:

M. A. Medkov, Head of Laboratory of Processing of Mineral Raw Materials, e-mail: medkov@ich.dvo.ru

S. I. Ivannikov, Junior Researcher, Laboratory of Sorption Processes

A. A. Yudakov, Deputy Executive Officer on Scientific Work and Innovations (Engineering-Technological Center)

ammonium thiosulfate leaching method, which allows to extract up to 97% of gold in solution: 0.1 mol/l of sodium thiosulfate; 0.2 mol/l of aqueous solution of ammonia; 0.015 mol/l of copper sulfate; pH = 10.4, L:S = 1:2. Anion-exchange resin AB-17 showed the best results in gold precipitation from solution leaching. Extraction rate without adjustment of pH at L:S = 1:100 reached 95%. The optimum composition of leaching solution for thiocarbamide leaching method, allowing to extract up to 93% of gold in solution, was established: 30 g/l of thiocarbamide; 10 g/l of sulfuric acid; 2 g/l of ferric chloride; 20 g/l of peroxodisulfate ammonium; L:S = 1:3. Method of electrochemical deposition on carbon fiber cathode showed the best results during the gold precipitation from leaching solution. Graphite rod was used as shunt. Efficiency of gold extraction on carbon material from leaching solution reached 95%, at the current density of 300 A/m². 

This work was carried out with the financial support of the Ministry of Education and Science of Russian Federation (agreement No. 02. G25.31.0035) and the grant of the Presidium of Far East Division of Russian Academy of Sciences (project No. 15-I-3-014).

This work was carried out with the financial support of the Ministry of Education and Science of Russian Federation (agreement No. 14.578.21.0015 of June 05, 2014. Unique identifier of the agreement is RFMEFI57814X0015).

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