Promising geotechnologies for gold placer mining in Eastern Transbaikalia

Abstract

The Transbaikal Region holds a large stockpile of gold reserves in placers. Gold placers differ in structural tectonics, morphology and parameters of productive strata, their specific mineralogical and geochemical composition, grain-size composition and shape of gold grains, roundness and fineness of gold particles, etc. The drop in the gold content and thickness of productive sand at placers being currently mined necessitates studying refractory gold, including encapsulated, dispersed and chemically bound gold. This article discusses new patent-protected methods for identifying nanoscale gold. New geotechnologies for gold extraction from placer sands using solutions with active chloride complexes pumped into productive formations via wells are presented. Alongside with pumping out pregnant solutions, it is proposed to use the electro-diffusion deposition of dissolved gold from a conventionally immobilized pore solution onto ion-exchange resins placed together with submersible cathodes in wells. The authors express their gratitude to Professors A. I. Trubachev, V. S. Salikhov, Yu. I. Rubtsov and Cand.Eng.Sci. Yu. S. Shevchenko from the Chita Division of the Institute of Mining, SB RAS, and to Cand.Eng. Sci. N. V. Zykov, Director of the Transbaikalia Mining College, for their help in the pilot trials of the electro-diffusion leaching technology. The studies were carried out using the scientific lab equipment and instruments of the Center for Processing and Storage of Scientific Data of the Far Eastern Branch of the Russian Academy of Sciences, supported by the Ministry of Science and Higher Education of Russia under Agreement No. 075-15-2021-663. The production research and chemical analyses were implemented at the Center of Mineralogical Research of the Khabarovsk Research Center, Far Eastern Branch of RAS.