Institute of Mining, Far Eastern Branch, Russian Academy of Sciences, Khabarovsk, Russia

V. S. Alekseev, Leading Researcher, Candidate of Engineering Sciences, Alekseev.igd.khv@mail.ru
R. S. Seryi, Leading Researcher, Candidate of Engineering Sciences
T. S. Banshchikova, Senior Researcher

At present, resources of placer gold mining are almost depleted, and easy of approach deposits are almost completely mined out. Therefore, placers located in difficult subsurface conditions and in hard-to-reach areas with no infrastructure are increasingly involved in operation. The sands of such deposits contain a significant amount of heavy minerals and clay particles. Often, development of such deposits is associated with excess losses, which significantly reduces the profitability of their operation. On the basis of many years of experience, the Mining Institute оf the Far Eastern Branch of the Russian Academy of Sciences has developed a comprehensive method for studying the efficiency of sluice boxes, dredges and bullion gold-concentrating plants, especially in terms of extraction of fine-grained gold, including: mineral analysis, study of gold surface by electron microscopy, determination of content of gravitationally recoverable gold, study of morphological parameters of gold particles, identification of accessory minerals, analysis of technological parameters of washing apparatus, development and implementation of recommendations for increasing gold recovery. The use of this method allows: determining gold loss and the loss causes; developing methods to ensure complete recovery of gold of all sizes, including fine-grained gold; substantiating sand processing and concentrate beneficiation flowsheet; increasing resources of placer gold mining through the development of substandard manmade placers, silt-detention basins and tailings dams.
The study was supported by the Russian Science Foundation, Grant No. 24-17-20026, https://rscf.ru/project/24-17-20026/.
The mineral analysis, electron microscopy and gravity concentration were carried out at the Shared-Use Mineral Research Center at the Khabarovsk Federal Research Center, Far Eastern Branch, Russian Academy of Sciences.

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