Melnikov Research Institute for Comprehensive Exploitation of Mineral Resources, Russian Academy of Sciences, Moscow, Russia:

T. N. Matveeva, Head of Department, Doctor of Engineering Sciences, tmatveyeva@mail.ru
V. A. Chanturia, Chief Researcher, Academician of the Russian Academy of Sciences
N. K. Gromova, Researcher
L. B. Lantsova, Researcher

The article presents the experimental research results on development and testing of reagent regimes for fine gold recovery from tailings using new complexing collectors from the class of dithiocarbamates—modified diethyldithiocarbamate (DEDTCm) and dibutyldithiocarbamate (DBDTC). The currentness of new efficient domestic-manufacture agents consists if the feasibility of more complete recovery of gold and other noble metals at their reduced loss with tailings. The theoretical framework for the development of new reagent regimes for Au recovery from flotation tailings is high activity of dithiocarbamates relative to noble metals, with formation of stable compounds on the surface of Au-containing sulfide minerals—pyrite, arsenopyrite, chalcopyrite, as well as with generation of strong hydrophobic coating ensuring transition of these minerals to concentrate. The physicochemical effect of the flotation agents on micro- and nano-gold on the surface of sulfides is studied using original procedures of complexing of minerals containing invisible or submicron Au. The experimental tests of interaction between DEDTCm, DBDTC and the surface of Au-containing sulfide minerals using UV spectrophotometry, analytical scanning electron microscopy (LEO 1420VP INCA Oxford 350), laser microscopy (KEYENCE VK-9700) and X-ray phase analysis determined selective adsorption of DEDTCm and DBDTC components at micro- and nano-particles of Au. New data are obtained for the scientific validation of expediency of using complexing dithiocarbamate collectors for recovery of fine Au from flotation tailings of polymetal ores. The laboratory experiments with technological samples of polymetal ore flotation tailings find that application of DEDTCm and DBDTC raises the content of gold in concentrate by 2.5% at the increased recovery by 4.5%.
The study was supported by the Presidium of the Russian Academy of Sciences, Program No. 15.
The authors express their thanks to Candidates of Geologo-Mineralogical Sciences E. V. Koporulina and V. A. Minaev for the assistance in the experiments with scanning electron and laser microscopes.

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