| Реферат: | eng: Wastes of the ore cyanide process are prone to oxidation and acid leaching that causemobilization,migration, and precipitation of elements, including noble metals. The issues ofwaste oxidation, aswell as release and transport of oxidation products, are of principal environmental concern and a focus of active geochemical research.We study the behavior of Au and Ag in the natural-industrial system 'sulfide wastes-surface/pore waters-particulate matter-bottom sediments' in the presence of different elements (Na, Mg, K, Ca, Al, Fe, Cu, Zn, Se, Ag, Au, Hg, Pb, REE, etc.), at the Novo-Ursk auriferous pyritic deposit (Salair, Kemerovo region, Russia). The wastes include processed primary ore (wastes I) and ore from the gold-bearing weathering profile (wastes II) that store, respectively, 0.5 ppm Au, 18 ppm Ag and 0.26 ppm Au, 13 ppm Ag. Gold in wastes I occurs in the native formwith Cu and Ag impurities and also Au exist as invisible species in pyrite. Inwastes II, gold is adsorbed onto the surfaces of secondary mineral particles (kaolinite,montmorillonite, hydromica, and Fe(III) compounds) while silver is an isomorphic impurity in alunite-jarosite minerals. The oxidation of wastes produces acid mine drainage (AMD) water, with pH = 1.9 and high concentrations of sulfate, Fe, Al, Cu, Zn, Pb, As, Se, Te, Hg, Cd and REE, which flows into the Ur River (a tributary of the Inya). The streamtransports gold and silver existing in dissolved+colloidal and particulate forms. Dissolved+colloidal gold and silver have similar distribution patterns with their contents inversely proportional to pH. Dissolved + colloidal gold in theAMDwater is more abundant than silver (0.4-1.2 ppb Au against 0.1-0.3 ppb Ag). Gold changes from the dissolved + colloidal (in AMD) to particulate (till 0.03 ppb) forms and precipitates in progressively larger amountswith distance from the tailings. Silver inmost of the analyzed natural and tailings-impactedwaters exists as suspended particles (to 1 ppb). The concentrations of gold and silver are the highest (1.8-2.1 ppb Au and 4.5-5.7 ppb Ag) in peat pore waters within the geochemical trains of the tailings, apparently as a result of re-precipitation on organic barriers. © 2015 Elsevier B.V.
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