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Yekaterinburg, Russia

Nevidimov V.N.,Ural Federal University | Vatolin A.N.,Ural Federal University | Korolev A.A.,JSC Uralelectromed
Tsvetnye Metally | Year: 2014

An experimental study of viscosity and electrical conductivity was carried out on oxide melts, containing silicon oxides and lead. An oscillating viscometer and alternating current method were applied for measurement of viscosity and electrical conductivity respectively. Viscosity and conductivity depend on composition and temperature. Evidence of the dependence of physical and chemical properties on temperature in silicate melts was described. Viscosity is decreased with increasing of basicity and iron content in slag. Viscosity decreasing can be reached both by increasing of slag basicity and by increasing of iron content in slag. However, concentration of iron and calcium oxide in slag should be varied within a definite range. There was obtained the value of the ratio (CaO + FeO)/SiO2, corresponding to minimal losses of gold and silver with slag. The ratio (CaO + FeO)/SiO2 is recommended to be hold in the range of 0.25-0.30. The ratio (CaO + FeO)/SiO2 needs the determined value in order to sustain minimal losses of gold and silver with the slag. Increase in electrical conductivity is caused by additions of aluminum and calcium oxides. Recommendations on composition of reflective copper smelting slag are given for reduction of gold and silver losses.

Gromov O.G.,RAS Institute of Chemistry | Savel'ev Yu.A.,RAS Institute of Chemistry | Kunshina G.B.,RAS Institute of Chemistry | Lokshin E.P.,RAS Institute of Chemistry | And 2 more authors.
Russian Journal of Applied Chemistry | Year: 2013

The decomposition of silver selenide and sulfide to metallic silver and chalcogen containing oxygen compounds by sintering with an equimolar mixture of sodium nitrate and nitrite was examined. It was found that 100% recovery of silver in a metal phase is reached at 5% excess of sodium nitrate and nitrite and a time of the isothermal exposure at 375 °C 1 hour or half an hour at 400°C. © 2013 Pleiades Publishing, Ltd.

Mastyugin S.A.,JSC Uralelectromed | Lastochkina M.A.,LLC Institute Gipronikel | Naboychenko S.S.,Ural Federal University | Voinkov R.S.,JSC Uralelectromed
Tsvetnye Metally | Year: 2014

Earlier developed technology of processing of copper-electrolyte slime of JSC "Uralelektromed" ("autoclave copper extraction - flotation") allows its 4-4.5 times enriching with regard to gold, silver and selenium content, and removing about 70% of lead and antimony, contained in slime, into flotation tails. More thorough admixtures removing is restricted by structural composition of slime. Spherical particles of silver selenide with dimensions of 4-10 μm, containing lead and antimony oxides, do not allow to divide these components in flotation time. Ultra-fine crushing processes in planetary and bead mills were studied for the following operations: destruction of spheroids; fuller division of chalcogenide and oxide components of slime; decrease of precious metal losses, conditioned by their removing with flotation tails. Various process products were tested for crushing: initial slime, autoclave leaching cake, primary float concentrate and its re-cleaning products. Application of bead crushing for treatment of III re-purification concentrate, with small amount of acidcontaining phases, gives the best results on milling fineness and subsequent flotation efficiency. Minimum transfer of precious metals into flotation tails (less than 3%) and minimum transfer of selenium into autoclave leaching solution (about 0.5%) provide deriving of float concentrate, containing up to 0.37% of lead, 0.53% of antimony, over 65% of silver and 25% of selenium. Flotation tails contain over 40% of lead and about 20% of antimony with 98.3 and 90.4% of these metals yield to the product, correspondingly. During the flotation modes testing, there was found out that liquid glass improves the process efficiency as oxide compounds depressor. Besides, there were closed some issues, related to water balance while product flotation treatment after crushing.

Lobanov V.G.,Ural Federal University | Mastyugin S.A.,JSC Uralelectromed | Voinkov R.S.,JSC Uralelectromed | Korolev A.A.,JSC Uralelectromed | Naboychenko S.S.,Ural Federal University
Tsvetnye Metally | Year: 2014

The article is devoted to the problem of hydrometallurgical processing of copper-electrolyte slime. It describes principal peculiarities of hydrometallurgical technologies. The article presents the data on pressure leaching of slime with subsequent flotation generation of chalcogenide-based concentrates and, first of all, generation of silver selenide. Lead sulfate is the main component, participating in tails flotation. The article specifies advantages and disadvantages of known methods of hydrometallurgical break-down of chalcogenide and oxide phase. Oxidation leaching of float concentrate in acid and alkaline medium is complicated due to low solvability of silver selenide, conditioned by formation of intermediate hardly soluble products that passivate the surface of concentrate particles. Thermodynamic analysis demonstrates the possibility of silver selenide recovering leaching. The distinguishing feature of such process is silver transfer into metallic phase. Selenium in this case is passed into solution in sodium selenide form. Besides, this article analyses some reagent options of the foregoing process, whereupon conclusions on advantages of soluble reducing agents were made. The carried out test experiments proved the possibility and prospect viability of selenium reducing leaching in leach solutions from decoppered slime and float concentrate. The carried out experiments proved the possibility of lead leaching from slimes with the help of industrial complexing agents. Economic efficiency of the given approach is conditioned by regeneration of leaching solutions with deriving of lead as commodity product.

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