Extractive metallurgy of nonferrous metals

Tomina V.N., Khrennikov A.A., Lebed A.B., Naboichenko S.S. Heap leaching of copper from ore of the “Volkovskoe” deposit
Heap leaching of oxidized, mixed, and dump copper ores from the “Volkovskoe” deposit is considered. Based on the investigation results, preliminary granulation of crushed ore with sulfuric acid (2575 kg/t ore) is recommended. Introduction of this operation results in reduction of the leaching duration by 15–30 % and allows production of more concentrated solution by copper. Extraction of copper into the solution for 90–100 days amounted to 65?72 % from dump ore, 76–78 % from oxidized ore, and 46?50 % from mixed ore. Increase of leaching duration results in raising copper extraction from all ore types.
Key words: copper ore, hydrometallurgy, fine crushing, granulation, heap leaching, extraction.

Vasiliev E.A., Darintseva A.B., Naboichenko S.S. Experimental investigations of indium cementation
The contactdeposited indium precipitate growth dynamics results and its structural characteristics variation in time to allow reasonably to approach to selection of the indium cementation parameters and predict the properties of obtained powder are given. Using mathematical description of the dynamics of this process and taking the accompanying reduction of hydrogen ions into account, the effect of different factors on the rate and structural parameters of dendritic precipitates has been studied. The experimental data and results of model analysis have promoted to estimate the important characteristics of the cementation process: optimal conditions; distribution of precipitates by dendrite tip radiuses connected with grainsize distribution of produced powder; density of growing dendrite tip array affecting the dendritic structure of produced precipitates.
Key words: indium, cementation, sulfate solution, properties of precipitates, dendritic structure of precipitates, dynamic model.

Mukhetdinova A.V., Bychinsky V.A., Tupitsyn A.A., Finkelshtein A.L. Improvement of alumina determination technique in electrolyte
A procedure of determination of mass portion of alumina in electrolytes containing additives of magnesium fluoride has been developed to improve the reliability of the chemicalanalytical data on the base of which the process of electrolytic aluminum production is controlled. A physicalchemical model is presented to determine the content and forms of elements in solution, solid phases, and gas products that are produced in interaction of electrolyte with water solution of aluminum chloride. An example is given to use the physicalchemical model as a matching method of chemicalanalytical data as well as checking the accuracy of determination of mass portion of alumina in electrolyte by leaching technique.
Key words: alumina, electrolyte, physicalchemical model, “Selector” bundled software, aluminum production.

Pogodaev A.M., Proshkin A.V., Polyakov P.V., Shimansky A.F., Yakimov I.S., Yarosh I.A. Processes in refractory materials of cathode assembly of electrolyzers for aluminum production
The failure of barrier (refractory) materials is the main reason of aluminum producing electrolyzer shuttingdown. Finding the main regularities of fluoride salt and barrier material interaction among numerous possible ones is an objective of this work. The thermodynamic analysis of the processes running in refractory materials of the cathode assembly of electrolyzers as well as the results of Xray phase analysis of refractory fragments made it possible to determine the primary mechanism of their failure, the mechanism being contained in running gasphase reactions. Based on it, recommendations were developed to prolong the life of barrier materials of aluminum producing electrolyzers.
Key words: processes in refractory materials, sodium penetration, aluminum electrolysis, cathode assembly of electrolyzer, barrier materials.

Tuzhilin A.S., Lainer Yu.A., Surova L.M., Surov V.N. Alkaliacidic method of aluminum chip processing with producing aluminum hydroxochloride
Investigations have been carried out of the process to produce coagulating agent: aluminum hydroxochloride from aluminum chip by alkaliacidic method according to which the main part of impurities being in the starting raw material is separated during filtration of produced aluminate solution. Reagent for removal of lube oils, petroleum products, and coolantcutting fluid from the aluminum chip surface was chosen. Proposed is a process flow diagram of the coagulating agent production by alkaliacidic method that allows obtaining coagulating agent with minimum content of impurities with simultaneous chlorine emission for water sterilization and sodium hydroxide for alkali dissolution of aluminum chip.
Key words: coagulating agent, aluminum hydroxochloride, aluminum chip.

Perekhoda S.P., Lainer Yu.A. Investigation of scientific bases and development of complex spent hydrotreatment catalyst processing procedure
Physicalchemical principles of complex processing of spent hydrotreatment catalysts have been experimentally investigated: kinetics and mechanism of dissolution of Mo(VI) oxide from spent catalyst have been studied in water solutions of mineral acids and sodium carbonate with the use of models of formal heterogeneous kinetics for the purpose of selection of reagent and leaching conditions; behavior of the main components of the system has been determined in sintering of alumina residual with sodium carbonate, and the optimal conditions on the basis of thermodynamic simulation of sintering with the use of “Astra” software complex have been selected. A process flow diagram of industrial processing of spent hydrotreatment catalysts with obtaining ammonium paramolybdate, alumina, or coagulants has been developed.
Key words: spent hydrotreatment catalysts, molybdenum (VI) oxide dissolution kinetics, aluminate solution, ammonium paramolybdate, coagulants for cleaning drink and drain waters.

Extractive metallurgy of less-common and precious metals

Bataev Ya.S., Zaikov Yu.P., Lokhmotko Yu.A., Polovov I.B., Rebrin O.I., Chuikin A.Yu., Yamshchikov L.F. Hafnium dioxide chlorination with gaseous chlorine over carbon
Thermodynamic simulation of hafnium oxide chlorination processes with gas chlorine over carbon at T = 450?1000 °С has been carried out. The primary products are shown to be gaseous hafnium tetrachloride, carbon mono and dioxide, CO partial pressure increasing and that of CO₂ decreasing when temperature raises. The variations of enthalpy, entropy, and Gibbs energy of chlorination reactions have been calculated as well as the composition of gas phase under the conditions of thermodynamic equilibrium has been determined. It is found in the course of studying HfO₂ chlorination reaction kinetics over carbon in a range of T = 600950 °С that its limiting stage is dependant on the process temperature: its rate below 700 °С is restricted by chemical reaction on the surface of nonporous solid spherical particles of body with formation of volatile product and above 700 °С its rate is restricted by mass transfer of gas substances.
Key words: hafnium oxide, chlorination, kinetics, thermodynamics, hafnium tetrachloride.

Upolovnikova A.G., Udoeva L.Yu., Chumarev V.M. Investigation of oxidized Nb–Alfume leaching process
Sulfuricacid leaching of oxidizing roastingsintering of fumes in the course of electronbeam remelting of niobium with sodium carbonate has been investigated by design of experiments. The possibility of Nb concentration in solid phase at the cost of transferring accompanying elements (Al, Fe, Cr, Si) into solution is considered. Multifactorial mathematical models of sulfuricacid leaching are constructed, the kinetic parameters of process are determined on the basis of which the conditions of production of niobium chemical concentrate suitable for crude metal smelting are optimized.
Key words: niobiumaluminum fumes, sinter, leaching, mathematical model of process, kinetics.

Materials science and heat treatment

Belov N.A., Alabin A.N., Karacharova E.G., Yemelina N.B. On expediency of silumin alloying with titanium and zirconium additives
Using the Thermo–Calc program package, isothermal and polythermal sections of the Al–Si–Zr and Al–Si–Ti diagrams have been plotted and analyzed. Calculation and experimental techniques were used to plot liquidus lines for the given systems for 5 and 10 % Si in content. Titanium and zirconium additives are shown to heavily raise the liquidus, as requiring the melting and casting temperature increase as compared with the customary conditions for silumins. Nonoptimality of the compositions of a series of grade silumins (in particular АК8М3ч, АК8л, АК8М, АЛ4М & В124) admitting as many as 0,3 % Ti and as many as 0,2 % Zr is substantiated.
Key words: multicomponent phase diagrams, aluminum alloys, modification of aluminum solid solution, microstructure.

Metal forming

Seledkin E.M., Kukhar V.D., Tsepin M.A. , Apatov K.Yu. Calculation of reversing gas molding of hollow sheet shells powder materials and coatings
A finite element scheme has been developed for calculation of transferring reversing gas molding with the use of a special movable die or an insert in die body permitting the sheet domeshaped shell wall unevengauge reduction by braking and strain redistribution in the prescribed direction.
Key words: metal forming, stamping, superplasticity, reversing gas molding, computeraided engineering, finiteelement method.

Powder materials and coatings

Simonov Yu.A., Kritsky A.A., Rychkov V.N., Tomashov V.A. Investigation of associated zirconium and silicon dioxides processing with water solution of ammonium fluoride
Zirconium dioxide extraction process from dissociated zircon (associated ZrO₂ and SiO₂ mixture) by processing with water solution of ammonium fluoride has been studied. Based on laboratory investigations, ZrO₂ solubility and effectiveness of its SiO₂ scrubbing in water solution of ammonium fluoride have been determined depending on its concentration, excess F^–ion content, and processing temperature. The optimal conditions of commercial zirconium dioxide extraction are found.
Key words: carbon loam, cake, dissociated zircon, associated dioxides mixture, zirconium dioxide, silicon dioxide, ammonium fluoride, concentration , excess, solubility.

Economics and management

Naumov A.V., Naumova M.A. On current state of world lithium market
A survey of world’s lithium market development is made. Postcrisis perspectives are under consideration. The current state and development prospects of Russian lithium industry are analyzed.
Key words: Li minerals, brines, demand, proposal, production capacity, postcrisis prospects