Nonferrous ore concentration

Yevdokimov S.I., Panshin A.M. Development of efficient aftertreatment process for goldcontaining gravioconcentrates
The closedcycle skimping technology has been tested and optimized at one of industrial gold mining areas during gravitation concentrate aftertreatment with using PGShOK502 sprinkler. The regression equation has been derived that adequately describes the dependence of Goden selectivity rate on the stroke and frequency of cone oscillation, specific underscreen water consumption, and height of artificial bed under such an operation. As it is found, in increasing Au content in the starting product, to which the closed skimping cycle is related, its recovery into concentrate () comes up as well. The effect of deck frequency and stroke as well as the angle of its lateral tilt angle in optimizing the shaking table operation. Tailings from all apparatuses, used for final concentration of gravioconcentrates, are retreated by column flotation before removal into dump. Its kinetics has been investigated for gold grains of various sizes. As a result optimization of operation of MOD0,2 skimping machine and SKO0,5 shaking table, metal extraction from crude concentrate into the product meeting the requirements of refining (> 92 % of placer gold) is increased by 1,4–1,7 % and amounts to  98 %. Increase in skimping machine output at the cost of using the closedcycle skimping process and stable operation of shaking table provides for increase in productivity of the skimping workshop section of the schlichdressing plant as a whole.
Key words: crushed gold ore, skimping, closed cycle, table concentration, optimal conditions, column flotation.

Ignatkina V.A. Investigation of copper cation sedimentation process with sulfhydryl collectors
The processes of copper cations sedimentation with diethyldithiocarbamate, (ethyl and butyl) xanthogenates, and isobutyl dithiophosphate have been investigated by potentiometric and optical methods. Minimum potential of copper electrode (ECu) during sedimentation conform well with solubility product (SP) and forms the following row: copper diethyldithiocarbamate (ECu = –335 mV, SP = 2,8·10–30) > butyl xanthogenate (ECu = –225 mV, SP 10–26) > ethyl xanthogenate (ECu = –163 mV, SP = 4·10–24) > isobutyl dithiophosphate (ECu = –60 mV, SP  10–18). Visible associates of precipitate particles are observed in all investigated sulfhydryl collectors (xanthogenates, dithiocarbamates, dithiophosphates) with ethyl group of hydrocarbon radical. Butyl xanthogenate and isobutyl dithiophosphate form colloid precipitates with copper cations.
Key words: flotation, sulfhydryl collectors, cations, copper, electrode potential, precipitate, solubility product, adhesion, selectivity.

Extractive metallurgy of nonferrous metals

Naguman P.N., Karimova L.M., Tokaeva Z.M., Shinbaeva U.B. Multifactor simulation of oxidized molybdenum product leaching process in sulfuric solutions
The process of molybdenum extraction into solution under roasting of pure materials has been investigated by the mathematical experiment planning method. Particular and generalized functions of molybdenum extraction ratio into solution have been obtained according to Protodiyakonov equation, which has been corrected inclusive of the restrictions by reacting degree (no more than 100 %) by introduction in exponent. The activation energy was calculated. Diffusion is shown to be a limiting stage.
Key words: mathematical planning, multifactor models, molybdenum, roasting, leaching.

Malyshev V.P., Kazhikenova S.Sh., Turdukozhaeva A.M. Qualitative and quantitative estimate of processes in metallurgy of nonferrous metals
The work suggests a formula for calculating the complex indeterminacy of a group of technological operations to be analyzed before and after their improvement, as well as technological schemes as a whole in the information units. The formula allows us to find the predictability and technological reliability of the operations.
Key words: entropy, extraction operation, information estimate of product quality or technological operations, complex uncertainty.

Vasyunina N.V., Vasyunina I.P., Mikhalev Yu.G., Vinogradov A.M. Alumina solubility and dissolution rate in acidic aluminacryolite melts
Alumina dissolution rate (v) in aluminacryolite melts with cryolite ratio (CR) lower than 2,1 has been estimated to determine an opportunity of further increase in AlF3 concentration in industrial electrolytes for the purpose of the current yield in the modern electrolyzers. The v value was found by electrochemical technique based on measurement of equilibrium EMF of the concentration cell after loading an alumina batch into the melt. Decrease of CR < 2,1 is found to result in significant drop in solubility of alumina and its dissolution rate. According to the dependence of v value on the alumina content in the melt, the predominant stages are shown to be the mass and heat transfer processes.
Key words: electrolytic production of aluminum, lowtemperature electrolytes, acidic aluminacryolite melts, alumina solubility, alumina dissolution rate, electrochemical technique.

Mukhetdinova A.V., Bychinsky V.A., Tupitsyn A.A., Finkelshtein A.L. Investigation of electrolytes for aluminum production with physicalchemical simulation
Physicalchemical simulation of electrolyte melting process has been carried out for the purpose of the development of testing technique for impurity element content. A physicalchemical model has been tested that allows cutting time and expenses for chemicalanalytical investigations of the properties of aluminum bath electrolyte to be necessary for stable conduct of electrolysis process. A possibility of determining the phase composition of the main components and impurity elements in the electrolyte, which are formed in the process of carrying out analytical procedures at the melting, evaporation, and solidification stages, is shown.
Key words: chemicalanalytical investigations, fluorides, phase composition, physicalchemical simulation.

Extractive metallurgy of less-common and precious metals

Strizhko L.S., Normurotov R.I., Kholikulov D.B. Investigation of gold recovery from goldcontaining magnetic fraction by chlorization
The perspective of chloride volatilization in the technology of mineral raw materials arises from high chemical activity of chlorine providing the fullness and complexity of precious component recovery from the starting raw materials. The process is of very important for rebellious materials the processing of which by other methods is hard and inefficient. There is the necessity for oxidizing roasting of Aucontaining magnetic fraction; its process parameters are determined. Chlorinating agent for chloride volatilization of gold is selected from the results of analyses. The interacting rate of gold with gas chlorine is found to be higher than in using solid chlorides or HCl. The temperature and process duration dependences of Au extraction during chloride volatilization are given.
Key words: gold, processing, extraction, magnetic fraction, chlorization, chlorination, chloride volatilization, temperature, oxidizing roasting, phase, sublimates, volatility, chlorides.

Medvedev A.S., Aleksandrov P.V. Pilot trials of processing lowgrade molybdenite concentrate by nitric method
The trial experiments have been carried out to process lowgrade molybdenum concentrate of the Bugdainsky deposit by nitric method. Leaching conditions (S : L ratio, reagent concentration, process duration and temperature) are optimized. Molybdenum recovery from the starting concentrate into solution exceeds 95 % under the optimal conditions, and the throughout recovery from ore into commercial product is at the level of 85–86 %. As the kinetics shows, the concentrate decomposition by nitric acid proceeds in the kinetic mode in the initial time. The addition of sulfuric acid into the solution speeds up the process.
Key words: molybdenite concentrate, processing, nitricacid process.

Materials science and heat treatment

Belov N.A., Alabin A.N., Prokhorov A.Yu. The effect of zirconium addition on strength and electric resistance of coldrolled aluminum sheets
The effect of Zr additive in amount of 0,3–0,6 mas.% and annealing modes on electric resistance and mechanical properties of coldrolled sheets produced from cast ingots based on A7E grade commercial aluminum has been studied. All Zrcontaining alloys are shown to hold strain hardening after 1hour annealing at 300 °С unlike unalloyed aluminum. The mechanical properties rise when Zr concentration increases, as connected with combining two effects: straining and dispersing ones. It is found that, when Zr content increases, electric resistance of coldrolled sheets grows essentially but after annealing the characteristic is determined first of all by zirconium concentration in aluminum solid solution and depends on the heat treatment parameters.
Key words: low aluminum alloys, dispersoids, conductance.

Powder materials and coatings

Yermilov A.G., Bogatyreva E.V., Sviridova Т.А. Composition and parameters of tungstencontaining nanocrystalline structures of organometallic compounds
The effect of temperature and dilution of tungstencontaining organometallic compounds by triethanolamine on the phase composition and phase structure formed during thermal destruction of the mixtures has been analyzed. The optimal parameters of dilution to provide maximum use of carbon from organometallic compound for tungsten carburization are determinaed.
Key words: organometallic compound, tungsten carbides, nanocrystalline structure, lattice constants, microdeformation, Xray crystallography, thermal destruction.

Surface engineering. Multifunctional films. Corrosion and metal protection

Pogrelyuk I.N., Tkachuk O.V., Proskurnyak R.V. Corrosiveelectrochemical behavior of PT7M titanium alloys after oxynitriding
The corrosiveelectrochemical behavior of PT7М titanium alloy after oxynitriding has been investigated in 0,9 % aqueous solution of sodium chloride. Oxynitriding was carried out by the oxygen modification of nitride layer formed at the thermaldiffusive saturation in the molecular nitrogen atmosphere. It is established that the protective properties of alloy are determined by quantitative ratio of oxynitride and oxide phases in the surface modified layer. It is shown that with the increase of oxynitride phase content in surface layer and decrease of oxygen component in its composition the anticorrosive characteristics of alloy’s surface are improved.
Key words: PT7М titanium alloy, oxynitriding, thermaldiffusive saturation, sodium chloride.

Process control and automation

Strizhko L.S., Loleit S.I., Novakovskaya A.O. Dynamic model ofsilver biosorption process
The work is important in designing the system to control hydrometallurgical processes, in particular the sorption and biosorption processes. It analyzes the kinetics of silver biosorption from secondary process solutions. Decomposition of the service capacity of the unit is executed according to the peculiarities of the running processes. The dynamic model in the form of usual parametric differential equations describes the variations of the starting substances in circulating solutions and the filling of sorption capacity of biosorbents. The presented structuremodel assumes realizing the procedure of numerical solution of the simultaneous equations with the RungeKutta method. The calculation of nonlinearities of the model is made in a separate section that specifies the approximation of variables by the values of the variables from previous iteration.
Key words: biosorption, desorption, reactions, flow rate, concentration.

Chronicle

International scientificpractical conference “Metallurgy of nonferrous metals. Problems and prospects”