Mineral processing of nonferrous metals

Nikanorov A.V., Sedykh V.I., Polonsky S.B., Ershov P.R. Man-caused raw-material processing possibilities in column apparatuses with downward movement of pulp-air flow
The results of experimental-industrial tests are given for flotation in column apparatuses with downward movement of pulp-air flow of the man-caused raw material – carbon foam of the electrolysis production. Advantage of the apparatuses of this class is shown.

Extractive Metallurgy of Nonferrous Metals

Khasanov A.S., Sanakulov K.S., Atakhanov A.S. Process flow sheet of complex processing of slag from Almalyk Copper Smeltery
The current state in copper production at Almalyk Copper Smeltery is considered and a possibility to increase production indices with expanding the range of products manufactured is shown. Maximum use of the existing production potential and essential reduction of industrial discharges in the environment is planned.

Naboichenko S.S., Kharitidi E.Z. Dissolution of cobalt-bearing materials in presence of sulfur dioxide
Dissolution of a number of cobalt-containing materials, where cobalt is presented by oxide forms, in presence of sulfur dioxide was investigated. Consumption of SO₂, temperature, and dissolution duration were optimized. Determining effect of dissolved reaction gas concentration and hydrodynamic conditions in the system are mentioned.

Natorkhin M.I. Solubility of PbCl₂ in salt bath
Solubility of PbCl₂ in 38 % HCl was experimentally determined, and a formula enabling to calculate solubility of PbCl₂ was derived at HCl concentration from 0 to 38 % and temperature T = 0¸ 110 ° C.

Begunov A.I. The effect of anode width on metal loss in industrial electrolyzers to produce aluminum
Mass transfer in the metal/electrolyte phase boundary was studied using the physical model of vertical two-dimensional section of an electrolyzer in 1:1 scale. The Plexiglas made model was filled by liquids practically insoluble in each other: water (“metal”) and organic-silicon liquid PES-1 (“electrolyte”). Characteristics of mass transfer between metal and electrolyte were found by water concentration in PES-1 and on the basis of material balances of the system. Density of metal mass flow transferred into the electrolyte (J_m/f) is dependent of anode width (B) accurate within 15 %. The value of J_m/f » 0 at B » 0.6 m, almost coinciding with determining size of calcined anodes. Standing waves and metal emulsification into the electrolyte is practically lacking, ensuring achievement of the greatest current efficiency (94- 96 %) of metal.

Metallurgy of less-common and precious metals

Istomin V.Ya., Matyukha V.A., Mochalov Yu.S., Selikhovkin A.M., Smagin A.A., Kitler V.D., Naiborodenko Yu.S., Sergeeva E.G. A study of the composition and structure of products forming in interaction of selenium hexafluoride with copper
Composition and structure of condensed inorganic products of selenium hexafluoride to copper interaction have been studied by X-ray structure analysis and local microrentgenoscopy. Products with heterogeneous structure are a result of interaction of copper with selenium hexafluoride. They were established to contain copper compounds both with fluorine (CuF₂) and with selenium (Cu₂Se, CuSe, and CuSe₂). Formation of CuF₂ occurs with clearly marked faceting.

Ryabtsev A.D., Serikova L.A., Kotsupalo N.P., Vakhromeev A.G. Utilization of natural brines to produce lithium fluorides and lithium-containing fluorides for the purpose of applying them in electrolytic aluminum production
For the first time, lithium-containing brines of calcium-chloride type, being widespread in the south of the Siberian platform, are proposed to use for producing cheap fluorides enriched by lithium fluoride. Their application will allow us to have an effective additive to the electrolyte during aluminum electrolysis. The process developed to produce lithium-containing fluorides comprises selective extraction of lithium out of the brines using granulated sorbent on the basis of LiCl× 2Al(OH)_3× mH₂O and fluorination of obtained eluates enriched by lithium chloride. During fluorination of eluates of selective lithium sorption after their concentration, which contain as little as 40 g/l LiCl and impurities of magnesium and calcium chlorides, a mixture of fluorides (LiF, MgF₂, CaF₂) with LiF contained no less than 55 % was produced. Magnesium and calcium impurities removal from the eluates allows us to obtain lithium fluorides of high purity degree (to 90 %). Alkaline eluates (for example, LiCl and NaOH mixture) can be used for utilization of fluorine from waste electrolysis gases, reducing detrimental HF emissions into the atmosphere.

Casting Production

Pikunov M.V., Gerasimov S.P., Yudin V.A. On possible cause of the effect of aluminum impurity on the metal “growth” during crystallization of LTs16K4 silicon brass castings
An interrelation has been studied between hydrogen evolution during crystallization of LTs16K4 brass and contaminant content in the melt with Al₂O₃ oxide inclusions. A qualitative estimation of gas-evolving processes during solidification of the castings and the formed defects depending on the methods of saturation of the melt by hydrogen and changing the number of Al₂O₃ oxide inclusions in the melt. An analysis of the gas-evolving process during crystallization of hydrogen saturated binary copper-based alloys is given.

Znamensky L.G., Kulakov B.A., Ivochkina O.V. Application of electromagnetic-impulse treatment of molding materials and mixtures during investment casting
The results of theoretical and experimental studies of the processes of hydrolysis and polycondensation of binders and liquid glass electrodialysis under the effect of non-sinusoidal electromagnetic pulses are given. Techniques of preparation of ethyl-silicate and liquid-glass binders to produce high-quality nonferrous alloy castings have been developed on the basis of established relationships and mechanisms of running processes.

Metal Forming

Moroz B.S., Myuller K.B. An optimal version of equipment updating for extrusion with active friction
The paper analyzes technical possibilities of pressing plants for press forming under the conditions of active friction with two versions of drivers of their moving crossheads. The degree of using power possibilities of plant drivers with a movable and stationary container is estimated. The plant with the stationary container is shown to be more efficient with technological possibilities being equal. An example of optimal version of modernizing a horizontal hydraulic tube-profile press with force of 8,32 MN to press with active friction by means of equipping it with a supporting cylinder of the extrusion stem by force of 6,4 MN and the programmable system to control extrusion stem moving speed.

Sidelnikov S.B., Galiev R.I., Dovzhenko N.N. Experimental studies of forming and energy-power parameters of the process of joint rolling-extrusion of rods made of aluminum alloys
The results of the studies of a new joint rolling-extrusion process characterized by active friction forces for production of aluminum alloy rods are given. Metal forming features with joint rolling-extrusion method are described. The results of experimental studies to determine forces affecting rolls and die during deformation of a bar made of alloys of the Al–Ti–B system as well as AD1 and AD31 alloys are given. Dependences of sought quantities on such parameters as drawing, deformation rate, bar heating temperature, reduced diameter of rolls, etc have been found.

Physical Metallurgy and Heat Treatment

Belov N.A., Istomin-Kastrovsky V.V., Alabin A.N. The effect of zirconium on structure and mechanical properties of low alloys of the Al–Fe–Si system
Structure and mechanical properties of Al–Zr–Si system alloys containing 2 % Si and 1,2 % Zr have been studied. Solubility of zirconium in aluminum solid solution in the cast state is shown to be able to reach no less than 0,5 % with silicon content as little as 2 % inclusive. Little addition of silicon (beginning from 0,2 %) significantly accelerates strengthening of Al–Zr-alloys because of formation of Al₃Zr metastable phase during annealing. Rolling of cast ingots followed by annealing in alloys with 0,5 % Zr is shown to allow us to reach significantly greater strength as compared with industrial alloys of AA8111 types on the basis of the Al–Fe–Si system, as stipulated by keeping the unrecrystallized structure.

Elantsev A.V., Popov A.A., Demakov S.L., Elantseva E.V. The effect of thermomechanical treatment on structure and properties of granular aluminum alloy of the Al–Zn–Mg–Cu system
The effect of plastic deformation on the structure of the Al–Zn–Mg–Cu system alloy produced according to granular technology has been studied by electron microscopy, microdurometry, and thermal analysis. Deformation was made by rolling between heterogenization annealing and quenching. The effect of deformation degree and temperature heating conditions for quenching on change of structure and properties of the alloy has been studied. It is shown the positive effect of similar deformation on the complex of mechanical properties at the cost of significant size reduction of recrystallized grains (s = 880 MPa, d = 6 %).

Powder Materials and Coatings

Dorofeev Yu.G., Bezborodov E.N., Sergeenko S.N. Features of hot-deformed material formation on the basis of mechanochemically activated aluminum powder
An experimental-analytical dependence has been obtained describing the change of grain-size composition on duration of mechanochemical activation (MCA). The multistage character of particle agglomeration-dispersion process was found during MCA of aluminum powder. Times of formation of primary (0,25¸ 0,5 h) and secondary (3,0¸ 3,2 h) particle agglomerates during MCA were measured. It was established that the particles of average size no more than 300 m m are subject to agglomeration. The effect of the MCA conditions on formation of physical-mechanical properties of processed aluminum powder was studied. The effect of processing duration and average powder particle size on density and properties of hot-deformed powder material was found. Maximum shear strength is shown to be ensured in using highly-dispersed (d_av £ 63 m m) MCA-aluminum powders processed for 1 h.

Shlyapin S.D., Ilyin A.A., Kolachev B.A., Yagudin T.G. Mechanical alloying of powders for binders of diamond-containing composite materials
The results of studying some properties of different binders for diamond-containing composite material are given. A method of mechanical alloying to obtain binder of improved characteristics has been proposed. Based on the data of differential thermal analysis and study of compressibility of different powder compositions it is shown that proposed conditions of mechanical alloying of powder copper-tin mixture results in practically complete binding of elemental tin.

Surface engineering. Multifunction films. Corrosion and metal protection

Korznikova G.F., Aksyonov V.I., Korneva A.V., Korznikov A.V. Evolution of structure and microhardness in magnetically-hard alloy 25Kh15K during shear deformation under pressure
Evolution of the structure and microhardness of magnetically hard alloy 25Kh15K has been studied during shear deformation with different rotation angles in the Bridgemen anvils. Intensive plastic deformation of high-coercivity (a ₁ + a ₂)-state is shown to result in dissolution of a ₁-phase in the initial stage. Further increase in deformation degree gives rise in formation of the single-phase nanocrystalline structure with grain size of 50 nm. Dissolution of a ₁-phase in a ₂-matrix in the process of intensive plastic deformation stipulates increase in characteristics of strength and plasticity of 25Kh15K alloy with all studied deformation degrees.

Energy saving and environment protection

Nikiforov A.S. A study of the working conditions of electrodes in ore-thermal furnaces
The paper presents a procedure and the results of calculating the thermostressed condition of self-baking electrodes during their drying and heating. A ratio of maximum temperature stresses to differential temperature across the section of an electrode in the moment of reaching the maximum in the heating process is of interest.

Process Control and Automation

Malyshev V.P., Teleshev K.D., Nurmagambetova A.M., Ibishev K.S. Probabilistic models of static and dynamic strength of agglomerate
Application of probabilistic models of static and dynamic strength of agglomerate has been studied as to the yield of whole pieces. The models adequately describe the experimental data for agglomerate produced from chromium ore.