Mineral Processing of nonferrous metals

Pavlenko S.I., Ni L.P., Laktionova V.I., Selezneva M.A. Extraction of aluminum oxide from ashes of the Kuzbass Heat Power Plant
A non-lime technology was developed for extraction and enrichment of high-siliceous alumina by hydrochemical technique with the use of alkaline solution. Solid residuum as a result of chemical enrichment represents a product, which can be processed into alumina. Al₂O₃ content in the middlings is up to 42-50 % (with 25-28 % in starting raw material). The concentrate enriched by Al can be processed by sintering or hydrochemical technique. It is proposed that silicoalkaline solution from the chemical enrichment can be processed into silicate products (cement, zeolite, silicate glass, soda ash).

Zubareva G.I., Nasrtdinova T.Yu. Flotation extraction of chromium (VI) compound from aqueous solution
An opportunity in principle has been established to apply cationic trialkyl hydrazine chloride collector of general formula [(CH₃)₂C_nH_2n+1NNH₂]⁺Cl^– (n = 12-14) for flotation extraction of chromium (VI) compound from aqueous solution. Optimum conditions of flotation of chromium (VI) were determined: pH = 0-4, duration of flotation 15 min, [Cr(VI)]:[SAS]=1:1. An ion-exchange mechanism of interaction between chromium (VI) compound and cationic SAS in the aqueous solution in flotation extraction of metal and probable composition of floatable sublate are proposed.

Metallurgy of less-common and precious metals

Golounin A.V., Pashkov G.L., Zakharova O.V. Extractants of metals from aqueous alkali solutions
Data related to the use of organic substances to extract metals from aqueous alkaline solutions are given. Phenols with ortho-substituents, which contain sulfur, nitrogen, or oxygen atoms have the most extractive ability. The micella generation accompanying the extraction from alkaline solutions can be inhibited if the extraction process is carried out in the presence of quarternary ammonium bases (salts) or if the extractants are used along with amine-alkyl-substituents.

Rychkov V.N., Pakholkov V.S. Sorption of zirconium from chloride solutions by polyampholytes
The estimated and experimental data for sorption of zirconium ions from chloride solutions by aminocarboxylic and aminophosphate ampholytes are analyzed. Zirconium in chloride solutions is shown to form a whole series of complex (chloride, hydroxo-, and mixed hydroxochloride) ions. The major reactions of the processes proceeding in the solutions and concerned analytical dependences are given. The equilibrium of zirconium ions in the course of their sorption from chloride solutions has been studied. The behavior of zirconium ions from hydrochloric solutions in a wide range of concentrations is explained from the point of view of ionic state of metal in the solution and the structure and functional features of ionites.

Gasanaliev A.M., Salmanova S.D., Gamataeva B.Yu. Phase diagram of the Li₂WO₄-Na₂WO₄- CaWO₄- SrWO₄ quaternary system
A quaternary system of alkali and alkaline earth metal tungstates has been studied by a complex of physical-chemical methods: visual-polythermal, differential thermal, projective-thermographic analyses. A crystallization tree was drawn up by prognosis of the phase complex. Two nonvariant points of eutectic and peritectic nature of the melting T = 473 and 483 ° C respectively were found in the system.

Casting Production

Ten E.B., Nam Ch.U. Continuous melting of oxygen-free copper
A problem of regular provision of the horizontal continuous casting process for manufacture of oxygen-free copper billets with high-quality liquid metal has been analyzed. A device is described which makes it possible to realize a three-chamber variant of melting within the crucible hollow and to provide the continuous casting process with melt by feeding it directly from the melting plant without additional discharge into a casting holding furnace. Features of the complex pure oxygen-free copper melting process are posed, in that case the process covers charge melting in the separate crucible chamber in protective-reducing environment and combined refining treatment in continuous circulating conditions by means of inert gas blowing, filtering and permanent effect of carbon-bearing deoxidizer on the melt.

Metal Forming

Kharitonov E.A., Burov I.A., Volshonok I.Z. Designing the rolling units of radial-shear mill with increased carrying capacity of bearing supports
The paper describes a designing procedure of rolling units of a radial-shear mill. Up-to-date units, for example radial-shear mills, should have increased loading ability for successful deformation of high-strength complex-alloyed materials. All this requires reliable operation of entire equipment, but especially high remands are made to rolling units of the mill that are exposed to significant dynamic loads during operation. Application of the designing procedure made it possible to develop rolling units, differing by increased reliability and life, at the running and designed equipment.

Physical Metallurgy and Heat Treatment

Kanunnikova O.M., Korolev D.A., Ghilmutdinov F.Z., Bayankin V.Ya., Trapeznikov V.A. The mechanical effect on electronic structure of Fe-Sn powders
The composition and electron structure of surface layer formed during compaction of Fe-Sn powders by plastic deformation under pressure were studied by X-ray photoelectron spectroscopy. Differences in the spectra of valence band of powder-like and compacted specimens are discussed from the viewpoint of the configuration composition of substance.

Strucheva N.E., Novozhenov V.A. Physical-chemical studies of ytterbium alloys with magnesium and aluminum
Interaction between ytterbium with magnesium and aluminum was investigated by TA, X-ray analysis, calorimetry of dissolution, and chemical analysis. Ytterbium interacts with magnesium and aluminum at T = 763-873 K. A ternary compound Yb_0,12Mg_0,88Al₂ is formed in the Yb-Mg-Al system.

Titlyanov A.E., Radyuk A.G., Yakoev A.G. The effect of mechanical-thermal treatment of zinc gas-thermal coatings on superficial crack form
Defects imitating cracks, which had been observed on copper specimens and billets, were created on the surface of copper specimens. Heat treatment (700 ° C, 2 and 4 h) and subsequent cold rolling are shown to assure their entire healing.

Belov N.A., Lavrishchev Yu.V. Optimization of the composition and structure of heat-resistant casting aluminum alloys with additions of cerium, iron, nickel, and zirconium
A study is made of the effect of composition and structure on mechanical properties of cast alloys of the Al-Ce-Ni-Fe-Zr system in which binary and ternary eutectics with participation of low-alloyed aluminum solid solution and Al₄Ce, Al₃Ni, and Al₉FeNi phases are crystallized. It is found that microhardness of eutectics is heavily dependent on the volume fraction of aluminides and their dispersity. It was shown that essential hardening of aluminum matrix can be achieved at the cost of a zirconium additive in quantity of 0.6 % when using two-stage manufacturing operation. Experimental compositions of Al-10 % Ce-5 % Ni-0,6 % Zr and Al-1,5 % Fe-1,5 % Ni-0,6 % Zr on the basis of ternary and binary eutectics respectively as billets essentially exceed industrial heat-resistant cast aluminum alloys AK12MMgN and AM5 as to a set of room and high-temperature mechanical properties and hot brittleness index.

Powder Materials and Coatings

Yermolaev A.A., Laptev A.I. Dependence of polycrystalline diamond formation temperature on catalyzing alloy composition
Initial temperatures for the formation of polycrystalline carbonado diamonds were determined in the nickel-chromium-carbon and nickel-molybdenum-carbon, Kh20N80-boron(carbon)-carbon, Kh20N80-titanium(tantalum, molybdenum)-carbon systems. It was found that minimum temperature of carbonado formation could be determined by melting temperature of a catalyzing alloy.

Polushin N.I., Laptev A.I., Pozdnyakov A.A. Optimization of the container material composition and sintering parameters made of stabilized zirconium oxide for diamond monocrystal growth procedure
The comprehensive work related to the optimization of container material composition for seeding-based synthesis of diamond monocrystals was carried out by using temperature gradient. It was found that refractory oxides are the most suitable class of materials on the basis of physical, chemical and mechanical characteristics. Stabilized zirconium oxide was chosen among the class of oxides. The containers were manufactured by powder metallurgy with subsequent machining by diamond finishing to necessary dimensions. The effect of container porosity on ability to propagate pressure was studied. Good results were obtained on using the developed container during the synthesis of diamond monocrystals up to 1,5 carat in weight in the “Split Sphere 300” plant.

Antsiferov V.N., Shveikin G.P., Ghilev V.G., Shtin A.P. Physical-chemical properties of porous sialons
Phase composition and properties of porous sialon materials synthesized from kaolin of the Kyshtym deposit were studied. It was shown that carbothermic reduction and simultaneous nitriding of kaolin in compacts in the mixture with graphite S-1 ensure manufacture of sialon materials of 50-60 % porosity. The sintering process is followed by shrinkage at the initial annealing stages when transformation of kaolinite into mullite and amorphous SiO₂ takes place. At the later stages for about 3 h of hold time the removal of carbon as CO and nitrogen saturation occur. Porous b -sialon-based materials, synthesized by reaction sintering of campacts from a mixture of kaolin with graphite in nitrogen, have a promising combination of high strength and gas-permeability with small diameter of channel pores. The materials have high stability against hydrochloric acid.

Yermilov A.G., Safonov V.V., Doroshko L.F., Kolyakin A.V. The effect of preliminary mechanical activation on heat generation during the reaction in tungsten-carbon charge
The effect of preliminary mechanical activation on the parameters of interaction (reaction temperature, heat generation) in the tungsten-carbon charge of stoichiometric composition was analyzed. The effect of different machining terms (activating agent filling degree, duration of mechanical influence) on the reaction parameters of activated charge was estimated. Formation of tungsten monocarbide is shown to proceed in two stages with intermediate formation of tungsten semicarbide, heat generation depending at the first stage of carbidizing treatment not only on a portion of energy stored during machining but on the heating rate of activated charge up to reaction temperature. The relaxation parameters of energy stored during activation in the process of activated charge heating are estimated.

Structural macrokinetics. Self-propagating high-temperature synthesis

Levashov E.A., Kurbatkina V.V., Kolesnichenko K.V. Features of the effect of preliminary mechanical activation on reactive ability of titanium based SHS-mixtures
Interaction in Ti-Si, Ti-B, Ti-Si-C, Ti-B-Si, Ti-B-C mixtures subjected to mechanical activation in a centrifugal planetary mill was studied by X-ray phase technique, differential thermal analysis and low-temperature gas adsorption. Qualitative estimates were carried out for the contribution of mechanical activation energy into burning activation energy which are based on well-known Zeldovich equation for heat generation rate of the “solid-liquid” systems interacting according to the reactive diffusion mechanism in the approach of narrow burning zones. The decrease in activation energy is shown to be tens percents.

Surface engineering. Multifunction films. Corrosion and metal protection

Levashov E.A., Kudryashov A.E., Potapov M.G. New SHS-materials for electrospark alloying using nanosized powder
The effect of a nano-component (nanosized diamond powder) on the mass transfer of new electrode SHS-materials of SHIM grade (TU 1984-1-11301236-93) was studied. Thickness, continuity, and microhardness of electrospark coatings produced on different materials (stainless steel 12Kh18N10T, quick-cutting steel R6M5, titanium alloy VT9), coating structure, element distribution in the coating, and wear-resistance were investigated. The X-ray phase analysis was carried out. An optimum content of nanosized diamond powder (up to 5 %) in the electrode material was found.

Gribkova O.V., Kazakevich A.V., Sidorova E.A. Decorative copper coatings
Decorative-matted coatings such as “velour” and “velvet” with low reflection factor produced from solutions containing stabilized emulsion make it possible to add a qualitatively new aspect to articles. Organic compounds based compositions “Satin” and “Velour” were developed to deposit coatings of “satin” and “velour” nature with different roughness degree (10-100 m m). Additional finishing decoration of the developed coatings not only conceals but intensifies the decorative effect of velvety surface too. The articles of velvety surface look most effectively after electrochemical coloring to produce “gold” and “old bronze” surface.

Timoshenko A.V., Buldygin A.V., Sergeev K.S. Micro-plasma oxidization of AMg6 alloy in pulse mode
The effect of a series of impulses of different duration and amplitude, superimposed on alternating-polar signal in the process of micro-plasma oxidation, on mechanical and corrosion properties of coatings produced on aluminum alloy AMg6 was studied. It was found that maximum high properties of the coatings could be achieved at impulse duration of 1 ms. The thickness of coatings formed in the studied mode is shown to be greater than in the mode without impulse imposition under the same values of passing quantity of electricity.

Chronicle

The 75^th Anniversary of V.K. Kulifeev