Mineral processing of nonferrous metals

Mironov V.P., Shlyufman E.M. Raman scattering in diamonds from concentrates and reject materials of the combined mineral processing flow sheet
The article describes investigation of a Raman scattering (RS) phenomenon in diamonds produced from concentrates of the combined mineral processing flow sheet of -5 +2 mm size grade from one of the deposits exploited by AK "ALROSA" as compared with minerals extracted into concentrate with X-ray luminescent separators jointly with diamonds. Poor unsteadiness and dependence of RS signal level on processed size grade and an opportunity of technical realization of mechanical mechanisms and electronics being analogous to realization of X-ray luminescent separators allow us to state that separator with using the RS effect can surpass X-ray luminescent and tenacious separators (taken together) in selectivity and completeness of diamond extraction.

Melik-Gaikazyan V.I., Voronchikhina V.V., Emelianova N.P., Draganov A.V., Ermakov K.G. The main characteristic of flotation activity of non-polar reagents
Based on the results of the experimental work fulfilled and the literature data, it is shown that the liquid-gas boundary is the main place where non-polar reagents act during froth flotation of particles with hydrophobic or hydrophobized surfaces, and effectiveness of a reagent is determined by the content in it or pulp of substances (surface active substances) being active along the boundary. A method of determination of such surface active substances is described. The method is essentially simplified in using a digital photographic apparatus. Different devices for its realization are given.
Abdrakhimova E.S., Abdrakhimov V.Z. Application of concentration rejects of the nonferrous metallurgy in the production of acid-proof products
It was found from the results of the studies carried out that it is expedient to use argillaceous portion of reject materials remaining from gravity-separation of zircon-ilmenite ores as argillaceous component of acid-proof materials. It is shown that introduction of pyrophyllite into the composition of ceramic masses facilitates formation of mullite that defines the main physical and mechanical properties of acid-proof materials. The method of linear regression was used for studying the effect of pyrophyllite on acid resistance of ceramic materials.

Extractive Metallurgy of Nonferrous Metals

Tsymbulov L.B., Tsemekhman L.Sh., Burylev B.P. Measurement of carbon solubility in melts of the Cu Ni S system
Using the method of isothermal exposure time at T = 1673 K, solubility of carbon was investigated in the Cu-Ni-S melts in a wide range of concentrations. Procedural features of the experiments were described: choice of pure components, sequence of operations, chemical analysis of equilibrium products, and compositions of the phases being formed. The results were compared with the experimental data of other authors as to solubility of carbon in melted nickel and Ni-Cu and Ni-S alloys. The bases of calculation in particular Cu-Ni-Csat and Ni-S-Csat are shown.

Lebedev V.A., Tarabaev M.V. Interdependent thermodynamic characteristics of magnesium-containing chloride melts
Systematization and mathematical treatment of known calorimetric data and the results of electrochemical measurements allowed us to derive generalizing equation for calculation of excess thermodynamic characteristics MgCl2, standard and conditionally standard potentials of magnesium in melts of arbitrary composition diluted in its chloride (x 0,15) including those applied in the industry.

Metallurgy of less-common and precious metals

Sokolova Yu.V., Koryakov V.B., Per'kov P.G. Scandium (III) extracting concentration with production of fluoride concentrate
The article describes the process of extraction concentration of Sc(III) during its extraction from the solution, produced by autoclave leaching silicate-carbonate ore, of the following composition (in g/l): 0,032 Sc(III), 7,1 Fe(III), 2,3 Al(III), 8,8 Mg(II), 0,52 Ca(II), 0,085 Ti(IV), 0,115 Zr(IV), 0,09 U(VI), 58 H2SO4 by extraction of mix extractive agent 0,2 M D2EGFK + 0,1 M TBP in hydrocarbon mixture with volumetric ratio of water and organic phases as W : O = 5 as well as re-extraction of 4 % solution of NaF at W : O = 1 with production of rough fluoride concentrate (RFC) when operating in the cycle. It is shown that the parameters of stable operation are following: Sc(III) extraction degree is 95 %, re-extraction degree is 86 %, concentration of Sc(III) in concentrate is 4,3 % after 20 % (vol.) renewal of the re-extractive agent solution. Averaged RFC contains 2,7-4,3 Sc(III). An opportunity of RFC production with content of 1-2 % Sc(III) and 8-10 % concentrate Ti(IV) was experimentally proved in extracting Sc(III) from hydrolytic titanium acid by 0,16 M D2EGFK solution in kerosene with two-step re-extraction by sodium fluoride and mixture of 2-3 % NaOH + 5-7 % Na2CO3 respectively. The results of RFC purification in its treating by 1 % HNO3 solution in a periodic mode with production of 25 32 % fluoride Sc(III) concentrate are given. Summary extraction of Sc(III) in the process of extracting concentration with obtaining 25 32 % concentrate is ~78 %.

Buinovsky A.S., Sofronov V.L., Cherviakov A.L., Drozdetskaya N.V., Makaseev A.Yu., Kruglov S.N., Ryabov A.S., Shamin V.I. Nitro-acid technology of processing REM-containing orthite ores
The results of studies related to processing rare-earth metals (REM) containing orthite ores of the Bogatyryok deposit (Kemerovo Region) are given. Hydrometallurgical production comprises some main processes: breakdown (leaching) of orthite by nitric acid, extractive purification of REM by 100 % TBP from thorium and ballast impurities, extraction separation of REM in light and medium-weight groups. The effect of different factors (temperature, process duration, grain size, concentration of nitric acid, velocity of solution movement relative to the surface of solid phase) on the leaching degree from orthite concentrate of REM and other elements is shown.

Krasikov S.A., Istomin S.A., Selivanov A.A. Surface tension of niobium-containing oxide-fluoride melts
The effect of Nb2O5 on surface tension ( ) of melts based on CaF2 and CaF2-30 % Al2O3 at T = 1673 1873 K has been studied using the method of maximal pressure in a gas bubble. It was established that the value of melts decreases in the range of 239-312 mJ/m2 and temperature coefficients / T are -(0,054 0,160) mJ / (m2 K) when concentration of Nb2O5 grows from 0 to 25 %. The data obtained are evidence of the complexing nature of niobium in oxide-fluoride melts.

Casting Production

Balashova N.P., Pikunov M.V. Relation between metal crystallization process and casting solidification process mechanisms
Dimensions of a dendritic cell and a portion of non-equilibrium eutectic in the microstructure were determined on experimental castings (cylinders and spheres of 10-30 mm and 15-40 mm respectively) of Al + 3 % Cu alloy. It is shown that the figures change from the surface to the center of casting section along the curves with a maximum: in cylinders - approximately on 1/2 radius; in spheres - at length < 1/3 radius from the surface. A monotonous increase of a dendritic cell size and decrease of the portion of non-equilibrium eutectic from the surface to the center of casting section were observed in casting-plates. The changes of the microstructure are related with the solidification process mechanisms of castings of different configuration. Average dendritic cell size and cooling rate dependences of interaction factor F were found for Al + 3 % Cu alloy.

Metal Forming

Polyakov A.P. Impact extrusion of rod stock through conical die
The process of impact extrusion of a rod stock through a conical die has been analyzed. An analytical solution is obtained, which makes it possible to determine the starting velocity of the stem for a specified rod stock to instrument weight ratio. The behavior of the velocity during extrusion was shown. An example of calculation of impact extrusion of a rod stock prepared from a sintered titanium briquette is given, and the effect of drawing and friction coefficient between the rod stock and the die on energy-power parameters of the process is estimated.

Shevelev A.I., Beigelzimer Ya.E., Synkov S.G. Processing of cast secondary aluminum alloys by screw extrusion method
The article gives the results of experiments on forming of cast secondary aluminum alloys using the new deformation method - screw extrusion. It is shown that worm screw extrusion with back pressure gives rise to good processing of the cast structure and fragmentation of brittle intergranular skeleton in casting blocks of secondary aluminum. As a result, ductility of alloy increases and a possibility appears to use traditional methods of metal forming for the purpose of obtaining necessary form.

Physical metallurgy and heat treatment

Aksenov A.A., Solonin A.N., Istomin-Kastrovsky V.V. Structure and properties of composite materials based on aluminum which are produced by method of mechanical alloying in the air
Structure and phase composition of composite materials based on Al-4,7 % Cu and Al-4,1 % Mg alloys processed in high-energy planetary mill in the air atmosphere was investigated. A possibility in principle is shown to produce composite materials based on aluminum alloys strengthened by synthesizing during the mechanical alloying by oxide particles in the air. Features and kinetics of oxidation of composite materials during processing in the mill were studied. Aluminum is shown to be oxidized partially and magnesium does in full.

Powder materials and coatings

Kozhuro L.M., Romanova T.K., Shcherbo D.M. The effect of high-speed steel powder composition on structure and phase composition of coatings formed in electromagnetic field
The article gives an analysis of the effect of separate alloying elements and the chemical composition of powders prepared from high-speed steels on the characteristics of coatings produced by electromagnetic welding deposition. Such coatings are found to have heterogeneous non-equilibrium structure, which is formed from the melt, based on saturated solid solutions of the power components in - and -iron as well as on alloyed carbides. The size and structure of the hardened layer zones were established to be dependent of the material composition of the powder being fused and the diffusion mechanism.

Structural Macrokinetics. Self-Propagating High-Temperature Synthesis

Levashov E.A., Rogachyov A.S., Shtansky D.V., Grigoryan A.E., Leyland A. Self-distributing high-temperature synthesis of composite cathodes of TiCxNy-Ti5Si3-TiB2 composition
Characteristics of combustion in the Ti-C-B-Si3N4 system and structurization of products of self-distributing high-temperature synthesis (SHS) in proceeding four parallel chemical reactions of titanium carbide, diboride, nitride, and silicide formation were investigated. Dependences of adiabatic and experimental combustion temperatures on the composition of initial charge mixture were derived. It is shown that noticeable growth of combustion temperature from 2173 to 2723 K and combustion wave distribution rate from 0,85 to 1,97 cm/s takes place with increasing weight portion of 2Ti + C + 2B reagents in the initial charge mixture (charging parameter X), the structure of combustion front changing insignificantly according to the data of high-speed video filming. The processes of phase formation and structurization of synthesis products were studied. A correlation between stoichiometry of titanium carbonitride and charging parameter was found. Lattice spacing of TiCxNy titanium carbonitride in the synthesis products rises from 0,4269 nm for TiC0.33N0.58 to 0,4307 nm for TiC0.7N0.23 when X increases from 20 % to 80 %. It is shown that TiCxNy phase presumably arises along with titanium diboride at the stage of primary structure formation. The microstructure of the synthesis products was studied. Growth of TiCxNy and TiB2 grains was established with increasing parameter X. Composite targets of different composition in the system of TiCxNy-TiB2-Ti5Si3 were produced according to the process of power SHS-compaction; the targets are intended for ionic-plasma spraying of nanostructural multi-functional coatings. Being dependent on the composition of a compact product, hardness changes in a wide range of values: from 84 to 91 HRA, and relative density is 98 99 %.