Mineral processing of nonferrous metals
Bocharov V.A., Ignatkina V.A., Chanturia E.L., Lapshina G.A., Melnikova S.I. Technology of complex concentration of sulfide gold-containing ores difficult for concentration
The features of material composition of gold-containing copper-zinc-pyrite sulfide ores are considered. Application of interstage flotation in the grinding circuit or the gravity dressing cycle is recommended for increasing gold extraction. The data for using new flotation collectors S-703, F-100 and SIG independently and in a mixed form with xanthate are given. Combined use of S-703 reagent and xanthate in weight ratio of 1 : 1 promotes improving extraction of gold into gold-sulfide concentrate by 3- 5 % and xanthate and SIG reagent by 4 %. Application of soda as a regulator of the medium was shown to affect gold flotation in the favorable manner as compared with lime and sodium hydroxide, however extraction of pyrite into gold-sulfide concentrate increases as well.
Melik-Gaikazian V.I., Draganov A.V., Emelianova N.P., Ermakov K.G. Estimation of relaxation characteristics of non-polar flotation reagents and their combination with different substances
An analysis of the relaxation data recorded for industrial non-polar reagents makes it possible to estimate the content of active, slow-acting and inactive constituents in them. Application of digital cameras connected to the computer may accelerate this process to tens minutes and opens ways to its use for operational control of the process. Adequacy of the method applied for investigation of the relaxation curves was confirmed by analyzing a synthetic curve composed of exponents with preset parameters; as a result, the full coincidence of calculated and initial values of the parameters was obtained.
Metallurgy of less-common and precious metals
Sokolova Yu.V., Koryakov V.B. Sorption concentration of Sc(III) in processing silicate carbonate ore
The article analyzes sorption concentration of Sc(III) from pulp obtained in the course of processing of complex silicate-carbonate ore that has the following composition (in g/l): 0,01133 Sc(III), 0,05 Y(III), 0,055 (V(IV) + V(V)), 0,41 U(VI), 1,2 Fe(III), 3,0 Fe(II), 2,52 Al(III), 0,3 Ca(II), 6,4 Mg(II), 65 SO42- (pH = 2,35) with solid phase content of 2 % and using ionites of different grades. Nitrogen and phosphorus containing polyampholyte PA-1 is recommended for extraction of Sc(III). The main characteristics of a sorption cycle were calculated as a result of the data processing related to the statistics and kinetics of Sc(III) sorption.
Skopin D.Yu., Lebed' A.B., Naboichenko S.S. Kinetics of dissolution of silver in nitrate solutions
The silver dissolution kinetics in nitrate solutions was studied at the elevated temperatures under the hydrothermal conditions using the rotating disk technique. The results obtained were generalized in the form of kinetic dependences, the values of process rate constants were determined, and the kinetic behavior of the process development was found at the prescribed intervals of the parameters. The effect of ammonium nitrate on the silver dissolution process was shown.
Chekanova L.G., Radushev A.V., Shabalina L.S., Tiunova T.G. Extraction of nonferrous metal ions from solutions and their complexation with 1,2-diacilhydrazines
Equilibrium in solutions at complexation of 1,2-diacylhydrazines (H2DAH) with ions Cu(II), Ni(II), Co(II) during ionic flotation has been investigated. A mechanism of complex formation was offered and equilibrium quantitative characteristics – values of solubility products of precipitates were found. The structures of precipitated complexes were proved.
Metal forming
Polyakov A.P. On the scheme of rigid blocks in the problem of porous blank extrusion
A solution of the problem was analyzed concerned with extruding a blank of non-compact material in flat and axial-symmetric flow with help of the scheme of rigid blocks. Used is the model of plastically compressed porous medium subject to cylindrical type yielding flow and concerned defining relationships to support independent slip mechanisms and compaction of porous mass. The data obtained allow us to estimate pressure and residual porosity in a sufficiently wide range of changing initial porosity (from moderate to small one), matrix cone angle, and friction coefficient between the blank. The approach proposed is simple in realization and, at the same time, has sufficient precision, being proved to be satisfactory coincidence results of different authors.
Sidelnikov S.B., Katareva A.A., Dovzhenko N.N. Simulation of combined continuous casting process and nonferrous metal and alloy rolling-and-pressing
Methods of combined casting and rolling-and-pressing (CCRP) developed by the authors are discussed. The results of solving a variational problem on determination of optimal geometrical parameters of a CCRP plant for closed box and beam passes are presented. Conclusions and recommendations are given for application of different pass forms to deform nonferrous metals and alloys and the conditions of operating practices to realize the processes.
Kolmogorov G.L., Filippov V.B., Kuznetsova E.V., Trofimov V.N. Extent of deformation in composite blank drawing
A method to estimate the deformation degree under drawing a composite blank consisting of two and more components is proposed. The deformation factor is defined as a sum of the rates of sequential small deformations of particle shearing under drawing tool deformation. The method is used in manufacturing superconductive composites consisting of superconductive core and sheath by means of drawing. Formulas for calculation of deformation degree in these components as well as intermediate layers of the composite blank were proposed.
Металловедение и термическая обработка
Physical metallurgy and heat treatment
Volodin V.A., Kolachev B.A., Vorobiyov A.I., Moiseev V.N., Vorobiyov I.A. The effect of ageing on structure and hardness of hardened alloy VT35
The effect of ageing duration at temperatures equal to 350- 650 ° C on hardness of VT35 alloy quenched in water from 820 ° C was investigated. It was shown that the largest ageing effect was observed at temperatures of 450- 500 ° C for 10- 20 h. A diagram of phase isothermal transformations taking place during ageing of quenched VT35 alloy was plotted. According to the diagram, metastable b -phase had two minimums of stability at temperatures of 500 and 600 ° C that might be due to different mechanisms of dispersed a -phase nucleation: diffusive one at high temperature and martensite one at lower temperature.
Buinovsky A.S., Sofronov V.L., Shtefan Yu.P., Yeshchev V.A. Solid-phase alloying of magnetic Nd- Fe- B-based alloys
A binary process of solid-phase alloying for magnetic characteristics of Nd- Fe- B-based magnetic materials was proposed. Four groups of materials: Nd-enriched Nd- Fe-B alloys, Nd- Dy- Fe- B alloys, REM3(Fe- Co) alloys, heavy REM(Dy2O3, Tb4O7) oxides were chosen as alloying components. The results of the studies and appropriate recommendations for solid-phase alloying are given.
Trykov Yu.P., Shmorgun V.G., Slautin O.V., Abramenko S.A. Properties of layered intermetallic composites Cu¾ Al produced according to complex technology
The structure and micromechanical properties of a diffusion layer in composite material of the copper – aluminum system obtained by means of complex technology are investigated. The mechanical properties of 3- and 9-layer composites of copper M1 + aluminum AD1 composition with various contents of intermetallic compounds are determined.
Powder materials and coatings
Panov V.S., Serdyuchenko K.Yu. A role of plasticizer in production of hard alloys
The effect of different plasticizers used in the hard-alloy industry on the pressing and sintering processes was considered. The reason of instability of operating properties of hard metals was shown to be circulation of destruction products and methane conversion giving rise to destabilization of carbon balance in the course of compact sintering.
Aleksandrovsky S.V., Li D.V., Sizyakov V.M. Production of titanium carbide nanopowders by magnesium-thermic reduction of chloride mixture
Strong associates that providing production of titanium carbide close to stoichiometry is formed during magnesium-thermic reduction of TiCl4–C2Cl4 mixture. The content of bound carbon in the titanium carbide increases and the content of free carbon decreases in the case of decreasing the flow rate of initial chloride mixture and temperature rising. The lattice parameter of such titanium carbide approaches the lattice parameter of standard stoichiometric TiC phase. Nanopowders of titanium carbide of 40- 60 nm in size were produced.
Ermilov A.G., Levchenko V.A. Morphology of coating produced by thermic decomposition of nickel carbide under the conditions of substrate temperature cycling
The morphology of nickel coating formed during thermic decomposition of nickel carbonyl under the conditions of heat cycling of the substrate was studied by scanning electron microscopy. The effect of different filling rate of substrate defects of different energy was found. A mechanism was proposed of the cited filling and the self-healing stages of coating defects during heat cycling. Coating of different grain size is formed in the course of sorption of carbonyl vapors on the defect of different energy.
Structural macrokinetics. SHS
Grigorian E.G., Niazian O.M., Arutyunyan A.B., Kharatyan S.L. Non-isothermic kinetics of reduction of copper oxide with combined reducer
Interaction between copper(II) oxide and polystyrene was studied in the temperature range of 20–600 ° C using derivatography. The experiments were carried out for the stoichiometric mixture of reagents at the heating rates of 2,5–20,0 ° C/min. Based on DTA and DTG curves and the results of the data processing, it was shown that the reduction process is characterized by different activation energy being dependent on the conversion degree: the activation energy is low at its little values (5–30 %) and that is significantly higher at lager values (85–90 %) (88 and 120 kJ/mole respectively). A supposition is made that these facts are related to charging the content of products evolving during decomposition of polystyrene.
Chronicle
Stepan Ivanovich Pol'kin: To the 100-th birthday
Albert Ivanovich Begunov is 70 years
