Nonferrous ore concentration
Yevdokimov S.I., Panshin A.M. Surface forces in the particle aggregating and flotation processes
The temperature dependence of residual volume formed on the porous partition during kinetic suspension destruction has been established. In rising temperature, hydrophilic particles are found to build up denser residuals of small volume at the cost of weakening the forces in the contacts among particles and hydrophobic particles do skeleton residuals of great volume due to the growth of the mentioned forces. It is assumed that, in rising temperature, increase of hydrophilic repulsive and hydrophobic attractive forces can be related to the surface forces of structural origin: growth of water density and normal dipole orientation in case of hydrophilic repulsion and decrease of density and tangential dipole orientation for the forces of hydrophobic attraction.
Key words: flotation, hydrophobichydrophilic interactions, residual volume, interacting forces.
Baltukhaev G.I., Solozhenkin P.M. Beneficiation of goldantimony ores of Republic of Sakha (Yakutia)
An analytical review of the main goldantimony deposits in the RF is given. The practice is described and the results are set out with respect to beneficiation of Au–Sbores from Sarylakh, Sentachan, and Maltan deposits (Republic of Sakha (Yakutia)). A number of selective reagents for flotation of antimonite from complex goldantimony ores are considered. The data of industrial tests of sodium dimethyldithiocarbamate in processing goldantimony ores, flotation, antimonite, flotation agents are given and its effectiveness is shown.
Key words: goldantimony ores, flotation, antimonite, flotation agents, sodium dimethyldithiocarbamate.
Extractive metallurgy of nonferrous metals
Ovtsyn D.V., Kostyunin V.V., Potapov V.N., Kozhevnikov G.N. Molybdenite concentrate firing technique
A new method of molybdenite concentrate firing has been developed. A plant was used to fire material in oxidant vortex flow with obtaining cinders. Conversion of MoS2 into MoO3 (98,7 %) and sublimating of 85 % rhenium were occurred within 0,5 h at temperature of 600 °C, air consumption of 100–120 m3/h. Sulfur content in cinder is less than 1,8 %. In processing cinder by potassium carbonate solution, 96,5 % Mo is extracted. The method gives high productivity; it is characterized by simplicity and does not require high expenses for equipment and operation. The firing method is highlyperspective and can be applied for firing of other materials containing metal sulfides.
Key words: concentrate, molybdenite, firing, cinder, molybdenum trioxide, vortex facility.
Volkovich A.V., Zhuravlev V.I., Trofimov I.S., Gorbachev A.E. Power yield of barium during electrolysis of chloride and oxidechloride melts with liquid cadmium and zinc cathodes
The effect of current density (i) and duration of electrolysis on the power yield of barium (ВТВа) into alloy with zinc and cadmium during electrolysis of (K–Na)Cleq26 mol.% BaCl2 melts containing 0,4 mol.% dissolved BaO at T = 973 К has been investigated. The current density dependence of ВТВа is found to pass through the maximum: ВТВа value in alloy with zinc is 86 % and 74 % with cadmium at i = 0,18 A/cm2. Increase in electrolysis time and barium oxide being in the molten salts result in decrease in the power yield of barium into the molten salts.
Key words: power yield, cathode, zinc, cadmium, chloride and oxidechloride baths, selectivity coefficient, intermetallic compound, electrolysis, current density, alloy, barium oxide.
Casting production
Pikunov M.V., Gerasimov S.P., Yudin V.A. On the effect of aluminum oxide inclusions on hydrogen dissolving and releasing process in aluminum and copper melts
Based on the results of the publications, a conclusion is made of the correctness concerning the conjecture, hazarded by the authors earlier, on action of nitrogen bubbles being on aluminum oxide shellsinclusions, which are formed in contacting aluminum melts with the air, as completed centers of hydrogen emission in the form of bubbles from the solutionmelt. Using this proposition, the results of many industrial and laboratory studies of the association between impurity of aluminum melts by oxide inclusions and the porosity of castings caused by hydrogen bubbling can be logically explained. The proposition is true for brasses and bronzes including aluminum as an alloying component or as an impurity. The direct experiments with water containing dissolved air or carbon dioxide demonstrated dramatically the action of the mentioned mechanism. Irrelevance of "bifilm" term for designation of double oxide shells and inadmissibility of its use in the russian metallurgical literature are pointed out.
Key words: hydrogen dissolution, aluminum oxide, aluminum melts, copper melts.
Konovalov A.N., Pikunov M.V., Gerasimov S.P. On melt "boiling" in copper remelting
The conditions and mechanism of molten oxidized copper "boiling" have been investigated. The "boiling" is caused by interaction of oxygen dissolved in the molten copper and carbon in the crucible material. The characteristic properties of the interaction are determined.
Key words: copper, melt, boiling, oxygen, carbon.
Metal forming
Dobrov I.V. Power parameters of drawing process in roller die
Using the inversion method in analyzing the kinematics of deformation zone, a method of assessing the power parameters of drawing process in roller dies has been developed. Calculating formulas are established for determination of contact and drawing stresses depending on the technological characteristics of this process and the design version of reducing dies. The method can be used both for selection of rational design of the roller die and for determination of optimal drawing run with application of roller dies of a certain design.
Key words: roller die, inversion, physical model, coefficient of sliding friction, coefficient of static friction, superficial friction factor, contact stresses, drawing stress.
Kontsevoi Yu.V., Ignatiev I.E., Ignatieva E.V., Pastukhov E.A. Calculation of power and kinematic parameters of deformation zone in rolling multilayered systems with dispersed layer
A model of multilayer system rolling where some layers can be powdertype is proposed. A procedure is developed to calculate the distribution of energy consumption in the deformation zone involving a powder layer in the system.
Key words: rolling, multilayer packet, powder layer.
Materials science and heat treatment
Solonin A.N., Churyumov A.Yu., Sharkova S.A., Zolotorevsky V.S. Calculation of yield strength of silumins using the characteristics of their structure
A model has been constructed and a possibility is shown to calculate the yield strength from the structural characteristics of the Al–Si–Cu and Al–Si–Mg systems alloys in natural and artificial aged conditions. The model has good predictive capability at copper concentrations up to 5 %, magnesium up to 1 %, and silicon up to 11 % under the conditions of 140–220 °С in aging temperature and holding time up to 100 h. Maximum possible values of yield strength for industrial silumins of the considered system are determined.
Key words: silumins, yield strength, simulation.
Gabidullin A.E., Ovchinnikov A.V., Alpatov V.P., Chernoglazova T.A. Prediction of structural state and properties of compacted aluminum semiproducts using QForm CAEsystem
As an example of AK6 alloys, the conditions of structure and mechanical property formation of compacted semiproducts have been analyzed from the viewpoint of the achievements of modern materials sciences and successes in development of the systems related to computer simulation techniques of plastic deformation processes. Based on the effect of different factors on intensification of strainrelief crystallization processes, the most effective methods of controlling structure and mechanical properties of semiproducts are shown. From the results of laboratory tests of rods compacted under different conditions, the main regularities of the effect of temperaturespeed parameters on the mechanical properties of AK6 alloy have been established.
Key words: structural strengthening, structural state diagrams, CAE system, AK6 alloy.
Powder materials and coatings
Rudneva V.V., Galevsky G.V., Yurkova E.K. Compaction of silicon carbide and compositions on its basis: analysis of domestic and foreign experience
The domestic and foreign experience has been generalized and systematized in relation to compaction of silicon carbide and its based compositions to produce structural and shock resistant materials: dimensional, phase and other characteristics of carbide powders from different producers are compared; various technological variants of compaction (solidphase sintering, hot isostatic compaction, sintering in highpressure chambers), relation of thermopowered parameters and properties of obtainable materials, nanolevel of powders and forming structure are analyzed.
Key words: silicon carbide, solidphase sintering, hot isostatic compaction, sintering in highpressure chambers, micro and nanopowders.
Process control and automation
Alkatsev M.I., Alkatseva V.M. Investigation of nickel sulfide concentrate roasting indices in fluidizedbed furnaces in dependence on different factors by method of simulation planned experiment
Using the method of the simulation planned experiment, the dependence of nickel sulfide concentrate roasting indices (fluidizedbed temperature, furnace specific productivity, specific blasting consumption, and others) on various factors (blasting surplus factor, concentrate humidity, oxygen content, and others) has been studied. Software in the form of mathematical roasting model including material and heat balances as well as the regression equations is proposed. The factors were ranged by their affect on the fluidizedbed temperature.
Key words: fluidizedbed roasting, simulation modeling.
Zalazinsky A.G., Polyakov A.P., Polyakov P.A. System simulation of technological complex for manufacture of composites for electrical purposes
The system simulation of the (Nb–Тi)+Cu system fiber composite manufacturing process has been executed. The maximum finished product yield was taken as a performance criterion of the process flow diagram and the maximum initial material yield into the finished products was taken as a quality criterion. Extruding, drawing, and heat treatment processes are emphasized as the main process stages that define the kinetics of defect formation in the composite components. The synthesis of the process system model has been carried out and the vector optimization problem has been solved. The material component damage prediction is performed on the basis of the phenomenological failure theory. For the computerized modeling, a program complex has been developed in the MATLAB system to solve the problems of plastic fibercomposite deformation.
Key words: composite, computerized modeling, system analysis, optimal control, damage.
Chronicle
Evgeniy Aleksandrovich Levashov is 50 years old
