Mineral processing of nonferrous metals
Nikanorov A.V., Ershov P.R., Suslov K.V. To question on calculation of structural elements of column apparatuses with downward pulp-air movement
A theoretical calculation has been made of structural components and running conditions of equipment operating on the heterogeneous media – columned floatation apparatuses with downward movement of pulp-air spray. Based on the mechanism of mass mineralization in the real conditions of floatation pulp, integrity of the floatation complexes in steady downward flow was shown to depend on hydrophobic behavior of mineral particles only. Selection of mineral particles is determined by reduction of included gas (increase of capillary pressure in a bubble) along the downward flow and a difference of hydrophobic behavior of minerals, i.e. separation of mineral particles is caused by selective demineralization the extent of which can be controlled by the depth of steady downward pulp-air flow. Diameter and height of the last are the structural parameters according to which initial theoretical calculation of the floatation columned apparatus is possible as a whole for a certain ore type.
Extractive metallurgy of nonferrous metals
Trofimov E.A., Mikhailov G.G. Physical-chemical analysis of the processes of interacting elements, dissolved in molten copper, to oxygen
Using the thermodynamic calculations, the surfaces are plotted of oxygen solubility in metal melts being in equilibrium with oxide phases for the Cu–Sn–O, Cu–Zn–O, Cu–Co–O, Cu–Sb–O, and Cu–Si–O systems that can be used for investigation of the process technologies related to interaction of oxygen to appropriate elements in copper melt. Adequacy of the used calculation method is verified for the systems mentioned.
Begunov A.I., Ivanov S.D. Estimation of static friction coefficient between rod and self-calcinating anode in aluminum electrolytic cell with upper current lead
Thermomechanical interaction has been analyzed in the rod–anode system of an aluminum electrolytic cell with upper current lead. An analytic dependence of thermal stresses along the rod–anode boundary on vertical coordinate was obtained. Static friction between the rod and the anode body was estimated. The static friction force between the rod and the anode body is shown to exceed the anode weight.
Chzhan A.V., Zadvorny A.G. Determination of liquidus temperature by pyrometric method
Based on registration of thermal flow emitted by a sample in its short-term submersion in the hot melt, a pyrometric method has been proposed for determination of liquidus temperature Tl. It is shown to possess a number of advantages as compared with the contact measurement methods and can be used in melts of low fusion heat and thermal capacity values since it is faster one. As the receiving device is held away from the melt, such a method can be used for measurements of Tl in corrosive media. It is shown that the method proposed can be used for investigation of fast-carrying processes in the moment of contacting a cold sample to the hot melt. A qualitative explanation of the results obtained is given.
Tuzhilin A.S., Lainer Yu.A., Surova L.M. A study of interaction kinetics of aluminum metal and hydrochloric acid
Interaction kinetics of aluminum metal and hydrochloric acid of 0,5, 1,0, and 1,5 wt % in concentration at T = 70, 80, and 90 ° C has been investigated. Dependences of a degree of aluminum transformation on contact time to hydrochloric acid at different initial temperatures and initial concentrations of hydrochloric acid are given. They show the change of the last from 0,5 to 1,0 and 1,5 % to noticeably raise the degree of aluminum dissolution. Three possible mechanisms of interacting aluminum metal to hydrochloric acid are examined: monomolecular, bimolecular, and bimolecular taking the surface of aluminum powder into account. The reaction constant was obtained in each case, and adequacy of the mechanism was carried out.
Metallurgy of less-common and precious metals
Kochneva N.N., Buchikhin E.P., Erisov A.G., Chekmarev A.M., Golubtsov A.M. Development of iodide process of extraction of precious metals out of waste from electronics. Report 1: Study of anodic dissolution of precious metals in alkaline iodide solutions
A process of anodic dissolution of noble metals in alkaline solution of potassium iodine has been investigated. The kinetics of gold solution process was measured by coulometry. It was found that the process is limited by kinetic factors (Ea = 48 kJ/mol) at the concentration of potassium iodine CKI < 0,0075 mol/l. When KI content increases, the process passes into the diffusion region (Ea = 21,3 kJ/mol). A strong passivation of silver arises in solution with CKI < 0,03 mol/l at increase of anodic polarization potential +0,4 V relative to silver-chloride electrode, the cause of which is deposition of a film of poorly-soluble common silver iodide on the electrode surface. The effect of electrode potential and concentration of I– and OH– ions on the gold dissolution rate has been studied. The reaction was found to be of the first order in I–. The greatest gold dissolution rate in 0,03 M solution of KI is observed at OH– concentration equal to 0,25 mol/l. An attempt is made to explain the effect of OH– ions on the gold dissolution process kinetics.
Begunov A.I., Belykh P.D., Filatova E.G., Rybnikova V.G. Electrical conduction of the “water¾ hydrochloric acid¾ magnesium chloride” system solutions
The results of experimental study concerned with electrical conduction of the three-component “water–hydrochloric acid–magnesium chloride” system are given. Specific electrical conduction of H2O–HCl–MgCl2× 6H2O was measured at T = 20 ° C and different concentrations of HCl (2–30 wt %) and MgCl2× 6H2O (0–60 wt %). The isotherms of specific electrical conduction were plotted for this ternary system. Equivalent electrical conduction of the solutions studied was calculated. A temperature dependence of electrical conduction of some system compositions was studied. In the case of diluted solutions, the results comply in practice with the coefficients for strong acids in known Kohlrausch's formula.
Casting production
Gerasimov S.P., Yudin V.A., Neverov P.A. On formation of buildups (metal “growth”) on the LTs16K4 silicon brass casting surface
An interrelation has been studied between hydrogen evolution during crystallization of LTs16K4 brass castings containing this dissolved gas and a metal “growth” – formation of buildups on the free surface of the castings. Calculations of zinc vapor pressure and maximum possible hydrogen pressure over the melt with open melting of LTs16K4 brass as well as the content of dissolved hydrogen in the brass have been made depending on temperature taking zinc vapor pressure into account. Based on the dependences obtained it was experimentally found that for Т = 950¸ 1050 ° С molten LTs16K4 brass is capable to actively become saturated with hydrogen, owing to which castings made of such metal are affected by buildup on the free surface. In overheating the hydrogen saturated melt to initial boiling (³ 1125 ° C) the metal “growth” does not observed because of melt self-degassing by zinc vapors.
Metal Forming
Raikov Yu.N. Effectiveness of up-to-date processes of copper-wire blank production
The main types of assemblies are compared in continuous casting and rolling of copper wire blank. The paper gives their performances and ranges of application related to production capacities of the assemblies and quality of produced blank as to oxygen content, which determines possibilities of wiredrawing to various diameters.
Physical Metallurgy and Heat Treatment
Kremnyov L.S. Crack growth resistance and “crack resistance energy”
New evidences of the main equations of linear fracture mechanics are given. It is shown on their basis that necessary and sufficient conditions of brittle and quasi-brittle fracture come from the works of N.G. Kolosov and C. Inglies. The origin of peculiar dimensionality of crack growth resistance K1c [Pa× m1/2] is discussed. A criterion of crack growth resistance as “crack resistance energy” A1c [J / m2] is proposed dimensionality of which is of evident physical sense.
Powder Materials and Coatings
Vazhenkov M.V., Chekmarev A.M., Seleznev V.P., Klimenko O.M. Chemical method of dispersed power production
The redox method to produce copper dispersed powder in nonaqueous media has been studied. An opportunity of significant widening of some quantity of initial copper compounds, organic acid-reducing and medium-constituting amides was demonstrated. Very stable (up to a few years of storage) copper powders were produced with prevailing particle size of 30–50 nm.
Malyshev V.V., Uskova N.N., Soloviev V.V. Electrolytic deposition of boron powders, silicon coatings, and electrochemical synthesis of chromium borides and silicides
The paper studies electrolytic reduction of silicon and boron against the background of dispersed boron powders, silicon coatings, and electrochemical synthesis of dispersed chromium boride and silicide powders out of chloride-cryolite-oxide fused electrolytes.
Energy saving and environment protection
Ulanovsky Ya.B., Krupennikov S.A., Levitsky I.A. Mathematical modeling of heat transfer at high-speed electron-beam evaporation of metals and vapor deposition on moving band-substrate
A mathematical model of heat transfer has been developed at high-speed electron-beam evaporation of materials and vacuum deposition of vapors on moving band-substrate designed for calculation of the temperature conditions of condensate formation. Taking account of band movement, heat transfer along its length and width as well as using the diagrams of direction of radiation and vapor fluxes appropriate to a model of isothermal crater that is formed on the surface of the melt during evaporation is a feature of the model.
Svetozarova G.I., Andreeva O.V., Paretsky V.M., Miroevsky G.P. Mathematical model of the process to reduce nickel protoxide using solid reducer in rotary tube furnace
A mathematical model of the process to reduce nickel protoxide with addition of coke in a rotary tube furnace is proposed. It includes differential equations describing change in nickel protoxide and carbon contents in solid materials, concentrations of reducing reagents (carbon oxide and hydrogen) and oxygen in the gas phase as well as temperature along the length of the furnace. The mathematical model is realized in a computer, its identification has been carried out, and its adequacy with real process is shown with reasonable precision.
Process control and automation
Shubladze A.M., Salikhov Z.G., Gulyaev S.V., Cherepova T.I., Salikhov M.Z. Control systems, optimal in degree of stability, of objects with “unstable” numerator of transfer function
The synthesis method of control systems, optimal in the maximal level of stability, for the objects with “unstable” numerator of the transfer function was given and a possibility of their existence was proved. Different classes of the control objects, for which the synthesis of automated control systems is related to difficulties in application of classical methods of the automated control theory, are analyzed. The programming algorithms are obtained for automatic devices to choose optimal parameters of industrial microprocessors-regulators capable of compensating the disturbance of almost any amplitude and the control actions for which uncounted nonlinear and delays become apparent.
Economics and Management
Kiselev A.G. Experience of introduction and operation of ERP-system at the metallurgical enterprise
A general structure is proposed for ERP-system as 7 “contours” (blocks), and a “nucleus” is determined for first-priority introduction. An approach to segregate business processes in ERP is formulated and technology of their practical realization at an industrial enterprise with taking specific character of the metallurgical production (range, taw materials, chemical composition of raw materials, batches, specificity of business accounting of raw materials) into account is described. Adaptation problems of “Parus-8” product as ERP-system, peculiarity of interface in ERP, realization of the scheme of reserving the base for stable operation are considered. The technologies used for introduction and the operational characteristics reached by the example of ERP/“Parus-8”/Oracle at OAO “Novosibirsk Tin Integrated Works” are given.
Information
- Gorelik S.S. On physical metallurgy as the science
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- Valentin Petrovich Bystrov is 70 years old
