Extractive metallurgy of nonferrous metals

Khalimullina Yu.R., Zaikov Yu.P., Arkhipov P.A., Ashikhin V.V., Skopov G.V., Kholkina A.S., Molchanova N.G. Thermodynamic characteristics of Pb–Bi alloys in the KCl–PbCl₂ melt
Using equilibrium EMF measurement, the thermodynamic properties of the Pb–Bi alloys containing from 1,5 to 95 mole % Pb have been investigated in a temperature range of 723 through 873 K in fused potassium and lead chlorides mixture. Partial and integral thermodynamic characteristics of the system are calculated and its small negative deviations from the ideality are found.
Key words: lead, bismuth, EMF method, thermodynamic characteristics.

Vershinina E.P., Ghildebrandt E.M., Frizorger V.K. Plastic properties of homogenized coke–pitch compositions
Rheological properties of coke-pitch compositions after their mechanic-activation treatments (MAT) in the hydraulic-impact-cavitation field for three compositions of coking charge containing finely divided coke fractions have been studied. The comparison of rheological properties of these mixtures and compositions, which have not been exposed to MAT, is made. It is found that the plastic viscosity diminishes as a result of MAT. In increasing temperature, this value initially drops and then becomes practically permanent. Apparent activation energy of viscous flow increases with the growth of the contents of finely divided coke fraction and has the same order of magnitudes for the compositions before and after MAT.
Key words: Soderberg anode, coke, pitch, coke-pitch composition, mechanic activation, rheological properties, plastic pro-perties, viscous flow activation energy.

Extractive metallurgy of less-common and precious metals

Yolshin V.V., Shagun V.A., Kolodin A.A., Ovsyukov A.E. Study of hydroxyl-ion effect on the mechanism of interaction of gold cyanides with active surface of carbon sorbents
Within the limits of quantum-chemical simulation methods, investigation of the possible participation of hydroxyl groups in the auracyanide sorption and desorption processes on the active surfaces of aromatic character has been carried out. Saturation of the active surface with hydroxyl groups is shown to result in significant decrease of sorption and desorption barriers. The effect can be used for intensification of gold and silver desorption process from active coals.
Key words: quantum-chemical calculation, potassium auracyanide, hydroxyl group, sorption mechanism, activation energy.

Casting production

Konovalov A.N., Urumbaev S.M. Peculiar properties of interaction of copper melt with air oxygen after deoxidation
Copper melt holding time dependence of the content of dissolved oxygen after using different deoxidizing agents in the laboratory conditions has been examined. It is found that the melt oxygenation rate is high in melting in alumina crucibles in the air without protective covering flux. Among the studied deoxidizing agents the most effective protection of the melt against the air oxygen is ensured with zirconium.
Key words: copper, smelting, oxygen, deoxidation.

Sharshin V.N., Kechin V.A., Sukhorukova E.V., Sukhorukov D.V. Improvement of iron receiver configuration in casting with melt centrifuging
Theoretical and experimental researches of various iron receiver designs in casting with melt centrifuging have been carried out. It is found that iron receivers of traditional design with sharp stream quarter turn do not ensure the demanded rate of mould inflow because of loss of initial dynamic head, melt slippage off the mouths of collecting drums, and the turbulent flow origination. The iron convergent type receiver configuration is proposed allowing to eliminate the mentioned disadvantages and to raise the discharge coefficient up to 0,6–0,8. The basic design data of the iron receiver are optimized.
Key words: iron receiver, rotating mould, melt centrifuging casting, simulation, discharge coefficient, hydrodynamic para-meters.

Metal forming

Kolmogorov G.L., Kosheleva N.A., Kuznetsova E.V., Chernova T.V. Temperature conditions and modes of residual strain formation during wire drawing
The temperature conditions resulting in thermoplastic deformations and residual stress formation are considered in drawing of superconducting wire stocks.
Key words: superconducting materials, residual stresses, contact heating-up, thermoelastic state, temperature conditions, drawing.

Fastykovsky A.R. Feasibility range of extrolling process and effective modes of deformation
The effect of design features of groove design, location of the die relative to the line connecting the centers of rolls on extrolling process parameters has been studied. The area of the process feasibility is established, power efficient deforming modes are determined, and the recommendations on rational arrangement of deforming unit are given. The energy demand control capabilities in carrying out the extrolling process are shown.
Key words: extrolling, area of feasibility, groove design, power efficient deforming modes.

Materials science and heat treatment

Grigoriev V.M. Investigation of zirconium-containing aluminum alloys
New zirconium foundry alloy provides increasing the physical-mechanical properties of aluminum at the expense of structure crushing and formation of strengthening phases by alloying elements with aluminum.
Key words: aluminum, zirconium, ore zirconium concentrate, zirconium-containing aluminum structure, micro-X-ray spectral analysis, element microdistribution in aluminum.

Belov N.A., Alabin A.N., Mishurov S.S. The iron and silicon effect on phase composition and structure of heat-resisting casting nikalins strengthened by Al₃Zr (L1₂) nanoparticles
Analysis of phase composition of the Al–Ni–Mn–Fe–Si–Zr system with reference to thermostable nikalin, being aluminum alloys of a new generation on the basis of the Ni-containing eutectic hardened by Al₃Zr (L1₂) nanoparticles, has been carried out. Iron and silicon presence is shown to essentially complicate the phase composition as compared with AN4MTs2 basic alloy. Silicon strongly expands the crystallization range thus augments propensity of the alloy to firecracking during casting. Economically-alloyed AN2ZhMts nikalin concerning the basic performances (thermal resistance, mechanical and processing properties) essentially exceeds the most refractory branded foundry aluminum alloys of AM5 type.
Key words: foundry aluminum alloy, high-strength, economically-alloyed, thermally stable, refractory, unit strength.

Powder materials and coatings

Malyshev V.V., Gab A.I. High-temperature electrometallurgical synthesis of molybdenum and tungsten carbides
The product compositions of electrolysis of melts on the basis of eutectic sodium chloride – lithium fluoride and sodium tungstate mixture containing molybdenum (VI) or tungsten (VI) oxides, lithium or sodium molybdates, tungstates, and carbonates have been investigated. Carbon, molybdenum, tungsten, their bronzes and carbides are shown to be electrolysis products depending on the contents of melt components. The electrochemical plating conditions by molybdenum and tungsten carbides onto carbon, nickel and copper bases have been specified.
Key words: ionic melts, molybdenum, tungsten, electrometallurgy, synthesis, carbides, powders, coatings.

Process control and automation

Salikhov Z.G., Gazimov R.T., Shubin M.V., Bekarevich A.A. Automated diagnosis and elimination of envelope and lining cleavages in rotating furnace without its shutdown
A mechanism of forming patch and its cleavages is analyzed. Based on the mechanism, a new automatic technique is proposed to clear cleavages without inserting considerable corrections into the process conditions of the furnace and its shutdown. Operating mechanisms for this technique are determined and the principle of their action is described, control actions are selected, and formal relations among them are derived. This allows us to compile a program algorithm of automatic control of patch reclamation in a rotating furnace in real time. The presented techniques and algorithms are the base for creation of a computed system to find and clear the defects of patch and lining in rotating furnaces in order to minimize the duration of forced outages, risks of occurrence of severe accidents and to cut production cost by 10–15 %.
Key words: rotating furnace, patching cleavages, automated control system, algorithms.

Economics and management

Golfаnd I.Ya., Krapukhina N.V., Fokina E.M. Characteristic properties of decision making in company management in nonferrous metallurgy for gold mining company taken as an example
The article describes the concept and implementation of a mathematical algorithm of constructing a strategic plan of the company based on the theory of fuzzy sets and alternative graphs. The algorithm is constructed for the actual problem of maximizing the value of Highland Gold Mining Company. The methods in use allowed us to consider all possible limitations of the company: internal (resource availability) and external macroeconomic constraints. The algorithm test has revealed the most effective management solutions for the company value maximization.
Key words: cost of metallurgical enterprise, organization management under the conditions of indeterminacy, algorithm of constructing the strategy of metallurgical enterprise, theory of fuzzy sets and alternative graphs in decision making.

Chronicle

• Professor A.S. Medvedev is 70 years old