Extractive metallurgy of nonferrous metals

Natorkhin M.I. Colorimetric determination of silver and copper in solutions of chloride leaching
The paper considers an opportunity of joint determination of silver and copper in the solutions of chloride leaching using colorimetry and gives comparisons with the atomic absorptive analysis.

Mechev V.V. To the theory of autogenous processes of copper-bearing sulfide stock processing
The data are given on aliquation of copper melts in the converting processes and autogenous smelting. Examples of using the obtained results for improvement of existing processes and developments of new ones are considered.

Metallurgy of less-common and precious metals

Miklushevsky V.V. Investigation of Li₅AlO₄ synthesis using dry and repulping charge material mixing processes
A Li₅AlO₄ synthesis process using the charge produced as a result of dry and repulping mixing has been studied. Charge repulping mixing was carried out in the saturated lithium carbonate (13,3 g/l) with ratio of S:L = 1:4. Applying thermogravimetry, IR-spectroscopy and X-ray analysis, it has been established that in using the repulping charge the chemical reaction rate increases, the synthesis temperature decreases, and the apparent density of pentalithium aluminate increases. The charge repulping mixing enables us not only to improve the technical and economic indices of the synthesis process but to produce Li₅AlO₄ that is more preferable for the following aluminothermic reduction by its granulometric composition.

Miklushevsky V.V. New developments related to utilization of lithium chemical current sources and production of lithium salts suitable for aluminothermic reduction
The ranges of application and production of lithium are steadily expanding. In the recent years the production of lithium chemical current sources (LCCS) was developing most dynamically, and with connection of the above, a part of lithium metal consumption is steadily increases in the total balance, lithium wastes are also raising putting questions on necessity of their utilization and development of a process to produce lithium from utilized lithium-bearing products. The works carried out in Moscow State Steel and Alloys Institute on utilization of lithium-bearing wastes allow the following LCCS processing scheme to be proposed: decomposition of element body, leaching of cathode mass and anode blocks obtaining lithium-bearing solutions and manganese dioxide, precipitation of lithium out of the solutions as lithium carbonate and lithium hydroxodialuminate (LHODA), synthesis of lithium aluminates by sintering of lithium carbonate with LHODA, aluminothermic reduction of lithium aluminates in vacuum producing lithium metal.

Aitkulov D.K., Shevko V.M. Thermodynamic modeling and kinetic mechanisms of lead chloride-sublimation from the PbS¾ ZnO¾ CaCl_2¾ O₂ system
The results of thermodynamic modeling using the program complex ASTRA-4 and kinetic studies of interactions in the PbS- ZnO- CaCl_2- O₂ system are given. Using the thermodynamic modeling the effect of temperature (800- 1700 K) and pressure (0,01–0,1 MPa) was established on the distribution of Pb, S, Zn, O, Ca, Cl among the participants of the reaction in the system. Lead chlorination is noticed to be observed at T = 800 K and that of zinc does only at T ³ 1500 K. The practically complete transition of Pb (³ 98 %) into gaseous PbCl₂ and PbCl is observed at T ³ 1300 K (P = 0,1 MPa) and T ³ 1100 K (P = 0,01 MPa). It was found by studying the kinetics of lead chloride-sublimation that in the range of 1173- 1373 K it cannot be restrained by evaporation of lead chloride being produced. The process proceeds in the kinetic range and is restrained by chlorination of lead compounds.

Kritskaya E.B., Burylev B.P., Moisov L.P., Kostenko N.B. Measurement of boiling temperatures and calculation of vapor pressure and thermodynamic values for lead and zinc chloride melts
Pressure of saturated vapor over melted mixtures PbCl₂–ZnCl₂ was measured experimentally within the range of T = 850¸ 1150 K over all range of compositions. The data are given as equation lgP = –(A ± D A)/T + (B ± D B), where constants are calculated by the least-squares method. Evaporation enthalpy and normal boiling temperatures have been calculated. Total pressure in the system was found taking the literature data on activities of the components into account. The calculated data obtained were compared with the experimental ones, their coincidence for certain compositions and temperatures was shown, and the causes of differences were explained. Activities of components at T = 1000 K were calculated from the experimental data. The fusion diagram was analyzed taking the experimental data and the results of calculation on the basis of studying deviation from Raoult's law into account. The results have shown that the fusion diagram of PbCl₂–ZnCl₂ relates to eutectic type, and T = 260 ° C and x_PbCl2 = 0,2 are the most probable coordinates of the eutectic point.

Metal Forming

Polyakov A.P., Zalazinskaya E.A. Dynamic compaction of compacts of non-compacted metal stock
An analytical solution related to the problem of dynamic compaction of compacts from non-compact material has been considered, taking non-uniform distribution of residual porosity through the compact height and character of its transformation during deformation into account. When density being close to theoretical one, residual porosity is shown to be distributed through height practically uniformly whatever friction coefficient and initial rate of the tool. However the porosity jump through height can reach 0,06–0,08 for compacts with average residual porosity ³ 0,1 produced at sufficiently high initial rates.

Physical Metallurgy and Heat Treatment

Shikov A.K., Nikulin A.D., Silaev A.G., Vorobieva A.E., Pantsyrny V.I., Vedernikov G.P., Dergunova E.A., Potanina L.V., Plashkin E.I., Sudiev S.V. Development of superconductors for the ITER Magnetic System in Russia
A review is given of the present state in development and production of Nb₃Sn and Nb- Ti superconductors for the Model Coil and the real Magnet System of the International Thermonuclear Experimental Reactor (ITER) in Russia. It is shown that Nb₃Sn based superconductors, produced according to the “bronze” technique, for insertion of the model coil of the central solenoid meets the requirements of the ITER. A crucial current density in the cross section without copper is ³ 550 A/mm² in field of 12 T at T = 4,2 K, the level of hysteresis losses does not exceed 200 mJ/cm³, and the resistance ratio of stabilizing copper envelope of chromium-plated superconductor is 150. The results of developing and testing the Nb₃Sn based superconductors with an inner tin source are given. They verify an opportunity of using this material for the magnetic system coils. Properties of Nb- Ti based superconductors are considered for toroidal coils. An opportunity in principle of producing such Nb₃Sn and Nb- Ti based superconductors is shown with application of large composite billets of 300 mm in diameter, revealing the prospect of creating large-scale industrial production of the materials for the ITER magnetic system at the rate as great as several tens tons a year.

Butovsky M.E. Synthesis of copper-tin amalgams
A mechanochemical process has been developed for synthesis of copper-tin amalgams made of copper and tin powders and mercury metal, which advantage is complete lacking of any drainages (in contrast to traditional ones) as well as its high rate. A reactive composition of intermetallic compounds can be produced in changing quantitative ratio of copper, mercury, tin, and silver additives. The last can interact with mercury at the room temperature, enabling filling material to be produced excluding the heating stage – this is very important for stomatology. A low-stage process of copper-tin amalgams has been developed, their pilot lots in palletizing form were produced, and technical conditions were developed.

Powder Materials and Coatings

Andreev E.I., Bocharov A.S., Ivanov A.V., Libenson G.A., Lisin A.N., Malovik V.V. Mathematical model of optimization of uranium dioxide powder fuel-pellet producing process
A role of porosity in formation of sintered pellet density has been considered. A complex mathematical model was proposed for calculation of the parameters of active and passive porosity in all stages of uranium dioxide powder fuel-pellet producing process, enabling us to optimize the conditions to produce starting powders and pellets for the purpose of regulation of their porosity during sintering.

Ermilov A.G., Safonov V.V., Nesterov N.V. The effect of heat treatment on diffusion processes in the boundary layer between coating and substrate
The paper discusses the effect of different factors (duration of heat treatment, conditions of substrate preparation to metallization) on the parameters of forming the diffusion layer between coating and substrate. The coating being formed is shown to ideally reproduce its relief during thermocycling of the substrate in the process of thermal decomposition of carbonyl. This defines the formation of uniform diffusion layer during heat treatment of the coatings formed on both as-reduced substrate and the substrate with oxide layer.

Ghilev V.G., Busovikova T.M., Loginov M.G. Porous carbide-silicon materials sintered in reactive systems under negative volume effects
Carbide-silicon microporous materials have been produced by reaction sintering in reactive systems with negative volume effects. Reactions of carbothermal reduction of silicon oxide and SiC synthesis of the elements were used. The process based on the synthesis of the elements is most promising. Carbide-silicon materials with pores of 0,2 m m in size were produced during preliminary grinding of silicon and graphite mixture and sintering the compacts for 15 min in argon. The results of estimating selectivity of the membrane materials produced with respect to typical toxic impurities of industrial and utility waste waters are given. Carbide-silicon materials sintered in liquid phase from SiC powders with CaSiO₃ binder were tested as substrates in fabricating two-layer membranes. Lacking and minimal shrinkage in reaction-sintered and liquid-phase-sintered materials respectively enabled us to fabricate two-layer samples with substrate strongly bound to the selective layer synthesized from silicon and graphite mixture.

Structural Macrokinetics. Self-Propagating High-Temperature Synthesis

Filonov M.R., Anikin D.Yu., Pecherkin K.A. Mechanisms of interaction of Co¾ B and Fe¾ B melts with ceramic materials
Stability of ceramic materials has been studied in the medium of melts being rendered amorphous. Measurements of limiting wetting angle for these materials were carried out on the ceramic surface. Two conclusions were made from the results of the experiments: melt–ceramics interaction takes place mainly through the slag phase; boron nitride is the most stable ceramics for melting and pouring of melts being rendered amorphous in the air. Materials on the basis of BN were synthesized by the self-propagating high-temperature synthesis. Other refractory compounds were introduced in the ceramics composition for the purpose of improving such service properties as fire resistance, thermal resistance, mechanical strength, stability of compounds to the effect of reaction-active melts. The most promising refractory compositions were determined from the results of the studies.

Energy saving and environment protection

Shchetinin A.P., Salikhov Z.G., Spesivtsev A.V. Modeling of mass transfer in melt bath of horizontal converter
A mathematical description is given of the metal-melt converting process in a horizontal converter from the condition of representing a flame as a localized pulsed “bag2 with intermittent gaseous and melt phases. An equation of convective diffusion as partial derivatives of changing chemical elements as a function of time and state coordinates was derived. Using the mathematical model proposed the curves of changing average concentrations of substances were obtained at different Pecklet numbers. A comparative estimate of reliability of model and actual curves of changing sulfur content in the melt bath is given.

Process control and automation

Malyshev V.P., Teleshev K.D., Nurmagambetova A.M., Larikov V.A. System invariants of integrity and destruction of conglomerates
Twin-step character of destruction of agglomerates has been explained on the basis of system-wide invariants of stability. Taken chromium agglomerate and briquettes of copper charge mixture as an example, the close proximity of relation of loads under partial and full destruction to the golden ratio for both static and dynamic loading was shown.

Information

• Kolachev B.A. A review of “Progress in Hydrogen Treatment of Materials” boo
• Soloviyov V.P. On the procedure of introducing amendments in the State standards of the Higher Professional Education
• International Conference-Exhibition “Siberian Aluminium-2003”