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Izvestiya. Non-Ferrous Metallurgy

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Mineral processing of nonferrous metals

Melik-Gaikazyan V.I., Ermakov K.G., Emelianova N.P., Draganov A.V. Physicochemical factor that determines intensity of foam formation
Earlier used physicochemical factor ( = d - e) being equal to the difference between dynamic ( d) and equilibrium ( e) values of the surface tension measured in pulp has been proposed for estimating activities and consumption of foam makers. Application of a digital photographic camera was substantiated for estimation of e value. Knowledge of factor can be useful in studying and choosing the optimal reagents of foam-suppressors.

Luzin B.S., Golik V.I. The prospects of gold mining development in Kazakhstan
A characteristic of the gold-ore fund of Kazakhstan is given including the technogenic one with the distribution by origin criterion. The results of the practical activity of the Kazakhstan enterprises "ABS" for gold leaching out of poor ore and dressing tails are given. Typification of gold-containing minerals by processability index is proposed. The problems restraining the rates of gold mining by means of heap leaching and the trends of development of gold production under the market conditions are formulated.

Zlobin M.N., Mityukhin S.I., Mironov V.P. The prospects of application of modular plants in processing ores of low-productive and remote gold deposits
Diamond kimberlite pipes are scattered over a wide territory of unsettled regions being practically unreclaimed and scarcely suitable for residence. Therefore, construction of large-scale ore mining and processing enterprises, which will be unclaimed upon completing operation of native sources or placers, is inexpedient. Development of modular dressing plants is one of feasible directions in exploitation of the Arctic deposits. All operations of ore-preparation and prior concentration at remote and inefficient deposits can be performed with help of connected to each other modular plants of flushing device types widely used in dressing of alluvial gold. Such a system of plants can produce just several hundreds of kilograms of the concentrated product after processing 1000 tons of ore. The product can be delivered by, for example, a helicopter to the nearest functioning concentrating mill for further concentration and final processing. Use of modular plants for processing of large-volume samples of remote pipes of the Munsky kimberlite field can be the starting stage of their industrial exploitation.

Extractive Metallurgy of Nonferrous Metals

A set of articles devoted to the 70-year-old of Yu.A. Lainer, Professor

Gurevich R.A., Balmaeva L.M., Malyshev V.P., Lainer Yu.A., Yampurov M.L. Investigation of caolinite dehydroxylation process and chemism of meta-caolinite and aluminum oxide dissolution in sulfuric acid

Based on the data of thermographic, X-ray phase, and crystal-optic analyses, a scheme to convert thermically caolinite of alumina-containing calcined rock was proposed. A theoretical analysis of the mechanism of its dehydroxylation and chemism of the reaction of meta-caolinite to sulfuric acid interaction has been carried out. The analysis permitted proposing existence of a conglomerate consisting of chemically bound compound of meta-caolinite with unsaturated bonds and amorphous mixture of aluminum and silicon oxides. The aluminum oxide dissolution process in sulfuric acid is analyzed by equilibrium-kinetic method. The main factors obtained allow us to make a general kinetic and thermodynamic prediction for the dissolution reaction of alumina- and silicon-containing materials in H2SO4. The process is established to be adequate with intra-diffusion model.

Balmaev B.G., Lainer Yu.A., Gurevich R.A., Malyshev V.P. Mathematical simulation and optimization of the process to produce aluminum products of alumina-containing coaly waste of the Borlinsky deposit
The process of leaching of alumina-containing rock calcined under the optimal conditions has been studied. A mathematical model was developed, and the first stage of hydrometallurgical processing of alumina-containing coaly waste was optimized. The optimal conditions are as follows: T = 95 C, = 120 min, concentration of H2SO4 is 350 g/l, and its amount to stoichiometry is 100 %. The design degree of alumina extraction into the solution is 67,90 %, and the experimental one is 67,82 %. Additional optimization of the process by means of dosed supply of calcined rock to pH = 2 for 120 min and then to pH = 2,7 (60 min) allows us to rise the degree of aluminum extraction up to 83,02 %. Based on the mathematical model, the kinetics of leaching of calcined rock was studied, the equation for process rate was derived, and activation energy Ea = 74,3 kJ/mole was calculated. Internal diffusion was found to be the limiting leaching stage.

Todorov S.A., Lainer Yu.A., Medvedev A.S. Utilization of low-concentrated solutions with application of electrodialysis
A method of utilization of industrial discharges and used process solutions from the enterprises of the alumina industry (weak aluminate solutions), i.e. electrodialysis with ionite membranes, was analyzed. The studies were carried out in a two-chamber laboratory electrodialysis plant with stainless steel electrodes, which was fitted with a cationite membrane MK-40. A linear dependence of alkali concentrating rate on current density (i = 2 4 A/dm2) was obtained. 15 %-concentration of alkali was reached in the cathode chamber, as allowed us to use it repeatedly in the process cycle.

Lainer Yu.A., Tuzhilin A.S., Perekhoda S.P., Samoilov E.N., Vetchinkina T.N. Complex processing of aluminum-containing waste with production of alumina, coagulants, and building materials
Physicochemical bases and techniques for processing aluminum-containing wastes (hydroalumocarbonate sediments, underslime waters, foundry slag, slimes, catalysts, mineral part of coals) to produce alumina, coagulants for purifying drinking and sewage waters, rare metals and building materials in using acidic, chloride, and thermal-electric methods were developed. Physicochemical bases of processing of aluminum-containing waste include studying the kinetics of interacting the main components of the waste with alkali, acids, and chlorine; properties of aluminate, sulfate, nitrate, and chloride systems containing aluminum, iron, alkali elements, and rare metals; separation of aluminum compounds in water solutions from iron and silicon oxides; determination of chemism and mechanism of transfer of sulfates into aluminates in decomposing sulfate compounds of aluminum, potassium, and sodium; extraction of germanium, scandium, gallium, zirconium, and other minor impurities from the waste for the purpose of more complex use of them.

Lainer Yu.A., Lyakishev N.P., Alymov M.I., Kalita V.I., Levashov E.A., Senatulin B.R. Development and synthesis of inert anodes for aluminum industry
Studies for synthesis of inert anodes and their tests in three main groups of materials: ceramic metals (cermets), metallic compounds, and encapsulated gradient materials have been carried out. The cermet anodes were produced by compaction followed by sintering or gas-thermal sputtering. Optimal conditions to reach high densities and sufficient uniformity of the composition were found for samples produced by the first method. The process with local gas protection was developed and realized for the second method. It was shown for metallic compounds made of different alloys (Hastelloy, high-strength iron, and others) that they cannot work without preliminary preparation, since a massive oxide layer is formed on the surface. Increasing in size, the layer exfoliates from the sample as a single whole. It was noted that development of porousless multi-alloyed composition of anode with barrier protective layers capable to increase resistance of anode simultaneously to the effect of atomic oxygen and to electrochemical corrosion in the process of electrolysis holds much promise.

Metallurgy of less-common and precious metals

Malyshev V.V. Electrochemical synthesis of powders of refractory compounds of metals of IV-VIA groups of the Periodic System of elements from ionic melts
Well-known electrolytes for high-temperature electrochemical synthesis of borides, carbides, and silicides of IV-VIA group metals of the Mendeleev Periodical System of elements are systematized in the classes of compounds being synthesized. The conditions of their deposits from the electrolytes different in the composition are generalized. The results of recent investigations in this field are given. Assumptions on possible mechanisms of synthesis processes are given.

Krasikov S.A., Istomin S.A., Selivanov A.A. Density of niobium-containing oxide-fluoride melts
The effect of Nb2O5 on density of melts based on CaF2 and CaF2-30 % Al2O3 was studied by the method of maximum pressure in a gas bubble in a temperature range of T = 1673 1873 K. It was found that when Nb2O5 concentration grew from 0 to 25 %, the melt density increases in the range of = 2450 3020 kg/m3 and the temperature coefficients are d /dT = -(0,12 0,62) kg/(m3 K). The data obtained are evidence of increased volatilization of the components from oxide-fluoride melts and the complexing mode of niobium and aluminum in the systems studied.

Metal Forming

Bakh F.-V., Zilberg Yu.V., Rodman M., Yablonik L. Investigation of deformability of magnesium strips during rolling
The deformation conditions have been investigated when fracture of lateral and front edges in the course of rolling of AE 21 alloy specimens of different thickness and width with different drafting schedules on dry and lubricated rolls at the room temperature and the temperatures of 300 C and 430 C as well as fracture of metal in vicinity of the surface hollows arise. A conclusion was made of the deciding effect of deformation non-uniformity on fracture of metal under the conditions studied.

Physical Metallurgy and Heat Treatment

Levinsky Yu.V. The P-T-x state diagram of the gold cadmium system
Based on the analysis of thermodynamic data obtained by different methods, the Р-T- and РCd-T-state diagrams of the gold-cadmium system within a whole range of concentrations at T = 400 1200 C and P = 1 105 Pa as well as sections of the state diagram: isobaric section at P = 130 Pa and isothermal one at T = 500 C were first calculated and plotted. The diagrams obtained characterize most completely the equilibrium conditions of condensed and gaseous phases in the Au-Cd system.

Powder Materials and Coatings

Lopatin V.Yu., Dubynina L.V. Preparation of macro-homogeneous mixtures of metallic powders with salt poreformer during its great-scale volume content
An analysis of properties of inorganic compounds used as poreformers being removed has been carried out. Ammonium chloride, sodium hydrocarbonate and carbonate were chosen according to the results of the studies, and their properties and specific surface of different fractions were determined. The mechanism providing production of stable macro-homogeneous mixtures for high concentrations (about 95 vol. %) of the salt poreformer was found. The maximum nickel content was determined in a mixture when the mixture can be considered as macro-homogeneous one. The experiments showed an opportunity of principle to produce pressings of mixtures consisting of PNK-1L8 and iron with powder-like NaHCO3, Na2CO3 and NH4Cl which are characterized by strength being sufficient for further operations.

Process Control and Automation

Kudryavtsev V.S., Strashinin E.E., Lisienko V.G. Adaptive fuzzy controller and its application in temperature control in the process of autoclave bauxite leaching
A version of application of adaptive fuzzy controller for improving the combined control system with program constituents is considered. Some theoretical bases of the proposed control algorithm and its structure are shown. A system of the adaptive fuzzy controller, principles of its operation and self-training are given. An opportunity of its application for improving the characteristics of the temperature setting algorithm in the second autoclave of the battery for leaching bauxites at Bogoslovsky Aluminum Plant. Modeling made showed that the use of the method allows us to improve essentially control performance as compared with the initial system.

Economics and Management

Kiselev A.G. Problem of optimum IT-system of an industrial enterprise Large-scale IT-systems have been analyzed.
A concept of resources being overlapped is introduced. Problems of IT-systems including multiple images and overlapping are considered. The criteria of optimum IT-systems as large-scale human-machine systems in the view of queuing systems are proposed. Practical results on ERP and MES are obtained as applied to OAO "Novosibirsk Tin Plant".

Chronicle

Scientific cooperation between Russia and Great Britain is now gathering strength

No 3 (2004)


ISSN 0021-3438 (Print)
ISSN 2412-8783 (Online)