Preview

Izvestiya. Non-Ferrous Metallurgy

Advanced search

Articles devoted to the 75th anniversary of Chair of Nonferrous Metallurgy of Irkutsk State Technical University

Chernyak A.S.To the 75th anniversary of Chair of Nonferrous Metallurgy of Irkutsk State Technical University

Mineev G.G., Zhuchkov I.A., Punishko O.A., Mineeva T.S., Aksenov A.V. Biometallurgical and chemical methods of gold and silver extraction from non-conventional ores, concentrates and technogenic raw stock
The scientific data and the results obtained in the technological tests of new progressive metallurgical and biochemical processes to extract gold are generalized. A special attention is given to the development of biotechnological methods of breaking down and extracting metals from persistent materials. Using IR-spectroscopy, the composition of resulting complex compounds is determined and the process mechanism was established. The physical-chemical foundations and the conditions of conducting the process of absorption of dissolved and collaurin by microscopic fungus are considered. Water-alkaline solutions of organic cyanogen-bearing (malononitril, acetonecyanohydrin), sulfur-bearing (thiosulfate, thiocyanate) and chloride-hypochlorite reagents, the mechanism and kinetics of gold and silver dissolution in them were studied. Using X-ray spectrum analyses the investigations of structural conversion and thermal activity of pyrite and arseno-pyrite during mechanical operation were carried out. A process of gold and silver extraction from persistent sulfide concentrates on the basis of mechanochemical degradation, heat treatment, and soption leaching was developed. Techniques of tail dump processing at gold-extracting mills were proposed. They provide for additional extraction of significant gold from off-balance raw materials at the enterprises of Siberia and Transbaikalia.

Anfilogova L.A., Belousova O.V., Kuz'mina M.Yu., Bogidaev S.A. Effective technologies in processing rare-metal raw stock and materials
Tantalum niobates were established to alter their physical-chemical properties under the conditions of electrochemical treatment of mineral pulp. The favorable results on flotation and magnetic separation of this kind of raw stock in introduction of preliminary electrochemical treatment were obtained. A method of low-temperature sintering of wolframite concentrates with ammonia sulfates with creation of closed technological circuit was developed. A degree of tungsten oxide extraction makes up 93- 95 % in this case. The investigations, which are directed to simplification and unification of the technological circuits of the molybdenum metallurgy, were performed. Electrochemical oxidation of titanium was carried out in nitrate-nitrite solutions with producing films, which possess high corrosive resistance in acid solutions.

Chalykh V.I., Nemchinova N.V., Ayushin B.I., Bogdanov Yu.V.Technical and economic comparison of electrolyzers with baked anodes and self-baking anodes and upper current carrier
A comparative analysis on different performances of two electrolyzer types for aluminum production: with prebaked and self-baking anodes is given. Such parameters as specific consumption of electric power and carbon, fist cost of unit of manufactured products, ecological effectiveness were used. Rehabilitation of enterprises with transfer to baked anodes was proposed to carry out in the single-storey buildings equipped by electrolyzers of S-2 and S-3 types and in the buildings with side current-supply electrolyzers. To construct new production capacities is much efficient on the basis of powerful electrolyzers with baked anodes designed for I ≥ 300 kA.

Sedykh V.I., Baranov A.N., Nikanorov A.V., Ershov P.R. Ways to cut down fluoride emissions in the aluminum production
Solid fluoride emission lowering is one of actual problems of the aluminum metallurgy. The processes developed at the chair of nonferrous metals metallurgy of the Irkutsk State Technical University allow us to cut down, to a great extent, the fluorine losses along with solid waste in the course of aluminum production in the electolysers of upper current supply. Implementation of column flotation machines with descending pulp-air flow in a cycle of coal foam flotation at OAO “BrAZ” and OAO “SUAL-IRKAZ” results in increase in yield of flotation cryolite down to 4- 6 % fluorine content in flotation tailings. The transfer of aluminum plants of the Eastern Siberia to lithium-containing electrolytes is recommended for cutting down the fluoride losses along with waste gases. Rich brines of the Irkutsk District are a source of lithium. The processes proposed permit producing lithium-containing cryolite directly by aluminum plants using standard equipment.

Elshin V.V., Mineev G.G., Golodkov Yu.E. Investigation of the process of autoclave desorption of gold from activated carbon
A mathematical model of autoclave desorption of gold from activated carbons with stationary sorbent layer was derived. Kinetics and some aspects of the desorption mechanism were investigated using the model. Limiting stages of the process were found and the coefficients of internal and external mass transfer in affecting the main desorption parameters are determined. A hypothesis on formation of gold intermediates of [Au(CN)(OH)]- kind in the sorbent phase in lack of free cyanide is suggested.

Kurkov A.V. A role of S.I. Pol¢ kin in development of the theory and practice of rare-metal ore processing (to 100th anniversary of birthday)
The critical moments and the main ideas composed by S.I. Pol¢ kin in the field of rare-earth raw stack and the theory of flotation process are described. Development of the given regulations under the present-day conditions is shown and the new ones are produced, which are based on the fundamental results obtained by S.I. Pol¢ kin.

Bystrov S.V., Koshel¢ D.Ya. Nickel sulphidizing from oxidized nickel ore by pyrrhotite
The investigations of nickel sulphidizing out of oxidized nickel ore in the reducing atmosphere by pyrrhotite under the conditions close to Vanyukov¢ s melting process have been carried out. The results produced allowed us to establish the effect of blowing time, settling duration, amount of sulphidizing agent, and temperature to extract metal into matte.

Kozhevnikov A.V., Lysenko A.P. The effect of technological parameters on current yield in processing anode deposits in high-purity aluminum production
Electrolytic processing of anode sediments from the production of high-purity aluminum at OAO “KrAZ” with extraction of aluminum-silicon alloy on the cathode was studied. A formula to determine the current yield that takes the kinetics of electrode processes into account was represented. It is shown that the following parameters: current density 0,84 A/cm2, electrolyte composition 35 % BaF2, NaF and AlF3 are rest with cryolite ratio < 2, the interpole distance is 5 cm and more, process temperature of 950 ° C are optimal technological conditions. Maximum current yield under the laboratory conditions calculated according the formula makes up 92 % on the cathode and 96 % on the anode.

Ivanov V.A., Krylosov A.V., Rebrin O.I., Shtutsa M.G. Production of alloys containing rare-earth metals by method of high-temperature exchange reaction
A possibility of preparation of alloys containing rare-earth elements by high-temperature exchange reactions with simultaneous alloy-formation is shown. Investigations on choosing electrolyte for production of such alloys have been carried out. Analysis and the properties of model and real salt mixtures were found to well agree with each other. Therefore preliminary modeling of salt mixtures has an important technological significance. The process to produce alloys on the basis of magnesium and aluminum with simultaneous alloying by other components has been investigated. The effect of process conducting temperature, duration of reaction, electrolyte composition, metal to salt ratio on concentration and degree of rare-earth metal yield into the alloy was considered.

Malyshev V.V. High-temperature electrochemical synthesis of nickel(cobalt)-molybdenum(tungsten) alloys and intermetallics in oxide tungstate melts
Electrochemical extraction of nickel and cobalt in tungstate solution and the effect of the electrolyte conditions on composition and structure of sediments of nickel (cobalt)-molybdenum (tungsten) alloys and intermetallics in oxide tungstate solutions has been studied. The phase composition of cathode deposits was shown to change from nickel through alloys and intermetallics nickel (cobalt)-molybdenum (tungsten) of different composition to pure molybdenum (tungsten) in increasing concentration of molybdenum (tungsten) and decreasing of nickel (cobalt) content in the melt.

Panov E.I., Eskin G.I., Galkin A.M., Kon¢ kov A.O. Plastometric investigations of limiting ductility and resistance to torsion deformation of hypereutectic 01390 grade silumin as applied to the process of helical rolling of bars and tubes
Rheological properties of hardly-deformed hypereutectic silumin of 01390 grade were investigated during torsion tests in a plastometer in a range of helical rolling temperatures at real deformation rates. A comparative estimation of limiting ductility and resistance to deformation under the stressed state and real temperatures and deformation rates by torsion and tension method is given. A possibility of computer modeling describing the process of bar rolling and bottle conversion by helical rolling is shown. The results obtained allow us to obtain necessary data for optimization of the helical rolling process in manufacturing bars and pipes from hypereutectic silumins.

Pevzner M.Z. Analysis of the effect of technological factors on formation of cracks in brass tube welding
In investigating the effect of different factors on formation of crack during tube welding the multiple regression analysis of structure, technology and results of processing tube skelps from 115 batches and mathematical modeling of changing these parameters have been used. Cold rolling with intermediate annealing, limitation of maximum permitted grain size of tube skelp by adjustment of annealing regimes and modifier addition has been proposed. This allowed us not only to prevent cross crack formation in welding tubes but also to expend essentially permitted limits of content of lead impurities.

Kolachev B.A. Review for tutorial of S.A. Golovin “Physical grounds of plastic deformations”

Standards and regulations

Levashov E.A., Mal¢ tsev V.V. Memorial Paper about a Teacher

No 2 (2005)


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