Metallurgy of nonferrous metals
Diyachenko A.N., Kraidenko R.I. Copper oxide-sulfide ores with ammonium chloride
A method of copper raw material processing to copper oxide has been proposed and investigated. It is based on the decomposition of copper oxide and sulfide by ammonium chloride followed by leaching of copper chloride compounds and sedimentation of copper hydroxide from solution. The thermodynamics has been calculated and thermo gravimetric analysis of the processes has been carried out. The kinetics of the copper and iron sulfide as well as calcium oxide chlorination by ammonium chloride is studied experimentally. A process flow diagram consisting of the closed cycle of copper containing raw material processing by ammonium chloride is proposed.
Key words: copper sulfide, iron sulfide, ammonium chloride.
Rubanovskaya S.G., Velichko L.N. Using nontraditional materials in extracting ions of heavy metals by hydrometallurgical methods
There has been investigated a number of materials possessing extractive, sorption, reducing, and coagulation properties and sometimes combining them simultaneously. There have been found optimum conditions of carrying out the processes both of joint and selective extraction of metal ions. The process mechanisms with the use of selected materials are determined.
Key words: extraction, heavy metal ions, extractive properties, sorption properties, coagulation properties.
Sargsyan L.E., Oganesyan A.M. Activated sulphatizing roasting of chalcopyrite concentrate for sulfuric-acid leaching
The sulphatizing roasting of chalcopyrite concentrate with various pyrite content in activated conditions to obtain predominantly sulfate roast calcine better suitable for acid leaching for effectively recovery of copper and accompanied iron has been investigated. The activating effect of trivalent iron sulfate formed as a result of low temperature oxidation of pyrite as well as of steam air environment on the kinetics and completeness of concentrate sulphatization is showed.
Key words: sulphatizing roasting, chalcopyrite concentrate, pyrite, activated roasting, roast calcine, leaching.
Khrennikov A.A., Vasiliev E.A., Lebed' A.B., Naboichenko S.S. On interaction of indium and zinc sulfides with arsenite-ion in sulfuric-acid solutions
The exchange interaction of indium and zinc sulfides with arsenite ions in sulfate medium has been investigated at the laboratory conditions. Based on found regularities, a method of In and Zn after extraction from industrial sulfide cake obtained in the course of indium containing solution purification from arsenic is proposed.
Key words: arsenic, indium, zinc, hydrometallurgy, purification, precipitation, indiumcontaining solution, sulfide cake.
Metallurgy of less-common and precious metals
Gudkov A.S., Zhuchkov I.A., Mineev G.G. Mechanism and kinetics of sulfite-thiosulphate dissolution of gold
The mechanisms of precious metal dissolution in water solution of sodium thiosulfate, sodium sulfite, and their mixtures at normal conditions (without the solution heating) in acid and alkaline medium are described. The conditions of solution process intensification are assessed. Investigations of reaction rates have been carried out. As a result of the obtained data, a conclusion on expediency of application of sulfite thiosulfate dissolving agents for precious metals from concentrates at the normal conditions is made.
Key words: precious metals, dissolution kinetics, sodium sulfite, sodium thiosulfate, sulfitethiosulfate dissolution, aqueous sulfur solutions.
Physical metallurgy and heat treatment
Psaryov V.I. Investigation of precipitate formation kinetics in decomposing supersaturated solid solutions
The features of microparticle system formation during decomposition of supersaturated solid solutions have been analytically described taking the size factor of interfacial energy into account. The proposed calculation has revealed the physical nature of phenomena, which are correspondent to the phase transformation in homogeneous and heterogeneous regimes. The decisive characteristic of such possibility in the stage of nanostructure nucleation is the matrix phase supersaturation. Unimodal and bimodal microparticle systems can be formed at certain values of this parameter. The reliable experimental facts confirm the conclusions of the theoretical analysis. The solutions obtained can be extended to diverse bulk and surface microparticle systems.
Key words: nucleation, critical size, distribution function, interphase factor, analytical formula, supersaturated solution, homogeneous and heterogeneous regimes.
Structural macrokinetics. Self-propagating high-temperature synthesis
Levashov E.A., Kurbatkina V.V., Patsera E.I., Pogozhev Yu.S., Rupasov S.I., Rogachyov A.S. Self-propagating high-temperature synthesis of promising ceramic materials for functional nanostructural coating depositing processes
In view of the demand for composite targets – precursors for ion-plasma processes of depositing functional nanostructural coatings, the work gives a review of recently produced and earlier unpublished results on the synthesis in the combustion conditions of number of chemical classes of the systems differing in combustion mechanisms and structure formation. The experimental results of self propagating high temperature synthesis in the following system: Ti–Al–C, Cr–Al–C, Ti–Cr–Al–C, Cr–B, Ti–Cr–B, Ti–Ta–C, Ti–Si3N4–Al–C are given. The compositions of reaction mixtures and the conditions of the most interesting and demanded materials with high mechanical properties and hightemperature oxidation resistance have been found.
Key words: self propagating high temperature synthesis, combustion mechanism, kinetics, MAXphases, titanium carbide, tantalum carbide, titanium boride, chromium boride, titanium carbonitride, phase composition, structure, mechanical properties, heat resistance.
Energy saving and environmental protection
Choshnova D.K., Stefanov B.S. Investigation of the circulating zone formation conditions in laboratory model of flare melting furnace
In the "Outokumpu" furnace for flash smelting, the flow movement pattern in the working space determines specific process features. Physical chemical and thermophysical processes proceed at the conditions of high temperature multiphase multicomponent dispersed medium. Physical modeling makes the possibility to study and visualize the flow movement in similar media and investigate the effect of different factors on the unit operation. Using the laboratory model of reaction shaft and a charging burner, the conditions of flow recirculation formation in the reaction volume of a flare furnace have been investigated.
Key words: flash smelting, physical modeling, static pressure, flow recirculation.
Chronicle
- Galevsky G.V., Rudneva V.V. Professor T. Hall and diamond synthesis process (to 90-year since birthday)
- Shimov V.V. Metallurgical department of Ural Federal University (UGTU-UPI) is 90 years
