Extractive metallurgy of nonferrous metals

Khrapunov V.Е., Isakova R.A., Zhunusova G.Zh., Abramov A.S., Trebukhov S.A., Sadvakasov D.A. Evaporation of mercury at decreased pressure
A dependence of velocity and degree of mercury volatilization on residual pressure (0,13- 92 kPa), temperature (200–400 ° C), and duration of the experiment has been investigated. When the furnace temperature being higher than the temperature of mercury saturation at the given pressure, the evaporation rate upon reaching the maximum during heating in the beginning of the experiment goes down, as connected to the decrease in mercury weight and its heat-receiving surface area accordingly. Different mercury evaporation rate at the same pressure, temperature, and geometric surface of evaporation can be explained by distribution of the evaporation process in the depth of mercury, i.e. even by boiling in vacuum. Under the boiling conditions, the Hg temperature depends poorly on the furnace temperature and it is close to the saturation temperature at the given pressure. When boiling, the features of heat exchange exert noticeable influence on the evaporation process. Calculated according to the furnace temperature, the activation energy of mercury evaporation process is close to the evaporation heat at high pressure, and when pressure declines it decreases indicating a shift of evaporation process towards the boiling range. The activation energy calculated according to the mercury temperature without boiling changes poorly with changing pressure, and in boiling it increases more if the process moves more to the boiling range. The degree of dependence of maximum evaporation rate on pressure is higher at less temperature.

Kozin V.F. Anode processes in refining cadmium in its melt
A dependence of current yield of cadmium has been studied in the process of electrorefinement of cadmium in its chloride melt. A mechanism of anode dissolution of cadmium depending on current density and the process temperature was proposed. In dissolving cadmium in melted electrolyte the increase in anode current yield is caused by formation of cadmium of the lowest oxidation degrees.

Sedykh V.I., Tupitsyn A.A., Bychinsky V.A. Thermodynamic analysis of oxidation-reduction processes with participation of copper (I) sulfide
Behavior of copper (I) sulfate in the oxidizing and oxidation-reduction conditions has been studied by the technique of free energy minimization. It was fount that copper (I) oxide, mixture of oxide and sulfate or copper oxysulfate CuO× CuSO₄ can be the primary product of oxidation of Cu₂S depending on oxygen content in the Cu–S–O system. Formation of copper metal and copper (II) oxide takes pace in the result of secondary reactions. In the presence of carbon, the chemical mechanism of oxidation of copper (I) sulfide remains unchangeable as a whole. At low temperatures, carbon reacts with oxygen forming CO₂ and it exists in such a state within all the range of temperatures. Presence of CO₂ in the gas phase shifts the beginning of a series of reactions towards lower temperatures.

Begunov A.I., Zaichenko V.V., Shtelmakh S.I., Yakovlev S.A., Yakovleva A.A. An analysis of causes of instability of current yield in electrolyzers to produce sodium
The results of measurement of the process indices are given for BGK-N-30 electrolyzers applied for production of sodium by electrolysis of melted sodium chloride. The electrolyte temperature, voltage drop between the electrodes as well as between the cathode and diaphragm are used as such indices. The analysis of the results shows instability of heat and electric fields in the BGK-N-30 electrolyzers. It is the cause of a significant decrease in current yield of sodium. A physical model has been developed and it represents a plane section of the BGK-N-30 electrolyzer. Directions of electrolyte flows saturated by gas inclusions are found with the model. It was found that active penetration of chlorine through the diaphragm into the cathode space in the top part of inter-electrode space. Reliable separation of catholyte and anolyte will allow us to prevent oxidation of reduced sodium by small chlorine bubbles. Screening of the top part of the diaphragm was proposed for provision of such a separation.

Metallurgy of less-common and precious metals

Rychkov V.N., Sotnikov S.G. Sorption of zirconium out of sulfate solutions by polyampholytes
The article considers and discusses the calculated and experimental data on sorption of zirconium ions out of sulfate solutions by aminocarboxyl and aminophosphate ampholytes. Based on the calculated data, zirconium in sulfate solutions is shown to form a whole series of complex ions (sulfate, hydroxo- and mixed hydroxo-sulfate ones). Equilibrium of zirconium ions during their sorption out of sulfate solutions has been studied. Behavior of zirconium ions during their sorption out of sulfuric acid solutions in a wide range of its concentration is explained in the view of ionic state of the metal in the solution, structure, and functional features of ionites. The conclusions made as to the chemistry of sorption have been proved by the data of IR studies.

Tsurika A.A., Chub A.V., Drobot D.V. Solubility of higher niobium and tantalum chlorides in titanium tetrachloride under increased pressure
An original outfit has been designed and manufactured, it allows us to measure solubility of MCl₅ (M = Nb, Ta) under excess pressure. Solubility of niobium and tantalum pentachlorides in titanium tetrachloride up to the pressure of 5 atm (gage) has been experimentally investigated. Content of MCl₅ in the vapor phase has been measured. The information of solubility of MCl_x (x = 3÷6) in titanium tetrachloride were systematized with the use of the factor of intermolecular interaction.

Panov V.S., Suvorov K.A. A study of behavior of a plasticizer in heating specimens of hard alloys
Destruction of synthetic rubber of CKDSR grade, change in the furnace atmosphere during heating, carbon balance, and sample weight were studied in pusher-type electric resistance furnace in the hydrogen current in the temperature range of 20–1250 ° C with hard alloy of T5K10 grade taken as an example. It is shown that the atmospheric state during heating and carbon content essentially change depending on the place of a sample in the furnace. Destruction of CKDSR plasticizer during heating the hard alloy is accompanied by reactions of methane conversion with formation of carbon at T > 850 ° C and oxidation at T > 600 ° C, that affecting the properties of sintered hard-alloy workpieces.

Buchikhin E.P., Shatalov V.V., Chekmarev A.M., Kuznetsov A.Yu. Processing of zirconium metal waste with producing structural materials. Part 2. A study of features of precipitation and heat treatment ammonia complexes of zirconium tetrachloride
Precipitation of solvated zirconium tetrachloride by gaseous ammonia has been studied. It was found that a complex of ZrCl_4× 8NH₃ make-up is formed which is insoluble in N,N’-dimethylformamide. Thermal destruction of the complex produced was studied. Zirconium dioxide was found to be formed during its high-temperature treatment. As it is shown it is possible to produce ceramic materials out of zirconium dioxide stabilized by yttrium oxide during the combined precipitation of zirconium and yttrium chloride ammines and their heat treatment.

Gasanaliev A.M., Gamataeva B.Yu., Akhmedova P.A. Phase equilibria in the LiF¾ Li₂WO_4¾ K₂WO_4¾ CaWO₄ four-component system
The LiF¾ Li₂WO_4¾ K₂WO_4¾ CaWO₄ four-component system has been investigated for the first time with the use of a complex of physical-chemical analyses, in particular differential-thermal, visual-polythermal, and X-ray phase ones using the projection-thermographic technique. The tree of crystallization in the system was plotted. The coordinates of nonvariant points were determined.

Casting production

Znamensky L.G., Kulakov B.A., Ivochkina O.V. Electron-ionic activation of sand blends in investment pattern casting
Theoretical bases of treatment of plaster particles being in the fluidized condition by power electric field are considered. Electron-ionic technique of activation of plaster molding mixtures has been developed providing improvement of the quality of aluminum alloy casts.

Metal Forming

Fastyrkovsky A.R. Energy-power parameters of the process to roll and compact nonferrous metals and alloys
A calculating procedure for energy-power parameters of the process to roll and compact nonferrous metals and alloys has been developed. Experimental checkup of the theoretical concepts of the works showed a good convergence of the results.

Physical Metallurgy and Heat Treatment

Barsukov A.D., Mamzurina O.I., Trots V.S., Kholopova M.N. To the question on liquidus and solidus lines of the Nb–Mn state diagram in the range being rich of niobium
Liquidus and solidus lines of the Nb–Mn state diagram in the range being rich of niobium were determined by thermodynamic calculation with different approaches.

Powder Materials and Coatings

Ivanov A.N., Korshunov A.B., Yakovtsova M.M. X-ray determination of Ti_{1- x}W_xC complex carbide composition
Determination of the makeup of Ti_{1- x}W_xC compound carbide has been proposed according to its lattice spacing dependence on WC molar portion. The dependence is shown to allow us to determine the compound carbide makeup with great reliability (precision).

Dorofeev Yu.G., Bezborodov E.N., Sergеenko S.N. Kinetics of mechanochemical activation of D-16 aluminum alloy shavings, features of compaction of “shavings” powder and formation of the material produced
The effect of content of saturated water solution of ortho-boric acid C_ss, mechanochemical activation time t _MCA on the dispersion processes of D-16 aluminum alloy shavings, compaction of half-finished products during cold and dynamic compression, physical and mechanical properties of material based on “shavings” powder. Maximum bending strength, hardness, and machinability without destruction of hot-deformed material are ensured at = 22 wt % and t _MCA = 3 h. The process of producing hot-deformed material has been developed on the basis of “shavings” powder with increased mechanical properties.

Larin V.K., Kondakov V.M., Maly E.N., Matyukha V.A., Dedov N.V., Kutyavin E.M., Sennikov Yu.N., Stepanov I.A., Ivanov Yu.F. Plasma-chemical method of producing nanosized powders of metal oxides and prospective trends of their application
The article gives the data related to plasma-chemical process of oxides of different compounds: the process is highly productive, it has few stages, it demands no reagents to deposit salts, the powders formed can be regarded to be nano-sized materials, chemically active, homogeneous, and they represent solid solutions. A mathematical model for calculation of a reactor is given, its sizes are determined (time of drop evaporation and salt decomposition is 0,05¸ 0,10 s over 0,7 m at T = 1200¸ 1800 K); and the technological scheme is described. The morphological constituents of the powders (spheres, their fragments, films) are shown with zirconium oxide taken as an example. The prospective trends of application of developed plasma-chemical process are shown: mixed uranium-plutonium fuel for nuclear reactors, charge material for piezo- and structural ceramics.

Smetkin A.A., Konyukhova S.G., Yarmonov A.N. Application of porous permeable materials in dental implant technique
The results of physical-and-mechanical and morphological-and-radiological researches of the combined design of titanium implant consisting of porous and compact parts are given. The advantages of titanium permeable materials are shown from the point of view of osteointegration optimization in dental implantation.

Energy saving and environment protection

Svetozarova G.I., Andreeva O.V., Korsunsky V.I., Paretsky V.M., Miroevsky G.P. Statistical investigations of relationships of parameters of nickel protoxide reduction process in rotary tube furnace using hard reducing agent
A statistical treatment of computer experiments for the mathematical model of nickel protoxide reduction process in rotary tube furnace has been carried out. An algorithm to correct the calculation results on regression equations in relation with possible effect of unaccounted factors for difference of measured and calculable temperature values was proposed.

Process control and automation

Arunyants G.G., Rutkovsky A.L., Salikhov Z.G., Sidorov D.V., Shchetinin A.P. To the question on optimal distribution of loads among energy-consuming installations operating in parallel
An analysis of various approaches for the control of energy-consuming technological objects functioning in parallel and having non-stationary character has been carried out. The task of optimal load distribution among the aggregates functioning in parallel and characterized by after-effect was set and formalized. Special universal computer-aided algorithms of its decision were developed. Analytical methods of the optimal control strategy synthesis for the objects with “after-effects” based on the approximated suboptimal control algorithms of quasiopen type are given. An effective procedure was proposed for identification of the concentrated estimation of the system activity by means of minimization of a specially chosen approximate function. A two-level algorithm has been developed for solving a task of finding an optimal deterministic control, for example, a boiling bed furnace, aggregates functioning in parallel, on the basis of dynamic programming supplemented with the procedures that narrow the range of admissible states (loads) at each stage.

Lisienko V.G., Tashkinov A.Yu., Nasyirov Ya.A., Klimov M.I., Altman P.S., Goncharov A.E. Features of distribution of voltage drop over the arc voltage and frequency of drip shorting depending on current and spark gap during vacuum arc melting
An experiment on melting of a 515 mm electrode of titanium alloy into an ingot of 670 mm in diameter has been commercially carried out. Dependences of voltage drop on arc and frequency of drip shorting by arc current (7,5–15 kA), spark gap (0–160 mm), and pressure (9–15 m m Hg) with the help of the statistical models developed. A correlation was found for distribution of voltage drop over the arc and frequency of drip shorting depending on the spark gap. A model was proposed which can be used for controlling the melting process.

Chronicle

• To the 80th anniversary of the chair of technology of electrochemical productions at the Ural State Engineering University, the city of Ekaterinburg
• In memory of Gennady Ya. Gun (1933-1993)