Mineral processing of nonferrous metals
Abdrakhimov D.V., Abdrakhimov V.Z., Abdrakhimova E.S. The effect of some waste from productions of nonferrous metallurgy on physical-mechanical properties of bricks
It was found that introduction of the clay portion of tailings from gravitation of zircon-ilmenite ores, ash from thermoelectric power stations and dump overburden coaly-clay shale - country rock of gold-ore deposit - into the compositions of ceramic masses for brick making improves physical and mechanical properties of bricks. The regression analysis showed the experimental data to be described sufficiently well by linear second-degree equations.
Extractive Metallurgy of Nonferrous Metals
Troshkin A.M., Melnikov Yu.T. Kinetics of carbonate formation of lead sulfate
Kinetic mechanisms of PbS04 conversion into PbC03 in Na2C03 and (NH4)2C03 solutions at 7" - 293-343 and 283-308 К respectively have been investigated. The effect of Na2CO3 excess (with respect to the stoichiometric quantity) on the depth of PbS04 desulfurization has been established. The reaction orders on both sodium carbonate and ammonium sulfate were calculated: 1,6±0,1 and 1,1±0,2 respectively. Seeming activation energies were calculated for PbS04 desulfurization processes in the solutions of sodium carbonate and ammonia carbonate being 27,8±5,5 and 36,1±1,6 kJ/mole respectively. The carbonate formation rate was found to be weakly dependent on solution mixing intensity and restricted by reagent diffusion through the layer of nascent lead sulfate.
Smirnov B.N., Kozhurkov A.V. Deposition of copper powders on permanently renewable surface
The effect of cathode material and a number of process parameters on the process of electrochemical crystallization of powder-like copper has been investigated with permanently renewable cathode. Application of electrolyzers with permanently renewable surface allows us to increase the machine time of baths, produce powders of the narrow size range, control powder particle size, mechanize and automate the process, improve the working conditions, and cut down the heavy manual labor.
Partenov D., Stefanova V., Avramov A., Chimbulev M. Hydrometal-lurgical processing of polymetallic concretions of the Pacific Ocean
The article considers one of the variants of hydrometallurgical processing of concretions from the Pacific Ocean including leaching in water S02 solution, sulfide precipitation of nonferrous metals and obtaining purified manganese sulfate solution to be used for the electrolysis extraction. Leaching was carried out with mixture of gaseous S02 and the air bubbled in the concretion pulp and H2S04 water solution at the initial room temperature. In the course of separation of solid and liquid phases, Fe2+ oxidizes to Fe3* with MnO2 that contains in the concretions. The processes of Fe3* oxidation and hydrolysis were executed at Т = 87+2 °C and pH = 3,2+3,8. Sulfide precipitation of nonferrous metals was carried out with ammonia-sulfide solution at the room temperature and intensive mixing. Selective precipitation of copper sulfide has been reached at solution acidity of 10-15 g/I H2SO4 and complete precipitation of Ni, Co, Zn, and Fe do at pH = 6,5*7,1- Total quantity of Ni, Co, and Zn in the mixed concentrate rose to > 55 % by chemical enrichment. Nonferrous metal and iron contents in purified manganese sulfate solution of 38-40 g/I Mn concentration amounted to <0,001 g/I.
Patrakhin I.Yu., Mikhalev Yu.G., Isaeva L.A. Absorption and losses of fluorides by different alumina being on crust
Laboratory and industrial studies of effectiveness of catching fluorides by alumina layer being on the crust of the aluminum cell have been carried out. Some types of alumina from different producers as well as fluorinated alumina (after dry scrubber system) have been studied. The industrial studies showed the crust to prevent from coming fluorides into the alumina layer as evidenced by constant fluorine concentration in the top layer of alumina covering. During charging, alumina collects fluorine on average of 0,2 wt % for fresh alumina and 0,5-0,7 % for fluorinated alumina, and at a later time its concentration does not change, at least, for 8 h. In the laboratory conditions, fresh alumina in the top layer of the alumina covering was found to be able to absorb as little as 2 % fluorine and fluorinated alumina do as little as 1,8 %. The study of fluorine desorption from the surface of fluorinated alumina taken from the dry scrubber system of the smelter has shown the starting fluorine content to be < 1,1 wt % for decreasing fluorides losses concerned with desorption in feeding the cells with fluorinated alumina.
Golovnykh N.V., Bychinsky V.A., Istomin S.P. Aluminothermic processes in using sodium-aluminum fluorides in production of aluminum
Based on the results of thermodynamical modeling, the equilibrium compositions of salt product (sodium-aluminum fluorides) and Al-Si smelts which are formed during interaction of sodium silicofluoride with aluminum at Т -= 650+1500 °C and molar ratios of Na2SiF6 : Al = 3 : (4+32) are established. Providing the surface and bulk contact of reacting substances, plants and constructions are recommended to process sodium silicofluoride by alumino-thermic technique.
Metallurgy of less-common and precious metals
Koryakov V.B., Sokolova Yu.V. Modeling and optimization of scandium extraction and re-extraction with producing rough fluoride concentrate
The article gives the results of an experimental study and optimization of the parameters of Sc(lll) extraction out of the solutions of the following composition, g/I: 0,024-0,034 Sc(lll), 8,6-11,9 Fe(lll), 0,11-0,19 Ti(IV), 0,09-0,28 Zr(IV), 0,080-0,155 U(VI), 80-130 H2SO4 by D2EGFK (0,1-0,3 M) solution in kerosene as well as re-extraction by 1-4% solution of NaF with producing rough scandium fluoride concentrate. It was established that the characteristics of Sc(lll) extraction during working in a cascade are determined by D2EGFK concentration and residual Sc(lll) concentration in reverse organic phase. Mathematical models of Sc(lll) extraction and re-extraction have been proposed; they make it possible to derive nomographic charts that permit determining as much as possible scandium extraction and as much as allowable relation of the phases in the operations. Extraction and concentration of Sc(lll) in rough scandium fluoride are shown to be determined by NaF concentration in the re-extractant and the phase ratio in an operation. Optimum and admissible conditions of scandium re-extraction have been determined in joint consideration of the mathematical models. Residual Sc(lll) concentration in NaF solution has been established to be determined by Sc(lll) concentration in the saturated organic phase and U(VI) concentration in the starting solution.
Casting Production
Belov V.D., Semyonov V.A. The effect of magnesium and casting temperature on structure, mechanical and casting properties of alloy from the Al-Mg system
A possibility of principle has been considered to replace conventional hypoeu-tectic foundry silumin by alloy of the Al-Mg system in manufacturing ingots for important purposes. The effect of magnesium content on mechanical, technological properties and structure of VAL 16 alloy was established. Optimal temperature of alloy casting was found.
Pikunov M.V., Piletskaya E.G. Quantitative description of non-equilibrium crystallization of binary alloys with taking starting supercooling into consideration
Based on the phenomenological approach to the crystallization process, a method of quantitative description of non-equilibrium crystallization of alloys is described taking initial supercooling into consideration. Calculations made according to the mentioned method have shown the initial supercooling to considerably affect the crystallization run and structure of the alloys formed. The results of the calculations agree with the published experimental data.
Physical Metallurgy and Heat Treatment
Kudashov D., Bocharova E., Martin U., Baum Kh., Khaintsel G. A study of processes concerned with formation of dispersion-strengthened copper during mechanical alloying by high-resolution scanning electron microscopy
High-resolution scanning electron microscopy was used to investigate the processes of microstructure formation in dispersion-strengthened copper during mechanical alloying. A function of intragrouped correlation was used for quantitative estimation of strengthening particle distribution. It was shown that, in studying the microstructure change during mechanical alloying, it can be used not only for characterizing the particle distribution but also for determination of their average sizes and distance among them. Distribution of strengthening particles in copper matrix free of their accumulation was found after 20 h of milling in a high-energy planetary mill. A correlation among formation of the laminated structure in powder, strengthening particle size reduction and formation of their accumulation was found. If strengthening particles are distributed irregularly, nanosized granular matrix structure is found to be irregular too.
Pevzner M.Z. The effect of process factors on formation of rolling and annealing texture of AMg2 alloy
The effect of cast method, high-temperature ingot homogenization, reduction distribution in cold roll passes, intermediate annealing conditions, and cold rolling conditions for strip texture of finished size was investigated. An important role of process factors related to ingot production and an insignificant role of the cold rolling rate were found. There is a necessity of correcting the equation of relation between textural parameter and mechanical properties in changing the ingot production process, however inevitable changes of the cold rolling parameters along the length of a coil being rolled do not affect this relation.
Bokshtein B.S., Smirnov A.N. Grain-boundary segregation in alloys of the copper-antimony system
The results of the studies are analyzed which have been carried out with equilibrium grain-boundary segregation of antimony in copper alloys by AES and XPES methods while changing Sb concentration from 0,33 to 2,56 at. % in the temperature range of 673-1073 K. Based on Langmuir-Mac-Lean isotherm, Sb concentration (Xb°) was calculated in filling of all available cites in the first layer being in equilibrium with the second and next ones and the bulk as well (i.e. in saturation). The Xb° values do not exceed the Sb concentration in the chemical compounds being in equilibrium with the solid solution. Segregation capacity of the grain boundaries of copper alloys with respect to Sb is 0,38 through 0,65 of a monolayer.
Metal Forming
Fastykovsky A.R. To the problem of rolling-pressing process
A procedure has been developed to calculate strains on the die surface as applied to the rolling-pressing process. The effect of parameters in the deformation zone, position of the die relative to the plane going through roll axes, and the pass design are taken into consideration. Objectivity of the dependencies derived was testified by comparison between the calculated strains and the literature experimental data.
Powder Materials and Coatings
Antsiferov V.N., Porozova S.E., Filippov V.B., Shtutsa M.G., Il'en-ko E.V., Kolotygina N.S. Refining of high-temperature uranium melt by flirtation through foam-ceramic filters
An opportunity of applying foam-ceramic filters of corundum-mullite composition has been studied in refining natural uranium melt. Uranium melting conditions were chosen depending on technical characteristics of the foam-ceramic filters. When their using, a portion of nonmetallic inclusions decreases by 20-30 % (as little as 2,0-3,5 % ingot weight), their size is reduced and their distribution in the ingot volume is equalized, contamination of uranium by the filter material being failed to be noticed. The parameters of foam-ceramic filters are optimized for provision of stable characteristics of uranium melt filtration process.
Bugakov V.I., Laptev A.I., Pozdnyakov A.A., Ustinov I.V. A method of determination of pressure and its distribution in high-pressure chamber in producing diamond-containing elements
Measuring the nickel compact density that are produced in the high-pressure chamber according to the process of manufacture of diamond elements of stone-destructive instruments, pressure distribution in the working zone of the high-pressure chamber was studied. Pressure losses for friction and elastic loading of assembly elements were found to be 20 % and pressure gradient in the working zone of the high-pressure chamber was 0,2 GPa.
Process Control and Automation
Alkatseva V.M. Algorithm of calculation of bauxite leaching in autoclave battery with multiple separations
The algorithm and calculation computer-aided program of the autoclave bauxite leaching with the multistep pulp separation were developed. Mathematical models in the algorithm were obtained by the reference-sources data processing. The principle flow diagram of the calculation algorithm for the autoclave bauxite leaching with the multistep pulp separation is given.
Alekseev V.P. Effectiveness of control systems of technological type at different confidence levels of on-line input information
The questions to evaluate efficiency of the control system of technological type at different confidence levels of on-line input information are analyzed. It is proposed to evaluate the efficiency of process control system using the model of expected throughout rate depending on the factors essentially affecting the control process, model making up on the basis of the methods of multifactor correlation analysis. Application of the method proposed allows determining effectiveness of the control systems at their design phase with the use of a certain complex of technical means with specific characteristics of reliability and noise stability as well as establishing requirements to this complex.
Economics and Management
Kiselev A.G. Modeling and experimental investigations of quantitative characteristics of the ERP-system
The ERP-system is analyzed from the point of view of structural decomposition. The technologies of experiments in ERP, the results obtained (practical ones with respect to ОАО "Novosibirsk Tin Integrated Works") and quantitative characteristics in the implemented industrial system are given including generalization in conducting the project as a whole.
Soloviev A.E., Starykh V.B., Sadchikov I.A. What future is for major nickel producers
The article declares an assessment of possible changes in sales volume of major nickel producers in 2003-2004 subject to currency exchange rates and metal price variations in the world. The concept of sensitivity is used to define the effect of the above external factors listed on the revenue. Based on the average sensitivity indices and metal prices as well as exchange rates, possible changes in the -revenues of major nickel producers in 2003-2004 in comparison with 2002 are forecasted. The calculations made allow us to say that the main indicators, which affect the revenues of the companies, are nickel price and national currency/US dollar ratio. A predictable strong growth of average annual nickel prices in 2003-2004 will bring to significant increase in revenues and overbalance the negative effect of possible variations in currency exchange rates.
Miklushevsky V.V., Prokoshkin A.S., Baranov V.V. Development of the system of automated management accounting and budgeting in educational institution
A problem of development of automation system for management accounts and budgeting in the higher school is considered. A necessity of automating the management accounts and budgeting as an important component of the process improving effective activity in the higher school is shown. A methodology of making and implementing the automated information system of the management accounts and budgeting in the higher school has been developed, advantages and disadvantages of different approaches to development of such a system and a choice of variants in sequence of its implementation are considered. Objectives and structure of measures on realization of psychological maintenance of innovation concerned with implementation of automation system. A brief description of the integrated automated information system "Formation and cost estimation accounting of the Institute for subdivisions" developed and implemented in Moscow State Steel and Alloys Institute (Technological University) and destined for automation of accounting the data on planned and actual cost estimations related to intake and withdrawal of monetary funds in the Institute in the activity direction and subdivisions.
