Nonferrous ore concentration

Yevdokimov S.I., Panshin A.M. Investigation of flotation mechanism in airborne column flotation machine
In raising temperature, the induction time is shown to shorten when an air bubble adhere to hydrophobic and hydrophilic particles, and in its lacking, it decreases when hydrophobic particles adhere to each other and it increases in case of adhering hydrophilic particles. The established difference of stability of moistening and symmetrical films depending on temperature can be explained by the fact that hydrophobic forces (including those acting on the part of a “hydrophobic” bubble) have greater effective range than the forces of hydrophilic repulsive interaction. The found regularities made possible to develop a new flotation method, i.e. with air-steam mixture; the pith of the method is that, at the cost of steam condensation, to heat the surface bubble layer only (not the entire volume of pulp) where the action of structural forces is localized. The method efficiency has been proved by the example of flotation concentration of diverse useful minerals.
Key words: flotation, moistening film, column flotation, surface tension, hydrophobic and hydrophilic forces

Extractive metallurgy of nonferrous metals

Okunev A.I., Krasikov S.A. On possibility of proceeding heavy nonferrous metal and iron sulfide oxidation reactions according to chain mechanism
Thermodynamic estimation of oxidation of heavy nonferrous metals sulfides have been carried out. It was shown that values of Gibbs energy of oxidation reactions were located on decreasing absolute value for the type of sulfides in row: FeS, Ni₃S₂, CoS, NiS, ZnS, PbS, CdS, CuS, Cu₂S. The thermodynamic probability of the chain mechanism stages of sulfide oxidation with separation of gaseous oxygen and sulfur in atomic type was also estimated.
Key words: thermodynamics, oxidation, sulfides, heavy nonferrous metals, reactions, chain mechanism, stages

Syrykh Yu.S., Dudarev V.I., Afonina T.Yu., Moskaeva N.Yu. Adsorption extraction of nickel(II) ions from aqueous solutions
The nickel(II) ion sorption processes from water solutions over carbon-base adsorbing agents synthesized on the basis of mineral coals have been investigated. Maximum adsorption is observed in the neutral medium. The adsorption isotherms are obtained at different temperatures and static conditions. They are shown to be described satisfactorily with the Langmuir equation. The adsorption value decreasing during temperature growth exhibits the process exothermicity. The kinetics of the process has been studied and thermodynamic sorption parameters have been determined.
Key words: sorption, carbon-base adsorbing agents, water solutions

Naguman P.N. Production of manganese dioxide under the conditions of diaphragmless electrolysis
The manganese dioxide producing conditions of the diaphragmless electrolysis have been investigated. The optimal process conditions depending on current density, process duration, and acidity are established.
Key words: manganese dioxide, electrolysis, cathode, anode, diaphragm, current output, extraction, modification

Dashkevich R.Ya., Aleksandrov A.V. Investigation of the effect of cooling conditions on quality of alumina-containing cakes
Increase of в-C₂S and decrease of б'-C₂S was found in the laboratory conditions in holding nepheline cake for t = 0ч30 in a range of 630–680 °С. Industrial tests in a fire grate cooler have confirmed the effect of cake holding duration at T = 630ч680 °С on its quality: increase of t from 1.6 to 4,9 min results in raise in в-C₂S content by 3 % and reducing б'-C₂S by 4 %.
Key words: dicalcium silicate, alumina recovery, cake, nepheline ore, fire grate cooler, hydration, refrigeration conditions

Skopov S.V., Naboichenko S.S., Galkova L.I. The effect of anode quality on process of electrolytic production of manganese dioxide
In conducting electric synthesis of manganese dioxide, anode material and anode-current density (i_a) affect the electrolysis process performance and the quality of resultant product. Anode activation, consisting in applying titanium-manganese alloy by thermodiffusion method on the titanium base of the electrode, prevents the passivation at i_a = 100 and 200 A/m². The electrochemical values of electrolysis for built-up activated titanium-manganese and pilot activated thermodiffused anodes at i_a = 100 and 200 A/m² have close values: tank voltage does not exceed 2,2–3,0 V, current output is 95–98 %, power consumption is 1,33–1,80 kW×h/kg. Chemical composition and crystalline modification of electrolytic manganese dioxide meet the requirements of GOST 25823-83. Activated thermodiffused anodes behaves as well known built-up activated titanium-manganese ones. No changes in their surface layers were found after electrolysis.
Key words; chemical current source, manganese dioxide, electrolysis, leaching, anode

Gildebrandt E.M., Frizorger V.K., Vershinina E.P. The effect of grain-size distribution and content of coke charge material on viscosity of coal-tar pitch compositions
Viscosity of dust-pitch compositions containing 30 % and 50 % coke dust with particles of –0,124+0,08 mm in size has been measured in a temperature range of 480–750 К. Viscosity is found to grow when coke content and the degree of coke dust particle dispersiveness increase. The obtained results allow us to predict the behavior of anode mass in varying temperature and composition of coke charge mixture.
Key words: coal-tar pitch, petroleum coke, coke charge mixture, dust fraction, dust-pitch compositions, viscosity, Soderberg anode

Metal forming

Polyakov A.P. The effect of dynamic loading parameters on the behavior of shock-wave distribution in powder
Based on earlier developed mathematical model of powder material compaction process with titanium sponge taken as an example, the effect of starting tool rate and tool weight to billet weight ratio varying in a range of 10²–10⁴ on the shock-wave velocity in the powder has been investigated. The irreversible changes of material volume that take place under their action are considered in accordance with the model on the basis of the general equations of mass, linear momentum, and energy conservation written for the shock front. It is shown that the relation between the shock-wave front velocity and tool velocity can be approximated by linear dependence in the studied range of dynamic loading parameters. The pressure value in the shock-wave front and the duration of shock impulse were determined.
Key words: dynamic loading, powder compaction, shock wave, pressure impulse, tool velocity, porosity

Structural macrokinetics. Self-propagating high-temperature synthesis

Prokudina V.K., Borovinskaya I.P., Ratnikov V.I., Merzhanov A.G. Standardization and certification of innovative SHS-processes
Standardization considerations of innovative SHS-technologies at different stages of the manufactured product cycle are analyzed. The SHS-processes are described, which can be practically realized (innovative ones) and developed due to an investor (investment ones). Taken them as examples, packages of documents are shown, which are developed according to the requirements of national Russian standards accorded with the requirements of international standards (GOST R15, GOST R ISO 9000): construction documentation (drawings and technical descriptions), for technology (production procedures, manual, laboratory prescription), for products (specification, passport and service instruction), for testing technique connected with (obligatory and voluntary) certification of new products.
Key words: SHS-technology, standardization, documentation, certification

Process control and automation

Kokoeva N.B., Alkatseva V.M. Investigations of zinc cake sulphation process optimization
Investigations of zinc cake processing have been carried out according to the scheme including oleum sulphation and leaching with sulfuric acid solution. For the purpose of studying the effect of zinc cake sulphation operating conditions on zinc, copper, and iron extraction into the solution and the content of precious metal in the sulfate cake leaching residue, the Box three-factor design has been realized. The optimization has been carried out with the use of obtained mathematical models. The following sulphation conditions: oleum volume 125 ml (per 100 g zinc cake), temperature of high-temperature stage 250 °C, and duration 4 h are proposed as optimal ones.
Key words: zinc cakes, oleum sulphation, leaching

Lisienko V.G., Malikov G.K., Morozov M.V., Kirsanov V.A., Bulatov K.V., Melnikova A.V. Mathematical zonal-nodal model of copper-smelting furnace for the stage of exploratory designs
A mathematical model of calculating a reverberating furnace has been developed to choose the most optimal ways of its updating. The efficiency of application of dynamic zonal-nodal calculating method (or two-net method) is shown. Adaptation of the mathematical model for existing operating conditions has been carried out and the calculation data are compared with the experimental data. Modeling of feed and distribution of finely-dispersed calcine with particles of 70 µm in mean diameter is the important feature of the developed model. The effect of flour particle cloud on the detailed pattern of complex gas-dynamic and temperature processes in all places of the furnace space has been investigated. Good agreement of the calculated and experimental data was obtained, thus using with certainty the developed model for determination of optimal design and operating conditions of furnace during its rebuilding.
Key words: mathematical modeling, mathematical model, dynamic zonal-nodal method, reverberating furnace, furnace rebuilding, calcine

Economics and management

Naumov A.V., Grinberg E.E. On some peculiar properties of analyzing rare scattered metals market after 2004
Peculiar properties of the modern world market related to rare scattered metals (RSM) have been examined and an analysis of the trends of its development has been carried out for the last years (2004–2007) with account of the changes in existing conjuncture-forming figures and appearance of new factors, that should be considered in analyzing of the world and Russian RSM for the earliest period.
Key words: rare scattered metals, price determination, development of RSM market

Chronicle

Seminar and conference on training of scientific higher-qualification brainpower
90-year anniversary of scientific school on metal forming at MISiS