Nonferrous ore concentration

Streltsov K.A., Abryutin D.V. A study of regularities of copper ionic flotation process with using sodium diethyldithiocarbamate
Regularities of copper ionic flotation process with using sodium diethyldithiocarbamate (DEDTC) in the MISiS designed apparatus have been considered. The results of produced copper DEDTC sediment structure investigation are given. The size distribution of air bubbles in the new flotation apparatus is analyzed. The effect of a number of factors on the level of copper ion removal from model solutions is shown.
Key words: ionic flotation, copper diethyldithiocarbamate, sewage water, sediment formation, frothers, image analysis.

MelikGaikazyan V.I., Yemelianova N.P., Kozlov P.S. Development of methods to investigate the foam flotation process from the beginning of its wide industrial application. Part 2.
The methods to estimate the adsorption and orientation of heteropolar reagent molecules in an adsorption layer on the particle surface as well as reagent adsorption on the bubble surface are analyzed. To determine the character of adsorbed reagent molecule or ion orientation, one can use the tests of foamless flotation from turbulent medium, foam flotation methods with restricted air flow rate, measurement of breakaway force at the conditions simulating the foam flotation, determination of time of particle to bubble adhering, and measurement of contact angle. The static procedures of determination of surface tension (), techniques of relaxation curve (t) registration, and methods of estimating the foam formation and breakdown can be used for estimation of adsorption of reagents on the bubble surface. A relation between certain reagent properties and their specific action at the dynamic conditions of foam flotation can be seen.
Key words: foam flotation, foamless flotation, breakaway force, contact angles, adhering time, foam formation, foam breakdown, relaxation curves, static surface tension.

Extractive metallurgy of nonferrous metals

Karelov S.V., Barashev A.R., Anisimova O.S., Mamyachenkov S.V. A study of selective cadmium leaching from active mass of alkaline cells
The optimum conditions of cadmium leaching from active mass of alkaline cells in EDTA solutions have been established in the course of laboratory studies. About 99,2 % Cd is extracted into the solution at pH > 7, L : S = 7 : 1, and temperature of 60 °С; iron in amount remaining in the hydrated cake. Methods to recuperate the solvent and produce cadmium oxides suitable to fabrication of alkaline cells are proposed. The developed process is characterized by a high degree of cadmium extraction into the commercial product, selectivity, ecological safety, possibility of full recuperation of solvent, and lacking of bad effluents and secondary waste.
Key words: cadmiumcontaining waste, complexing solvent, potentiometric titration, selective leaching.

Zhukov V.P., Kniss V.A., Kniss S.V., Avdeev A.S. A study of the cobalt decarburation kinetics in arc directcurrent furnace
The kinetics of cobalt decarburizing with CoO additions has been investigated at the industrial conditions of an arc directcurrent furnace in a temperature range of 1530—1650 °С. The process rate is shown to be limited by carbon diffusion in the volume of liquid metal with activation energy of 58,74 kJ/mol when carbon concentration decreases down to 0,3—0,5 % in the melt. In the initial period of the process, saturation of the surface layer of the melt with oxygen and CoO dissolution are the controlling stages. To reduce diffusion obstructions and fire cobalt shapingup operation duration reduction, it is recommended to develop the convective flows in a bath at the cost of increase in the current load.
Key words: decarburizing kinetics, carbon diffusion, arc furnace, CoO dissolution.

Selivanov E.N., Nechvoglod O.V., Mamyachenkov S.V., Sergeev V.A. Electrochemical oxidation of nickel sulfidemetal alloys
The sequence of electrochemical oxidation of phase components in nickel matte has been supported and some variations in the composition of its surface during anode oxidation have been found. Being characteristic for the phase components of nickel matte — nickel and its sulfide, the regularities of this process are shown to be specific to nickel matte. Nickel sulfide oxidation in sulfidemetal melts commences at lower potentials (1,1–1,2 V) as compared with synthesized nickel sulfide (1,2–1,3 V). In the course of nickel sulfide oxidation, nickel metal is oxidized primarily, and only after completion of this stage the sulfide oxidation processes, which are accompanied by extraction of elemental sulfur, begin to develop. Copper impurities poorly affect the nickel matte, nevertheless the potential drift towards decrease is observed with growth of Cu/Ni ratio.
Key words: nickel sulfide, nickel matte, electrochemical oxidation, potentials, oxidation products.

Denisov V.M., Istomin S.A., Denisova L.T., Ryabov V.V. Viscosity and electric conductivity of the GeO₂–PbO system melts
The temperature dependence of viscosity and conductivity of GeO₂–PbO melts containing 25; 40; 50; 62,5; 66,8, and 75 mol.% of PbO have been measured. The obtained results were related to the structure of investigated melts. It was shown that carrying current ions determine also the viscous flow.
Keywords: viscosity, electric conductivity, GeO₂–PbO melts, viscous flow.

Rimkevich V.S., Pushkin A.A., Malovitsky Yu.N., Yeranskaya T.Yu., Girenko I.V. Complex processing of kaolin concentrates by fluoride metallurgy
Based on physicalchemical investigations of the fluoride metallurgy processes, the optimum thermodynamic and kinetic conditions of kaolin concentrate processing, which facilitate contrasting distribution of aluminum and silicon compounds in coexisting phases, have been determined. This resulted in the development of a fluoride method of integrated extraction of alumina, aluminum, amorphous silica, silicon, and other useful components from the abovementioned raw material. The industrial implementation of this process will allow the aluminum industry of the Russian Federation to expand the raw materials source.
Keywords: kaolin concentrates, integrated processing, alumina, aluminum, useful components, fluoride method, industrial implementation.

Frizorger V.K., Gildebrandt E.M., Vershinina E.P. Results of industrial tests of “colloid” anode mass manufacture for Soderberg anode
The results of industrial implementation of a new type of anode mass with lowered (from 28 % to 24 %) content of coaltar pitch and with increased content of dust fraction of oil coke are given. Such an approach provides improvement of the ecological setting at the production and increase of the economical indicators of the aluminum electrolysis production. The Soderberg “colloid” anode manufacturing area diagram is described. The properties of coal tar and coke have been investigated and a qualitative estimation of produced anode mass has been performed. The results of industrial tests give evidence of the competitive ability of aluminum electrolysis using Soderberg anode.
Key words: Soderberg anode, coal tar content, homogenization, “colloid” anode, properties of anode mass, anode quality, ecology.

Materials science and heat treatment

Apakashev R.A. The effect of precrystallization flow of copper and aluminum melts on mechanical properties of resulting ingots
The effect of copper and aluminum melt flow before crystallization on hardness and wearability of producible ingots has been studied. The melts were passed through circular pipes to obtain the flow. Hardness of metals was determined by Brinell technique. Wearability was estimated in the plant for study of friction properties of materials. The stability of the chemical composition of metals was tested by spectral chemical analysis. It has been found that copper and aluminum specimens subject to flow in the melted state have hardness increased by 8–17 % and 7–10 % and wearability less by 11–15 % and 10–11 % respectively. Taking the results of the spectral chemical analysis into account, there is a strong probability that the above property change of the metals is caused not by the variations of the chemical composition but firstly by directional flow of the corresponding melts prior the crystallization process.
Key words: metal melt, precrystallization flow, ingot, mechanical properties.

Metal forming

Bitkov V.V. Breakage minimization in case of drawing smallgauge nonferrous wire
The production of metal round wire without internal defects is especially of current concern in terms of its further use, for example for manufacture of lead wires. One of the directions of preventing rejects as central bursts or cracks as chevron is development of wire drawing routes with the optimal parameters, which are determined with the criteria of the cold deformation without formation of defects. This work considers a group of criteria based on the geometrical parameters of the deformation zone. They have been compared from the viewpoint of the practical use for predicting the occurrence of internal defects (metal uniformity discontinuity type) in the course of round oxygenfree copper wire drawing. Recommendations for routing this process with minimum possibility of formation and development of internal bursts are given.
Key words: axisymmetric wiredrawing, conical die channel, deformation discontinuity, deformation zones, fracture criteria, section reduction per pass, die semicone angle, field of velocities, flow stress, formation of cracks, tensile stresses, drawing route.

Powder materials and coatings

Simonov Yu.A., Kritsky A.A., Rychkov V.N., Tomashov V.A. Determination of optimal conditions in production of associated zirconium and silicon dioxide mixture by sintering of ZrSiO₄ with MgO
The dissociated zircon (mixture of associated zirconium and silicon dioxides (ZrO₂, SiO₂)) producing process by sintering of ZrSiO₄ with MgO followed by leaching of the resulting coal tar by strong hydrochloric acid has been investigated. The ZrSiO₄ + MgO mixture sintering mechanism has been established on the basis of the laboratory investigations. The optimal process parameters (molar ratio of components, temperature and duration of heating at final temperature) for maximum transformation of zircon to zirconium dioxide have been determined.
Key words: dissociated zircon, sintering, molar ratio, zircon, magnesium dioxide, zirconium dioxide, silicon dioxide, hydrochloric acid.

Heat engineering and environment protection in metallurgy

Yanchenko N.I., Baranov A.N. Parameters of fluorine, sulfur, and sodium distribution in the Baikal region in production of primary aluminum
Fluorine, sodium, and sulfate ion distribution parameters have been analyzed in the ambient medium of the Baikal region by the example of Bratsk city. Their content in the atmospheric precipitation (rain, snow, aerosol, snow cover) and the load intensity over the territory in 2008–2009 have been determined. The results have been obtained on the basis of snowchemical survey, selection of ad hoc samples of the atmospheric precipitation and aerosols. A map of the snow cover contamination with watersoluble fluorine is given and the hydrogen fluoride pollution source capacity is evaluated. The HF emission reduction is proposed at the cost of application of lithium additives as fluorinecontaining lithium salts produced with application of lithium brines of the Eastern Siberia.
Key words: aluminum, electrolysis, the Baikal region, emissions, pollution of environment, fluorine, sulfur, sodium, atmospheric precipitation, aerosols, hydrogen fluoride.

Chronicle

The chair of metallurgy of heavy nonferrous metals in UGTU–UPI is 80 years old