Mineral processing of nonferrous metals
Shchelkunov S.A., Malyshev O.A. Dimethyl(isopropenyl acetenyl)carbinol is an effective nonionized frothing collector
The effectiveness of dimethyl(isopropenyl acetenyl)carbinol (DMIPAC) application for nonferrous metal ores from the deposits of Russia, Kazakhstan, and Chile has been investigated. Additional extraction makes up (in %): 1,2–5,8 Cu; 1,3–4,3 Mo; 10,1–20,0 Zn; 0,9 Ni. The quantumchemical estimations made it possible to determine the mechanism of floatation agent adsorption over sulfides. Based on comparison of the results obtained, the principal distinction of interaction between DMIPAC and ore surface both from ionized sulfur containing collectors and from nonpolar hydrocarbons has been surmised. It has been found that the effectiveness of DMIPAC application depends on the energy of interaction between carbontocarbon bonds in floatation agent and sulfides as well as on the degree of hydrophobic nature of the environment around nonferrous metal cation.
Metallurgy of nonferrous metals
Karelov S.V., Mamyachenkov S.V., Anisimova O.S., Sergeev V.A. Cleaning of lead trilonate solutions from impurities with solvent regeneration
Laboratory investigations of cleaning trilonate solutions obtained by leaching of lead cakes of zinc production have been executed. The lead sulfate sediments and ethylenediaminetetraacetic acid formation conditions are determined by potentiometric titration. In this case the cations of impurity metals: zinc, copper, iron remain in the solution. The influence of initial lead concentration in the solution and рН on the cleaning indices has been studied.
Alkatsev M.I., Svistunov N.V., Trotsenko I.G. Regeneration of WC–Co hard alloy by gaseous zinc
The WCCo hard alloy regeneration process by gaseous zinc has been developed. It is shown that Zn diffusion in the alloy proceeds basically along interphase boundaries between tungsten carbide and cobalt with a high rate comparable with Zn diffusion rate in water solutions. The new technology allows decreasing essentially the power consumption owing to reduction of operation duration in comparison with the classical zinc process. Experimental values of activation energy of zinc diffusion in the hard alloy and cobalt, being equal to 1,74 and 13,97 kJ/mol, have been found.
Chekushin V.S., Oleinikova N.V. A review of investigations on thermodynamics of copper reduction from oxygen and sulfide compounds
The thermodynamics of copper reduction from oxygen and sulfide compounds at T = 298ё1273 К is analyzed. The lacking of correlation between DG0 values of copper reduction from oxygen compounds and their formation is confirmed. The reducing ability of sulfur in sulfide, elemental, and sulfite forms has been investigated in relation to copper in Cu(I) and Cu(II) oxides. The interrelation between probability of metal reduction and stability of reducing substance is found. The possibility of copper reduction from sulfide compounds has been investigated with hydrogen and metals as well as with the use of electric donor properties of own sulfide sulfur. The conditions to realize the reducing process are found.
Yanchenko N.I. Procedure of calculation of lithium in semiproducts and aluminum
The procedure of calculating the quantity of lithium in flotation cryolite has been proposed to control Li content in aluminum in the electrolysis shops where introduction of a specific additive of its carbonate into the electrolyte is not stipulated. The content of 0,0001 % Li in aluminum in the B and C shops will be reached in the course of work of the only A shop for 2–3 months. It was calculated that an additional increase in lithium content in aluminum in the shop, where Li2CO3 is applied, is possible at the cost of Li supplying with flotation and regeneration cryolite, metal adhered to ladle, and recycled electrolyte. For example, its additional growth by 0,0001 % in the A shop with operating 720 baths on lithium carbonate will be ensured for 1 month.
Lipin V.A. On mechanism of interaction between slimes of aluminous production and carbonate solutions
It has been found in the course of laboratory investigations that desiliconization slimes of the aluminous production have the selective properties in relation to alkali metals when interacting with carbonate solutions. As to the sorbing ability by slimes, alkali metal cations are arranged as Li > K > Rb > Cs. As a whole, the selectivity of slimes is determined both by ionexchange properties and by formation of double and thribble alkali metal and calcium carbonates
Metal forming
Maltsev I.M. Electroplastic metal rolling with high-density current
The properties of commercialpure metals are analyzed after electric discharge deformation in the course of rolling with current of high density: 108–109 А/m2. By the example of aluminum, titanium, and copper, it has been found that, during electroplastic deformation, increase in strength and ductility retention at temperatures below recrystallization one. The degree of appearance of electroplastic effect is different and it depends on ability of metal conductor to be deformed to heating by Joule component of electric current.
Physical metallurgy and heat treatment
Shevchenko V.V., Nizkin I.D., Malkov A.V., Lukianova E.V. Peculiarities of hydrogen-alloyed VT5-1kt titanium alloy granule compaction
The effect of hydrogen on consolidation of VT51kt alloy granules as well as the structure, mechanical characteristics, and fracture micromechanism in a compact made by hot isostatic compaction has been studied. It is found that hydrogen allowing allows us to obtain VT51kt alloy compacts of 100 % density with a high complex of properties for several minutes in such temperaturepower conditions in which the consolidation of hydrogenfree granules cannot be realized. It is shown that the process of consolidation of hydrogencharged granules proceeds within the (a+b)range.
Rusin N.M. Change in AM60 + 0.3TiC magnesium alloy structure during rotation forging
For the purpose of grain structure grinding, staged rotary forging of AM60 + 0,3%TiC alloy rods at t = 350 °С has been carried out. Upon reaching deformation of ~ 0,5, the material with grain size of 6–10 µm was produced. The further forging stipulates the retardation of the processes of dynamical recrystallization and formation of subgrains, elongated in the direction of flow of material, inside new grains. The development of substructure is accompanied by reduction of lead plasticity and accomplished by material cracking predominantly along the grains under deformation of ~ 1,0. The trouble in plastic flow and the restriction of structural changes under great reduction rates are caused mainly by precipitation of second phase particles along the grains and inside the body as well as the development of stable texture and inhomogeneity of material precipitation hardening. A conclusion is made that, under the conditions of optimally chosen modes to heat and cool samples and the deformation value at every stage, rotary forging may be used as an alternative procedure, compared with severe plastic deformation, to grind the grain structure of magnesium alloys.
Tikhomirov A.V., Aksenov A.A., Shelekhov E.V., Kaloshkin S.D., Zadorozhny V.Yu., Skakov Yu.A., Milovzorov G.S. Calculation and measurement of background temperature of mechanical alloying in planetary mill with ball charge and quasi-cylindrical grinding bodies
The background temperature of mechanical alloying (MA) in a planetary mill with ball charge and quasicylindrical grinding bodies (QGB) has been estimated by computer simulation and experimental measurements. The MA applied with QGB is shown to be characterized by lesser background temperature (by 140–280 °С) as compared with the traditional MA with ball charge. The dependencies of MA background temperature on treatment time, hardness of material treated, pinion carrier rotation velocity, and friction coefficient in friction pairs of “grinding body – grinding body”, “grinding body – container wall” were studied. It was found that the MA with QGB allows us to increase significantly the treatment intensity at the cost of increasing pinion carrier rotation velocity without excess heating of the material treated.
Powder materials and coatings
Andreev E.I., Glavin K.V., Libenson G.A., Lisin A.N., Malovik V.V., Panov V.S. Application of mathematical model for description of uranium dioxide powder consolidation and compaction
A mathematical model, which allows analyzing the processes to consolidate and compact uranium dioxide powders of ceramic grade and mixtures on its basis, has been proposed and experimentally confirmed. It enables a possibility to forecast the final parameters of simpleformed powder articles on the basis of the results obtained in applying moldingpowders based on the function of powder body deformation with two compacting pressures without the following sintering, thus reducing the time and costs in comparison with the operating testing used in the production.
Andriets S.P., Dedov N.V., Kutyavin E.M., Selikhovkin A.M., Serenkov V.N., Sitnikov N.I., Stepanov I.A., Ivanov Yu.F., Kozlov E.V. Structure and properties of plasmachemical aluminum oxide powders
Using the advanced analytical methods, investigations of phase composition, structure and properties of aluminum oxide powders synthesized by plasmachemical method are carried out. A possibility in principle of plasmachemical technology of processing dispersed raw material to produce submicro and nanosized aluminum oxide particles is shown.
Information
On extension courses carried out in MISiS on the basis of the chair of powder metallurgy and functional coatings
