North-Caucasian State Technological University and the chair of «Metallurgy of Non-Ferrous Metals» is 70 years old
Preface
- Khadonov Z.M. North-Caucasian State Technological University is 70 years old
- Alkatsev M.I. V.Ya. Mostovich is a founder of the chair of «Metallurgy of Non-Ferrous Metals»
Kazimirov M.P., Evdokimov S.I., Solodenko A.B. Hydro-strake jigging device for gold placers
A new washing device has been developed for gold output. The device is based on sand concentration in strakes of deep filling, jigging, and three-step table concentration. Heavy mineral concentrate finishing on three-sieve vibrating screen is performed using gravitational, centrifugal, magnetic, and magneto-fluid separators. Industrial tests of the device in Amur Area proved its effectiveness.
Gegelashvili M.V. Stress state of loose material in rectangular channel
The features of stressed state of loose material in the channel of rectangular cross-section are considered. The justification of transition from three-dimensional task of volumetric loading to flat axially symmetric is given. It is analytically shown that stagnant zones can be formed in angles of the rectangular channel. Sizes and shape of the zones are determined by a relation of internal and external friction of the loose body. Equilibrium of an elementary layer of the loose material in the rectangular channel is considered. The law of radial stress distribution in apparatus height was derived. It is of exponential type and its shape is similar to the law for round section. A procedure of numerical integral computation over the cross-section area is given depending on lateral pressure. The expressions derived make it possible to describe the components of stress originating in the loose body through the whole volume of the apparatus of rectangular cross-section.
Kazimirov M.P., Solodenko A.B., Evdokimov S.I. Development and experience of application of permanent-magnet separators for extraction of uncombined gold
An analytical method of determination of magnetic parameters in the systems of permanent magnets has been developed for design of magnetic and magneto-fluid separators. Programs for calculation of force lines and mechanical trajectory of particles in inter-pole gaps of the separators have been drawn. Magnetic and magneto-fluid separators were developed for finishing of gold-bearing concentrates. Examples of their application in the practice of heavy min+eral concentrate finishing at the gold-mining installations are considered. Industrial service of the separators has proved the effectiveness of their application for extraction of uncombined gold.
Khetagurov V.N., Kamenetsky E.S., Muzaev I.D. On the main parameters of vertical centrifugal mill
A mechanic-mathematical model has been developed which describes the movement of ground material in cavities of the rotor of vertical centrifugal mill. The model is represented by a system of differential equations of hydrodynamics with variable stream flow along the movement and additional members, which determine the physical and mechanical properties of the ground material. The model makes it possible to determine dynamic characteristics of inner moving medium: stream flow and velocity of material in the sectors of the rotor, intensity of lateral inflow and flow-out as well as capacity of the mill in the case of discharge of ground material through openings in the grids of inclined wall of the rotor. A basic expression was derived for calculation of capacity of electric motor taking the crushing and grinding processes in a centrifugal mill into account as well as an area of rational application of the mills was determined.
Extractive metallurgy of nonferrous metals
Alkatsev M.I., Bugulov D.R., Alkatseva V.M. An estimate of optimal parameters for electrolytic nickel refining
A computer simulation program has been developed which makes it possible to estimate optimal parameters of nickel electro-refining for the purpose of minimization of power consumption.
Voropanova L.A. Deactivation of discharges containing nonferrous metal ions by means of their extraction by mixture of oleic acid and triethanolamine
Extraction of nonferrous metal ions aqueous solutions with a mixture of oleic acid and triethanolamine has been studied. The optimum conditions of the extraction were determined, and a possibility of selective extraction of nonferrous metal ions was shown.
Heat engineering and environment protection in metallurgy
Meshkov E.I., Gerasimenko T.E. Study of carbon raw material calcinations process by machine simulation experiment
A mathematical model of carbon raw material calcinations process in a tube rotary calciner is described. Its conformity to the process is proved as a result of parametric identification. Results of studying the anthracitic coal calcinations process by machine simulation using the mathematical model and a program package developed for computer calculations are given.
Process control and automation
Kondratiev Yu.I. Current and voltage distribution between mineral and electrolyte in case of applying the external electromagnetic fields
The paper gives analytical mechanisms of current and voltage distributions in the mineral-electrolyte system in the course of ordinary leaching and the effect of continuous, variable, reversible, and pulsed currents. The mathematical descriptions developed make it possible to determine rational parameters of current effect for any ores and leaching solutions. Possible methods of the process control for mentioned leaching processes are determined. Possible reduction of power inputs for leaching process when using rectangular current pulses of alternating polarity was found.
Rutkovsky A.L., Khadzaragova E.A., Zhukovetsky O.V. Criteria in tasks of process identification
The types of identification criteria have been analyzed: for synthesis, analysis, and auxiliary criteria. A recurrent algorithm for estimating parameters was constructed using proposed square-law criteria of synthesis that choose a modulating function only. It was recommended to save the unimodality of the criteria as auxiliary root criteria with roots in local extreme points of the analysis.
Alkatseva V.M. An algorithm of heat engineering computation of leaching tungsten concentrates by soda solutions in autoclaves
Algorithms for heat engineering computation of leaching tungsten concentrates by soda solutions in horizontal rotary autoclaves and in autoclave batteries have been developed, computer programs being prepared on their basis. Having obtained from mathematically processes reference tabular data the following models found their application in the algorithms: a model relating steam pressure over soda-wolframate solution to temperature and sodium wolframate and soda content of the solution; a model of pressure dependence of steam saturation temperature; and a model of temperature dependence of steam enthalpies and steam condensate. Practical application recommendations for the models developed are given in the paper. A schematic flow diagram of computation algorithm for leaching tungsten concentrate with soda solution in the autoclave battery is also illustrated.
Physical metallurgy and heat treatment
Papers prepared in the issue are devoted to 75th birthday of I.I. Novikov, Professor (see № 4, 2001)
Aksenov A.A., Solonin A.N., Portnoi V.K. Distinctions of formation of aluminum alloy structure and properties mechanically alloyed by aluminum oxide
Structure of composite materials on the basis of alloys Al-4 % Cu, Al-6 % Zn-1,5 % Mg-1 % Cu, and Al-12 % Si-1,2 % Mg-2 % Cu-1 % Ni-1 % Fe-0,5 % Mn strengthened by Al2O3 particles was studied in different stages of production by mechanical allowing technique. Preliminarily ground cuttings were used as matrix alloys of composite materials, establishing the prospects of secondary raw materials recovery. The composition of the composite materials is shown not to affect the sequence of structure formation in the course of mechanical alloying as a whole but it determines time period to achieve homogeneous structure in the material.
Eskin D.G., Zadeima Ya. (j), Katgerman L. Linear shrinkage in the range of binary and commercial aluminum alloy crystallization
Linear shrinkage in the solidification range is one of the most important characteristics to understand and model hot tearing, macroscopic segregation, and contraction during DC casting. The experimental technique that represents development of I.I. Novikov’s ideas allowed us to determine linear shrinkage in the solidification range of some commercial wrought aluminum alloys. Using Al-Cu alloy as a model we showed the effects of the structure and applied force on the linear contraction. Temperature of the linear shrinkage onset was correlated with the solidus temperature and the volume fraction of solid phase in the solidification range.
Belov N.A., Zolotarevsky V.S. Low-silicon silumin composition optimization for improving mechanical properties in the cast state
Principles of low-silicon silumin composition optimization to reach the best complex of casting and mechanical properties in the cast state are proposed. It is shown that high plasticity (d > 8 %) with satisfactory strength (sB > 210 MPa) in the cast state in die castings can be produced in silumins with silicon up to 4 % and copper about 3 %.
Barsukov A.D., Trots V.S., Timofeev A.E., Marinina N.V., Politiko A.S. A correlation between difference of atomic volumes and increment of hardness in solid solutions
A correlation between an increment of hardness and difference of atomic volumes of solid solution components has been found using conception on amount of bonding electrons and data on calculated periods of the crystalline lattice of two-component solid solutions.
A review of «Manganese» written by K.N. Trubetskoi, V.A. Chanturia, A.E. Vorobiev, et al
Сhronicle
Aleksandr Sergeevich Medvedev is 60 years old
