The present work is aimed at analysing the characteristics of known thermal storage materials featuring phase transition and studying the effect of the main operational parameters (thermal cycling, insufficient long-term stability, phase segregation, corrosion, supercooling) on the thermophysical and operational properties of these materials. Here, analytical research methods are applied based on the generalisation and analysis of a significant amount of empirical information on thermal storage materials, the classification of materials according to their main properties and the synthesis of recommendations on the practical use of thermal storage materials in heat supply systems using solar energy. The selection criteria for a medium using the latent heat of the phase transition for thermal receivers are considered. One of the main requirements formulated by the authors for the medium consists in the preservation of thermophysical properties, such as melting point, latent heat of melting, as well as their variation ranges, during in-operation repeated phase transitions. The effect of the transition number (100-1500 thermal cycles) on the stability of the thermophysical properties of materials is demonstrated with the recommendations provided on the selection of thermal storage materials for thermal energy storage in solar heat supply systems. In terms of heat storage materials with a phase transition for solar energy systems operating at relatively low temperatures (30-60°C), both organic (paraffins, fatty acids) and inorganic (crystalline hydrates of salts) materials are applicable. In order to increase the efficiency of thermal transfer processes in thermal storage systems based on materials with a low thermal conductivity coefficient (0.148-0. 6 W/m•K), the application of special technical solutions is recommended, including an increased area of thermal transfer surfaces, the introduction of inclusive additives (for example, inserting a porous metal foam and a metal matrix in the thermal storage material, the addition or dispersion of nanoparticles), etc.

The study is aimed at the creation and testing of a search algorithm for the adaptive weighting trajectory corresponding to the smallest ultimate active-power flow for the current circuit-mode situation in terms of aperiodic stability in a power system. To develop the algorithm, a cluster analysis approach was taken using the Jacobi matrix determinant in RastrWin, Microsoft Excel and Matlab software environments alongside various mathematical statistical methods. As a result, the proposed algorithm was developed (in the programming languages of Visual Basic Script and Visual Basic for Applications) and tested based on a change in the numerical value of the Jacobi matrix determinant depending on changes in the active power of both the generating equipment and the power system loads (in the diagram for a part of the Irkutsk power system). Sensory load nodes were determined for the investigated controlled section No. 1 connecting the energy district with the rest of the energy system. An increase in the power (by 0.197, 0.076 and 0.112 MW for nodes of 220, 110 and 6-10 kV, respectively) in these nodes was shown to result in significant changes in the values of the Jacobi matrix determinant (by 0.103, 0.926 and 0.33 p.u. for nodes of 220, 110 and 6-10 kV, respectively). The difference of 27 MW between the values of the limiting power flow both determined by the static aperiodic stability and calculated using the weighting trajectory is explained in terms of the difference between the initial calculation models used for mode weighting. Testing the algorithm on the controlled section No. 1 of the Irkutsk power system led to a conclusion concerning its applicability in searching for an adaptive weighting trajectory with subsequent application in calculating and analysing ultimate active-power flows in the controlled section in terms of static aperiodic stability.

The study is aimed at analysing the causes of ash wear leading to failure of boiler unit equipment, as well as reviewing existing approaches to increasing the service life of boiler convective heat transfer surfaces. An analytical forecasting procedure was applied, including the calculation of abrasive wear depending on the type of burned coal fuel and the method of pipe surface diagnostics performed by low-frequency electromagnetic fields without special preparation. The implementation of pipe surface diagnostics was proceeded using the "Heating surface condition" software combined with Autodesk AutoCAD 3D models. Together with analytical forecasting of the ash wear, the application of the scanning-based convective surface diagnostics was demonstrated to provide the systematic monitoring of the surface condition of boiler heating units. The following approaches to reducing the abrasive wear intensity during the operation of boiler units are proposed: reduced quantity of coal fuel having abrasiveness of >63%; reducing the fineness of coal dust to the value of 30-35% by grinding; installation of protective metal devices on heat exchanger pipes; control of the gas flow rate (for low- and high-abrasive coal, the flow rate was limited by 10-12 and 6-8 m/s, respectively); regular diagnostics of the pipe surface (every 50,000 hours of operation and every 25,000 hours in the case of pipes reduced in thickness by 0.5 mm or more). The proposed measures ensure an increase in the service life of boiler heating surfaces by 2-3 times. The necessity of using non-destructive methods for monitoring the condition of pipe surfaces in combination with adjustment of the gas flow rate in the gas duct, as well as selecting the optimal grinding for the fineness of coal dust depending on the coal type, is demonstrated to be an effective means of avoiding unplanned shutdowns of boilers.

The study is focused at the development of new technical devices for separating dust particles up to 10 microns in size from flue gases of thermal power plants, along with the creation of an engineering methodology for the proposed separation device and obtaining calculated dependences for determining operational maintenance intervals. In order to determine the efficiency of particle deposition on the surface of the separation device, previously verified methods of mathematical modelling were used based on the laws of momentum and heat conservation, as well as a solution to hydrodynamics equations. The proposed original trapezoidal separator design is equipped with several rows of arcuate elements for concentrating dust during the operation of the apparatus due to the action of inertial and centrifugal forces. With an increase in the input velocity of the gas flow from 3 to 11 m/s and efficiency values of 0.5, 0.7 and 0.9, the operation time of the separator is decreased by an average of 3.7 times. The minimum operation time is established to be about 50 days at a dust flow rate of 11 m/s and a dust concentration of 8 mg/m3. The maximum operation time of the separator was determined to be about 465 days at a dust flow rate of 3 m/s and a dust concentration of 5 mg/m3. The proposed design of the trapezoidal separator ensures the separation of particles both larger and smaller than 10 microns from the flue gases of thermal power plants with an efficiency of 99.0-99.9 and 61.7%, respectively, resulting in reduced atmospheric emissions. Using the developed methodology, the main structural dimensions of the proposed separator can be determined under given gas flow parameters.

The aim of the study involved the development of a methodology for optimising the structure of an autonomous energy complex consisting of photovoltaic panels, accumulator batteries and a diesel generator, as well as its implementation in a software and computer complex. In order to optimise the structure of the complex, a particle swarm method was used that does not require the exact gradient of the optimisation function to be known. In terms of an optimisation function, the cost price of the electricity generated by the energy complex was chosen. During the optimisation process, changes in the consumer load demand, local actinometric and meteorological conditions, as well as technical characteristics of photovoltaic panels and batteries were taken into account. Additionally, a choice of three following options for installing photovoltaic panels relative to the horizon is provided: horizontally; inclined to the horizon; inclined to the horizon on a rotary uniaxial base with a vertical rotation axis using a sun tracking system (selecting an angle of inclination equal to the latitude). For Kyzyl-Khaya village in the Republic of Tyva, currently supplied from a diesel power station, the average monthly values of horizontal surface insolation are calculated with the total installed capacity of the power generating elements for an autonomous energy complex optimised by the particle swarm method equal to 450.1 kW and having a battery capacity of 22.2 kA×h. The developed technique for optimising the structure of the energy complex is implemented in the MATLAB software environment. Following optimisation by the proposed methodology, the structure of an autonomous energy complex with an inclined arrangement of photovoltaic panels, the cost of electricity generated by it amounted to 26.978 roubles/kW h with a capital cost of 16956.853 thousand roubles. This optimised structure of the complex provides for changing the power supply schedule from 18 to 24 hours a day and additional possible reduction in diesel fuel consumption by 70% compared to the same setup having an 18-hour power supply schedule from a diesel power plant.

The aim of the study consists in establishing the temperature variation effect appearing in individual banks of solar panels under conditions of partial shadowing on the current- and watt-voltage characteristics of the entire solar power plant, as well as in determining the mathematical model most adequate for reproducing this process. During the study, three different mathematical models (single-diode explicit, single-diode and two-diode) of solar panels were used as implemented in the MATLAB Simulink software package. In the modelling process, temperature variation for individual groups of solar panels is assumed to occur in the range from +35°C to+60°C under the conditions of shadowing from clouds of various density. In the present study, verification of the obtained data for implemented mathematical models based on Kyocera KC200GT solar panels with the same presented in the manufacturer's technical documentation was performed to prove the ability of these models to adequately reproduce the current- and watt-voltage characteristics. The most significant error in the obtained data (up to 18.31%) was a characteristic of a single-diode explicit mathematical model, while that of the single-diode model error was equal to 3.42%. The two-diode mathematical model was established to be the most adequate for reproducing the current-voltage characteristics of solar power plants in the conditions of partial shadowing. In order to obtain accurate output characteristics when modelling powerful solar power plants operated under conditions of partial shadowing, it is necessary to consider not only the change in the illumination rate for individual groups of solar panels, but also the corresponding temperature variation. In addition, for obtaining satisfactory results of mathematical modelling for a solar power plant under the studied conditions, an equivalent two-diode mathematical model of a solar panel is recommended.

The study is aimed at assessing the influence of the physical and chemical properties of coal burned at thermal power plants in the Irkutsk Region on the operational characteristics of boiler units. In order to forecast the application proccess for coal of the Mugunskoye and Irbeyskoye deposits in terms of fuel types not previously used at the PJSC Irkutskenergo thermal power plant, mathematical methods were used in the SAF software package developed by the authors on the basis of the Microsoft Excel. In analysing the mineral composition of the Irbeyskoye deposit coal, slagging of heating surfaces and superheaters (by the example of boiler units at the Novo-Irkutsk thermal power plant) as a result of its combustion in a temperature range above 900ºС is anticipated due to the high content (16.2%) of iron (III) oxides in the ash. In the SAF software package, indicators calculated for determining the slagging and polluting properties of solid fuels included a tendency to ferriferous, sulphate-calcium and active alkali-based depositing, slagging indices of the combustion chamber, pollution of boiler unit screens, etc. Recently-used new coal types of the Mugunskoye and Irbeyskoye deposits were revealed to have a high tendency to form ferriferous deposits equal to 0.683 and 0.678 p.u., respectively. In addition, the slagging index of the combustion chamber remains at a high level (above 0.75) during the combustion of the studied coals. It was proposed to equip the BKZ-420-140 boiler unit with more modern water soot-blowers with the commission of the full-time long-retracting soot-blowers for cleaning the superheater from ash deposits. The proposed measures ensure an increase in the service life of boiler heating surfaces by 2-3 times. In order to avoid emergency situations leading to unplanned shutdowns of boilers, the need for expert assessment of the slagging and polluting properties of fuels previously unpractised at thermal power plant is demonstrated.

A state estimation algorithm for assessing the state of a power delivery network according to the measurement information performed by smart meters is proposed and its efficient use in a real low-voltage three-phase four-wire secondary distribution network demonstrated. Nonlinear state estimation is performed by a method of simple iterations, at each step of which an overdetermined system of linear equations of measurements is solved by the method of weighted least squares. State estimation is performed independently for each phase and the neutral wire; phase voltage estimates relative to the neutral wire are determined according to estimates of the phase wire voltages and the neutral wire relative to the ground. Testing of the method is carried out on the example of a real 11-node main feeder, on the poles of which MIR S-04, MIR S-05 and MIR S-07 single-phase and three-phase meters of Russian production are installed. For the state estimation, information was used on the hourly average power of loads and voltage modules for 576 measurement sections taken from the protocols of an automated commercial electricity accounting system. The high accuracy of the obtained estimates is confirmed by no more than 1.2 V residues between the measured values of the variables and their estimates. Two methods for determining energy losses by estimating voltages - with respect to earth and a neutral wire, respectively - are presented. The possibility of balancing loads by moving single-phase loads of the most loaded phase to a less loaded phase is demonstrated. The calculations performed for a real network show the proximity of variables measured by smart meters to their estimates, confirming the effectiveness of the presented algorithm for assessing the state of the secondary distribution network with explicit consideration of the neutral wire.

The aim of the study involved the development of a dual-zone speed control method for a permanent magnet inverted motor applied as a drive for various machines and mechanisms of cyclic action or positional type. In the study, modelling methods were applied based on the contemporary theory of electric drives (using Gorev-Park equations) accompanied by methods derived from classic control theory. As a result, the dual-zone speed control method for an inverted motor was developed based on a previously tested single-circuit control system applicable for speed values below synchronous with full compensation of the stator current along the d longitudinal axis. A method is described for controlling the speed of the value of the stator current superior to synchronous due to incomplete compensation (specified by the coefficient) along the longitudinal axis. A nonlinear model of an inverted motor (based on the Gorev-Park equations) was developed to support a study of its functioning modes at speeds both higher and lower than synchronous. For an engine with specified parameters, the modelling included starting and braking modes, smooth transitions from one speed to another (by selecting the setpoint changing speed), as well as abrupt drops and increases in the load. For the control, a single-circuit control system with a proportional integral differential controller was used. The developed model ensures the selection of the necessary pattern for voltage change along the q transverse axis of the studied motor stator, thus preventing the current overload of the frequency converter during the motor operation both above and below the synchronous speed. Dynamic modes of the "frequency converter - inverted motor" closed-loop system were investigated in the Simulink environment of the Matlab package. The obtained equations of static modes support a determination of the restrictions on speed and torque for two versions of the drive. Thus, the developed inverted motor control system is simpler than the classic dual-circuit system that lacks frequency converter disconnection during overloads.

The study is aimed at increasing the machining efficiency of cutting tools made of high-speed steel using high-performance equipment. The study is based on the choice of progressive technological approaches and an analytical review of contemporary technologies for manufacturing rotating cutting tools using machines having computer numerical control (CNC) of machining center type. The process efficiency expressed in the rate of material removal and the quality of tool processing (surface roughness, geometric accuracy, mechanical properties) were used as criteria for evaluating effectiveness. Multi-tasking machines, performing turning, milling and other types of operations in one cycle, were categorized as equipment meeting the requirements for optimal high-performance machining of a rotating cutting tool. Progressive technological processes used in the manufacture of cutting tools on multi-tasking machines include milling turning, rotary and polygonal turning. The application of combined milling-turning was demonstrated to eliminate the grinding operation from the technological process with a reduction in the product cost by 77%. Milling is subdivided into orthogonal and tangential machining processes characterized by their own characteristics for the determination of optimal cutting speeds when assigning cutting data. When obtaining a given workpiece shape, turning combined with milling was revealed to be problematic. Along with depth of cut, the ratio of tool and workpiece rotation speeds was established to be the most significant factor affecting roundness deviation, which reached a maximum of 2 mm. The relation between roughness and milling width is demonstrated. Based on the performed analysis, the application of combined milling-turning technology is recommended in the manufacture of rotating cutting tools, due to providing an increase in the productivity of the machining for a rotating cutting tool by 2-5 times without workpiece quality loss, as well as reducing surface roughness by 10 times. In this case, the cutting force and the temperature in the cutting zone are reduced along with increased tool life and elimination of flow chip formation.

The present work is focused at the study and experimental confirmation of the possibility for increasing the efficiency of an electric modular descending furnace in terms of reducing the specific energy consumption of roasting vermiculite concentrates by obtaining the most rational structural furnace design. Research methods were based on a theoretical analysis of the working process energy characteristics for the furnace unit, such as performance factor and specific energy consumption, the laws of thermal radiation physics and thermal engineering, as well as on the analysis of experimental data obtained during testing of the experimental furnace model under laboratory conditions at a temperature of 730-780ºС and an annealing time of 2.48-3.06 s. Due to changes in the structure of the six-module furnace, the specific vermiculite roasting energy consumption was reduced to 188.9 and 197.0 mJ/m3 in accordance to calculated and experimental data, respectively. As compared to the minimum value for a standard similar furnace, the decrease in the specific energy consumption for the modernised furnace amounted to 17.9%. The effect of reducing energy consumption was shown to be due to the structural transformation of the furnace unit by transferring the lower module with a lowest performance factor and installing it in parallel with the upper module, leading to a significant increase in the overall efficiency of the furnace. Additional efficiencies were obtained by applying suspended heating systems to the furnace under consideration. According to calculations and experimental studies, due to the furnace unit structural transformation and the use of more energy-efficient suspended heating systems in the furnace energy blocks, the expected combined effect of reducing the specific energy consumption in roasting vermiculite concentrates averaged up to 147.3 mJ/m3 for various types and size groups of furnaces.

The aim of the present work is to carry out an experimental study of vibration occuring at the nodes of the electric locomotive wheel and motor unit during motion in small radius curves (R = 250-350 m) of a mountain-pass section (with gradients up to 17‰). The vibration measurement was carried out experimentally at the 3ES5K Ermak electric locomotive using AR-2038-10 and AR-2038-100 vibration transducers mounted on the axle box of the first wheel pair, gear cover and traction engine frame. A specially designed system was used to continuously record the signal from vibration transducers over eight channels with a sampling frequency of 12.8 kHz. Experimental data on the parameters of vibration occurring the specified locations of the electric locomotive were are obtained during the wheel-rail interaction of the electric locomotive on an almost jointless trajectory of small radius curves. The level of vibration at the entrance to the small radius curves along the three coordinates of X, Y and Z was established to be almost an order of magnitude higher than outside the curve. In the case of traction mode operation of the electric locomotive, a sharp increase in the amplitude (up to 10 times) of harmonics with multiples of the gear frequency was shown to be caused by a coincidence with the natural frequencies of the gear cover. In coasting mode, in the frequency region of about 1.5 kHz, a pseudo-random vibration is recorded on the axle box with the RMS acceleration value of above 100 m/s², which is comparable to the acceleration values when passing a junction. The obtained data of the vibration parameters suggest the reliability of locomotives operating in mountain pass areas having many small radius curves to be significantly less than for flat area operation with the alternative of a jointless trajectory representing ineffective measure of reduction vibrations in small radius curves.

The aim of the present work consists in studying the effect of the g rake angle (in the range from -8° to +10° with a constant a relief angle of +6°) of a VK8 hard material turning tool on the output parameters (cutting force, roughness, wear of the cutting edge at the rake and flank surfaces) in turning a VT22 titanium alloy billet. In order to determine the cutting forces, a dynamometric analysis was performed using the STD. 201-1 laboratory bench. The turning of the billet was carried out at a constant cutting speed of 50 m/min, a cutting depth of 3 mm and feed values of the tool movement along the billet equal to 0.11, 0.15 and 0.21 mm/rev. A TR200 profilometer and Micro Vu-Sol-1 measuring machine were applied for determining the roughness and wear of the cutting edge, respectively. The highest value (2000 N) of the tangential cutting force was established to be achieved with a 0.21 mm/rev feed, while the largest difference (400 N) of the tangential cutting force was recorded depending on the g value variation in the range from -8° to +10°. For a feed rate of 0.11 and 0.15 mm/rev, this difference amounted to 300 and 100 N, respectively. The roughness measured at specified feed values lies within the acceptable range of surface cleanliness corresponding to 8-9 grade (except for g = +10°). Based on the results, the following mode selection algorithm for turning of a VT22 titanium alloy billet is proposed according to various criteria: fixed tangential cutting force - 0.11 mm/rev feed rate (g = +10°); roughness values - 0.11 and 0.21 mm/rev feed rate (for all selected g values) or 0.15 mm/rev (for g = -4, 0, +4, +8°); wear of the cutting edge - feed rate of 0.11 mm/rev at g from -8° to -2°, 0.15 mm/rev (at g = -4°, 0°, 2°, 4°, 8°, 10°), 0.21 mm/rev (at g = -4°, -2°, 2°, 4°, 6°, 8°, 10°).

Aim - to develop an effective method for polishing the surface of products using a magnetic field, facilitating the necessary removal of material and resulting in a low degree of workpiece roughness. The object of research was a sample of SKD11 steel having a cylindrical profile and a diameter of 16 mm, coated with a 1 mm layer of Ni-P. For polishing such steel according to the Taguchi experimental method, magnetic-liquid suspension patterns containing magnetic iron grains and abrasive grains having various diameters and at different working distances to the the magnet attached to the polishing equipment were used. The experimental polishing system included a permanent magnet (with magnetic induction equal to 0.45 T), a disk carrying a magnetic-liquid suspension and two electric motors. A distribution of containing magnetic iron grains and abrasive grains in the magnetic-liquid suspension on the working surface of the treated surface was studied by scanning electron microscopy and energy dispersive X-ray spectroscopy. It was found that magnetic-liquid suspension containing large diameter MIGs (7 μm) and smaller diameter AGs (1 μm) should be used with the same polishing distance (= 1 mm) and be set to surface-finish the mirror surface of Ni-P coated SKD11 steel when using an emulsion based on magnetic iron grains; the roughness of the specimen surface of 3.6 Nm was achieved without leaving scratches or adhesion of abrasives with the magnetic-liquid suspension mixture on the treated surface. The use of a magnetic-liquid suspension, containing magnetic iron grains, is an effective method for obtaining precision on the workpiece surface to the nanoscale when the diameter of magnetic iron grains is greater than the diameter of abrasive grains. In terms of cost and performance, this mixture combination has good prospects for implementation in polishing technology compared to the expensive magnetic-liquid suspensioncontaining magnetic iron grains with ZrO₂ coating.

The present work is aimed at obtaining a metal composite material based on Al - 5%Cu aluminium alloy by the addition of B₄C boron carbide and studying the microstructural features and mechanical properties of cast billets based on this material. Aluminium alloy cast billets containing 5%wt. of Cu with a boron carbide content varying from 2-7 wt% were prepared in laboratory die casting machines. Immediately prior to casting, B₄C particles with a size of 5-7 μm were introduced into the melt under continuous stirring. A tensile test of the samples having an elongation of 0.1-0.5 mm was carried out by Shimadzu tensile testing machines in accordance with ASTM standards. The microstructure of the experimental samples was studied by scanning electron microscopy using an INSPECT S50 microscope (FEI, Netherlands). In terms of the aluminium matrix microstructure following the introduction of boron carbide, the composite was established to contain inclusions of the Al₂Cu intermediate crystallisation phase and B₄C particle inclusion matrices distributed throughout the entire sample volume. Porosity zones were detected in the form of weak contact of the matrix material with the embedded surface of the boron carbide reinforced particle. A high level of wetting by the matrix melt was observed, leading to a uniform distribution of particles in the matrix. The best indicators of hardness (113 HV) and tensile strength (~180 MPa) are characteristic of the samples with the addition of boron carbide in an amount of 5%. At this content, due to the low observed particle segregation in the volume of the Al-Cu matrix, a uniform fine-grained billet structure for the selected composition of the alloy was obtained. According to the research results, the composition of the alloy obtained by die casting based on Al-5%Cu alloy with the addition of boron carbide in amount of 5% can be recommended as a suitable material for the manufacture of products with due to its attractive hardness and strength properties.

An evaluation of technical and economic efficiency parameters of a previously proposed technological solution for processing dust from electric steel production by the pyrometallurgical method is presented. The technological approach consists in the reduction of iron and zinc from their oxygen-containing forms (ZnFe₂O₄ and ZnO) by active carbon-containing materials. Experiments were carried out on samples with a 26.02 and 37.7%wt. of ZnO and Fe₂O₃, respectively, to evaluate the processing of industrial dust of PJSC Magnitogorsk Iron and Steel Works in a laboratory facility based on the LHT 08/17 high-temperature furnace (Nabertherm, Germany). "Small long-flame nut" brand charcoal was applied as a carbon reducing agent, with lime and quartz sand serving as sources of slag-forming components. Commercial products were obtained in the form of granular cast iron (96.75 and 2.92%wt. of Fe and C, respectively) and a zinc oxide product (90.21%wt. of ZnO). The extraction of iron and zinc in cast iron comprised the values of 94.0 and 91.0%, respectively. As a result, an annular hearth furnace is recommended as the main technological unit for the industrial implementation of the process. The basic technological scheme is proposed including dosing raw materials, preparing charge briquettes, performing reduction smelting, separation of smelting products (cast iron and slag) and trapping zinc-containing sublimates. To assess the technical and economic efficiency of the developed technology on an industrial scale, the costs of building a dust processing plant involving one annular furnace with an average diameter of 12 m having a steel production capacity of 15 000 tonnes per year were taken into account. The proposed technology was shown to be capable of supporting commercial granular cast iron and zinc oxide products in the amount of 33264 and 4435 tonnes per year, respectively. Considering the investment period, the estimated payback period is determined to be 34 months with the expected net profit equal to 535.59 million rubles/year.

The aim of the research was to analyse the influence of cathode casing design on electrolytic cells with self-baking anodes taking the following magnetohydrodynamic characteristics into account: magnetic field, speed and circulation direction of cathode metal, margin of magnetohydrodynamic stability. The most common type of electrolysers having a Söderberg anode and S-8BM top current lead, for which both counterforce and cradle cathode shell types were used, was taken as an object of study. To simulate the magnetohydrodynamic phenomena occurring in the electrolyser, we used the specialised Blums v5.07 computer program. The following settings were identical for both versions of the models: type of bus, anode assembly parameters, cathode material properties, formation features of the anode mass sintering cone and form of the working space. The calculation of the magnetic field of the electrolyser was carried out using an analytical research method based on the integration of the Poisson (for regions occupied by current) and Laplace (for regions not occupied by current) equations. According to calculations of the speeds and directions of movement of the cathode metal, both types of cathode casing of the electrolyser were shown to be characterised by a four-circuit circulation system, determined by the corresponding location of the anode risers at the inlet and outlet ends of the electrolyser. The results of mathematical modelling show that for electrolysers with a cathode shell of the cradle type, the transverse and vertical components of the magnetic field are less compensated than for cells having a counterforce shell, which affects the average speeds of the cathode metal: circulation speeds will be 0.02 cm / s below. However, the margin of magnetohydrodynamic stability is almost identical for both cathode shell designs. With the same shape of the working space, as well as interpolar distance (41 mm) and metal level (34 cm), the calculated margin of magneto-hydrodynamic stability was 360-380 mV.

The present study is aimed at the development of a method for computer control and management of mineral formation and emissions of hazardous compounds during processing of nepheline ore by sintering in tubular rotary kilns. Technological, mathematical and mineralogical research approaches taken when developing the method included physical and chemical modelling using the Selector software package. In accordance with the technological stages of obtaining sintered mass (drying, dehydration, decarbonisation, reflow, sintering and cooling), the developed physical and chemical model is conventionally divided into six thermodynamic tanks (furnace zones) with simulation of mutual mass and energy transfer. Coordination of the simulation results with the production and statistical data of RUSAL Achinsk JSC was carried out by analysing a furnace operation with a processing volume of 120 tons of charge per hour. During the processing of nepheline charge with the production of alumina and sodium products (having a standard analysis methodical accuracy of 1-5%), the deviation of production indices for the extraction of Al₂O₃ from the predicted results was shown to comprise 0.1-0.6 and 1.5-2.1% for physical and chemical modelling and thermophysical field controlling, respectively. The applied sintering process modelling using the Selector software package provides for a significant increase in the degree of control and management of the raw material processing cycle. The proposed method of thermodynamic analysis is shown to provide high-precision control of the mineral formation processes in technological zones of the alumina charge sintering furnace and to guarantee a deviation of Al₂O₃ content in the sintering mass from the predicted data of no more than 0.1-0.6%. The 85.8% rate of Al₂O₃ extraction calculated using the physical and chemical modelling corresponds closely with the average value of 85.7% according to production data.