ABSTRACT. Today, the global trend in the development of renewable energy sources is the implementation of integrated processing of organic waste with the production of biogenic gases such as biomethane. In this case, an essential focus is the study of biogas purification processes to methane. This paper focuses on the process of modeling biochemical purification of biogas from hydrogen sulfide to develop the direction of biomethane production. Simulation of hydrogen sulfide bio-oxidation process with the use of granulated carrier based on phosphogypsum was conducted using experimental data from previous studies to verify the adequacy of the proposed mathematical model. Thus, to implement the process of phosphogypsum utilization in technological systems of biogas purification, it is important to consider the level of bioactivity in the immobilization of bacteria on the loading surface of phosphogypsum and the degree of biotransformation of phosphogypsum components in the oxidation of carbon dioxide and hydrogen sulfide impurities to achieve the highest ecological effect. Also, the use of overlay visualization allowed to form the main clusters of development of research potential in the field of biogas technologies for Ukraine.

ABSTRACT. There are presented results of developing a conceptual trigger chart of the functioning mechanism of the decision support system. The suggested model of visualizing algorithms as a trigger net of states of the computer decision support system provides for interaction of power objects of mining and metallurgical complexes and regions. The authors introduce new interpretation of components of the network trigger model. The model is interactively connected with both the user-operator’s actions and states of power system components. With that, the state of the automatic model is associated with realizing a set of metarules to control the logic output. The authors elaborate a new formalism of representing algorithms of controlling knowledgebases interacting with the outer environment which aggregates primitives of conditions, triggers and transactions of operations and greatly generalizes standard languages of algorithm visualization. It enhances elaboration of standardized smart systems interacting with the external environment. This allows description of functioning algorithms of knowledgebases and the event-driven output to ensure development of reliable standardized smart systems interacting with control objects of power systems in mining and metallurgical regions.

ABSTRACT. The paper discusses the influence of low-quality electricity on the temperature modes of operation of an asynchronous motor. In the course of experimental and analytical studies, the heat transfer coefficients and heat capacity of a particular electromechanical converter were determined. Experimental and analytical dependences of temperature changes of an asynchronous motor on time are given when it is connected to a supply voltage with different coefficients of sinusoidal distortion and negative sequence. The resulting model is tested for its adequacy to the real process and can be used as an element in the energy-economic model of an asynchronous motor to assess its uptime.

ABSTRACT. The article deals with the research of the efficiency of modelling the dynamics of voltage change in lithium-ion rechargeable batteries in charging/discharging modes using nonlinear block-oriented systems. Drawing on experimental data, a structural and parametric identification of the Hammerstein, Wiener and Hammerstein-Wiener models with a polynomial structure of the linear dynamic block and piecewise linear static nonlinearities was performed. It has been established that the best modelling accuracy was ensured by using the Hammerstein-Wiener system with a linear model having the 6th order of the numerator and denominator polynomials and an input delay of 3 samples. It showed 15.67% and 6.2% higher accuracy compared to the Wiener and Hammerstein systems, respectively. The application of those models in battery management systems will make it possible to improve the control quality for battery assemblies of solar and wind power plants in the context of the variable nature of the charging/discharging processes due to the variability of weather conditions and fluctuations in power consumption during a 24-hour period. This will ensure a wider introduction of renewable power generation into existing power systems, which is currently the leading way to ensure sustainable development of the energy sector.

ABSTRACT. This paper aimed at studying the current state of development of liquid biofuels' world market. The authors considered the theoretical bases of liquid biofuels production, their types, disadvantages and advantages. The world experience of introducing stimulation mechanisms of development and their influence on the sectors' growth is analyzed. In this study's frame, there is outlined the world leaders in the production of liquid biofuels. The findings represent the peculiarities of state regulation in implementing mandates for creating transport fuels with bioliquids. The current state of investment in the production of liquid biofuels has been studied. The obtained results contribute to the prospects for developing world production of liquid biofuels to achieve the Paris Agreement's goals by 2030 under the SDS scenario.

ABSTRACT. The work is devoted to research of predictive control of induction motor drive. Using the predictive control system allows us to improve dynamic characteristic of AC drive. The influnce of motor's equivalent scheme changing on the performance of drive is shown by mathematical simulation in Matlab/Simulink

ABSTRACT. The paper deals with the problems of balancing the United Energy System of Ukraine caused by high renewable energy penetration and the impact of the COVID-19 pandemic on the energy sector. The paper analyses the trends in renewable energy development, the dynamics and structure of electricity consumption and export in pre-epidemic and epidemic periods and identifies the main challenges to operational security of the United Energy System of Ukraine. The methodical approach to improve the methodology for estimation of country’s energy security level by considering the index of developing capacities for balancing the United Energy System of Ukraine is suggested. In addition, proposals have been made to reduce threats to the stable work of the United Energy System of Ukraine by putting into operation of energy storage capacities, promoting the development of мaneuvering renewable energy capacities, and implementation of other appropriate measures in this field.

ABSTRACT. The principal of identification of isolation workability in relation to a ground was proposed. It is based on the electrosafety criteria usage and a minimum current flow to a ground. The conditions of workability of isolation of distribution network is calculated in look of changes of isolation workability restrictions in relation to regulations and standards.A mathematical model for the calculation of isolation workability in a look of a relation of workability indicators to the isolation parameters according to a ground. By analyzing the adequacy it as set that introduced formed models assumptions result in the appearance of a method error to 3,5 %.

ABSTRACT. The work is devoted to the study of performance of a multilevel electric energy converter using phase-shifted pulse-width modulation. Equations describing the state of a dynamic system multilevel converter - load are investigated and a mathematical model of the system in Matlab / Simulink environment is constructed. Variants of implementation of phase-shifted pulse-width modulation systems from the point of view of influence on harmonics of output voltage and magnitude of circulating current in the converter are investigated.

ABSTRACT. Widespread use of semiconductor radiation sources in optoelectronic devices for various purposes requires further study of the mechanisms of formation of photometric characteristics of the integrated device in the near illumination zone, where the law of inverted squares is violated. A mathematical model of the multicomponent beam-diode module is proposed. On its basis the analysis of influence of the parameters of separate beam sources on the deformation of the indicatrix of radiant intensity at transition from the far zone to the near one is carried out. It is shown that the determining parameter of the indicatrix change in longitude and polar distance is the distribution in the plane of the modulus of the product of the radiant intensity of a single diode on its polar radius vector. The displacement of the polar angle of the maximum of the vector of the diode radiant intensity is more significant for wide radiation patterns than for concentrated ones. For specific parameters of diodes and geometry of their location the suitability of the proposed model for a priori modeling of beam-diode modules is illustrated.

ABSTRACT. The article is devoted to the problem of increasing the efficiency of using energy resources of enterprises of the pulp and paper industry in Ukraine. Its solution will contribute to achieving the goals of sustainable development, reducing the energy and carbon intensity of the Ukrainian economy, and implementing the principles of the European Green Deal. It has been determined that the pulp and paper industry belongs to energy-intensive types of economic activity. The rate of use of energy resources here exceeds the rate of growth in the production of paper and cardboard. Based on the results of the correlation and regression analysis, a connection was revealed and an economic and mathematical model was formed of the dependence of energy costs for the production of 1 ton of paper on the productivity of paper machines, equipment wear and the volume of investments in energy saving measures. Application of the proposed model will improve information support for the analysis of the effectiveness of energy saving measures, forecasting energy costs and strategic energy management in general. The results of the analysis indicate that the pulp and paper industry with a powerful raw material base of Ukraine in terms of the use of renewable energy sources significantly lags behind the similar industry in developed foreign countries. Based on the results of the analysis carried out at pulp and paper mills, the main obstacles to replacing fossil fuels with biomass in heat production were identified. This made it possible to develop a scientific and organizational model for the energy modernization of enterprises in the pulp and paper industry. It includes financial and economic, organizational, environmental, regulatory, technological, scientific and educational (personnel) and other tools. Their application at different levels of management will help improve the financial and market infrastructure of enterprises in terms of the use of renewable energy resources, as well as enhance their energy independence.

ABSTRACT. The article investigates into the level of energy efficiency of main water pump stations of iron ore underground mines in case of time-of-day electricity rate. There are developed and suggested methods of analyzing the influence of pump electric capacity on electricity cost based on multifactor regressive models. The data on power consumption of iron ore mines indicates a complex character of analyzing the results obtained. However, application of information technologies enables using static materials in a new way including indices of power consumption, costs, water intake, mining depth, the number of pumps and their capacity by synthesizing mathematical models as complicated objects through in-depth procession of static materials and substantiation of the obtained results. For the first time, there are used multifactor regressive models considering multicollinearity and non-linearity of pump capacity in order to study its influence on power costs by using the elasticity factor. Analysis of mathematical simulation results relevant to static materials and applying the algorithm of studying dependency of the consumed power costs on pumps’ capacity reveals some critical values resulting in corresponding effects. The authors recommend to apply the elaborated algorithm to conducting corresponding calculations by for mining enterprises to monitor formation of the strategy of providing energy efficiency under time-of-day electricity rates.

ABSTRACT. The bucket positioning of the excavator in three-dimensions (3-D) is the precondition of the robotic excavator starting automatized works. The electric excavator is one of the most widely used machinery in the mining industry, mainly due to its versatility and portability. Among the tasks performed by the excavator, there is a significant number of repetitive movements associated with moving the bucket to the unloading point and back to the face. Using automated functions to perform such repetitive tasks will not only significantly increase overall productivity, but also reduce energy consumption. This research is carried out to create a method of coordinate control of electric drives of the boom, dipper stick, and bucket of an electric excavator to perform accurate and efficient work. On the basis of the kinematic analysis of the excavator's attachment system, the trajectory of the end of the working body can be determined from the point of view of the coordinated movement of the electric drives of the main mechanisms of the excavator. Thus, the complex algorithm of the excavator bucket 3-D position control can be carried out by coordinated control of the movement of three separate electric drives. This coordinate control algorithm was tested on the example of the EKG-8I excavator, and the results of the verification showed that this developed control method can satisfactorily perform the function of automatic control of the bucket position in three-dimensional space. Optimization of control will be further carried out based on the analysis of the energy efficiency of various possible trajectories.

ABSTRACT. The research deals with analyzing peculiarities of using active rectifiers in frequency controlled electric drives of underground mine hoists. There are developed MATLAB models aimed at comparing two types of control systems – hysteresis-based and the one with pulse-width modulation. The research aims to analyze power modes and parameters of active rectifiers, quality of voltage control, current and power of active rectifiers and to determine ways of improving power indices of electric equipment of hoists as well as provide power compatibility of electric equipment and underground mines’ grids. Main attention is paid to analyzing circuitry of control systems of active rectifiers, parameters of power transformers and reactor equipment at underground mines’ substations, frequency converters and synchronous slow-speed motors. There are also analyzed statistic data on power consumption at underground mines equipped with automated systems of commercial and technical power meters and specific consumption of power. The research results reveal advantages of the pulse-width modulation control system as compared with the hysteresis one by using such indices as speed-performance, quality of control, potential of controlling reactive power and the power factor. Application of the research results will enable determining structures and methods of adjusting control over the active rectifier in the frequency-controlled drive of underground mine hoists. Further research is aimed at improving energy efficiency of active rectifiers and reducing their impact on the grid.

ABSTRACT. The active and reactive power sharing of distributed generation sources (DGs) connected to isolated microgrids with a single point of common coupling (mono-PCC) to which the loads are also connected has already been the subject of several studies. A high penetration rate of DGs based on renewable energies has as a logical consequence the development and implementation of mesh and more complex multi-PCC microgrids. In this paper, a developed droop control method for synchronization and power sharing between different DGs connected to a mesh islanded multi-PCC microgrid with many distributed generation sources (DGs) and different type of loads (including active load (CPL)) randomly connected to different PCCs is applied. Then, a state model of the entire mesh microgrid is developed integrating the generators with their controllers, power lines, droop algorithms and dynamic loads. This model is then used to study the asymptotic stability and robustness properties of the system. The simulation results confirm the effectiveness of the applied strategies for the synchronization of the different DGs to the microgrid while ensuring an efficient active and reactive power sharing. also, they confirm the validity of the developed state space model of the system.

ABSTRACT. The worldwide environmental concern and awareness created a way towards the generation of pollution-free wind and solar renewable energies. Wind and Photovoltaic (PV) power plants of 10MW capacity located in the Shagaya area, west of Kuwait, were compared after one year of operation. The wind power plants recorded high capacity factors resulting in a yearly power production of 42.59 GWh, 21% higher than expected (contractual 31.160 GWh). It also reduced the emission of CO2 throughout the projected lifetime of 25 years by 118,303 tons. CAPEX (capital Expenditure) and OPEX (operation expenditure) were taken into consideration throughout the life of the plants along with investment costs resulting in a levelized cost of electricity (LCOE) for wind of 0,015 KWD/kWh or 0,046 USD/kWh, compared to 0,027 KWD/kWh or 0,082 USD/kWh for solar PV (44% lower than PV). Offshore, Boubyan Island, Northern Kuwait territorial waters, were found to be the foremost appropriate for wind energy generation, with Wind Power Density of more than 500 Watt/m2 in summer which is ideal for the high energy demanding season in Kuwait. The LCOE for offshore wind energy was 27.6 fils/kWh, compared to 39.3 fils/kWh for thermal power plants.

ABSTRACT. The paper discusses the questions of alkalinity changes in alkali activated cement-based materials at different stages of hardening. It was shown that use of alkali activated cement with dry alkaline component (“all-in-one system”) in the presence of basalt rock leads to the immediate decrease of pH value and strength drop of the material. On the other hand, using alkaline component in the form of alkaline solution provides almost normal hardening of systems. Taking into account obtained results a methodology of changes in concrete mix design was proposed. In general, for different cement systems under study pH value varies from 8.5 to 12 reflecting on the materials structure formation processes and strength gain. Shrinkage of the systems was within the ranges 0.3…0.6 mm/m at 28 days age and 0.3…0.5 mm/m for different systems. Absence of expansion witnesses about compensation of ASR results and normal structure developments processes in the material comparing to OPC.

ABSTRACT. Article is devoted to the investigation of suitability of low carbon Roman cement for restoration and finishing works. The history of the development of Roman cement as a natural hydraulic binder, which was commonly used to decorate building facades in the 19th and early 20th centuries, is presented. The properties of mortars based on Roman cement make it an excellent product for architectural restoration and conservation, as they are characterized by fast setting, high porosity typical for lime mortars, high resistance to weather conditions, high initial strength. At the same time, due to the high surface activity and increased water demand for cement, with the age of hardening, shrinkage deformations can develop, which leads to the formation of main cracks on the surface of the products. It is shown that the addition of gypsum is an effective regulator of the setting time of Roman cement and contributes to an increase in the strength of the cement paste. Analogs of Roman cement based on multicomponent cement binders modified with plasticizing and air-entraining additives are presented.

ABSTRACT. The influence of mineral additive, i.e. granulated milled blast-furnace slag on artificial gypsum stone humidity strains has been studied. The slag content was varied in the range from 0 to 0.33 by weight based on the total amount of the mixture. The measurements were carried out on prism samples with dimensions of 160x40x40 mm. The samples were placed vertically in containers with water, the deformations were measured using dial indicators. It was established that the humidity strain value depends on the content of the granulated milled blast-furnace slag. A maximum strain of over 0.001 m/m is observed for the gypsum stone with no mineral additive. A relative strain is decreased with an increase in the slag content. Minimum humidity strain of 0.0003-0.0004 m/m was observed for the artificial gypsum stone with the relative slag content of 0.05-0.1 and more than 0.27. This fact confirms our assumption that the water concentrated in the contacts between the individual crystals and particles of the structure of gypsum stone has a wedging effect that contributes to a low water resistance of gypsum. The values of the humidity strains of the artificial gypsum stone are suggested for the use as additional indicators of its water resistance.

ABSTRACT. Concretes mixed with seawater are characterised by enhanced performances, but action of chlorides and sulfates ensures the risk of reinforcement corrosion. Application of high consistency fresh concretes ensures changes in hardened concrete structure that causes the problem of steel reinforcement passive state ensuring. Thus mixing of plasticized concretes by seawater actualizes the search for means of steel corrosion prevention. Alkali-activated slag cements (further, AASC’s) reduce effect of ions Cl- and SO42- on steel reinforcement in concrete due to their exchange for ions OH- in the structure of zeolite-like alkaline hydroaluminosilicates. Complex additive «portland cement - calcium aluminate cement - clinoptilolite» was proposed to enhance the protective properties of AASC concretes to steel reinforcement. The results of DTA, X-ray diffraction, electron microscopy, microprobe analysis show that complex additive ensures to prevent steel reinforcement corrosion in AASC concrete mixed with seawater due to binding Cl- and SO42- ions in Kuzel's salt in AASC hydration products and exchange of these aggressive ions with OH- ions in the structure of clinoptilolite. This effect of complex additive confirmed by surface state and the absence of mass loss of steel rebars embedded in plasticized AASC fine concrete mixed with seawater after 90 d of hardening.

ABSTRACT. One of the essential tasks for a sustainable future is to reduce harmful emissions into the atmosphere significantly. Cement production is the world's largest industrial carbon pollutant, accounting for 8 % of global emissions. More than 2.2 gigatons of carbon dioxide are emitted into the atmosphere every year. Therefore, reducing the energy intensity of products and reducing the number of harmful emissions in cement production is becoming critical. One of the strategies to reduce cement production emissions is to reduce the share of the most energy-consuming component in cement — clinker. In this case, various activation methods are used for maintaining the same level of cement activity. One of these methods is the impact on the hardening binder with magnetic fields. In the paper presented the results of a study of hydration processes of blast–furnace cement activated by a magnetized ferromagnetic additive. The work established that the introduction of pre–magnetized ferromagnetic dust into blast–furnace cement composition has an activating effect on binder hydration. It shows that activation occurs both in the initial and long periods of hardening. The nature of the mutual influence of the components of the hydration system alite — lime — slag in a modified binder was revealed. The investigation determined that the ferromagnetic additive, intensifying the process of slag hardening, increases the proportion of hydrated slag by 1.5–2 times. It was revealed that the formation of the ettringite framework in the modified binder's gel is completed within one day. It is shown that in the subsequent periods, hydration of aluminates occurs mainly due to the formation of hexahydrate tricalcium aluminate, which excludes destructive processes in the late periods of binder hardening. It has been established that under the action of a ferromagnetic additive, the degree of crystallization of hydro silicates in the modified binder increases.

ABSTRACT. In connection with the growing need for saving natural resources used in aggregates for concrete, the importance of lightweight structural aggregates obtained from production waste is continuously increasing. Lightweight structural concretes on porous aggregates can significantly reduce own weight of structures, make it possible to manufacture larger structures, reduce transport costs, and improve the thermal insulation and acoustic properties of enclosing structures. The use of waste from the mining and metallurgical industry to produce construction materials significantly reduces environmental pollution. The article is devoted to studying the possibility of using wastes from the mining and processing industry of enterprises of the Kryvyi Rih iron ore basin to produce lightweight porous aggregate. The paper presents the results of studies of the effect of granulometric composition of the charge, the quantitative content of the raw mix components, and the temperature of heat treatment on the quality of aggregate. The most suitable raw material mixture for artificial aggregate has been determined. The results of X-ray diffraction thermographic analysis of raw granules are presented. The influence of technological factors on the aggregate density and strength has been studied using mathematical modeling. The obtained equations made it possible to reveal the regularities of the raw mixture's components and temperature for the optimal aggregate density and strength. The results of studying the structure and porosity of the developed aggregate are presented. The results of X-ray thermographic analysis of the aggregate explain the mechanism of pore formation in the pellets. The basic physical and mechanical properties of the obtained aggregate are investigated. Particular attention pairing to the study of the contact zone of the aggregate with the cement stone.

ABSTRACT. The report presents the results of research on the use of composite material - fiber-reinforced concrete for the manufacture of centrifugal pump bodies. The optimal composition of fiber-reinforced concrete with the required strength characteristics has been established. The method of casting a pump body and the results of industrial tests to determine the technological parameters of a centrifugal pump are presented. The results obtained showed that fiber-reinforced concrete bodies have an advantage over metal ones and can be recommended for use in mechanical engineering in the manufacture of centrifugal pump bodies.

ABSTRACT. The use of the structural scheme of the covering is considered, which allows the use of a lightweight roof structure using modern composite materials. A comparison is made of two options for cable-stayed covering of the circus auditorium: with an orthogonal mesh of cables (according to a standard design) and with a mesh of cables formed by two groups of stabilizing cables. The possibilities of reinforcement with composite material are analyzed. Calculation and preliminary selection of cable-stayed sections were carried out. The graphs of the dependence of the conditional volume on the relative sag arrows are plotted, with the values of the coefficient kq. An optimization problem was solved to design the cable-stayed coating and determine its characteristics. As a result, optimal cable-stayed sections were obtained. The calculation shows the inexpediency of using a heavy roof structure for saddle cable-stayed coverings due to the exclusion of stabilizing cables from the operation with a large roof weight.

ABSTRACT. The analysis of the process of thermal modification of wood, which was modified by a controlled process of pyrolysis of wood heating (> 180 ° C) in the absence of oxygen, which causes some chemical changes in the chemical structures of cell wall components (lignin, cellulose and hemicellulose), durability. It is proved that in the process of thermal modification the decomposition of hemicelluloses and the amorphous part of cellulose occurs, and therefore the amount of substances that are the environment for the development of fungi in wood significantly decreases. In addition, lignin and the formed pseudolignin undergo a process of polymerization and redistribution of cell volume and give cell walls greater density, hardness, increase hydrophobicity (water repellency), thereby reducing their ability to absorb moisture and edema. Polymerized lignin fills the inner cavity of the cell, forming a closed porous structure with a low ability to bind water. It was found that the most effective parameter for reducing such substances is the temperature and exposure time. The results of thermogravimetric researches are given, the dependence of weight loss on temperature of researches on the basis of which activation energy is calculated is defined. The results of determining the activation energy show that for hardwood species this value exceeds more than 1.5 times compared to softwood.

ABSTRACT. The article presents the main results of experimental studies on the identification of the main grade defects of oak lumber by the thermal non-destructive testing method. Regressional dependences of wood defects temperature display from the main factors for the studied grade defects are proposed. Indicators of infrared radiation (temperature range) of the main visible oak grade defects obtained as a result of experimental studies are presented. A conceptual scheme for the line control methods of identification of the main grade defects in lumber are proposed.

ABSTRACT. The work is devoted to the problem of increasing the production of gas condensate in gas condensate fields. It is established that ammonium carbonate salts, in the absence of chlorocalcium-type waters, interact with carbonate rocks, increase the permeability of reservoirs. Solutions of ammonium carbonate salts in interaction with formation water of the chlorocalcium type form chemically precipitated chalk in the pore space, while the permeability of carbonate rocks decreases. A set of experimental studies was carried out in order to displace and wash the properties of ammonium carbonate salts. It was found that ammonium carbonate salts have high displacing properties, the coefficient of displacement of kerosene by NH4HCO3 solution is 0.75-0.80, while reservoir water – 0.55-0.58. According to the results of laboratory studies of displacement and washing characteristics of ammonium carbonate salts, conclusions were made about the effect of bicarbonate solution (ammonium carbonate salts) on the production characteristics of the well in formation conditions at temperatures of 80-100 ° C and above. Industrial tests of ammonium carbonate salts showed an increase in gas flow by 30-50% at wells № 23 of Opishnya, № 115 of Mashivka, № 3 of Tymofiivka gas condensate fields. The effect of treatment of the formation with ammonium carbonate salts is achieved due to the cleaning of the bottomhole zone of the formation and increase the permeability of the reservoir. Condensate factor increase by 22-35% was observed at wells № 56, 108 of Yablunivka and № 58 of Tymofiivka gas condensate fields. The efficiency of this treatment is associated with the simultaneous cleaning of the bottomhole zone from asphalt-resin contaminants and increase permeability, as well as with the hydrophilization of the pore space and increase of condensate mobility, due to the action of carbon dioxide released by decomposition of carbon dioxide. Thus, experimental and industrial tests in Opishnia, Mashivka, Tymofiivka, Yablunivka gas condensate fields of Poltava region confirmed the effectiveness of using ammonium carbonate salts to increase hydrocarbon production. Prospects for further research are aimed at developing a technology to increase the production of liquid hydrocarbons through the use of ammonium carbonate salts.

ABSTRACT. Laboratory sintering of sinter charge based on hematite and magnetite iron ores of various sizes was carried out. The purpose of the study was to determine the effect of the type and size of the ore material on the gas permeability of the sintered layer, sintering performance and the need for fuel. The granulometric composition, cold strength, strength during recovery, and reducibility of the resulting agglomerate have been studied. Differences in the course of the process of agglomeration of hematite and magnetite ores at different sizes were revealed in the research. The established patterns have practical interest from the point of view of increasing the efficiency of the sintering process, improving the quality of the sinter and reducing the harmful impact on the environment.

ABSTRACT. Magnetic separation devices are widely used to separate tramp of iron from a specific feed of materials. Many industries rely on those devises and the variety of technological solution depend mainly on the characteristic of the tramp to be separated. In this paper, main characteristics of low intensity magnetic separation devices based on permanent magnets for dry feed are considered to evaluate force index computation.

ABSTRACT. Plants are natural sources of bioactive compounds, and the intensive use of wild plants to obtain them, in particular secondary metabolites, depletes natural biocenoses. Instead, modern biotechnological methods, especially cell and tissue culture in vitro, make it possible to get environmentally friendly, highly productive plant raw materials that are able to synthesize and accumulate specialized substances, which are valuable for pharmacology, cosmetology, and medicine. Regenerating in vitro-plants of different plant species such as Acorus calamus L., Phalaenopsis sp., and Salvia hispanica L. were obtained in our research. It was proved that by changing the cultivation conditions it is possible to change the content of substances of secondary metabolites in explants and in the nutrient medium under aseptic culture.

ABSTRACT. The methodology of calculating parameters of primary and secondary non-metallic inclusion formation in thermite alloys is offered. The regularities of the growth time of non-metallic inclusion in the form of corundum depending on its size, mass and quantity are analysed. It is shown that in the thermite alloy obtained by self-propagating high-temperature synthesis, the average size of corundum inclusions, surrounding the heterogeneous inclusions of chromium carbide, is 15.4 μm. It is shown that during the process of aluminothermic reactions of SHS process a significant number of small inclusions of corundum is formed. It is shown that the alumina particles are dissolved in the alloy and they are the centers of crystallization and play the role of inoculating modifier.

ABSTRACT. Ultrasonic cleaning is one of the most promising types of cleaning in terms of environmental friendliness, cost and efficiency. The condition of the cleaning body must be taken into account for optimal control of the ultrasonic cleaning process. This allows you to irradiate only those areas that really need it. The modeling of the process of ultrasonic cleaning of bodies of different configurations and the analysis of the parameters of ultrasonic responses at different stages of cleaning were performed. This allowed us to identify the parameters by which the assessment of the process should be formed. The main parameter was the change in the time of receipt of the threshold value of the signal, and the auxiliary - the change of the nonlinearity coefficient of the second order. The change in the time of receipt of the threshold value of the signal is an indicator of dirt peeling, and the change in the nonlinearity coefficient demonstrates the approach to the final result of cleaning. These parameters became clear input data for the 3-D fuzzy interval controller. The functions of affiliation were defined and the base of rules was formed. Modeling of the ultrasonic cleaning process using the established method of estimating the course of the process and the use of 3-D fuzzy interval controller showed about 35% energy savings.

ABSTRACT. The process of thermo-mechanically controlled rolling in the conditions of Steckel mill of Ferriera Valsider plant was developed for the first time for hot-rolled coils in the sizes of 12 mm × 1510 mm from steel of X65 grade for further production of electric welded pipes according to the API-5L standard. The developed process provides carrying out of the roughing-rolling in two stages to facilitating the forming of a smaller austenite grain and therefore more dispersed and homogeneous inherited ferrite structure in the finished rolled product. At the implementation of the process, the holddown of the temperature at the desired level at 1780 Steckel rolling mill has been carried out by adjusting the number of burners in furnace coilers. The process of controlled air cooling of rolled coils to a temperature of 400 ^oC after winding in the developed technology for Steckel's mill condition of Ferriera Valsider plant is applied for the first time that allowed to reduce the thickness of the air scale layer and to improve the surface quality. The performed research has been allowed to evaluate the feasibility of the operating equipment and to determine the possibility of coils fabrication related to the nowadays world requirements and satisfied to the demand of European electric-welded pipes manufacturers.

ABSTRACT. The proposed method for calculating the loading parameters makes it possible to determine the wear parameters after explosion hardening. The calculation method is simple and less time consuming compared with calculation methods that involve the use of nonlinear programming methods. The main methods of increasing the wear resistance of mining equipment parts using explosion methods are generalized. The reserve for increasing the wear resistance consists in the optimization of deformation parameters during the power and thermal intensification of processes and the development of new methods and technologies of hardening. The factors (parameters) of the studied processes: explosive cladding, alloying, hardening, are formulated. Optimization of the processes under consideration is possible by decomposing the process into simpler ones with subsequent optimization of the parameters of these processes and the synthesis of the obtained solutions. For the first time, a solution to the multicriteria problem of two-stage explosion hardening is presented. It is proposed to split the process into simpler ones. Optimization criteria are proposed for each of the simplified processes. The problem is reduced to a conditional extremum problem, which is solved by composing the Lagrange function. By transforming the wear equation, the optimal ratio of strength and ductility for parts operating under abrasive wear conditions is determined.

ABSTRACT. The development of a method for drawing cylindrical parts without pressing the workpiece flange, which allows reducing the cost of production due to the use of dies without a fit ring and single-acting presses. The performed research revealed that this method results in obtaining cylindrical parts with drawing coefficients typical of drawing with pressing. In this case, the different thickness of the finished product is several times less compared with the same type of semi-finished products obtained by drawing with a fit ring. Steel, aluminum and copper workpieces were researched. More plastic materials revealed the best results. This method cannot be applied to materials with thickness less than 0.25 mm.

ABSTRACT. Erdenet copper-molybdenum deposit is the biggest one in the world and has a significant impact on Mongolian society and economy. Today LIEBHERR-994B hydraulic shovels from Germany, electric shovels including EKG-10 and EKG-15 from Russia operate for the mining works and dump truck BelAZ - 75130 used for transportation. The causes of shovel downtime are classified as technical, technological, and organizational. During the study period, 41% of the total downtime of the excavator’s park was technical, 45% was technological, and 11% was organizational downtime. For shovels, 7% of technological downtime is due to blasting, and for dump trucks 8.7%. In open-pit mining, blasting is performed on a weekly basis, so the duration of this technological downtime can be considered almost constant. If the time between blasts or period of blasting can be arranged optimally, it will be possible to reduce mining equipment’s downtime due to blasting.

ABSTRACT. Ventilation when driving roadways is one of the most important considerations in coal underground mines. Ventilation efficiency depends on fan performance and ventilation ducting system. In recent years in Vietnam, ducts have often been produced domestically. However, parameters of the duct as duct leakage, duct resistance for designing auxiliary ventilation system are referenced from abroad handbook. This lead to inaccurate design results and needs to adjust efficiency of auxiliary ventilation during driving roadways. Determination of duct resistance; air leakage in ducting system have been undertaken. The research result has been used to optimize the auxiliary ventilation system.

ABSTRACT. The application of information technologies leads to the improvement of the companies’ production parameters in each sector according to the criteria for sustainable development. Naturally, in order to achieve efficiency, they must be tailored to the specifics of the industry, in this case the mining industry. The article proposes a methodology for the introduction of Distributed Ledger Technology (DLT) for the transport information flow at a mining company. Based on the chosen organizational structure, the participating actors and the data they share, the information channels are determined. According to the necessary rights of the participants to modify the transactions and the number of channels of the transport information flow, a consensus mechanism Practical Byzantine Fault Tolerant and the so-called smart contract have been chosen. Different DLT platforms are analyzed. Hyperledger Fabric was selected as an appropriate platform in order to ensure the continuity of the system, the asynchronous control of the various channels and the ability to include different actors.

ABSTRACT. The research is aimed at solving the topical problem of enhancing efficiency of iron ore magnetic separation by applying ultrasonic technologies to identify optimal technological parameters of magnetic separation, improving controlled structural parameters of a magnetic separator and pretreating slurry by high-energy ultrasound to clean the ore material surface from fine-dispersed particles of minerals and slime, as well as disintegrate ore aggregates fed to the magnetic separator. The main tasks involve identifying regularities of influence of slurry pretreatment by high-energy ultrasound on properties of iron ore magnetic separation, determining regulations of improving technological and controlled structural parameters of the magnetic separator using ultrasonic methods, developing and substantiating methods to enhance efficiency of iron ore magnetic separation by applying ultrasonic technologies.

ABSTRACT. The article is devoted to the development of an effective technology for processing serpentinite ores from the Bozymchak deposit in the Kyrgyz Republic. Based upon the analysis of mineralogical, physical and chemical parameters of the ore, the authors set reasons for the decrease in technological indicators of the existing concentrator and determine concentrating properties of the reviewed serpentinite resistant material by applying methods of intensifying the flotation process by using additional flotation collectors/depressors and introducing the process of mechanochemical activation of the pulp before flotation. In the proposed technological flowsheet, main requirements for the technological flowsheet and reagent suite of processing serpentinite ores are formed and it is acknowledged that an increase in the grinding size, introduction of the selective copper collector and additional depressor determines the prospects for improving the “reagent” component of determining factors of the set task. Materials of the article can be useful for mining and processing enterprises while involving resistant copper bearing, magnesian serpentinite ores in the processing in order to increase the raw material base of the existing mining and processing complex.

ABSTRACT. One of the main natural gas contained in the coal seams is methane. Most of it is adsorbed on the surface of the coal matrix, another is in free state in different in size and morphology pore spaces or dissolved gas in the waters that associate with the coal seams. The form of presence and the degree of gas saturation depends on the rank of the carbonization process, the petrophysical and physicochemical parameters of the environment. Methane in coal seams is accepted to be categorized as an unconventional energy resource. From this point of view, it is of interest in the Dobrudzha coal basin, located in the North-eastern part of Bulgaria. The specific geological conditions of the basin, the limited study, the presence of a thick covering aquifer make it difficult to extract coal by traditional methods. This requires the use of non-popular for the country methods for energy extraction and establishing relation between the basic parameters of coal seams and their gas saturation. The existing geological-geophysical, drilling and laboratory information is combined in a detailed petrophysical model, which extends over the best presented and studied coal seam (m5) from the field. The basic parameters that reflect the amount of adsorbed gas and are the subject of study are the content of moisture, carbon, ash and the degree of carbonization, expressed by the vitrinite and its reflectance.

ABSTRACT. Object of research - disturbed lands of Ingulets Iron Ore dressing Work (Ingulets GZK) The purpose of work - development and substantiation of technology of realization of principles of cascade waste use. Research methods – field experiment, comparative analysis, systems analysis. As part of the implementation of the cascade waste use principle, the results of research on the impact of the application of sewage sludge on formation of protosoils on the rocks of Ingulets GZK dumps are presented. The application of sewage sludge significantly increases the absorption capacity of overburden. A secondary soil absorbing complex is formed, which is able to accumulate and retain mineral nutrients of plants, especially calcium and magnesium cations. In the conditions of field research the influence of treatment of rocks with organic matter of sewage with introduction of seeds of perspective species was studied. Comparative analysis of vegetation shows a positive effect of the treatment of overburden with organic matter on productivity and morphometric performance of trees and shrubs. A comparison of the average condition of plant objects after treatment with organic matter and control studies shows the following: the vitality of herbaceous and tree species increases; the total projective cover and average height of plants increases; biodiversity.

ABSTRACT. The article contains research materials on the storage of man-made deposits, including phosphogypsum dumps. The consequences of long-term operation of phosphogypsum dumps and their negative impact on the environment have been established. The quantitative content of microelements to the soil within the storage of technogenic phosphogypsum deposit was determined. Graphical dependences of phosphorus, manganese, fluorine, mobile sulfur, zinc, nickel content depending on the depth of sampling and distance from phosphogypsum dumps to settlements and the Goryn River are presented. The directions of processing and utilization of the given waste are offered. The elemental composition of phosphogypsum dumps of PJSC "Rivneazot" has been established, in particular, the presence of a group of valuable rare earth elements.

ABSTRACT. The purpose of the study is to select an effective methods and equipment for observing deformations in dangerous areas of the terrain, such as areas that are undermined by underground mining. It is known that the topical task of the mine surveying service is to improve remote sensing methods for the state of movement zones with craters, dips, cracks. The research methodology is based on the results of the performed analysis of methods for observing deformations using modern devices and technologies, and experimental work using the developed methodology, which provides for the combined use of digital methods and GPS technologies. Experimental work was carried out at the facilities of the Ordzhonikidze mine using various remote sensing methods, including those developed by the authors. The research used a design consisting of a digital camera and a GPS receiver. The performed analysis of the obtained survey results, using the proposed design of two devices, has shown its effectiveness in remote methods of observing the objects deformations located in areas undermined by mining operations. The scientific novelty of the results obtained lies in the methods development for remote observation of deformations of the ground's surface and objects, based on the structure use from a digital camera and a GPS receiver. This method was developed to increase the efficiency of performing research on objects deformations located in places that are dangerous for finding a person. The efficiency of using terrestrial digital stereo survey when the coordinates of the photographing points are determined with the help of GPS has been proved. The practical significance of the study lies in increasing work efficiency the on monitoring deformations of the earth's surface, buildings and structures located in areas dangerous for field work by traditional methods, which are performed using leveling and measuring the distances between the benchmarks of profile lines, which are usually used on areas undermined by underground mining. The use of terrestrial digital stereo photography with the coordination of photographing stations using GPS allows remote determination of the spatial position of the observed points with the required accuracy. Key words: ground stereoscopic survey, collapse zone, digital camera, GPS.

ABSTRACT. The work analyzes current technologies of ore mining applying self-propelled equipment in underground conditions; studies practices of using the equipment in general and for broken ore transportation only; considers performance of mining enterprises in similar mining-geological and mining-technical conditions; analyzes and generalizes causes of high ore loss and dilution rates in underground mining in Kryvyi Rih iron ore basin, thus revealing a problem of providing high efficiency and increased ore extraction with minimal quality deterioration. Marketable ore production is affected by decreased quality and high broken ore losses. Incomplete balance ore extraction when breaking and drawing ore from the stope results in deterioration of mining indices. Ore dilution with waste rocks leads to decreased ore content in the mined mass as compared with that in the ore massif. The research enables development and substantiation of the rational technology of ore drawing and transportation as well as designing a new structure of the loading face to ensure increase of the drawn ore quality indices.

ABSTRACT. The main sources of methane emission are located in the undermined coal-bearing strata, which is not taken into account by the requirements of regulatory documents when determining the category hazard of coal mines. Gas emission from each undermined source is not equally dependent on the tons of coal mined. The relative gas emission changes during the cleaning work and cannot be a criterion for assessing the gas hazard of the entire mine. The volatility of the gas emission index per unit area of the underworked space, which was formed because of monthly movements of the working faces, was established. In essence, this indicator repeats the dependence of the relative gas content per ton of coal mined, since the area of the underworked space is functionally related to the amount of coal mined for a certain period. Without coal mining, the rate of movement of the working face is equal to zero, and gas emission from a unit area continues for several months. As a result, the considered indicators do not have their specific meaning and, due to their inconstancy, they cannot reliably reflect the gas hazard of mines.

ABSTRACT. The purpose of this article is to present modern approaches to data storage and processing, as well as technologies to achieve the quality of data needed for specific purposes in the mining industry. The data format looks at NoSQL and NewSQL technologies, with the focus shifting from the use of common solutions (traditional RDBMS) to specific ones aimed at integrating data into industrial information systems. The information systems used in the mining industry are characterized by their specificity and diversity, which is a prerequisite for the integration of NoSQL data models in it due to their flexibility. In modern industrial information systems, data is considered high-quality if it actually reflects the described object and serves to make effective management decisions. The article also discusses the criteria for data quality from the point of view of information technology and that of its users. Technologies are also presented, providing an optimal set of necessary functions that ensure the desired quality of data in the information systems applicable in the industry. The format and quality of data in client-server based information systems is of particular importance, especially in the dynamics of data input and processing in information systems used in the mining industry.

ABSTRACT. When mining ore bodies in Kryvyi Rih iron ore basin, underground mines apply open stoping or bulk caving systems in proportion of 55% to 45%. Most of underground mines prefer stoping with pillar caving. Yet, rock pressure contributes to growth of costs for workings maintenance and deterioration of extraction indices. Rock mass extraction indices can be enhanced by application of a protecting structure in the upper part of the block that will enable additional decrease in load on the draw level. There are a great many of methods for determining parameters of constructive elements of the protective structure that help keep its integrity for the whole period of block mining. The article suggests methods for determining parameters of the protective structure when mining steep ore bodies. The research conducted demonstrates that with the inclined protective structure, increase of unit load on it from 200 to 1200t/m2 leads to decrease of its thickness from 6.3-20.9m to 5.5-18.4m and increase of the crown length from 40m to 60m. The developed block caving system with application of the protective structure when mining steep ore bodies enables overall decrease of ore dilution in the block by 3%, increase of iron content in the mined ore by 1.3% without significant mining costs growth and decrease of loads on the workings of the receiving level.

ABSTRACT. The safety factors for different variants of operation development were obtained, on the basis of which the technical and economic indicators were established and the most expedient way of restoration of dump operations in conditions of the formed landslide was chosen. The solutions were proposed for the external dump No 2 of the Central Ore Mining and Processing Enterprise (COMPE), that allow to continue its future operation. When working in the conditions of the formed landslide, three variants of the further dump operation are modeled: the first one - with landslide removal and unloading of the upper dump horizons, the second one - without landslide removal and involvement of disturbed lands in land allotment, the third one - with the landslide loading. Based on the built sections of the dump and defined physical and mechanical properties, the stability factors were obtained for different options of the operation development, which made it possible to determine the appropriate option to eliminate the effects of the dump slide deformations. As a result of the calculations, the cost flows for each of the proposed options of the formation of the end contour of the dump No 2 are determined.

ABSTRACT. At mining and processing complexes, many parameters today are evaluated from the point of view of the total process from geology to the final product. Changes in certain mining parameters inevitable lead to the changes in the following downstream processes. In this article, the focus is on the ore fragmentation, which is one of the most important parameters in many mines as it affects the downstream ore preparation and processing efficiencies, productivities and costs. In most of the cases, the cheapest way to improve the fragmentation of the ore is by changing the drilling-and-blasting design parameters. It of course increases the mining costs, but at the same time decreases the costs of the following processes, which are normally significantly higher. Therefore, authors of this article propose a new way of optimization of the drilling-and-blasting process by introducing new blast design modifications. Based on the analysis, research of the scientific information and the mining practise, the authors discuss the way of creation of the preliminary stress in the block of the open pit and hence improving fragmentation. Physical experimental blasts in “Belaya Gorka” open pit were performed and shown positive results reflecting a potential for continuation of the research in this direction in the future.

ABSTRACT. Sustainable mining and mineral processing is of paramount importance for producing metals needed for our society development. Membrane processes are able to contribute to the comprehensive extraction of metals from mined ores, while at the same time decrease the amounts of used water and reagents and ensure discharge to the environment of wastewater meeting the legislation requirements. Membrane-based technologies are still underused in metals obtaining although their development and price have made their application affordable. The paper presents in brief membrane processes and displays examples of their application in various areas of mining and mineral processing, such as coping with acid mine drainage and mine influenced water, recovery of metals, reagents and water in hydrometallurgy, recovery of lithium from brines, and treatment of wastewater. Emphasis is placed on pressure driven membrane processes, as well as on the very recent studies in the area. Advantages of membrane processes application in mining and mineral processing are pointed out as well as constrains to be overcome.

ABSTRACT. A theoretical scheme of gas release from the coalbed under production by treatment workings has been developed. The sizes of zones of different intensity of gas release from the working thickness are set according to the characteristic points of muld shift of the earth's surface. Total amount of releasing gas is determined by the area of the developed space, over which there is an intensive movement of the mined coal. The formation of this area is associated with the development of cleaning operations within the boundaries of the excavation site and the speed of movement of the treatment face. During the development of the theoretical scheme, several assumptions were made, the validity of which was verified on the basis of experimental data obtained in the conditions of four mines at fifteen excavation sites. Coal seams with coals of grades G and A were worked out by them at a depth of 300-1195 m, the capacity of coal seams was 0.90-2.20 m, cleaning works were carried out at a depth of 300-1195 m, the length of the lavas was in the range of 74÷270 m. The monthly movement of the treatment faces and the amount of gas released during this period were taken into account for each excavation site. It is established that the relative gas release per unit area of the developed space remains a fairly constant value for some mining and geological conditions, if the total amount of gas is attributed to the area that determines the active movement of rocks over a moving treatment face. This allows you to use the previously obtained results of determining the categorical danger of mines by relative gas release per ton of coal production in terms of improving the forecast of gas release from the coalbed under production more efficiently.

ABSTRACT. In order to develop effective measures to ensure the operational condition of the development workings behind the face in the conditions of soft footwall rocks, the construction of local reinforced zones under the protection means has been proposed. The presence of such zones allows transferring the current load deep into the massif and creating a stable foundation under the protective structure. The results of researches concerning establishment of rational parameters of local reinforced zones with application of the method of finite elements, the method of experiment planning and the method of statistical processing of these results have been presented. The empirical dependence of the subsidence of the local reinforced footwall under the protection means on their load, deformation characteristics of the local reinforced zone and host rocks, width of protection means, strength of soft underlying rocks and geometric dimensions of the zone has been determined. The relative indicator of efficiency of local strengthening of a footwall which is used for determining of rational parameters of a locally reinforced zone has been offered.

ABSTRACT. For the time being, moisture effect to the useful quality of coals has been researched comprehensively in detail. Herewith, there are a lot of unsolved problems related to the safety working out of coal layers. Presence of different forms of moisture in fossil coals essentially influences the coal layers hazardous characteristics manifestation during the mining activities. The Article deals with the results of analyses of more than thousand samples of the Donets Basin coals from different deposits, to research the relationship of total moisture and organic matter components in the coal carbonizations during the metamorphic processes. The researches have allowed separation of 3 stages for the fossil coal conversions. It is noted that at the initial stage, the carbon content is about 80%, moisture proportion in carbonization is rather high—0.36; but it decreases abruptly down to 0.12, in case of the carbon content increasing up to 86.5%. And the proportion of components (hydrogen, oxygen, nitrogen, and sulphur) total increases essentially up to 0.88. At the next stage, at 86.5÷91.5%, the components proportion in carbonization changes insignificantly. At the final stage of coal metamorphic conversions, 4-time growth of moisture proportion takes place in carbonization. It is found that moisture proportion in any form to be found in the coals shall be considered as a rank index, which is necessary to determine the coal layers hazardous characteristics

ABSTRACT. Retreat longwall mining is the most productive system for underground extraction of tabulated deposits. However, the steady growth of the mining depth dramatically increased the ground pressure in chain pillars protecting the longwall entries. Therefore, several coal industries have tried to shift to pillarless mining and practiced maintenance of the head or tail entry behind the longwall in the stress relief zones using the backfill bodies in the thin coal seams. We modernized the pillarless variant of the retreat longwall system introducing the third roadway, which is driven in the consolidated goaf behind the moving longwall in a stress relief zone. We used a computer code FLAC3D to simulate stress redistribution during pillarless extraction of adjacent panels that assisted to determine optimal parameters of mining layout. This modernized technology provides for sustainable mining due to enhancement of transport, ventilation, safety conditions, and a comfortable environment because of the stability of the underground roadways, which serve the high productive longwalls.

ABSTRACT. The article presents innovative technologies for the extraction of minerals from underground mines with complex geological, mining, technical and geomechanical characteristics. The need to develop such mining technologies is discussed and the conditions under which they should be applied are presented. Principal variants of extraction technologies such as Raisbor technology, Raisbor technology in combination with the drilling and blasting method and the continuous development system using Alimak or KOV - 25 monorail complex are shown in the article.