Western Donbass Research Articles

Determination of the type of arched carbon fiber reinforced fastening of the preparatory opening for the conditions of the «Dniprovska» mine in weakly metamorphized rocks

The object of study is an arched carbon fiber-reinforced support of constant cross-section in a layered massif of weakly metamorphosed rocks. The article presents an analysis of the possible use of arched fiber-reinforced support of constant cross-section in a layered massif of weakly metamorphosed rocks for the conditions of the «Dniprovska» mine (Ukraine) around the preparatory opening. An analysis of the stability of mine openings in Western Donbas mines has shown that it is necessary to modernize the support system by introducing carbon fiber. The main reason for the low stability of the opening is the insufficient load-bearing capacity of the support, while its technical characteristics do not take into account the complex mining and geological conditions. The increase in stresses at mining depth is associated with impact safety, which is a serious problem during mining. Metal arch supports are deformable and have high rock loads and require a high level of energy absorption, i. e., to be very strong and flexible to withstand significant loads and avoid large displacements of the opening walls. Carbon fiber-reinforced plastic is able to ensure the stability of the fastening system and eliminate the existing disadvantages of typical metal arch fasteners, namely, high labour intensity, low production speed and high weight of the structure. In this article, the stress-strain state for the specified conditions and the carbon fiber-reinforced plastic arch support of constant cross-section was analyzed using the SolidWorks software product, taking into account the physical and mechanical properties of carbon fiber-reinforced plastic and layered rocks. Taking into account the results of laboratory tests of an equivalent layered array on a press made of PLA and carbon fiber, the dependence of deformations of the equivalent array with increasing load was established. The use of arched carbon fiber supports of various cross-sections can ensure the opening stability by reducing the intensity of stresses around its contour. On the basis of this study, a rational arched composite support of constant cross-section was proposed for the conditions of the «Dniprovska» mine. The obtained results indicate the need for further research, which will be considered in the author's future works.

Degassing methods and means analysis of mine workings and methane utilization to improve site degassing efficiency in the Western Donbas mines

Purpose. To analyze the methods and means of degassing excavation workings and methane utilization to improve the efficiency of site degassing in the Western Donbas mines. Research methodology. An integrated approach was used to achieve this goal including the analysis of existing geomechanical factors and the disclosure of the mechanism of their influence on gas production in underworked rock massif in the Western Donbas condition. Research results. The methods and means of degassing excavation areas and methane utilization were analyzed. The analysis showed satisfactory degassing efficiency with the prospect of extracting a methane-air mixture with a methane concentration of 25–45%, which creates conditions for the development of methane utilization by combustion in cogeneration units for the production of heat and electricity. At the same time, the analysis of modern research on methods and means of area degassing has proved the existence of significant reserves for increasing its efficiency by choosing rational parameters of the technology of this process, taking into account the influence of geomechanical and technological factors. Scientific novelty. Methane capture with its discharge to the Earth surface is much safer and cheaper than diluting it with air and transporting it through mine workings it has been establishedfor the first time.This makes it possible to use methane to compensate for the costs of degassing processes with the active development of the so-called site degassing. The trends in the influence of geomechanical and technological factors on gas separation processes were determined for the first time. The ideas about the mechanism of overburden displacement in the mines of Western Donbas were further developed in terms of determining the zones of stratification and fracturing of roof rocks during coal seams mining. Practical value. The obtained results prove that determining the regularities of the influence of geomechanical and technological factors on the processes of gas emission should be based on the study of the degassing mechanism, modeling of this process and assessment of reliability based on the results of mine experiments, which will contribute to the development of underground coal mining.

Study of methods for predicting the stability of preparatory workings in the mines of Western Donbas

Purpose. Analysis of the effectiveness and feasibility of existing methods for predicting preparatory workings. Research methodology. The research was conducted using an analytical method (analysis, explanation, synthesis, comparison) and statistical data processing method. Research results. The conducted research allowed determining that the coal-bearing sedimentary massif of the Western Donbas, as a result of complex tectonic movements, is characterized by developed and intensive tectonic disturbances of a ruptural and plicative nature. The appearance of plicative disturbances in the hanging wall of the coal seam, accompanied by an increase in their thickness, leads to the concentration of stresses in the areas of disturbances caused by approaching the mining face. Regional plicative disturbances cause the formation of zones of anomalous activity in the intact mining massif. In addition to gravitational forces affecting the geological structure, tectonic stresses directed along the bedding plane are added to this phenomenon. Tectonic stresses are oriented in the direction of the main curvatures of the natural surface of rock deposition and depend on their magnitude. Geological deviations of various types are key indicators of anomalies in the tectonic environment and zones of reduced strength in an intact mining massif. These anomalies can result from the complex interaction of geological processes, including tectonic activity, water flow activity, and other natural factors. These deviations become fundamental factors contributing to the occurrence of gas-dynamic phenomena and rockfalls during the preparatory mining stage. Scientific novelty. The regularity of the interaction of geomechanical parameters of elements of the "layered massif – excavation support" system has been established. Practical significance. Studying methods for predicting the stability of preparatory workings allows for the development of effective excavation support systems according to geological conditions and prevents possible accidents and rockfalls in mining working areas.

Optimization of mine water discharge with the river hydrograph. Case study Samara River in Western Donbas

The paper deals with modeling salt transport in surface watercourses affected by mine water discharge taking into account the river hydrograph, hydrogeological, and climatic data. The developed model enables optimizing the discharge parameters; thus, minimizing the mineralization of river water throughout the year. As the case study, we considered the section of the Samara River in the Western Donbas where mine water is discharged from three storage ponds located in the ravines of Kosminna, Taranova, and Svidovok. Taking into account the pond capacities, it is proposed to discharge at least 60% of mine water from all ponds in December-April, with more than 88% of the most mineralized waters from the pond in the Svidovok ravine. The increase of the river water mineralization at the exit from the coal mining area does not exceed 0.22 g/dm3 on average per year, with a maximum of 0.36 g/dm3 during the low water season. The model novelty is coupling natural and man-made factors forming the water and salt balance in the surface watercourse throughout the year with the optimization methods. The proposed technique can be used to optimize the mode of mine water discharge.

Substantiating the expedient route parameters for the location of the site outgassing wells in the Western Donbas conditions

The paper deals with the issues of substantiating the parameters of location outgassing wells, determining their expedient routes in the mining-geological and mining-technical Western Donbas conditions. Based on the conducted multifactorial computer experiment, the patterns have been obtained of influence of the coal-overlaying formation texture on the parameters of its shear into the mined-out area. When determining the patterns of influence of mechanical properties of the coal-overlaying formation lithotypes, they are divided into three generalized groups: low, averaged, high. At the same time, the influence of the height and distance parameters the strongest and hardest lithotype occurrence, such as sandstone, has been studied. It is noted that with low mechanical characteristics, the gradient angle of the line of changing curvature sign of the rock layers bending in the direction of the coal seam dip is steadily decreasing. Conditions have been identified and criteria have been developed for the most effective routes for the location of site outgassing wells. The developed criteria, in combination with the dependences of the coal seam shear parameters, make it possible to create a methodology for determining the expedient coordinates for drilling outgassing wells based on the results of modeling by the finite element method.

ЗАБЕЗПЕЧЕННЯ СТАЛОГО РОЗВИТКУ НА БАЗІ АНАЛІЗУ ТА ОЦІНКИ ХАРАКТЕРИСТИК ШАХТНИХ ВОД ЯК ДЖЕРЕЛ ВОДОПОСТАЧАННЯ ТА ОТРИМАННЯ ЦІННИХ РЕЧОВИН З ВІДХОДІВ ОПРІСНЕННЯ

Purpose. Rationale for the integrated use of the resource potential of coal-mining enterprises, which is aimed at obtaining technical and drinking water for their own production needs, local population and obtaining valuable substances from desalination waste. Methodology. Analysis of world experience, information about aquifer complexes in the Western Donbas mines, conducting chemical analyses of mine waters and salt mixtures obtained after using reverse osmosis products. Results. Based on the accumulated world experience in desalination of highly mineralized waters, it can be concluded that it is possible to effectively implement this experience at mining enterprises. Description of aquifer complexes has been given in detail using the example of the Zakhidno-Donbaska Mine of PJSC “DTEK Pavlohradvuhillia”, chemical analyses of water before and after discharge into settling ponds. A rational technological scheme for desalination, volumes of purified water obtained for drinking and technical water supply, as well as the quantitative and qualitative composition of the dry residue components of mine water desalination waste, and recommendations on possible use of products on the market have been determined. Scientific novelty. Analytical and laboratory studies have been conducted to determine the component composition of mine water desalination waste from Western Donbas coal-mining enterprises. It has been determined that the resulting salt product is a mixture of pure salts and valuable microcomponents, and the resulting distillate is fuel for the operation of hydrogen electrolyzers, which creates prerequisites for modern “green” hydrogen energy infrastructure. Practical significance. The qualitative and quantitative mine water parameters on complex use as an alternative source of water supply and obtaining related reverse osmosis products have been analyzed. The road services propose the consumption of the resulting salt products by municipal enterprises, and the dry distillation residue – to prevent dust. This approach allows solving not only the problem of desalination waste utilization, but also applying the separated valuable substances in the industrial market of food, medical, cosmetic, paint and varnish, chemical, as well as building materials, plastics and polymers production industries. Keywords: mine water, waste recycling, mineral resource, coal-mining enterprises.

Методичний підхід до обґрунтування способу газифікації кам’яного вугілля для виробництва синтетичних моторних палив

The aim of the article is to substantiate the most suitable method of gasification of Ukrainian hard coal for further production of synthetic motor fuel. For this substantiation, a methodical approach has been developed, the use of which has allowed to obtain the following results. As a raw material base, the article recommends long-flame coal of the Western Donbass, located on the territory of the Dnepropetrovsk region, where powerful enterprises for the extraction and enrichment of coal operate. The most common methods of coal gasification in the world are analyzed: Lurgi (counter-current steam-oxygen gasification of large-lump coal (or briquettes) in a stationary bed), Siemens (direct-flow steam-oxygen gasification in the pulverized coal stream), Texaco (direct-flow oxygen gasification in the flow of coal-water pulp). For each of these methods, material balances have been developed; the composition and quality of the generated gas, the possibilities of organizing the production of the necessary energy resources, the level of emissions of harmful substances into the atmosphere and wastewater discharge have been evaluated. A methodology for calculating the composition of generator gas is proposed, which takes into account the composition of the blast (content of oxygen, water vapor or water). All calculations were performed for an enterprise with a coal capacity of 550 thousand tons of working weight per year. Based on the calculations and comparison of their results, the Texaco method is recommended for industrial implementation. The advantages of this method are as follows: the absence of a stage of steam production for gasification, the scarcity of the water cycle, which practically excludes the formation of wastewater, and the possibility of using contaminated water from other sources for gasification; the highest total content of hydrogen and carbon monoxide in the resulting synthesis gas; the maximum assimilated capacity of production reactors and the largest number of capacities created in the world using this technology; utilization of the heat of the resulting gas to obtain a large amount of electric and thermal energy.

Coal mine methane utilization as a component of the complex mining concept in the context of conversion into thermal and electrical energy

The paper deals with multi-component complex mining of mineral raw materials in the context of sustainable development and its important component – coal mine methane utilization and its conversion into thermal and electrical energy. The conducted analysis of scientific and practical experience has shown the multi-parameter nature of this process and the influence of a large number of factors. The mining-geological conditions of the Western Donbas (Ukraine) are substantiated as the research object, which makes it possible to limit the variation of geomechanical factors, as well as to develop basic provisions and general principles for reasoning predictive assessments of outgassing during complete mining of coal reserves. The dependence of gas volume on specific gas content of lithotypes and the volume of their destruction related to the coal-bearing stratum shear mechanisms at different options of complete mining of the Western Donbas coal reserves, is presented. The patterns of influence of the main geomechanical factors on the propagation of disturbed rock zones are substantiated.

Territorial distribution of germanium in the c5 coal seam on the territory of the “Pavlohradska” mine

The actual issues of the distribution of germanium in the c5 coal seam in the territory of the “Pavlohradska” mine of Western Donbas were studied. Three zones with high germanium content were found on the territory of the c5 seam, and their spatial location was determined. It was established that the geological structure of the c5 coal seam in places with the highest germanium content has common features: minimal thickness, the presence of one or two partings, as well as the presence of at least two low-amplitude northeast-trending disturbances, which can be used as predictive criteria for determining zones with the largest germanium content. The increased variability of the thickness of the coal seam, its structure, the presence of discontinuities, and the lithologicalfacies variability of the immediate and main roof contribute to the increase in the gradients of the germanium content. The growth of the regional component of germanium content in the north-eastern direction was established. It has been proven that both syngenetic and epigenetic factors influence the content of germanium in the coal seam. The regression equation between these parameters is calculated, which allows you to predict the germanium content without conducting new tests and analytical studies.

Гідроекологічна характеристика сучасного стану Запорізького (Дніпровського) водосховища та його приток

Purpose: to determine the hydroecological condition of the different areas of the Zaporizhzhia (Dnipro) reservoir and its tributaries (Samara River, Konoplyanka River), which are under technogenic pressure. Methodology: classical methods of determining hydrochemical indicators (pH, dissolved oxygen, carbon dioxide, permanganate oxidizability, anions and cations of organic and inorganic compounds) and microbiological parameters (total count of microorganisms and count of saprophytes) were used during the study. The content of heavy metals was determined by atomic absorption spectrophotometry. Findings: The study of the current hydroecological state of the Zaporizhzhia (Dnipro) reservoir in the summer period showed that, according to most parameters, the water quality did not exceed the MAC (maximum allowable concentration) for fish farming. The exception was the reduced oxygen dissolved concentration (by 10-25%) in almost all areas of the reservoir, and the high mineralization of water in the Samara Bay (2 MAC), due to the discharge of highly mineralized waters of the Samara River. In the long-term aspect, there is an increase in the total mineralization of the Samara River (4 MAC, which is under the influence of the discharge mine waters of the coal mining industry of Western Donbas. The analysis of the content of heavy metals in the reservoir indicated an increase in the concentration of copper - from 13 MAC in the Samara Bay to 21 MAC in the lower part of the reservoir. The Samara River was characterized by a high content of cadmium (1.5 MAC), copper (13 MAC), and nickel (2.3 MAC). Indicators of the ecological state of the Konoplyanka River had significant differences in its different areas: in the upper reaches of the river, where the economic and domestic effluents of the city of Kamianske and the tailings storage facilities for radioactive waste are located, water did not meet the MAC for oxygen content, carbon dioxide, nitrites, nitrates, mineral ions (Ca2+, Mg2+, Cl’, SO4-2), general mineralization and the count of saprophytic microorganisms; at the mouth of the river, exceeding the MAC for nitrate content and saprophytic microflora was recorded. Originality: data on the hydroecological state of the Zaporizhzhia (Dnipro) reservoir and its tributaries in the conditions of the war have been obtained. Practical value: the results of the conducted study can be used to develop a strategic program for the restoration of the ecosystem of the Dnipro reservoirs in the post-war period. Key words: Zaporizhzhia (Dnipro) reservoir, tributaries, hydrochemical parameters, count of microorganisms, heavy metals.

Ecological-economic aspects of mining thin coal seams in the Western Donbas


 
 
 The paper draws attention to the ecological-economic aspects of mining thin coal seams in the strategic coal-mining region of the Western Donbas and studies their causes and consequences in detail. It has been analyzed and determined that as a result of coal mining with complete caving of rocks, the processes of the earth’s surface subsidence above the mine fields occur. Due to the proximity of groundwater to the surface, waterlogging of territories and a change in the landscape occur. Using analytical calculations, it has been determined that the total surface subsidence value above the mine field of one of the Western Donbas mines is 1.2 m, which, according to the monitoring of environmental authorities, correlates well with the range of subsidence values in the region of 0.7-1.4 m. The places and parameters of rock dumps accumulating on the earth’s surface in coal mines are identified and analyzed, and the sources of waste rock formations in the technological system of coal mines are also studied. It has been revealed that the largest ingress of all waste rocks to the surface is caused by the stope operations conducted with undercutting of bottom rocks – 39% and underground mining operations to prepare new coal reserves for extraction – 33%. To date, it has been found that the volumes of waste rocks generated in mines are 1.5 times higher than the volumes of their utilization, and the prospect of disturbed land reclamation is limited in time, which, with today’s mining technology, will lead to an increase in their accumulation again. Based on a comprehen- sive study of the mined coal seam structure with a complex texture, using the example of one of the mines, it has been revealed that in the formation of operational ash content, the friable roof caving amounts to 13.0%, the seam rock interlayers – 19.2%, the coal seam natural ash content – 12.8%, and the seam bottom rock undercutting – 55.0%. A close linear relationship has been determined between the value of bottom rock undercutting with a shearer based on collected mine data and the indicator of mined coal operational ash content, which confirms the greatest importance of this factor. It has been proved that the most important factor influencing the formation of the mined coal operational ash content is the undercutting of the seam bottom rocks by a shearer, and with a 2-fold decrease in the ash content of coal, its energy potential increases by 1.25 times. Possible scenarios for the coal mining development in the Western Donbas are considered and a rational direction for solving the leading ecological-economic problems of underground mining of thin coal seams is proposed.
 
 

The relationship between lowering the Earth's surface and bearing pressure above the advancing longwall face

This work aims to develop a method for determining the increase in stresses above an advancing longwall face of Western Donbas mines. The paper presents a solution to the problem. It is based on the analysis of geodetic instrumental observations of the earth's surface lowering and rock mass deformation above the advancing longwall face. Length and propagation in the roof and floor of the extracted seam are the main geometrical parameters of the zone of high rock pressure. Currently, the quantitative parameters of this zone are not considered. And its length under the conditions of Western Donbas is determined with an accuracy of 50%. Thus, research in this direction is relevant. The experimental basis for the research includes the results of observations performed at two vertical borehole extensometers and the results of data processing obtained at more than 30 observation stations on the Earth's surface. Thus, the research specified the geometrical parameters of the zone of high rock pressure and the nature of the vertical stress distribution within this zone. The paper introduces a method to determine a coefficient of stress increase above the advancing longwall face of Western Donbas mines. We also established the empirical coefficients of the vertical stress distribution function within the abutment pressure zone. There is a relationship between the lowering of the earth's surface and the values of the stress increase in the borehole edge part. The reliability of the obtained results is confirmed by geophysical studies in Western Donbas, as well as by the results of field observations.

Anomalous position of Paleozoic faults of Western Donbas

Statement of the general problem. The oil and gas-bearing province of Eastern Ukraine is located in the Dnipro-Donetsk Basin (DDB). It covers the Paleozoic structural floor and is buried under younger sediments. The Paleozoic structural floor of the territory is represented as a long rift graben. The maximum thickness of the sedimentary cover in the graben is 15–17 km. According to geophysical data, the thickness of the earth's crust is 31–32 km under the axial part of the DDB and increases towards the sides. But according to the maximum thickness and facies characteristics of the Paleozoic deposits, the thickness of the Earth's crust below them could not exceed 20 km. The modern thickness is 1.5 times higher. Therefore, such a geological-geophysical model of the structure of the DDB is contradictory. Analysis of recent research and publications. The removal of the contradiction is possible due to the detection of a series of Hercynian thrusts with total amplitude of thrusts of the order of 50 km. Such thrusts began to be established on the northern and southern flanks of the DDB. Hercynian thrusts have a southwestern vergence. In the north, the Voronezh crystalline massif is pushed onto the DDB along the Noviy thrust with an amplitude of 9–10 km. In the south, the South Donbas melange zone is established, which pushes the folded Donbas onto the Ukrainian shield. On its continuation to the northwest is the southern side of the DDB - the so-called Southern monocline. The well-studied Pavlograd-Petropavlovsk coal mining district of Western Donbass with operating coal mines is located within its borders. An unsolved part of the overall problem. Numerous faults with relatively small amplitudes are established within the Paleozoic Southern Monocline. Together, they form a system of horsts and grabens with a north-western extension. But the bottom parts of the grabens are 1–3 km higher than the tops of the horsts. Such a geological situation is anomalous. This indicates the post-fault dislocation of the horst-graben system as a whole. The purpose of the article is identification of the causes of the anomalous structural position of the graben-horst system in the modern geological structure of the Southern Monocline and in the general model of the geological structure of Eastern Ukraine. Research materials and methods. Were involved more than 390 geological sections, constructed based on the data of more than 10,000 wells. Of them, 265 wells revealed the folds that are being analyzed. In addition, were used data of catagenetic transformations of the sedimentary section. Presentation of the main research material. The South Donbas mélange zone falls to the northeast and continues under the Southern Monocline. It is located in the upper block of this regional thrust structure and is in an allochthonous setting. According to geological data, the true amplitude of the thrust of Western Donbas on the Ukrainian shield is 15–20 km, and the vertical component of this amplitude exceeds 3 km. Such spatial parameters explain the abnormality of the structural position of the horsts and grabens of Western Donbass - their southwestern flanks were significantly raised relative to the northeastern flanks during thrusting. Scientific novelty. Therefore, in the modern geological structure, the Dnipro-Donetsk "basin" is not a rift, but a post-rift Hercynian folded region. It is formed by high-amplitude thrusts on the northern and southern flanks. The Hercynian fold region is buried under Mesozoic and Cenozoic sediments and is further complicated by Laramian and Attic fold-thrust dislocations of lesser intensity. Conclusions. The thrust model brings the geophysical parameters into the correspondence with the geological data and is confirmed by the actual material.

Selection of the means of auxiliary transportation facilities and adaptation of their parameters to specific operation conditions

Purpose. To improve selection methods of operation schedules as well as means of auxiliary transportation facilities involving adaptation of their parameters to the specific application environment while preparing new extraction pillars for coal mining. Methodology. The current methods for substantiating the operational parameters of the means of internal mine transport do not take into account the impact of mining-geological and technological factors, which change inadequately in space and time, on their productivity. The recommended method for selecting transport and technological schemes and increasing their adaptability in the real conditions of the mine environment is based on the comprehensive use of methods of expert evaluation of the operational indicators of the new generation of auxiliary transport means and modeling of the conditions of their interaction with arch support and side rocks at the stages of mining and their operation when preparing new mining pillars for cleaning mining. Findings. The expert evaluation concerning technological features of mining field preparation as well as assembling and dismantling operations has determined that for the specific conditions of Western Donbas mines, the suspended diesel monorail locomotive and self-propelled machines are the most promising options. Gear clutch rail diesel locomotives are recommended as the auxiliary transport for the accelerated preparation of extraction pillar and introduction of a longwall into operation. Originality. New approaches have been substantiated to improve selection of the efficient means of auxiliary transportation facilities and identify their operational parameters for the well-timed preparation of extraction pillars for their removal under the intensified underground mining conditions. A transportation schedule has been proposed to supply heavy tonnage loads by means of the suspended diesel rail locomotives as well as methods to calculate the expected loads on suspension members of the monorail road taking into consideration physico-mechanical characteristics of roof rocks within a development mine working. Practical value. It has been proved that under the conditions of the intensified mining operations, the recommended engineering solutions meet the requirements of the well-timed preparation of new extraction pillars. In addition, they are considered as a new tendency to improve current schemes of auxiliary transportation facilities for regional mines and provide operational reliability of the available underground transport equipment.

MODELING OF SPATIAL DISPLACEMENT OF POINTS ON THE EARTH'S SURFACE BASED ON THE RESULTS OF GEODETIC OBSERVATIONS

The results of geodetic observations and the results of three-dimensional modeling of the earth's surface displacements at the observation station, laid over the longwall 124 of the Blagodatnaya Mine in the Western Donbass (Ukraine), are presented. To determine the displacements and deformations, the ground benchmarks of the profile lines were coordinated using a GNSS receiver and an electronic total station with an accuracy of their spatial position of 4-5 mm. Processing of the results of observations was carried out using the software product SAMARa (Automation System for Mine Surveying). Spatial 3D models of the displacement of points on the earth's surface in the zone of influence of mining operations have been built. With their help, it is possible to solve problems of establishing the actual values of displacements and deformations of the earth's surface in undermined territories. A 3D model of displacements of points on the earth's surface, predicted according to the methodology of the current State Standards of Ukraine, will make it possible to assess the impact of underground mining on the ecological situation of the undermining area and the safety of civil and industrial structures in the hazardous zone.

Statistical analysis of Samara River pollution impact on the population morbidity rate in Western Donbas (Ukraine)

The anthropogenic load on natural environment has reached a level that threatens the population health. The main causes of water sources pollution are the discharge of untreated or insufficiently treated wastewaters by industrial enterprises. These and other reasons lead to the spread of various types of diseases among the population. A cause-and-effect relationship between the qualitative and quantitative state of the surface waters of the Samara River and certain diseases of the population living in the Western Donbas region has been established. The method of statistical analysis based on Pearson correlation has been applied. Reliable correlation between the pollutants content in surface waters of Samara River and the increase of the population diseases in the investigated territory has been proven. With high degree of probability, the following diseases are closely related to water quality: diseases of the blood, hematopoietic organs and disorders of immune system; diseases of endocrine system, digestive and metabolic disorders; circulatory system and digestion diseases; diseases of the skin and subcutaneous tissues. The obtained results indicate the need for further research taking into consideration the regional specificity of conditions and factors of environmental pollution, development of advanced water treatment to reduce the morbidity rate of the population.

Development of ideas about the mechanism of coal-overlaying formation displacement in terms of its influence on local gas-drainage parameters in the Western Donbas conditions

Purpose. The research purpose is to study the mechanism of the influence of geomechanical-technological factors on the location parameters of the gas-drainage wells behind the longwall face in the area of stope operations under the conditions of weakly metamorphosed rocks. Research methodology. An integrated approach is used, including an analysis of existing research on the gas release patterns in the mine workings of extraction sites and local gas-drainage parameters, analysis of geomechanical processes, development of schemes for modeling by the finite element method, substantiation of methodological approaches for conducting experimental research into the rock pressure manifestations in extraction working, taking into account existing tendencies of the influence of stoping face advance velocity. Research results. The views on the mechanism of the stratified mass texture transformations of weak rocks have been developed during the study of the optimal extraction site gas-drainage parameters. The deformation development schemes have been constructed for any layer of the main roof behind the area of longwall face conjugation with the extraction working, displacement of coal-overlaying formation rocks along and across the extraction site with the location of gas-drainage wells. Based on the conducted research, recommendations on the rational location of gas-drainage wells have been obtained. Scientific novelty. The main characteristics of the weakly metamorphosed rock displacement process in the area of stope operations are studied in a spatial formulation, and the mechanism of the influence of geomechanical-technological factors on the expedient location parameters of gas-drainage wells behind the longwall face is represented on the relevant schemes. Practical value. The reliability of the proposed location parameters for gas-drainage wells behind the longwall face in the conditions of weakly metamorphosed rocks of the Western Donbas has been analyzed, taking into account the stoping face advance increased velocities.The conclusions drawn on the basis of rock displacement tendencies in the coal-overlaying formation are summarized in the schemes for identifying the mechanism of rock mass deformation near the area of stope operations.

Technology of combined fixing of preparatory products for efficient use of suspended monorail roads

Purpose. Justification of the parameters and design of the system of combined fastening of the monorail pond of the suspended monorail roads in formation underground workings to reduce dynamic loads on the elements of the arch fastening and the mining massif during the delivery of large-tonnage loads and equipment to preparatory pits and assembly chambers. The methods. The recommended method of substantiating the technological schemes of auxiliary transport, focused on the use of multifunctional mining equipment of the new generation, adapted to the modern conditions of performing assembly and dismantling works and preparing new mining pillars for cleaning extraction, which is based on the modeling of the parameters of the interaction of the rolling stock of suspended monorail roads with arch fastening elements and side rocks during transportation of large-tonnage cargoes. Findings. According to the results of research into the operational parameters of suspended monorail roads as part of a highly adaptive transport and technological system for the delivery of large-tonnage cargo, it was established that to reduce dynamic loads on the elements of the arch fastening and the mining massif in the specific conditions of the mines of Western Donbass, the most promising option is the two-level anchor fastening of the monorail stand and preparatory product. The originality. Innovative technical solutions to increase the operational reliability of the arch attachment during the transportation of large-tonnage loads and reduce dynamic loads on the mining massif by redistributing them to adjacent links of the monorail pond and modernizing the transport and technological system are substantiated. Practical implementation. It has been proven that during the intensification of cleaning and preparatory work, reasonable technical and technological solutions meet the requirements for the timely preparation of new mining pillars and are considered as a promising direction for improving the current schemes of auxiliary transport for the mines of the region and ensuring the operational parameters of mining transport equipment of a high technical level in the specific conditions of the mines of the Western Donbass.

ASSESSMENT OF THE EFFECT OF BIOCHAR ON THE PROCESS OF THERMOLISIS OF BIOMASS OF PLANTS GROWN ON RECLAIMED LANDS

Samples of soil contaminated with heavy metals for pot experiments with annual crops (maize, sweet and sudan sorghum) were taken near the mines "Pavlogradska" and "Blagodatna" in the coal-mining region of Western Donbass. The basis of the reclaimed areas was an 8-10 m thick mine rock (MR) dump, covered with different layers of black soil or red-brown clay by creating two types of soil artificial profiles with the addition of 30 cm of black soil (30 cm of BS +MR) and 50 cm red-brown clay (50 cm RBC + MR). Experimental soil samples were treated with 3.0% (w/w) biochar. The purpose of the study was to study the effect of the addition of biochar on the process of thermal destruction of the biomass of maize, sweet and sudan sorghum, grown on different substrates - components of artificial reclaimed profiles (upper layers of chernozem mass and red-brown clay). The process of thermolysis of biomass components of three agricultural crops was studied by the method of thermogravimetric analysis. Thermal destruction of the biomass of the three studied plant species occurred in two stages: evaporation of water and volatile compounds (stage 1) and decomposition of the main components: hemicellulose, cellulose and lignin (stage 2). The first stage took place in the temperature range of 50-180°С. The process was slow, the maximum speed did not exceed 5-8%/min, the extreme point was observed at a temperature of 100-110°C. Loss of body weight is insignificant, 4.5–7.5%. The second stage is divided into two phases: the decomposition of holocellulose with the beginning of lignin decomposition (phase 1) and the cessation of lignin decomposition, and the formation of non-combustible residue (phase 2). Destruction of holocellulose occurred in the temperature range of 190-390°С. Due to the large amount of hemicellulose in the biomass of the studied plants, its decomposition was shifted to the region of higher temperatures. Therefore, the degradation ranges of hemicellulose and cellulose overlapped, and only one extreme point was observed in the DTG curves. The process proceeded at high speeds with the peak of destruction in the temperature range of 280-310°C. Weight loss was also the most significant and was between 50 and 55%. Decomposition of lignin occurred rather slowly, with one insignificant peak in the temperature range of 420-440°C. A weight loss of 26-30% has been established. At the first stage, the process proceeded mainly with heat absorption; the reactions of the second stage were exothermic with noticeable thermal effects in the zones of cellulose and lignin decomposition. Differences in thermal characteristics of sugar sorghum biomass grown on different substrates and with the addition of biochar were determined in the process of thermolysis. Degradation of holocellulose occurred more slowly in biomass collected from a vessel with red-brown clay, in contrast to lignin, which decomposed faster than in the experiment where the substrate was a loose layer of chernozem. The share of non-combustible residues was almost 2 times smaller. A slight increase in the rate of the cellulose decomposition reaction (1,2 times) and a significant increase in the rate of the lignin destruction reaction (5 times) was observed. In the treatment with biochar, a more complete combustion of biomass was observed. The rate of cellulose decomposition in the experiment with red-brown clay became somewhat higher, although the decomposition of lignin occurred more slowly. The share of non-combustible residues increased by 1,8 times. Thermal destruction of Sudan grass biomass on both substrates occurred in a similar manner. The addition of biochar did not reveal significant deviations in the thermal behavior of biomass grown on chernozem, in contrast to the experiment with red-brown clay, where the addition of biochar contributed to a significant reduction in the duration of thermolysis. The first stage of thermolysis of corn biomass was somewhat shorter in the experiment with a bulk layer of chernozem compared to red-brown clay and was accompanied by a lower mass loss. The same trend was observed in the decomposition of holocellulose. At the same time, the destruction of lignin in the version with chernozem lasted longer, the extremum point was shifted to the region of higher temperatures, the speed of the process was almost twice as low as in the version with clay, and the proportion of non-combustible residue was 1,7. times higher. More complete combustion of corn biomass was also observed in the version with biochar.

Перспективна сировинна база процесів виробництва синтетичного рідкого палива з українського вугілля

The article considers the issue of raw materials for the production of synthetic liquid fuels from coal, which is relevant for Ukraine, which has relatively small oil deposits, but fossil coal reserves reach 50 billion tones. It is shown that the coal raw material base for industrial production of synthetic motor fuel in Ukraine should be based on low-metamorphosed coal of B, D, DG and G grades, which prevails in existing geological deposits and is characterized by proper reactivity due to the high oxygen content in the organic mass and the presence of reactive oxygen-containing groups: hydroxyl –OH, carbonyl =C=O and carboxyl –SOC. Due to the systemic crisis in Ukrainian coal industry, there are currently no free resources of raw materials to support new production. This necessitates the restoration or creation of new coal production facilities in the main industrial regions of Ukraine. To create them in eastern Ukraine, it is advisable to base the raw material base of the process on long-burning coal from the Lozova district of western Donbas. To ensure the raw material base for production in the regions of the Centre, it is necessary to restore the coal mining enterprises of the Dnipro lignite basin, primarily the Kostiantynivskyi mine, on a new technical basis. The raw material base for industrial production of synthetic motor fuels from coal in the Western region can be secured by completing the development of the design industrial capacity of Novovolynsk mine No. 9 or by developing the coal of the Tyaglivske deposit. The final choice of the option should be made based on the results of additional feasibility studies. Keywords: low-metamorphosed coal, synthetic motor fuel, Lozova coal-bearing area of Western Donbas, Dnipro lignite basin, Tyahlivske deposit. Corresponding author V.V. Shulga, e-mail: ko@ukhin.org.ua