Purpose. To establish patterns of change in methane content during formation of zones of unloading of rock mass caused by a longwall face progression. Methodology. Determination of gas content (methane content) of coal seams, ash content of Karaganda basin coals, methane content of mine workings was made on the basis of taking and cutting samples from the coal massif in the laboratory of “Management of special maintenance and gasification” of the Coal Department of JSC “Qarmet” according to the DMT methodology (Germany). The chemical structure of gases of k10 seam was determined in the laboratory of Scientific Research Center “Ugol” (Karaganda), as well as by samples of air-gas mixture of degassing wells and in the working area of Saranskaya mine. Findings. A model of geomechanical structurization of rock massif was developed, patterns of methane content changes were established, obtained in specific mining-technological conditions of the mine, which were used for productive and safe work on coal excavation. Originality. For the first time a model of geomechanical structurization of the coal-rock massif in the conditions of longwall faces was developed; a parametric model determining the intervals of the mining pillar to increased methane flows into the mined-out space was developed; a connection between the dynamics of geomechanical processes in the mined-out coal-rock massif and the methane content of the mine face was established. Practical value. The established regularities of change in methane content of mining pillar areas arising at rock shear make it possible to plan degassing of mining area, to provide safe working conditions for miners on gas factor, to forecast the moment of formation of the main roof vaults of different levels and methane emission into the mine face to control mining, which were tested at Saranskaya mine Coal Department of JSC “Qarmet”.

This article reveals the nature, causes, and main stages of occurrence and development of endogenous fires in coal mines. It is emphasized that one of the key tasks of fire protection specialists is the most accurate determination of the stage of oxidation and self-heating of coal. A review of existing gas analysis methods for identifying the initial and subsequent stages of endogenous fire development is conducted. Particular attention is focused on the importance of obtaining prompt reliable information on the self-heating temperature of coal and the dynamics of its change in the early stages of the process. Since self-heating zones are usually inaccessible for direct instrumental control, the main source of information is the gas analysis of air samples. The authors present the results of research on the dependence of the indicator gas content on the coal self-heating temperature. Based on the Graham criterion, the stages of thermal development of the process are predicted. Correlation dependencies between temperature and integral parameters of indicator gas concentrations are developed, allowing for a sufficient degree of reliability in determining the stages of coal self-heating and spontaneous combustion. Based on the results of the work, methodological recommendations for the prevention and warning of endogenous fires in coal mines and opencasts are proposed. They are based on the most informative and accessible signs suitable for quantitative assessment. The implementation of these recommendations will improve the level of industrial safety and reduce the risks of fires and explosions during mining operations.

This study utilizes Geographic Information Systems (GIS) to analyze soil cover in the Ayyrtau District, North Kazakhstan, focusing on soil types, degradation, and changes over the past 20 years. Chernozems, covering 45% of the area, are the most productive, while Solonetz soils (15%) present...

The primary objective of this study is to identify fracture systems based on drilling data and underground mining operations collected during engineering-geological surveys in the North Karasu deposit area.

Researches of thermodynamic processes of oxidation, self-heating and self-ignition of coal are necessary for studying of dependence of terminal parameters on a set of the influencing factors. In practice of coal mining by the underground method cases of coal self-ignition in the mined-out spaces of production units (lavas) are frequent. In this case one of the tasks consists in determination of temperature in arbitrary point of the nubbly-porous medium of the mined-out space. Need of the solution of this difficult task is caused by the probability of emergency situations in places with the explosive concentration of methane. It is possible that for each seam and grade of coal it is necessary to develop, substantiate and accept an individual indicator for assessing the state of fire hazard. It is proposed to systematize and methodically process the results of field measurements and observations on the analyzed and investigated cases of endogenous fires in problem areas of mines in order to create basin databases for subse- quent operational decisions in emergency situations.

Purpose. Development of a methodology for assessing the occurrence of sudden fractures in the soil on the example of the development of seam d6 of the Karaganda coal basin. Methodology. Theoretical and experimental studies on the gas content of a coal seam, analysis of technologies for its development. Findings. Studies have shown that sudden fractures of the overworked massif with and without a breakthrough of methane are of the same nature. A necessary condition for the formation of sudden fractures of the seam soil (SFSS) in a mine is the presence of a pack of coal or rock with reduced strength and high gas content in the soil; in this case, the breakthrough of methane into the development occurs only if the cracks formed in the soil of the workings reach the sources of gas release gas-bearing layers (interlayers) of coal. Originality. A predictive indicator of the hazard of the occurrence of SFSS in the working face is proposed, a dimensionless criterion which is the product of dimensionless coefficients reflecting the influence of the development depth, gas content of the seam, the width of the bottomhole zone, the thickness of the protective layer, the thickness of the crumpled coal pack of the lower layer, longwall withdrawal from the assembly chamber, the length of the working face. A nomogram is developed for assessing the risk of SFSS in the development of reservoir d6. Practical value. According to the results of the research, it was proposed to predict the SFSS at the design stage, for the early implementation of regional measures for their prevention. To assess the WSP, a nomogram is to be used for the prevention of SFSS, which includes advanced development of protective seams, measures to reduce the ability to delaminate coal in the lower layer, change in technology for coal mining with intensive degassing of the developed seam and use of interval hydraulic fracturing.