The results of the analysis of practical experience in the development of potash seams using longwall mining systems at the mines of OAO “Belaruskali” are presented. Positive changes in the technical and economic indicators of mines and an increase in the safety of mining operations were noted with the introduction of resource-saving technologies without leaving the pillars between the excavation columns or with leaving the pillars between the columns with dimensions at which they are destroyed by mining pressure in the goaf. It is noted that the use of mechanized stoping complexes characterized by high energy capacity, combined with large depths of development, is the main reason for the temperature increase in longwalls to values exceeding the maximum permissible air temperature regulated by sanitary standards. Based on production studies, it was concluded that the temperature regime along the length of the longwall face is determined by the temperature of rocks in the developed longwall space, heat emissions from the equipment of the power train, and the temperature of the rock mass ahead of the longwall. The conclusion has been drawn about the feasibility of using developed technological schemes in deep mining conditions, which provide a reduction in longwall temperature by 6-9 °C or more through isolated ventilation of longwall and power trains, as well as heat exchange between the airflow entering the longwall and the rocks in the developed space.
It is shown that the creation of the variants of resource-saving systems for the development of long-column mining is one of the main directions for improving the technological schemes for mining operations in the mines of the Kuang Nin coal basin. They provide a reduction in coal losses in the inter-column pillars and the cost of maintaining preliminary workings fixed with anchorage. The implementation of these directions is difficult (and in some cases practically impossible) when tight rocks are lying over the coal seam, prone to significant hovering in the developed space. In the Quang Ninh basin, 9-10 % of the workings are anchored, the operational losses of coal reach 30 % or more; up to 50 % of the workings are re-anchored annually. It is concluded that the real conditions for reducing coal losses and the effective use of anchor support as the main support of reusable preliminary workings are created when implementing the idea put forward at the St. Petersburg Mining University: leaving the coal pillar of increased width between the reused mine working and the developed space and its subsequent development on the same line with the stoping face simultaneously with the reclamation of the reused mine working.
Spontaneous combustion of coal remains an important problem for coal mines, which can lead to an explosion of methane and coal dust. Accidents associated with spontaneous combustion of coal can cause significant economic losses to coal mining companies, as well as entail social damage – injuries and loss of life. Accidents are known at the Kuzbass mines, which occurred as a result of negligent attitude to the danger of spontaneous combustion of coal, the victims of which were dozens of people. The analysis of emergency situations associated with spontaneous combustion of coal shows that the existing wide range of means of preventing endogenous fires does not provide complete safety when working out coal seams prone to spontaneous combustion, therefore, spontaneous combustion places continue to occur in mines. The consequences that may arise as a result of a methane explosion initiated by a self-ignition place indicate the need to improve the used technologies. The purpose of the work is to determine the impact of modern technological solutions used in functioning mines during underground mining of flat-lying coal seams prone to spontaneous combustion, and to develop new solutions that reduce endogenous fire hazard. Conclusions on the influence of leaving coal pillars in the developed space, isolated air removal from the stoping face through the developed space, the length of the stoping face and the excavation pillar, and other factors on the danger of the formation of spontaneous combustion places are presented. Conclusions about the possibility of using modern technological solutions in future are also drawn.
The article presents the results of the analysis of the Russian coal mines experience in using the variant of the long-pillar development system with the abandonment of coal pillars in the mined out areas of longwall faces. In the Kuzbass mines, this option accounts for 90-95 % of the total volume of coal mined by the underground method. It is pointed out that it is necessary to take into account the negative influence of the pillars left in the worked out space on the geomechanical conditions of conducting mining operations in the overworked (underworked) seams. A significant negative effect of the pillars is shown in combination with selective extraction of the adjacent layers on reduction of the balance reserves. The measures allowing to increase the efficiency of the use of long pillar mining systems for the development of adjacent series of seams are considered.
Results of the analysis of factors influencing the probability of accidental groundwater inrush into mine workings of salt (potash, potassium and magnesium) mines are given in the article. The cases of the potash mine flooding that occurred in different countries with developed mining industry are given. It is shown that at the present technical and scientific level of solving this problem the unexpected groundwater inrush in potash mines usually results in the shutdown of the enterprise and negative ecological consequences. It is pointed out that the underground waters flow into the mines through water-conducting fractures of either natural or technogenic origin which location and influence on a mine was almost impossible to predict at the design stage under existing regulations. The concept of reducing the risks of potash mine flooding caused by underground waters in-rush is formulated. Administrative and technical measures which allow reducing the risks of potash mine flooding caused by groundwater inrush into the excavations are considered.
The article focuses influence of disjunctive dislocations on parameters of secure zones on flat-lying adjacent coal seams is considered.
The most influencing the stopes walls stability factors have been determined. Physical-and-mechanical ore mass properties impact to the stopes height has been researched. Advanced ways to improve stopes walls stability have been considered.
In the article the problem associated with the necessity of application of the full goaf stowing technology in developing the steep coal seams in terms of Mao Khe deposit in Vietnam is presented.
The Memory Of A. A. Borisov,
The data characterized potentials of scientific school have been presented in the paper. The role of school in solving the problem of coal, ore and non-metallic deposits have been described. The perspective direction of scientific school development has been carried out.
The role of the Holodninsky ore deposit in ensuring need of the Russian Federation in extremely scarce raw materials – zinc and lead is shown. Technical solutions for decrease in ecological risks at extraction of this ore deposit are considered. Conclusions are drawn on prospects of extraction of the Holodninsky ore deposit.
The analysis of factors complicating the development of the Kholodninskoye deposit within the catchment area of Lake Baikal is carried out. Organisational and technical arrangements implementation of which reduces ecological risks while mining this deposit are worked out.
Mining systems for ore bodies of different thickness are developed for the conditions of Cholodninskoe deposit. Ration parameters of mining system are determined.
A complex of technology and organization methods to higher grade filling due to horizontal layers system of extraction rich ferrous metal ores for various stages of mining is presented.
The results of mine and analytical studies allowed us to create and justify the technological scheme of mining the Third potash layer in the zones of its thickness reduction at the borders of mine fields. The influence of the main mining and engineering factors on the key parameters of the scheme that determine the safety of the scheme's implementation was established.
Проанализированы причины длительного строительства Яковлевского рудника, а также факторы, оказывающие наиболее существенное влияние на выбор технологической схемы отработки железорудной залежи. Сделан вывод о том, что главным критерием приемлемости технологической схемы в специфических условиях участка первоочередной отработки Яковлевской залежи является исключение опасных деформаций толщи покрывающих пород, при достижении их возможно вторичное обводнение рудного массива на стадии ведения очистных работ. Предложены системы разработки, использование которых создает объективные предпосылки для обеспечения длительной конкурентоспособности Яковлевского рудника.
Рассмотрена схема подготовки участка первоочередной отработки Яковлевской залежи, варианты подсечки выемочных блоков и конструкция искусственного днища, создаваемого на откаточном горизонте при использовании комбинированной системы разработки с самообрушением руды.
Выполнен анализ основных недостатков применяемой на рудниках ПО «Беларуськалий» слоевой системы разработки. Обоснована концепция отработки Третьего калийного пласта в условиях глубоких горизонтов.
The main parameters on which the schemes of oil shale development under water-bearing sediments depend have been established. Resource-saving and environmentally friendly oil shale mining schemes were developed specifically for the Leningradskaya mine.
Prospective directions of improving technological schemes of shale formation development under aquifers, providing technical and environmental safety of underground mining works are analyzed. The expediency of using development systems with parameters that ensure the smooth deflection of the undermined massif without the formation of cracks that unite the aquifers is substantiated.
The analysis of domestic and world practice of development of technogenic resources shows that their development can serve as an additional source of obtaining non-ferrous and precious metals for mining enterprises, as well as contribute to the reduction of the harmful effects of toxic substances on the environment and the return to the economic turnover of previously withdrawn lands. For a number of mines, the development of man-made deposits is a priority source of existence of the mining enterprise. However, the practical development of such deposits is not carried out, as at the mining enterprises the technology and working projects of selective development of man-made deposits of minerals are absent. The requirements to the technological schemes of development of technogenic deposits are substantiated and the ways of selective excavation of useful components from the tailings of concentrating factories, providing the extraction of only the most enriched sections with leaving the main mass of rocks in place of their occurrence, are proposed.
A method for controlling the rock mass condition for the working faces using jetting units under unstable roof conditions has been developed. The necessity of increasing the rate of advance of the working face and the use of backfill of the mined-out space to ensure rock stability and uniform loading of the edge part of the formation has been proved. A formula for calculating the critical value of the filling mass suppression, which takes into account the caving step of the main roof, the loosening ratio, the thickness of the immediate roof rocks and can determine the compression properties of the filling mass by modern methods, taking into account the rate of advance of the face and the size of the squeeze zone, has been proposed. The proposed methodology substantiates an increase in the rate of face advance up to 4-6 m/day and the load on the working face by 30%.
An analysis of the causes of accidents associated with dynamic collapses of the roof rocks in the development system with sub-stage hydraulic extraction in the mines of OAO Prokopievskugol has been carried out. The hypothesis about the mechanism of dangerous dynamic collapses of coal and roof rocks is put forward. It is concluded that, when determining the height of the subfloor, it is necessary to take into account the width of the pushback zone formed at the boundary of the clearing works. The influence of the main geological and mining-technical factors on the parameters of the squeezing zone was studied. It has been proven that the following factors have the greatest influence on the width of the squeezing zone: the depth of the mining works, the thickness of the mined seam, the strength of the coal. Recommendations for determining the height of the subfloor, providing safe working conditions for miners in the conditions of the hydro mine Tyrganskaya are developed. The method of mining subfloors with an increased height is proposed. For its implementation the size of the squeezing zone and the length of the working jet of the hydraulic gun is calculated and the position of the undestroyed coal zone is determined taking into account these parameters. Coal massif de-strengthening in this zone is made to exclude the coal pack hang-up by, for example, hydraulic fracturing or explosion of explosive charges. The economic effect of implementing the developed recommendations has been calculated.
The data on the content of useful components in the wastes of non-ferrous metallurgy enterprises and the dynamics of their growth are given. The features of formation of technogenic deposits and distribution of non-ferrous metals within them are studied. It is established that although the content of metals in the technogenic deposit changes in different directions, the maximum changes are most often observed vertically. The requirements to technological schemes of technogenic deposits mining are substantiated and methods of selective excavation of useful components from tailing ponds of enrichment plants are proposed, providing for the extraction of only the most enriched areas with leaving the bulk of rocks in the place of their occurrence.
The results of scientific research of the Department of Underground Mining of Mineral Deposits, carried out in 2000 on problematic issues of underground mining of coal, shale and salt deposits, are presented. The requirements to the technological schemes of reservoir development in areas with limited size when using high-capacity mechanized mining complexes are formulated. Ways of increasing the efficiency of mining thin coal seams with the use of jet installations are proposed and substantiated. The causes of dynamic collapse of the roof rocks in the lower faces of the layered systems of development are investigated. Conclusions are made about the most promising ways of development of technogenic and oil and gas fields. Recommendations on underground coal combustion for steam and power generation have been developed.
Изложены результаты негативных тенденций изменения техника-экономических показателей при подземной добыче угля. Дан анализ причин возникновения этих тенденций и сформулированы приоритетные направления совершенствования технологических схем угольных шахт.
Опережающая отработка защитных пластов широко известна в настоящее время как региональный профилактический способ предотвращения горных ударов и внезапных выбросов угля и газа ...
Перспективы разработки угольных пластов на больших глубинах в значительной степени определяются тем, насколько своевременно и эффективно будет решен вопрос управления кровлей в очистных забоях для специфических условий глубоких горизонтов ...