Method for selecting locations for coal waste dumps

Abstract

FIELD: mining industry.SUBSTANCE: invention is intended for use in selecting locations for the placement of coal waste dumps during the development of natural energy resource deposits and the disposal of accumulated solid waste from coal mining. The method for selecting locations for coal waste dumps is that in a mining region, using geodynamic zoning, the boundaries of geodynamically active blocks of the earth's crust are identified and the width of the zone of influence of the boundaries of such blocks is determined. Then the coal waste dump site is placed by placing the centre of the site equidistant from the boundaries of the zone of influence of geodynamically active blocks, which represent linear sections of tectonic destruction of the rock massif, and orienting the longitudinal axis of symmetry of the site and its long sides in the east-west direction. After which a coal waste dump is formed. The coal waste dump site is placed near the heat consumer.EFFECT: integrated use of energy resources and improved environmental condition.1 cl, 1 dwg, 1 ex

Description

[0001] The invention relates to the mining industry, thermal power engineering, ecology and is intended for use in selecting locations for the placement of coal waste dumps during the development of natural energy resource deposits and the disposal of accumulated solid waste from coal mining.

[0002] Coal waste dump burning is a pressing environmental issue in mining regions. The long-term thermal destruction of stored solid coal mining waste has a significant negative impact on the environment.

[0003] As a powerful source of thermochemical atmospheric pollution, a burning coal waste dump is capable of annually releasing tens of tons of various gaseous substances into the atmosphere, including carbon monoxide, sulfur dioxide, hydrogen sulfide, and nitrogen oxide. Depending on the dump's thermal state, the gas emissions may contain compounds of cadmium, phosphorus, arsenic, and other toxic elements (Devyatova A.Yu. Gas-Phase Emissions into the Atmosphere During Coal Combustion / / Izvestiya Vuzov. Gorn. Zhurn. 2013. No. 5, pp. 29-34).

[0004] The thermal power of coal waste, prone to self-heating and subsequent spontaneous combustion, can reach 5 x 10 10 up to 8 x 10 10 kcal per 100 thousand m 3waste mass (Ishkhneli O.G., Limansky A.V., Voronkov G.Ya. Reducing environmental pollution during the liquidation of coal and rock waste dumps / / Coal. 2013. No. 10, p. 69). However, with an increase in the volume of waste rocks that have undergone thermal destruction, the thermal energy potential of such a dump steadily decreases.

[0005] In accordance with the existing systematization, one of the main areas of use of solid waste from coal mining is the reduction of environmental pollution and the creation of products from mineral resources concentrated in the waste (Popov S.M. Methodology of ecological and economic justification for the use of coal industrial waste / Abstract of dissertation for the degree of Doctor of Economics. Moscow. 2008. Pp. 14-15).

[0006] A method for selecting locations for coal waste dumps that takes into account the geothermal gradient is known. The method makes it possible to use geothermal energy and the heat of a dump located in a coal mining quarry with a depth of at least 100 meters through a heat exchanger laid on the underlying rock of the mined coal, see RU 2716534 C1, 12.03.2020, IPC E21C 41 / 32 (2006.01), E21F 15 / 00 (2006.01), F03G 4 / 00 (2006.01), F24T 10 / 15 (2018.01).

[0007] This method makes it possible to reduce the negative impact of a self-heating coal waste dump on the environment, namely to reduce the thermochemical pollution of the atmosphere, by extracting the heat of oxidizing (smoldering) waste rocks through a heat exchanger located at the base of the dump.

[0008] However, this choice of location for the coal waste dump prevents air from entering it, which reduces the oxidation rate of solid coal mining waste or even halts the thermal destruction of the waste rock. Furthermore, the sides of the deep quarry, which shield the waste dump surface from direct sunlight, particularly in the morning and evening hours, contribute to a reduction in the average annual thermal output of the waste dump. In other words, the known method does not create the most favorable conditions for sustainable heat production in the waste dumps.

[0009] The closest analogue of the proposed invention is a method for selecting locations for the placement of coal waste dumps, including identifying the boundaries of geodynamically active blocks of the earth's crust, determining the width of the zone of their influence for the subsequent placement of a coal waste dump outside this zone and determining the location of the site for the placement of a coal waste dump, see RU 2600948 C1, 10 / 27 / 2016, IPC E21C 41 / 26 (2006.01), G01V 11 / 00 (2006.01).

[0010] The identification of the boundaries of geodynamically active blocks in this method is carried out using the method of geodynamic zoning based on the use of topographic maps, aerial and space photographs of various scales, geological, geophysical, geomorphological and other materials with subsequent identification of these zones on the ground and their comparison with the planned location for the dump on the earth's surface.

[0011] This method is designed to prevent spontaneous combustion of coal waste dumps, thereby reducing the negative impact of these man-made formations on the environment.

[0012] At the same time, the placement of the dump outside the zones of influence of the boundaries of geodynamically active blocks of the earth's crust does not ensure the creation of stable and long-term conditions for the steady flow of air to the centers of self-heating in the body of the dump, which reduces the intensity of oxidation of solid coal mining waste or even stops their thermal destruction, which, in turn, does not allow the use of the dump as a generator and heat accumulator.

[0013] The proposed invention is based on the task of improving the method for selecting locations for the placement of coal-rock dumps, which creates conditions for the stable flow of air into the coal-rock dump through air-permeable zones at its base, ensuring stable and long-term accumulation in the coal-rock dump of heat generated as a result of the oxidation of solid waste from coal mining, as well as conditions for intensive and long-term heating of a significant area of ​​the near-surface zone of the coal-rock dump by solar radiation, leading to its self-heating.

[0014] The stated problem is solved in that in the method for selecting locations for the placement of coal waste dumps, which includes identifying the boundaries of geodynamically active blocks of the earth's crust, determining the width of the zone of influence of the boundaries of the geodynamically active blocks and determining the location of the site for placing the coal waste dump, according to the invention, the location of the site is determined so that its center is located equidistant from the boundaries of the zone of influence of the geodynamically active blocks, and the longitudinal axis of symmetry and the long sides of the site are oriented in the east-west direction.

[0015] It is advisable to determine the location of the site for the placement of the coal waste dump near the heat consumer.

[0016] The solution to this problem allows the use of coal waste as a generator and heat accumulator, thereby improving the environment and enabling the integrated use of energy resources.

[0017] The possibility of practical implementation of the proposed method is based on the fact that the earth's crust consists of hierarchically ordered geodynamically active blocks of different ranks, which are in constant interaction with each other (I.M. Batugina, I.M. Petukhov. Geodynamic zoning of deposits during the design and operation of mines. Moscow: Nedra, 1998. 166 p.). The boundaries between the blocks are called "geodynamically hazardous zones" and represent linear sections of tectonic destruction of the rock mass. The permeability of rocks at the block boundaries can be much higher than the permeability of rocks inside the blocks, which promotes gas mass transfer in the massif precisely through these zones. (Petukhov I.M., Batugina I.M. Geodynamics of the Subsoil. Moscow: Nedra Communications, 1999. 214 p.).

[0018] The practical achievement of the expected result is based on the fact that the coal waste dump, as an element of a natural-technical system, interacts with the geological environment and the atmosphere, which allows solar radiation to pass through. The geological environment is the source of the development of the dump's fractured-porous structure. When the dump is located within the influence zone of geodynamically active crustal blocks, conditions are created for air to enter the dump body through permeable zones at its base. This "saturation" of the dump with air facilitates the initiation and stable continuation of the heat-generating oxidation process of the waste rock. Furthermore, seasonal and daily temperature fluctuations, combined with precipitation, lead to increased air permeability in the near-surface zone, thereby increasing the intensity of biochemical heat-generating oxidation processes within the dump.In addition, under the influence of solar radiation, a significant area of ​​the near-surface zone of the dump heats up, as a result of which the thermal power of the dump increases.

[0019] The location of the center of the site for the placement of the coal waste dump equidistant from the boundaries of the zone of influence of geodynamically active blocks causes an increase in fracturing and porosity of both the central and peripheral areas of the dump base, which contributes to a stable and greater supply of air to the centers of dump self-heating.

[0020] The orientation of the longitudinal axis of symmetry of the site and, accordingly, its long sides, in the east-west direction ensures the greatest lengths of the slopes of the dump along the solar and shadow exposures, which makes it possible in the summer to significantly increase the average annual intensity of heating of the near-surface zone of the dump by solar radiation from the side of the solar (southern) exposure, and in the winter to create conditions for the appearance in the dump of a greater number of air-permeable zones caused by cryogenic (frost) cracks in the slopes of the shadow (northern) exposure.

[0021] In addition, determining the location of the site for placing the coal waste dump near the heat consumer leads to a reduction in heat energy losses during the transportation of the coolant from the man-made heat source (carbon waste dump) to the consumer.

[0022] The essence of the invention is explained by the drawing, which schematically depicts a coal-rock dump located on the site, where: 1 is the zone of influence of the boundaries of geodynamically active blocks of width b; 2 is the site for placing the coal-rock dump; 3 is the coal-rock dump; 4 is the zone of increased fracturing at the base of the coal-rock dump; 5 is the slope of the dump; 6 is the rock massif. In this case, the center O of site 2 is equidistant from the boundaries of zone 1 (AO=OC=l / 2b), and the axis of symmetry L of site 2 and its long sides are oriented in the east-west direction.

[0023] Example of the implementation of the claimed method

[0024] In a mining district of a region, using, for example, geodynamic zoning, the boundaries of geodynamically active blocks are identified and the width b of zone 1 of influence of the boundaries of geodynamically active blocks is determined. Zone 1 is then identified on the ground and compared with the planned location of site 2 for the placement of coal and rock dump 3. Next, the center O of site 2 is positioned equidistant from the boundaries of zone 1 (AO=OC=1 / 2b), which represent linear sections of tectonic destruction of rock mass 6, and the longitudinal axis of symmetry L of site 2 and its long sides are oriented in the east-west direction.

[0025] This location of site 2 facilitates the formation of multiple zones of increased fracturing 4 at the base of coal-rock dump 3 and on the sides of slope 5 of coal-rock dump 3, primarily due to the more complete coverage of its base by deformation processes leading to the formation of cracks and pores. The emergence of air-permeable areas in zones of increased fracturing 4 facilitates a stable supply of air to the dump's self-heating centers due to the draft arising from wind pressure and the pressure difference across the height of dump 3. This allows for the most complete and extended use of the dump's heat throughout its life cycle.

[0026] Even when the waste rocks have completely passed the stage of thermal destruction and waste dump 3 is in the stage of cooling of the foci, it is possible to rationally use both the previously generated heat of the waste rocks and the heat accumulated (stored) by waste dump 3 due to solar heating.

[0027] Utilization of waste heat from waste dump 3 allows for a significant reduction in the negative impact of such a man-made formation on the ecology of the mining region, and, above all, a reduction in the thermal and chemical pollution of the atmosphere.

[0028] Thus, the use of the proposed invention ensures stable and long-term accumulation of heat, which leads to self-heating of the dump and its use as a generator and heat accumulator, improving the environment and ensuring the comprehensive use of energy resources.

Claims

1. A method for selecting locations for coal and rock dumps, which consists of identifying the boundaries of geodynamically active blocks of the earth's crust in a mining region using geodynamic zoning, determining the width of the zone of influence of the boundaries of such blocks, locating a site for a coal and rock dump, placing the center of the site equidistant from the boundaries of the zone of influence of geodynamically active blocks, which represent linear sections of tectonic destruction of the rock massif, and orienting the longitudinal axis of symmetry of the site and its long sides in the east-west direction, and then forming a coal and rock dump.

2. The method according to paragraph 1, characterized in that the site for the coal waste dump is located near the heat consumer.

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