Coal and electricity combined camp strip mine mining method capable of reducing dust pollution

Abstract

The invention discloses a coal and electricity combined camp open-pit mine mining method capable of reducing dust pollution, which comprises the following steps: when large-scale stripping of an open-pit mine begins in spring, constructing a ventilation corridor in a dumping site in a dumping site propelling process; a multifunctional air plate is built at an inlet of the ventilation gallery; cooling pools are built at the pit bottom and on the two sides of the outlet position of the ventilation gallery respectively, and water pumping and injecting pipelines of the cooling pools extend to the earth surface through the bottom of the ventilation gallery and then are connected with a circulating pipeline of the thermal power plant; from spring of the second year, the multifunctional air plate and the water pumping and injecting pipeline arranged in the last year are dismantled, and the cooling pond is naturally buried along with advancing of the dumping site; and meanwhile, mining in the second year is started according to the mining method in the last year. The ventilation gallery can guide air flow to enter the pit bottom, transverse flowing of air at the pit bottom is accelerated, and the dust falling effect is achieved; the characteristics of dynamic mining and seasonal mining of the strip mine are fully combined, production and the final capacity of the dumping site are not affected, and the method is simple and easy to operate.

Description

Technical Field

[0001] This invention relates to an open-pit mining method, specifically to an open-pit mining method for coal-fired power plant joint ventures that reduces dust pollution. Background Technology

[0002] Currently, due to long transportation distances and high costs, open-pit mines in northern and northwestern my country are increasingly adopting coal-fired power (COP) systems to convert coal into electricity locally. While this reduces transportation costs, COP also faces three major problems: First, the direct discharge of heat from cooling water in high-power power plants leads to resource waste. Second, the vast space at the bottom of open-pit mines remains underutilized for extended periods, wasting resources. Third, the basin-like topography of open-pit mines makes them prone to forming small-scale temperature inversion layers above the pit during winter. This restricts dust dispersion, increases dust concentration, and exacerbates pollution. Artificially promoting horizontal and vertical air circulation can effectively improve the temperature inversion problem, but construction costs are high.

[0003] We face three common understandings: First, open-pit mining is a dynamic project, with large open-pit mines achieving annual progress of over 300 meters, providing a good window of opportunity for various engineering constructions. Second, most northern open-pit mines, due to the severe winters, often employ seasonal stripping methods, with primary stripping in spring, summer, and autumn, and limited stripping in winter. This results in faster progress of the spoil heap in spring, summer, and autumn, while the spoil heap remains relatively fixed in winter, providing opportunities for utilizing the space at the bottom of the pit. Third, to minimize the land occupied by spoil heaps, spoil heaps in open-pit mines are generally higher than the ground surface, and the wind speed at the top of the spoil heap is generally higher than at the ground surface.

[0004] Therefore, this invention proposes a method for open-pit mining in coal-fired power plant areas to reduce dust pollution, and comprehensively addresses the problems encountered above based on the aforementioned realities. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a method for open-pit mining in coal-fired power plant areas to reduce dust pollution. This method effectively utilizes the space at the bottom of the pit, achieving both dust reduction and preventing active dust generation, while simultaneously accelerating heat diffusion in the cooling pool and improving cooling efficiency.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for open-pit mining in coal-fired power plant areas to reduce dust pollution, comprising the following steps: When large-scale stripping begins in the spring, ventilation corridors are constructed inside the spoil heaps during the rollover process, with minimal or no rollover. The ventilation corridor entrance is located at the top of the spoil heap and above the ground level, while the ventilation corridor exit is located on the first rollover step above the bottom of the open-pit mine. The ventilation corridor exit is located on the central axis of the pit bottom and is inclined as a whole. The width of the ventilation corridor gradually narrows from the entrance to the exit, with the entrance width not less than 100m. When the main stripping task of the open-pit mine is completed in the autumn, the exit width is not greater than 40m. Construct multi-functional air panels on the spoil heap outside the ventilation corridor entrance; At the bottom of the open-pit mine, on both sides of the ventilation corridor exit, at a distance X from the lowest soil dumping step at the bottom of the pit, a thermal power plant cooling pool is constructed. The water injection pipelines of the cooling pools extend through the bottom of the ventilation corridor to the ground surface and are connected to the circulation pipeline of the thermal power plant. Starting in the spring of the following year, the open-pit mine began its main stripping work for the new year. At this time, the multi-functional air panels and water injection pipelines installed in the previous year were removed. As the open-pit mine's spoil heap was advanced, the cooling ponds were naturally buried. At the same time, mining for the second year began in accordance with the mining methods of the previous year.

[0007] Furthermore, the specific construction method of the ventilation corridor is as follows: The spoil heaps on both sides of the ventilation corridor entrance are dumped according to the design elevation. The ventilation corridor is located at the design slope, with less or no dumping. The steps of the spoil heaps are delayed, naturally forming a corridor with a height lower than the spoil heaps. If there is a significant secondary wind in the mining area during winter in addition to the prevailing wind, the spoil heap on the windward side of the ventilation corridor will be dumped according to the design elevation, while the spoil heap on the leeward side, adjacent to the entrance of the ventilation corridor, will be dumped one less spoil heap step than the design elevation, meaning it will be one spoil heap step lower than the design elevation.

[0008] Furthermore, the entrance direction of the ventilation corridor is parallel to the prevailing wind direction in the mining area during winter, the centerline of the ventilation corridor exit coincides with the centerline of the pit bottom, the ventilation corridor is inclined as a whole, and the width of the ventilation corridor gradually narrows from the entrance to the exit. The width at the entrance is not less than 100m, and the width at the exit is not greater than 40m when the main stripping task of the open-pit mine is completed in autumn.

[0009] Furthermore, during winter, the working line of open-pit mines is pushed forward, resulting in a small amount of soil being dumped and the dump site being pushed forward slightly. At this time, the width of the ventilation corridor exit is narrowed, but in order to ensure ventilation efficiency, the exit width is not less than 30m.

[0010] Furthermore, X = A + T, where A is the safety distance, ranging from 20 to 50 meters, and T is the advance distance of the open-pit mine spoil heap in winter, ranging from no more than 100 meters.

[0011] Furthermore, the multifunctional air panel includes several panels, slide rails, fixtures, and a steel frame, with the slide rails including an upper rail and a lower rail; The steel frame is set on the surface of the spoil heap. The upper and lower rails are set on the upper and lower parts of the steel frame, respectively. Fixers are installed at intervals in the middle of the steel frame. The upper and lower ends of the panel are equipped with pulleys, and the back of the panel is equipped with a tightening strap. The upper and lower ends of the panel are respectively engaged with the upper and lower rails by pulleys.

[0012] Furthermore, the slide rail is divided into a semi-circular slide rail and two straight slide rails. The semi-circular slide rail is located at the entrance of the ventilation corridor, and the center line of the semi-circular slide rail coincides with the center line of the entrance of the ventilation corridor. The two straight slide rails are parallel to the extension line of the side wall at the entrance of the ventilation corridor and are respectively connected to one end of the semi-circular slide rail.

[0013] Furthermore, the panel is provided with buckles at both the left and right ends.

[0014] Compared with existing technologies, the ventilation corridor of this invention is built on an inner spoil heap above the ground surface and adopts an elevation difference design, which can guide the airflow into the bottom of the pit, accelerate the lateral airflow at the bottom of the pit, and play a role in dust reduction. The design of wide inlet and narrow outlet can absorb more air volume into the ventilation corridor as much as possible, and increase the outlet air velocity, thereby improving the dust removal effect.

[0015] The ventilation corridor outlet is located on the centerline of the mine pit, maximizing the coverage area. The multi-functional air panel can guide more airflow into the pit bottom when the wind is light or the wind direction changes, and can also control the amount of air entering the ventilation corridor when the wind is strong, achieving flexible airflow adjustment, which both reduces dust and prevents active dust generation.

[0016] Constructing a bottom cooling pool in the open-pit mine fully utilizes the heat from the cooling water in the power plant, accelerates the vertical airflow at the bottom of the pit, and makes full use of the space at the bottom of the pit. The ventilation corridors and the bottom cooling pool work together to quickly break down the inversion layer, reduce pollution at the bottom of the pit, and accelerate heat diffusion from the cooling pool, achieving accelerated cooling. This invention fully combines the characteristics of dynamic and seasonal open-pit mining, does not affect normal production in the mining area, does not affect the final capacity of the spoil heap, and is simple and easy to construct. The plan is implemented annually, allowing for flexible continuity and easy adjustment, enhancing its applicability, and is both environmentally friendly and economical while achieving full utilization of energy. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall invention; Figure 2 This is a schematic diagram of a partial section of the multifunctional air plate structure of the present invention; Figure 3 This is a side view of the multifunctional air plate of the present invention; In the diagram: 1-Dumping area; 2-Main wind direction; 3-Ventilation corridor; 4-Surface; 5-Pit bottom; 6-Mining work line; 7-Secondary main wind; 8-Panel; 9-Pulley; 10-Snap fastener; 11-Tightening belt; 12-Fixer; 13.1-Semi-circular slide rail; 13.2-Straight slide rail; 14-Upper rail; 15-Lower rail; 16-Steel frame; 17-Cooling pool; 18-Water injection pipeline; 19-Power plant; 20-Circulation pipeline. Detailed Implementation

[0018] The invention will now be further described with reference to the accompanying drawings.

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] like Figure 1 As shown, the present invention provides a technical solution, a method for reducing dust pollution in open-pit mines in coal-fired power plant areas, including steps such as constructing ventilation corridors for spoil heaps, constructing multi-functional air panels, constructing cooling pools at the bottom of pits, and cross-year continuity.

[0021] Construction of ventilation corridors in spoil heaps: When large-scale stripping of open-pit mines begins in spring, ventilation corridors 3 are constructed inside spoil heap 1 during the advancement of spoil heap 1 in open-pit mines by discharging less or no soil.

[0022] The specific construction method of ventilation corridor 3 is as follows: The spoil heaps 1 on both sides of the entrance of ventilation corridor 3 are constructed according to the design elevation. At the location of ventilation corridor 3, spoil is reduced or eliminated according to the design slope. The advancement of the spoil heap steps lags behind, naturally forming a corridor with a height lower than spoil heap 1. If, in addition to the prevailing wind direction 2, there is a significant secondary wind direction 7 in the mining area during winter, the spoil heap 1 on the windward side of ventilation corridor 3 is constructed according to the design elevation. The spoil heap 1 on the leeward side, adjacent to the entrance of ventilation corridor 3, is constructed with one less spoil heap step than designed, meaning it is still one spoil heap step away from the design elevation. The purpose is to collect as much secondary air volume as possible. As spoil heap 1 continues to advance, the spoil heap steps on both sides of ventilation corridor 3 are constructed according to the original design height. The steps within ventilation corridor 3 are advanced with a lag, gradually extending to the design exit position. Bulldozers are used to shape the steps within ventilation corridor 3 into a single slope, reducing airflow obstruction. At this point, the construction of ventilation corridor 3 is complete.

[0023] The entrance to ventilation corridor 3 is located at the top of spoil heap 1 and is higher than the ground surface 4. The exit of ventilation corridor 3 is located on the first spoil heap step above the bottom of the open pit 5. The entrance direction of ventilation corridor 3 is parallel to the prevailing winter wind direction 2 of the mining area, and the centerline of the exit of ventilation corridor 3 coincides with the centerline of the pit bottom 5. Figure 1 The overall shape of ventilation corridor 3 shown represents the extreme case, where the prevailing wind direction 2 is parallel to the centerline of the pit bottom 5. In this case, the centerlines of the entrance and exit of ventilation corridor 3 coincide, and the overall shape of ventilation corridor 3 is a straight line. Otherwise, the overall shape of ventilation corridor 3 is arc-shaped, designed to more efficiently introduce air into the pit bottom 5 and ensure that the introduced airflow ultimately coincides with the centerline of the pit bottom 5. Ventilation corridor 3 is inclined, and its width gradually narrows from the entrance to the exit. The entrance width is no less than 100m, and the exit width is no more than 40m when the main stripping task of the open-pit mine is completed in autumn. The wide entrance is to absorb as much airflow as possible into ventilation corridor 3, while the narrow exit is to increase the exit air velocity to disperse dust pollution from the pit bottom 5 as much as possible. During winter, when the open-pit mine working line 6 is advanced, a small amount of soil is dumped, and the spoil heap 1 is also advanced slightly. At this time, the exit width of ventilation corridor 3 narrows somewhat, but to ensure ventilation efficiency, the exit width should not be less than 30m.

[0024] Constructing a multi-functional air panel on the spoil heap 1 outside the entrance of ventilation corridor 3: Constructing ventilation corridor 3 alone has the following disadvantages: First, although it can absorb wind from the main wind direction, its absorption capacity is limited for winds from other directions; second, when the main wind direction is strong, a large amount of air will enter the pit bottom 5, which will not only fail to disperse the dust at the pit bottom 5 but will also cause a large amount of dust to rise from the pit bottom 5, which is detrimental to safe production. These two disadvantages are mainly caused by the entrance direction of ventilation corridor 3. Therefore, it is necessary to construct a multi-functional air panel at the entrance of ventilation corridor 3 to achieve at least the following two objectives: first, when the air volume is low, guide more air into ventilation corridor 3 to disperse the dust at the pit bottom 5; second, when the main air volume is high, appropriately close the entrance of ventilation corridor 3 to prevent dust from rising from the pit bottom 5.

[0025] like Figure 2 and Figure 3As shown, the multi-functional air panel includes several panels 8, slide rails, fixtures 12, and a steel frame 16. The slide rails include an upper rail 14 and a lower rail 15. The steel frame 16 is set on the surface of the spoil heap 1. The upper rail 14 and the lower rail 15 are respectively set on the upper and lower parts of the steel frame 16. Fixtures 12 are spaced apart in the middle of the steel frame 16. The upper and lower ends of the panels 8 are respectively provided with pulleys 9. The back of the panels 8 is provided with a tightening strap 11 for connecting with the fixtures 12 to fix the panels 8. The left and right ends of the panels 8 are respectively provided with buckles 10 to connect two panels 8. The upper and lower ends of the panels 8 are respectively engaged in the upper rail 14 and the lower rail 15 by pulleys 9. The panels 8 can slide in the rails. The panels 8 are steel structure panels. The windward side of the panels 8 is curved to facilitate the airflow guidance function.

[0026] The slide rail consists of a semi-circular slide rail 13.1 and two straight slide rails 13.2. The semi-circular slide rail 13.1 is located at the entrance of the ventilation corridor 3, and the centerline of the semi-circular slide rail 13.1 coincides with the centerline of the entrance of the ventilation corridor 3. The two straight slide rails 13.2 are parallel to the extension line of the side wall at the entrance of the ventilation corridor 3 and are connected to one end of the semi-circular slide rail 13.1 respectively. The entire slide rail arrangement achieves full enclosure of the entrance of the ventilation corridor 3.

[0027] Construction of Pit Bottom Cooling Pools: On both sides of the outlet of the ventilation corridor 3 at the bottom of the open-pit mine 5, at a distance X from the lowest dumping step of the pit bottom 5, a thermal power plant cooling pool 17 is constructed, where X = A + T, A is the safety distance, ranging from 20 to 50 meters, and T is the winter advance distance of the open-pit mine dumping site 1, not exceeding 100 meters. This design ensures that the cooling pool 17 at the bottom of the pit 5 does not need to be relocated during a winter. The water injection and extraction pipelines 18 of the cooling pool 17 extend from the bottom of the ventilation corridor 3 to the ground surface 4 and connect to the circulation pipeline 20 of the thermal power plant 19. The cooling water of the thermal power plant 19 circulates through the pipeline to the cooling pool 17 for cooling and then returns to the thermal power plant 19, realizing the circulation of cooling water.

[0028] When a temperature inversion occurs at the bottom of pit 5 in winter, two scenarios arise based on the relative relationship between the strength of the natural wind and the heat diffusion capacity of the cooling pool 17. First, when the natural wind exceeds the heat diffusion capacity of the cooling pool 17, the strong wind can penetrate the ventilation corridor 3 into pit 5, accelerating the lateral airflow, breaking the temperature inversion layer, and dispersing pollutants. Simultaneously, as the wind rapidly passes near the cooling pool 17, the pressure change accelerates the heat diffusion process within the pool, thus speeding up cooling. Second, when the natural wind is weaker than the heat diffusion capacity of the cooling pool 17, the wind is weak or nonexistent, making it difficult for it to penetrate pit 5. In this case, the heat from the cooling pool 17 heats the surrounding air, causing it to rise and accelerate the vertical airflow at pit 5, breaking the temperature inversion layer and accelerating the discharge of pollutants from pit 5 to the outside. Simultaneously, the rising hot air lowers the air pressure at pit 5, attracting external air through the ventilation corridor 3 to further accelerate airflow and reduce dust.

[0029] When the natural wind direction deviates from the direction of ventilation corridor 3 or the wind force is small, the multi-functional air panel is activated. Several panels 8 are inserted into the track to form a guide wall. By sliding and adjusting the position of the panels 8, the front end of the guide wall is adjusted to be parallel or nearly parallel to the wind direction, and the rear end is parallel or nearly parallel to the ventilation corridor 3, so as to guide more airflow into the ventilation corridor 3.

[0030] When a strong natural wind blows into the ventilation corridor 3 and causes dust to rise at the bottom of the pit 5, a multi-functional air panel is needed to control the airflow entering the ventilation corridor 3. At this time, by sliding the adjustment panel 8, the center of the guide wall is adjusted to be perpendicular to the wind direction, guiding the airflow to diffuse more to both sides of the ventilation corridor 3 instead of entering the ventilation corridor 3.

[0031] New Year Continuation: Starting in the spring of the second year, the open-pit mine begins the main stripping work for the new year. At this time, the multi-functional air panel and water injection pipeline 18 installed in the previous year are removed. As the open-pit mine spoil heap 1 is advanced, the cooling pool 17 is naturally buried. At the same time, the mining of the second year begins according to the mining method of the previous year.

[0032] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0033] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any minor modifications, equivalent substitutions, and improvements made to the above embodiments based on the technical essence of the present invention should be included within the protection scope of the present invention.

Claims

1. A method of reducing dust pollution in an open pit coal mine of a coal power complex, characterized in that, The method comprises the following steps: When large-scale stripping of the open pit in spring starts, a ventilation gallery (3) is built inside the dump (1) by means of less or no dumping during the advancement of the dump (1); the entrance of the ventilation gallery (3) is on the top of the dump (1) and is higher than the ground surface (4), and the exit of the ventilation gallery (3) is located on the first dumping step above the pit bottom (5); A multifunctional air plate is built on the dump (1) outside the entrance of the ventilation gallery (3); At the pit bottom (5), two cooling ponds (17) are respectively built on both sides of the exit of the ventilation gallery (3) and at a position X away from the last dumping step of the pit bottom (5); the water pumping and injecting pipelines (18) of the cooling ponds (17) are extended to the ground surface (4) through the bottom of the ventilation gallery (3) and are connected with the circulating pipelines (20) of the thermal power plant (19); In the spring of the next year, the multifunctional air plate and the water pumping and injecting pipelines (18) built in the previous year are removed, and the cooling ponds (17) are naturally buried as the dump (1) advances; meanwhile, the mining in the second year is started according to the mining method in the previous year.

2. A method of reducing dust pollution in an open pit coal mine of a coal power complex according to claim 1, characterized in that, The ventilation gallery (3) is built as follows: The dump (1) on both sides of the entrance of the ventilation gallery (3) is dumped according to the designed elevation, the position of the ventilation gallery (3) is less or not dumped according to the designed slope, the dumping step of the dump (1) is delayed, and the gallery with a height lower than the dump (1) is naturally formed; If there is a secondary wind direction (7) in addition to the main wind direction (2) in winter, the dump (1) on the windward side of the ventilation gallery (3) is dumped according to the designed elevation, and the dump (1) on the leeward side of the ventilation gallery (3) is less dumped by one dumping step at the position close to the entrance of the ventilation gallery (3).

3. A method of reducing dust pollution in an open pit coal mine of a coal power complex according to claim 2, characterized in that, The direction of the entrance of the ventilation gallery (3) is parallel to the direction of the main wind direction (2) in winter, the center line of the exit of the ventilation gallery (3) coincides with the center line of the pit bottom (5), the ventilation gallery (3) is inclined as a whole, the width of the ventilation gallery (3) gradually narrows from the entrance to the exit, the width of the entrance is not less than 100 m, and the width of the exit is not greater than 40 m when the stripping task of the open pit in autumn is completed.

4. A method of reducing dust pollution in an open pit coal mine of a coal power complex according to claim 3, characterized in that, The working line (6) of the stope is advanced in winter, at this time, the width of the exit of the ventilation gallery (3) narrows, but the width of the exit is not less than 30 m.

5. A method of reducing dust pollution in an open pit coal mine of a coal power complex according to claim 1, characterized in that, X=A+T, A is a safety distance, and the value is 20-50 m, and T is the advancing distance of the dump (1) in winter, and the value is not greater than 100 m.

6. A method of reducing dust pollution in an open pit coal mine of a coal power complex according to claim 1, characterized in that, The multifunctional air plate comprises a plurality of panels (8), sliding rails, a fixer (12) and a steel frame (16), the sliding rails comprise upper rails (14) and lower rails (15), the steel frame (16) is arranged on the surface of the dump (1), the upper rails (14) and the lower rails (15) are arranged on the upper part and the lower part of the steel frame (16) respectively, the fixer (12) is arranged at the transverse middle part of the steel frame (16), the panel (8) is provided with a pulley (9) at the upper end and the lower end, the back of the panel (8) is provided with a tightening belt (11), and the panel (8) is clamped in the upper rails (14) and the lower rails (15) through the pulleys (9) at the upper end and the lower end. ​ 7. A method of reducing dust pollution in an open cut coal mine of a coal power complex according to claim 6, characterised in that, The slide rail is divided into a semicircular segment slide rail (13.1) and two straight line segment slide rails (13.2), the semicircular segment slide rail (13.1) is located at the entrance of the ventilation corridor (3), the center line of the semicircular segment slide rail (13.1) coincides with the center line at the entrance of the ventilation corridor (3), and the two straight line segment slide rails (13.2) are respectively parallel to the extension line direction of the side wall at the entrance of the ventilation corridor (3) and are respectively connected with one end of the semicircular segment slide rail (13.1).

8. A method of reducing dust pollution in an open pit coal mine of a coal power complex according to claim 6, characterized in that, The left and right ends of the panel (8) are respectively provided with buckles (10).

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