Transportation system for overlapping area of strip mine

Abstract

The invention provides a transportation system for an overlapping area of a strip mine. The transportation system for the overlapping area of the strip mine comprises a dragline stacking working line and a working line used for limiting the stacking operation of the dragline in the overlapping area of the strip mine. The dragline pouring working line lags behind the dragline pouring working line and is used for limiting the working line of the pouring operation of the pouring shovel in the overlapping area of the strip mine; and the dumping bridge is connected between the south return route of the dragline dumping working line and the north end of the south high-section step of the dragline dumping working line and is used for discharging accumulation generated by dumping operation, and the dumping bridge is propelled along the propelling direction along with the propelling of the dragline dumping working line and the dragline dumping working line. The dumping bridge is small in secondary stripping amount and low in secondary stripping cost, a truck enters an inner dumping site through the dumping bridge and is prevented from bypassing a dragline to be stacked on the end slope of the south portion of a working line, the comprehensive transportation distance of the truck can be effectively shortened, and the problems that in the prior art, along with propelling of the dragline working line, the advancing distance of the truck is increased, and the transportation cost is improved are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of open-pit mining, and in particular to a transportation system for an overlapping area of ​​an open-pit mine. Background Art

[0002] In the process of mining open-pit mines, the single bucket-truck process is widely used in open-pit mines because of its flexibility, high mining intensity and strong adaptability. Due to the rise in international diesel prices, the transportation cost of open-pit trucks has accounted for more than 50% of the total production cost of mines. The essence of the single horizontal bridge in the lower part of the open-pit mine is to establish a transportation channel that runs through the working side of the mining area and the inner dumping area in the lower part of the mining area, shortening the inner transportation distance of the stripping material within the service range of the bridge body, thereby saving the transportation cost of trucks. In order to reduce the amount of repeated stripping of the bridge body, the bridge deck of the lower horizontal bridge in the open-pit mine is usually set at the roof of the lowest or second lowest coal seam. The selection of the bridge deck in the horizontal direction affects the amount of stripping material walking on the bridge within the service range of the working side, and will also determine the transportation distance of the stripping material in the working side and the dumping area. In recent years, due to the sharp rise in oil prices, the transportation cost has increased. Therefore, the reasonable arrangement of the inner dumping development and transportation system and the reduction of the inner dumping work of the stripping material can effectively reduce the mining cost and improve the economic benefit, while reducing the emission of carbon dioxide gas, and achieve the purpose of building a green mine.

[0003] When transporting coal to the inner row of an open-pit coal mine by car, the traditional development transportation system usually adopts a double-ring inner row (an inner row transportation loop is established around the two side end walls) or a single-ring inner row (an inner row transportation loop is established around one side end wall). As the transportation road occupies a large width, the end wall transportation passage is compressed, affecting the economic benefits of open-pit mining.

[0004] During the mining process, an open-pit coal mine was restricted by the adjacent open-pit coal mine dump. A dragline dumping line was divided into a throwing blasting dragline dumping line and a dragline dumping line. The stripping process was complicated. The single-bucket truck line needed to strip part of the adjacent open-pit coal mine dump, which made the single-bucket truck line relatively lagging behind. The traditional internal dumping bridge refers to the single-bucket-truck stripping process. A dumping bridge is built on the coal seam roof to connect the mining area and the internal dumping area. The truck enters the internal dumping area through the dumping bridge. As the coal mining line advances, the dumping bridge is constantly moved. The height of the bridge is generally about 30m thick.

[0005] In the case of the above-mentioned open-pit coal mine throwing blasting heap dumping working line + dragline shovel heap dumping working line, the height of the high step of throwing blasting is about 75m, and it is impossible to build a bridge in the middle of its working line. As the lag distance of the single-bucket truck dragline shovel heap dumping working line relative to the throwing blasting dragline shovel heap dumping working line becomes larger and larger, the distance that truck transportation needs to bypass the end of the dragline shovel heap dumping working line is also getting longer and longer, which greatly increases the transportation cost of trucks.

[0006] Therefore, it is necessary to provide an improved technical solution to address the above-mentioned deficiencies in the prior art. Summary of the invention

[0007] The main purpose of the present application is to provide a transportation system for the overlapping area of ​​an open-pit mine, so as to at least solve the problem in the prior art that as the working line of the dragline advances, the distance traveled by the truck becomes longer and the transportation cost increases.

[0008] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a transportation system for the overlapping area of ​​an open-pit mine is provided, the transportation system comprising: a dragline heaping line, which is used to limit the working route of the dragline heaping operation in the overlapping area of ​​the open-pit mine; a dragline heaping line, which lags behind the dragline heaping line and is used to limit the working route of the dragline heaping operation in the overlapping area of ​​the open-pit mine; a soil discharge bridge, which is connected between the south return road of the dragline heaping line and the north end of the southern high step of the dragline heaping line, and is used to discharge the deposit generated by the heaping operation, and the soil discharge bridge is advanced along the advancement direction as the dragline heaping line and the dragline heaping line advance.

[0009] Optionally, the advancement step distance of the soil removal bridge satisfies that the double-loop weighted transport distance after bridge construction is less than or equal to the single-loop truck transport distance, that is: [(l / 4+l / 4+l z )V / 2+(l / 4+l / 4+l z +2D)V / 2] / V≤(l / 2+l / 2+l z ), wherein D is the advancement step of the soil dumping bridge, l is the length of the dragline of the dumping work line, l z is the tracking distance of the dumping area within the dragline of the dragline, and V is the stripping amount of the dragline of the dragline.

[0010] Optionally, the advancement step of the soil dump bridge also meets the transportation cost reduction after bridge construction C 1 Greater than or equal to the cost of repeated bridging C 2 .

[0011] Optionally, the transportation cost reduction amount C 1 Satisfy C 1 =(l / 2-D)QC / 1000, the repeated bridging cost C 2 Satisfy C 2 =AV q (a+L) / D; wherein, Q is the transportation volume saved by a single bridge construction of the spoil bridge, C is the freight per cubic meter of truck load per kilometer of the pile, a is the annual advancement of the open-pit mine, L is the distance between the starting end of the first bridge construction and the working line of the bucket shovel dumping, and A is the cost of repeated construction.

[0012] Alternatively, let f(D) = C 1 -C 2 , the advancement step D of the soil dumping bridge satisfies

[0013] Optionally, the top surface of the soil discharge bridge is 40m wide, and retaining walls are provided on both sides of the top surface of the soil discharge bridge, and the retaining walls on both sides are 4m wide.

[0014] Optionally, the height of the soil discharge bridge is 60m, the cross-section of the soil discharge bridge is trapezoidal, the slope angles on both sides of the soil discharge bridge are the natural repose angles of the backfill material, and the natural repose angle of the backfill material is 38°.

[0015] Optionally, the transportation system further includes: an overlapping area, located at the intersection of the mining direction of the dragline heaping line of the first open-pit mine and the mining direction of the dragline heaping line of the second open-pit mine, when the first open-pit mine and the second open-pit mine are tracking and mining, the distance L between the dragline heaping line of the first open-pit mine and the overlapping area is c Satisfaction: L c =h m cotα+B m +h d cotβ+B d +hcotγ+n(B+hcotγ); where h m is the thickness of the coal seam in the dragline, B m is the width of the coal step plate, h d is the dragline step height, B d is the working plate width of the dragline step, h is the height of the single bucket step in the dragline, B is the working plate width of the single bucket step in the stope, α is the coal seam slope angle, β is the dragline step slope angle, γ is the single bucket step slope angle, n is the number of single bucket steps, satisfying n=(G y -G m -h m -h d -h) / h,G y is the step elevation at the intersection of the two mines, G m It is the elevation of the coal seam bottom at the intersection position.

[0016] Optionally, the second open-pit mine portion of the overlapping area between the first open-pit mine and the second open-pit mine is at a distance L p Satisfaction: L p =h p cotα'+n'(B p +h p cotα')+L z ; Among them, h p is the height of the dumping step of the second open-pit mine, Bp is the flat plate width of the dumping step of the second open-pit mine, α' is the slope angle of the dumping step of the second open-pit mine, L z is the distance from the bottom of the dump of the second open-pit mine to the bottom of the coal seam in the mining area, n' is the number of dump steps of the second open-pit mine, and satisfies n'=(G y -G m ′-h p ) / h p , G' m It is the elevation of the bottom of the coal seam in the second open-pit mine.

[0017] Optionally, the overlapping area between the first open-pit mine and the second open-pit mine satisfies a minimum tracking mining distance L min Meet L min =L c +L j +L p / sin70°, where L j It is the minimum width of the intersection position in the overlapping area, which is greater than the sum of the transportation road width of the dragline dumping work line in the overlapping area, the bridge disposal road width, and the safety distance between the first open-pit mine and the second open-pit mine.

[0018] Applying the technical solution of the present application, the above-mentioned transportation system for the overlapping area of ​​the open-pit mine includes: a bucket shovel heaping working line, which is used to limit the working route of the bucket shovel for heaping operations in the overlapping area of ​​the open-pit mine; a dragline heaping working line, which lags behind the dragline heaping working line and is used to limit the working route of the dragline heaping operations in the overlapping area of ​​the open-pit mine; a soil discharge bridge, which is connected between the south return road of the dragline heaping working line and the north end of the southern high-section step of the dragline heaping working line, and is used to discharge the deposits generated by the heaping operation, and the soil discharge bridge is advanced along the advancement direction as the dragline heaping working line and the dragline heaping working line advance. The location and height of the dumping bridge are different from those of the previous dumping bridges at the lower section of the coal roof. The dumping bridge serves the stripping trucks in the southern mining area of ​​the dragline. The secondary stripping volume of the dumping bridge is small and the secondary stripping cost is low. Trucks enter the inner dumping area through the dumping bridge to avoid detouring around the southern end of the dragline. This can effectively shorten the comprehensive transportation distance of trucks and reduce transportation costs. The actual distance between the two mines in tracking mining is controlled so that the minimum tracking mining distance between the two mines is less than the actual distance between the two mines in tracking mining. The width of the intersection of the two mines meets the normal operation requirements and the two mines do not affect each other. The transportation system solves the problem in the prior art that as the dragline advances, the truck travels a longer distance and the transportation cost increases. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1A schematic diagram of a dumping bridge on two working lines of a transportation system for an overlapping area of ​​an open-pit mine provided in an embodiment of the present application is shown;

[0020] Figure 2 A schematic cross-sectional view of a soil discharge bridge provided according to an embodiment of the present application is shown;

[0021] Figure 3 A schematic diagram of an overlapping area of ​​two mines provided according to an embodiment of the present application is shown;

[0022] Figure 4 A schematic diagram of a partial distance of a dragline dumping working line of two mines tracking mining provided according to an embodiment of the present application is shown;

[0023] Figure 5 A schematic diagram of partial distance between two mines and a second open-pit mine spoil dump in tracking mining provided according to an embodiment of the present application is shown.

[0024] The above drawings include the following reference numerals:

[0025] 1. Dragline dumping line; 2. Dragline dumping line; 3. The second open-pit mine dumping area; 4. Dumping bridge; 5. Minimum width of the intersection of the two mines; 6. The second open-pit mine; 7. Part of the distance between the two mines in tracking mining of the second open-pit mine; 8. Part of the distance between the dragline dumping line of the two mines in tracking mining. DETAILED DESCRIPTION

[0026] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0027] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0028] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0029] As introduced in the background technology, in the prior art, as the lag distance of the single-bucket truck dragline heap dumping line relative to the dumping line of the blasting dragline becomes larger and larger, the distance that truck transportation needs to bypass the end of the dragline heap dumping line becomes longer and longer, and the transportation cost gradually increases. In order to solve the problem in the prior art that as the dragline advances, the truck travels a longer distance and the transportation cost increases, an embodiment of the present application provides a transportation system for the overlapping area of ​​an open-pit mine.

[0030] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0031] In this embodiment, a transportation system for an overlapping area of ​​an open pit mine is provided. Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 As shown, the transportation system includes:

[0032] Dragline dumping line 1, used to limit the working line of the dragline dumping operation in the overlapping area of ​​the open pit mine;

[0033] Dragline heap dumping working line 2, which lags behind dragline heap dumping working line 1, is used to limit the working line of the dragline heap dumping operation in the overlapping area of ​​the open-pit mine;

[0034] The soil discharge bridge 4 is connected between the south return road of the bucket shovel heaping working line 1 and the north end of the southern high-section step of the dragline heaping working line 2, and is used to discharge the accumulation generated by the heaping operation. The soil discharge bridge 4 advances along the advancing direction as the bucket shovel heaping working line 1 and the dragline heaping working line 2 advance.

[0035] Specifically, the drainage bridge 4 is 32m wide, with 4m wide retaining walls on both sides, a total width of 40m, and a slope of <8%. The drainage bridge 4 is 60m high, and the cross-section of the drainage bridge 4 is trapezoidal. The slope angles on both sides of the drainage bridge 4 are the natural repose angles of the backfill material. The location and height of the drainage bridge 4 are different from the previous low-section drainage bridge 4 of the coal roof. The drainage bridge 4 serves the stripping trucks in the southern mining area of ​​the dragline 1. The secondary stripping volume of the drainage bridge 4 is small, and the secondary stripping cost is low. The truck enters the inner drainage yard through the drainage bridge 4, avoiding the detour to the southern end of the dragline 2, which can effectively shorten the comprehensive transportation distance of the truck and reduce the transportation cost.

[0036] As the coal mining line continues to advance, the soil dumping bridge 4 needs to be constantly moved, and the soil dumping bridge 4 needs to be moved in time to save the stripping truck dumping distance to the maximum extent. During the advancement of the dragline 2, the bridge transportation road is kept unobstructed to form a "parallel open-pit mine tracking mining" situation. After the new bridge is completed, the old bridge is dismantled to recover the coal resources covered by the bridge body, so that the dragline 1 and the dragline 2 do not affect each other.

[0037] The purpose of building the earth-draining bridge 4 is to reduce the transportation cost. Therefore, it is necessary to comprehensively optimize the important factors affecting the economic benefits such as the bridge advancement step distance and the transportation distance.

[0038] This application takes into account that the longer the service time of the soil discharge bridge 4, the fewer times it is moved, and the less secondary stripping amount when mining the compressed coal at the bottom of the soil discharge bridge 4. At this time, the capacity loss of the electric shovel is smaller. Since the soil discharge bridge 4 is formed by the reverse inward discharge of the working gang stripping material when it is built, the longer the bridge body is, under the same conditions, the greater the truck transportation distance saved in building the soil discharge bridge 4. From this perspective, the larger the advancement step of the soil discharge bridge 4, the better. When the advancement step of the soil discharge bridge 4 is large, it means that the longer the bridge body is, the more delayed the amount of coal recovery is, and the longer the time required to recover this part of the coal resources. In order to penetrate the soil discharge bridge 4, the more the amount of stripping material that needs to be discarded is, and the longer the time is. From the above perspective, the advancement step of the soil discharge bridge 4 should be as small as possible. It can be seen that there is a minimum economic loss in the soil discharge bridge 4.

[0039] Therefore, the advancement step distance of the earth dump bridge meets the two criteria set based on the above factors:

[0040] First, the advancement step of the soil dump bridge satisfies the requirement that the double-ring weighted transport distance after bridge construction is less than or equal to the single-ring truck transport distance, that is:

[0041] [(l / 4+l / 4+l z )V / 2+(l / 4+l / 4+l z +2D)V / 2] / V≤(l / 2+l / 2+l z );

[0042] Where D is the advancement step of the dumping bridge, l is the length of the dragline of the dumping bucket, and l z is the tracking distance of the dumping area within the dragline of the dragline, and V is the stripping amount of the dragline of the dragline.

[0043] Secondly, the advancement step of the soil-draining bridge also meets the reduction in transportation costs after the bridge is built. 1 Greater than or equal to the cost of repeated bridging C 2 .

[0044] Furthermore, the transportation cost reduction C 1 Satisfy C 1 =(l / 2-D)QC / 1000, repeated bridging cost C 2 Satisfy C 2 =AV q (a+L) / D; where Q is the transportation volume saved by a single dumping bridge, C is the freight cost per cubic meter of truck load per kilometer, a is the annual advance of the open-pit mine, L is the distance between the starting end of the first bridge and the working line of the dragline, and A is the cost of repeated construction.

[0045] In a specific implementation, the dragline 1 is 1800m long, and the mining-related data of the dragline is brought in, and D=175.5m, so the value range of D is 175.5<D<900m. In this application, the advancement step of the dump bridge 4 is 340m, that is, it is moved every 4 sections, and the service time of the dump bridge 4 is 6 months, that is, it is moved every six months, which can effectively save the transportation cost of the stripping material.

[0046] The spoil bridge runs through the inner spoil yard transportation passage, and its bridge deck must meet a certain width. For the above-mentioned open-pit coal mine bridge scheme, in order to realize the 1800m "double ring" inner spoil passage, the width of the middle bridge must meet the requirements of two-way driving. The top surface width of the spoil bridge 4 designed in this project is 40m, the retaining walls on both sides are 4m, and the road width is 32m. The stability of the spoil bridge 4 body is calculated and analyzed, and the representative section of the spoil bridge 4 is selected for analysis. For this bridge, the high-platform electric shovel brush backfill is used to form the backfill. Its lithology is basically the same as that of the stripping material. The bridge body height is 60m, and the slope angle is the natural repose angle of the backfill material 38°.

[0047] Since there are loaded vehicles driving back and forth on the soil discharge bridge 4, vertical loads are applied to the top surface of the bridge slope. Therefore, the stability analysis of the middle bridge should include vehicle loads for comprehensive evaluation. A dump truck with a load of G drives at a constant speed on the middle bridge. All tires share the same ground pressure. According to the ratio of the number of tires on the front and rear axles (mining dump trucks generally have 2 wheels on the front axle and 4 wheels on the rear axle), 2 / 3 of the load is carried on the rear axle, that is, 2G / 3. There are 4 rear wheels, two symmetrically distributed on each side. The points of force of the two wheels on the same side are relatively close, and can be considered to be concentrated at one point. Then the shared load on each side of the rear wheel is G / 3. Taken together, the rear axle applies a vertical pressure of 2G / 3 to the top surface of its position.

[0048] In this embodiment, taking the truck's deadweight + load of 600 tons as an example, according to the distribution law of the relative pressure on the ground, the load shared by each side of the truck's rear wheel reaches: 600×1000×9.8÷3=1960KN. This load is incorporated into the bridge slope stability analysis and calculation, and the limit analysis upper limit method is used. The rock slope stability analysis program EMU is used for calculation. The results are as follows: Under the truck effective load condition, the slope stability coefficient of the soil dumping bridge 4 is 1.65, which is less than the initial sliding surface temperature coefficient of 1.81. The soil dumping bridge 4 is overall safe and meets the safety production requirements.

[0049] The advancing direction of the dragline 1 and the shovel heaping working line 2 in the open-pit mine of the present application is consistent with the advancing direction of the second open-pit mine 6, and there is an overlapping area between the dragline 2 and the spoil dump of the second open-pit mine 6 in the open-pit mine of the present application. The working line of the present application lags behind the other open-pit mine, so that the two mines form a tracking mining situation. The distance between the bottom working lines of the two mines is called the tracking mining distance. Due to the different advancement rates of the two mines, the tracking mining distance is constantly changing. If the tracking distance is too close, it will be difficult to arrange the production of the two mines at the intersection, affecting the normal production of the two mines. Therefore, according to the production situation of the two mines, the minimum tracking mining distance at which the intersection of the two mines does not affect the normal production of the two mines is studied.

[0050] The minimum tracking mining distance L between the two mines min The influencing factors are: the annual advancement of the two mines. When the annual advancement of the two mines is equal, the tracking mining distance remains unchanged; when the annual advancement of the open-pit coal mine in this application is greater than that of the second open-pit mine, the tracking mining distance will gradually decrease. When it is less than the minimum tracking mining distance, the intersection position will seriously affect the normal production of the two mines; on the contrary, the tracking mining distance will gradually increase. When it is greater than the minimum tracking mining distance, the intersection position will not affect the normal production of the two mines.

[0051] The dragline dumping line 2 has an overlapping area with the second open-pit mine dump 3 in the mining direction; the distance between the two mines in the tracking mining dragline dumping line is L c(i.e. the distance between the two mines tracking mining dragline dumping work line is 8):

[0052] L c =h m cotα+B m +h d cotβ+B d +hcotγ+n(B+hcotγ);

[0053] Among them, h m is the thickness of the coal seam in the dragline 2, B m is the width of the coal step plate, h d is the dragline step height, B d is the working plate width of the dragline shovel step, h is the height of the single bucket step in the dragline 2, B is the working plate width of the single bucket step in the mining area, α is the coal seam slope angle, β is the dragline step slope angle, γ is the single bucket step slope angle, and n is the number of single bucket steps.

[0054] In this embodiment, taking the following data as an example, h m is the thickness of the coal seam in the dragline 2, which is 34m. m is the width of the coal step plate, which is 85m, h d is the step height of the dragline, which is 35m, B d is the working plate width of the dragline shovel step, which is 220m, h is the height of the single bucket step in the dragline 2, which is 15m, B is the working plate width of the single bucket step in the stope, which is 100m, α is the coal seam slope angle, which is 75°, β is the slope angle of the dragline step, which is 65°, γ is the slope angle of the single bucket step, which is 65°, then:

[0055] L c =337.4236+106.9954·n.

[0056] If the steps at the intersection of the two mines remain unchanged, the number of steps in a single bucket n is a variable related to the height of the coal seam floor, and the relationship is as follows:

[0057] n=(G y -G m -h m -h d -h) / h.

[0058] Among them, G y is the step elevation at the intersection of the two mines, that is, the height of the pressure wall, G m It is the elevation of the coal seam bottom at the intersection position.

[0059] In this embodiment, G yThe step elevation at the intersection of the two mines is 1130m. The height of the pressure wall will decrease in the later stage, so 1100m is taken as an example; G m The elevation of the bottom plate of coal seam 2 at the dragline dumping working line at the corresponding position.

[0060] It is concluded that: n = (1046-G m ) / 15; after the pressure height is reduced in the later stage, n=(1016-G m ) / 15. The number of steps should be an integer. The decimal part of the calculation result of the number of steps is rounded up. That is, if the decimal part of the calculation result is less than 0.5, this half step will be combined with the previous step into a whole step, and the super-high step needs to be processed during production; if the decimal part of the calculation result is not less than 0.5, this half step will be divided into a separate step, and the normal working plate width will be reserved.

[0061] The two mines tracked the mining of the second open-pit mine. p (i.e. the two mines track and exploit the second open-pit mine part distance 7):

[0062] L p =h p cotα'+n'(B p +h p cotα')+L z ;

[0063] Among them, h p is the height of the dumping step of the second open pit mine 6, B p is the flat plate width of the dumping step of the second open-pit mine 6, α' is the slope angle of the dumping step of the second open-pit mine 6, L z It is the distance from the bottom of the second open-pit mine dump 3 to the bottom of the coal seam in the mining area.

[0064] In this embodiment, taking the following data as an example, h p is the height of the dumping step of the second open-pit mine 6, which is 30m. p is the width of the dumping step plate of the second open-pit mine 6, which is 60m, α' is the slope angle of the dumping step of the second open-pit mine 6, which is 38°, L z is the distance from the bottom of the second open-pit mine dump 3 to the bottom of the coal seam in the mining area, which is 60m. The result is: L p =98.4+98.4n'.

[0065] n' is the number of dumping steps of the second open-pit mine 6. Under the premise that the steps at the intersection of the two mines remain unchanged, the number of dumping steps of the second open-pit mine 6 is a variable related to the height of the coal seam floor of the coal mine, and the relationship is as follows:

[0066] n′=(H p -h p ) / h p=(G y -G m ′-h p ) / h p ;

[0067] Among them, G' m It is the elevation of the bottom of the coal seam of the second open-pit mine, and is the height from the step at the intersection of the two mines (pressure height) to the coal bottom plate of the second open-pit mine 6.

[0068] In this embodiment, G y The step elevation at the intersection of the two mines is 1130m. The height of the pressure wall decreases in the later period, so 1100m is taken as an example. The above formula is rearranged to obtain: n'=(1100-G' m ) / 30; After the pressure height is reduced in the later stage, n'=(1070-G' m ) / 30.

[0069] The minimum width L of the intersection of two mines j (The minimum width of the intersection of two mines is 5), including:

[0070] The width of the horizontal transport road and the width of the bridge and waste road of the dragline 2, the width of the bridge and waste road of the second open-pit mine 6, and the safety distance reserved for each of the two mines. In this embodiment, taking the following data as an example, the width of the horizontal transport road of the dragline 2 is 40m, the width of the bridge and waste road is 40m, the width of the bridge and waste road of the second open-pit mine 6 is 20m, and the safety distance reserved for each of the two mines is 5m; the minimum width of the intersection of the two mines is 5L j It is 110m.

[0071] The minimum distance between two mines at the intersection without affecting each other's normal mining is the minimum tracking mining distance L. min , L min =L c +L j +L p / sin70°.

[0072] When the minimum tracking mining distance calculated by the above formula is greater than the tracking mining distance calculated by the annual advancement rate, the mining of the two mines at the intersection will affect each other, that is, the distance between the two mines at the intersection is too small, and the ramp to the spoil dump cannot be arranged at this level. In order not to affect the normal production of the two mines at the intersection, the two mines must take corresponding optimization measures to meet the width of the intersection. At this time, the following measures can be taken:

[0073] 1. The minimum tracking mining distance at the intersection of the two mines can be met by slowing down the advancement of the dragline of the application and accelerating the mining progress of the second open-pit mine.

[0074] 2. Reduce the inner wall pressure height of the north end of the dragline of the application. In this embodiment, the wall pressure height can be set to 1100m, which not only reduces the number of steps in the lower part of the level, but also increases the width of the intersection of the two mines, reducing the degree of mutual influence between the two mines. The minimum tracking mining distance between the two mines is less than the actual tracking mining distance between the two mines, and the width of the intersection of the two mines meets the normal operation requirements, and the two mines do not affect each other.

[0075] In summary, the present invention provides a transportation system for the overlapping area of ​​open-pit mines, in which the location and height of the dump bridge are different from the previous dump bridge at the lower section of the coal roof. The dump bridge serves the stripping trucks in the southern mining area of ​​the dragline. The secondary stripping volume of the dump bridge is small, and the secondary stripping cost is low. Trucks enter the inner dump through the dump bridge to avoid detouring the southern end of the dragline, which can effectively shorten the comprehensive transportation distance of trucks and reduce transportation costs. The minimum tracking mining distance between the two mines is basically consistent with the actual tracking mining distance between the two mines. The width of the intersection of the two mines meets the normal operation requirements, and the two mines do not affect each other.

[0076] From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

[0077] The transportation system for the overlapping area of ​​the open-pit mine of the present application includes: a dragline heaping line, which is used to limit the working line of the dragline heaping operation in the overlapping area of ​​the open-pit mine; a dragline heaping line, which lags behind the dragline heaping line, and is used to limit the working line of the dragline heaping operation in the overlapping area of ​​the open-pit mine; a soil discharge bridge, which is connected between the south return road of the dragline heaping line and the north end of the high step in the south of the dragline heaping line, and is used to discharge the accumulation generated by the heaping operation. The soil discharge bridge is advanced along the advancement direction with the advancement of the dragline heaping line and the dragline heaping line. The setting position and setting height of the soil discharge bridge are different from the previous coal roof low-section soil discharge bridge. The soil discharge bridge serves the stripping trucks in the southern mining area of ​​the dragline heaping line. The secondary stripping amount of the soil discharge bridge is small, and the secondary stripping cost is low. The truck enters the inner soil discharge yard through the soil discharge bridge, avoiding detouring the southern end of the dragline heaping line, which can effectively shorten the comprehensive transportation distance of the truck and reduce the transportation cost. The actual distance between the two mines is controlled so that the minimum distance between the two mines is less than the actual distance between the two mines. The width of the intersection of the two mines meets the normal operation requirements and the two mines do not affect each other. This transportation system solves the problem in the prior art that as the dragline advances, the truck travels longer distances and the transportation cost increases.

[0078] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A transport system for overlapping areas of open pit mines, characterized in that: The transportation system comprises: Dragline dumping line, used to limit the working line of the dragline in the overlapping area of ​​the open pit mine; The dragline heap dumping line lags behind the dragline heap dumping line and is used to limit the working line of the dragline heap dumping operation in the overlapping area of ​​the open-pit mine; A soil discharge bridge is connected between the south return road of the dragline heaping working line and the north end of the southern high-section step of the dragline heaping working line, and is used to discharge the deposits generated by the heaping operation. The soil discharge bridge advances along the advancing direction as the dragline heaping working line and the dragline heaping working line advance.

2. The transportation system according to claim 1, characterized in that The advancement step distance of the soil dumping bridge satisfies that the double-loop weighted transportation distance after the bridge is built is less than or equal to the single-loop truck transportation distance, that is: [(l / 4+l / 4+l z )V / 2+(l / 4+l / 4+l z +2D)V / 2] / V≤(l / 2+l / 2+l z ); Wherein, D is the advancement step distance of the soil dumping bridge, l is the length of the dragline of the soil dumping work line, l z is the tracking distance of the dumping area within the dragline of the dragline, and V is the stripping amount of the dragline of the dragline.

3. The transportation system according to claim 2, characterized in that The advancement step of the soil dumping bridge also satisfies that the transportation cost reduction amount C1 after bridge construction is greater than or equal to the repeated bridge construction cost C2.

4. The transport system according to claim 3, characterized in that The reduction in transportation costs C1 satisfies C1=(l / 2-D)QC / 1000, and the repeated bridge construction cost C2 satisfies C2=AVq(a+L) / D; wherein Q is the transportation distance saved by a single bridge construction of the spoil bridge, C is the freight per kilometer of the pile per cubic meter of truck load, a is the annual advancement of the open-pit mine, L is the distance between the starting end of the first bridge construction and the working line of the bucket shovel dumping, and A is the repeated construction cost.

5. The transport system according to claim 4, characterized in that Assume f(D) = C1-C2, the advancement step D of the soil dumping bridge satisfies 6. The transportation system according to claim 1, characterized in that The top surface of the soil discharge bridge is 40m wide, and retaining walls are arranged on both sides of the top surface of the soil discharge bridge. The retaining walls on both sides are 4m wide.

7. The transport system according to claim 6, characterized in that The height of the soil discharge bridge is 60m, the cross section of the soil discharge bridge is trapezoidal, the slope angles on both sides of the soil discharge bridge are the natural repose angles of the backfill material, and the natural repose angle of the backfill material is 38°.

8. The transportation system according to claim 1, characterized in that The transport system further comprises: The overlapping area is located at the intersection of the mining direction of the dragline of the first open-pit mine and the mining direction of the dragline of the second open-pit mine. When the first open-pit mine and the second open-pit mine are tracked, the distance L between the dragline of the first open-pit mine and the overlapped area is c satisfy: L c =h m cotα+B m +h d cotβ+B d +hcotγ+n(B+hcotγ); Among them, h m is the thickness of the coal seam in the dragline, B m is the width of the coal step plate, h d is the dragline step height, B d is the working plate width of the dragline step, h is the height of the single bucket step in the dragline, B is the working plate width of the single bucket step in the stope, α is the coal seam slope angle, β is the dragline step slope angle, γ is the single bucket step slope angle, n is the number of single bucket steps, satisfying n=(G y -G m -h m -h d -h) / h,G y is the step elevation at the intersection of the two mines, G m It is the elevation of the coal seam bottom at the intersection position.

9. The transport system according to claim 8, characterized in that The second open-pit mine portion of the overlapping area between the first open-pit mine and the second open-pit mine is a distance L p satisfy: L p =h p cotα'+n'(B p +h p cotα')+L z ; Among them, h p is the height of the dumping step of the second open-pit mine, B p is the flat plate width of the dumping step of the second open-pit mine, α' is the slope angle of the dumping step of the second open-pit mine, L z is the distance from the bottom of the dump of the second open-pit mine to the bottom of the coal seam in the mining area, n' is the number of dump steps of the second open-pit mine, and satisfies n'=(G y -G m ′-h p ) / h p , G' m It is the elevation of the bottom of the coal seam in the second open-pit mine.

10. The transport system according to claim 9, characterized in that The overlapping area between the first open-pit mine and the second open-pit mine satisfies the minimum tracking mining distance L min Meet L min =L c +L j +L p / sin70°, where L j It is the minimum width of the intersection position in the overlapping area, which is greater than the sum of the transportation road width of the dragline dumping work line in the overlapping area, the bridge disposal road width, and the safety distance between the first open-pit mine and the second open-pit mine.

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