A method for sublevel caving blasting of coal with a thickness of more than 40 meters

Abstract

The application discloses a method for mining end slope coal with a thickness greater than 40 meters by segmented throwing blasting and leaning on the slope, divides the end slope into several steps, trims the slope surface of the end slope steps, sets throwing drill holes, simultaneously excavates loose drill holes to improve the breaking and throwing effect of the bottom coal, and provides support for the steep end slope after the blasting of each drill hole through blasting piles and internal material discharge. After the throwing blasting, the recovery steps are arranged on the loose raw coal, and the reserved platforms of the end recovery steps are used to discharge and strip the material in the reverse direction after the raw coal is mined. The application adopts the reserved slow end slope leaning on the slope mining method to recover in sections, reduces the exposed area and time of the end slope steep slope, and improves the stable slope angle. The end slope coal is recovered by using the throwing blasting method, the working time of personnel and equipment under the end slope is reduced, the production efficiency is improved, the safety coefficient is improved, the damage to the complete rock mass is reduced, and the integrity of the final slope coal rock mass and the slope stability are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of mining methods of relying on help, specifically a kind of end help coal segmented throwing blasting mining method of thickness greater than 40 meters. BACKGROUND

[0002] ‌At present, the bench height of open-pit mining operation is generally not more than 15 m, and the thick coal seam with a thickness greater than 40 m needs to be divided into three or more benches for mining, which leads to the following problems in the process of open-pit mining: first, the stable slope angle of open-pit coal mine is small, and the traditional end slope design will result in large amount of coal compression in the slope, and serious coal loss during mining; second, when directly using the current steep end slope mining for end coal recovery, the exposed area of local steep slope is large, and the time is long, which reduces the stability of the slope, and the equipment is operated under high and steep slope for a long time, which has safety production hazards; third, the traditional mining method of relying on help is mining layer by layer from top to bottom, which has long construction time, large secondary stripping amount and great influence on end slope transportation. Therefore, a mining method for such coal seam is needed to solve the above problems. SUMMARY

[0003] In view of the problems existing in the prior art, the present application provides a kind of end help coal segmented throwing blasting mining method of thickness greater than 40 meters, which has small coal loss, high safety and short construction time during coal mining.

[0004] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a kind of end help coal segmented throwing blasting mining method of thickness greater than 40 meters, comprising the following steps:

[0005] S1: in the advancing direction of open-pit mine, the end slope is divided into at least four benches in the height direction, and the upper stripping bench is arranged on the side of the uppermost bench close to the end slope; the platform width of the uppermost bench meets the normal end slope transportation arrangement of open-pit mine, and the platform width of each layer of bench meets the single lane transportation of open-pit mine;

[0006] S2: the bench slope surface of the end slope is trimmed while the working slope is mined, so that the slope angle of the bench increases layer by layer from bottom to top, and the maximum stable slope angle can be used for mining the uppermost bench of the end slope;

[0007] S3: a plurality of rows of throwing drill holes are arranged in each bench, and the opening direction of the throwing drill holes arranged in each layer is parallel to the slope surface of the layer, and the hole spacing is not less than 1.5 times the row spacing; the density of the throwing drill holes arranged in the lower bench is higher than that of the throwing drill holes arranged in the upper bench, so that the charging amount of the lower bench is 1.0-1.3 times that of the upper bench; a pre-splitting drill hole is arranged in the upper stripping bench at the position of the slope bottom line, and a pre-splitting drill hole is arranged in each layer of bench at the position of the inner side of the platform of the layer.

[0008] S4: In addition to the uppermost step, in the remaining step platforms close to the upper step side 1 / 3 range to the step interior open loose drill holes, loose drill hole opening direction is perpendicular to the downward or with the step slope surface reverse and with vertical 10-30 ° angle, loose drill hole interval open multiple rows;

[0009] S5: The initiation sequence is: all pre-splitting drill holes are initiated; the loose drill holes of the first layer of steps are initiated synchronously; the throwing drill holes of the first layer of steps are initiated row by row, while the loose drill holes of the second layer of steps are initiated synchronously; the throwing drill holes of the second layer of steps are initiated row by row, while the loose drill holes of the third layer of steps are initiated synchronously; and so on to the uppermost layer of steps;

[0010] S6: After the throwing blasting, not less than two mining steps are arranged on the loose raw coal, and multiple channels are arranged through the inner dump, working bank and pit bottom to transport out, wherein the stripped material naturally sliding onto the coal explosion pile and the material needing secondary stripping are transported out through the slope arranged in the inner dump; the loose coal explosion pile is transported out through the nearby road on the working bank side, forming a coal and rock separate mining and separate transportation system; the stripped material mixed into the loose coal pile is removed through working face selection and subsequent washing and selection;

[0011] S7: After the raw coal is mined out, the stripped material is removed from the reserved platforms of the end bank recovery steps in reverse to press the bank, and the amount of material removed from each step gradually increases from bottom to top, and the transportation channel is recovered by dumping the stripped material from the inner dump.

[0012] Further, the step S1 ensures the charging length of the lower two layers of steps.

[0013] Further, in the step S4, the loose drill holes and the throwing drill holes are arranged at intervals, and the spacing between the former is twice that of the latter.

[0014] Further, in the step S3, the hole pattern parameters of the throwing drill holes meet the requirement that the throwing blasting charge amount is not less than 1.5 times the normal loose blasting explosive consumption.

[0015] Further, the final hole positions of the throwing drill holes, pre-splitting drill holes and loose drill holes are located at the coal seam floor.

[0016] Further, in the step S4, the charging length of the loose drill holes is not greater than 1 / 2 of the length of the drill holes.

[0017] Compared with the prior art, the end slope coal is recovered in sections by using the reserved slow end slope-relying on slope mining method, the exposed area and time of the end slope steep slope are reduced, and the stable slope angle is improved. The end slope coal is recovered by using the throwing blasting method, the working time of personnel and equipment under the end slope is reduced, the production efficiency is improved, the safety factor is improved, and the lost coal amount is small during the mining process; the traditional relying on slope mining form from top to bottom is changed, the number of working faces and equipment that can be operated at the same time is increased, the construction time is short, the secondary stripping amount is small, and the influence on the end slope transportation is small. The throwing drilling, pre-splitting drilling and loose drilling are used in cooperation, the damage to the complete rock mass is reduced while the breaking and throwing effects of the raw coal are ensured, and the integrity of the final slope coal rock mass and the slope stability are improved. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a lower step diagram of the end slope under the relying on slope mining of the present application;

[0019] Figure 2 is a distribution profile diagram of the throwing drilling and loose drilling of the present application;

[0020] Figure 3 is a layout plane diagram of the throwing drilling and loose drilling of the present application;

[0021] Figure 4 is a material accumulation profile diagram after partial throwing blasting of the present application;

[0022] Figure 5 is a material accumulation profile diagram after full throwing blasting of the present application;

[0023] Figure 6 is a material accumulation plane diagram after full throwing blasting of the present application;

[0024] Figure 7 is a lower step diagram of the end slope after the coal resource recovery of the present application;

[0025] Figure 8 is a stripping material backfilling to form a transportation channel diagram of the present application;

[0026] In the figure: 1-end slope; 2-step; 3-slope angle; 4-step slope surface; 5-throwing drilling; 6-upper stripping step; 7-pre-splitting drilling; 8-loose drilling; 9-raw coal; 10-stripping material. EMBODIMENT

[0027] The present application will be further described below in combination with the drawings.

[0028] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0029] The present application provides a technical solution: S1: in the advancing direction of the open-pit mine, the coal seam of the end slope 1 is divided into several recovery segments, and the segment length is not less than the total height of the slope mining, such as Figure 1 As shown, the lower step 2 structure of the end slope 1 slope formed by optimizing mining according to the needs of segment throwing blasting to recover the end slope 1 coal divides the end slope 1 in the height direction into at least four steps 2, and the upper stripping step 6 is arranged on the side direction close to the end slope 1 of the uppermost step 2, and the platform width of the uppermost step 2 meets the normal end slope 1 transportation arrangement of the open-pit mine, and the platform width of the rest steps 2 meets the single lane transportation of the open-pit mine; wherein the two lower steps 2 are combined into one by segmenting, and the height of the lowermost step 2 is increased, but there is only one slope surface, so as to reduce the area occupied by the step 2 in the horizontal projection to ensure the charging length.

[0030] S2: as shown in Figure 2 and Figure 3 , the end slope 1 step slope surface 4 is trimmed during the working slope mining, so that the slope angle 3 of the step 2 increases layer by layer from bottom to top according to the needs of the throwing drilling hole 5, and the maximum stable slope angle 3 can be used for the uppermost step 2 of the slope mining; in order to improve the throwing effect and at the same time ensure the safety of the step 2 operation equipment, the slope angle 3 is generally set to 50°-80°.

[0031] S3: a plurality of rows of throwing drilling holes 5 are respectively arranged in each step 2, the opening direction of the throwing drilling holes 5 arranged in each step is respectively parallel to the step slope surface 4 of the layer, the hole network parameters should meet the requirement that the throwing blasting charge quantity is not less than 1.5 times of the normal loose blasting explosive unit consumption, and the hole spacing is not less than 1.5 times of the row spacing; the density of the throwing drilling holes 5 arranged in the lower step 2 is higher than that of the throwing drilling holes 5 arranged in the upper step 2, so that the charge quantity of the lower step 2 is 1.0-1.3 times of that of the upper step 2; the pre-splitting drilling hole 7 is arranged in the inner part of the uppermost step 2 at the position of the slope bottom line of the upper stripping step 6, and the pre-splitting drilling hole 7 is arranged in the inner part of each step 2 at the position of the inner side of the platform of each step 2, respectively, the opening position of the pre-splitting drilling hole 7 should be provided with a safety platform and a retaining wall between the slope bottom line of the step 2 of the platform and the next step 2, which meets the requirement of intercepting the falling rocks of the upper step 2 to prevent the pre-splitting drilling hole 7 from being blocked, the width of the safety platform is 3-5m, and the height of the retaining wall is 0.5-1m.

[0032] S4: Except the uppermost step 2, the loose drilling holes 8 are arranged in the inner part of the step 2 within 1 / 3 range of the side of the platform of the step 2 close to the upper step 2 to improve the breaking and throwing effect of the bottom coal, and the loose drilling holes 8 are not arranged in the uppermost step 2 to avoid damaging the final step slope 4; the arrangement direction of the loose drilling holes 8 is vertically downward or reversely to the step slope 4 and forms an angle of 10-30° with the vertical direction, and the loose drilling holes 8 are arranged in multiple rows; due to the influence of the inclination angle of the throwing drilling holes 5, the row spacing of the loose drilling holes 8 at the adjacent positions of the upper and lower steps 2 gradually increases with the hole depth, but the loose drilling holes 8 must be arranged when the row spacing increases to more than 1.2 times of the designed row spacing; from the perspective of reducing the construction amount and safety, the preferred scheme is to arrange the loose drilling holes 8 and the throwing drilling holes 5 at intervals, the spacing of the former is 2-3 times of that of the latter, and the blasting can be sufficient without causing excessive collapse of the coal seam during construction; the charging length of the loose drilling holes 8 is not greater than 1 / 2 of the drilling length; the final hole positions of the throwing drilling holes 5, the pre-splitting drilling holes 7 and the loose drilling holes 8 are all the coal seam floor.

[0033] S5: As shown in Figure 4 to Figure 6 , the detonation sequence is as follows: first step, all the pre-splitting drilling holes 7 are synchronously detonated; second step, the loose drilling holes 8 of the lowermost step 2, i.e. the first step 2, are synchronously detonated; third step, the throwing drilling holes 5 of the first step 2 are sequentially detonated while the loose drilling holes 8 of the upper step 2, i.e. the second step 2, are synchronously detonated; fourth step, the throwing drilling holes 5 of the second step 2 are sequentially detonated while the loose drilling holes 8 of the third step 2 are synchronously detonated; and so on, and the cycle is repeated to the uppermost step 2; after blasting, the steep end slope 1 is supported by the blasting pile and the internal discharge material to ensure that the end slope 1 does not deform.

[0034] S6: After the throwing blasting, not less than two mining steps are arranged on the loose raw coal 9, and multiple channels are arranged through the internal discharge dump, the working slope and the pit bottom to transport out, wherein the stripping material 10 naturally sliding onto the coal blasting pile and the material needing secondary stripping are transported out through the slope arranged in the internal discharge dump; the loose coal blasting pile is transported out through the nearby road on the side of the working slope to form a coal and rock separate mining and transportation system; the stripping material 10 mixed into the loose coal pile is removed through the selection and subsequent washing and selection of the working face; Figure 7 As shown in , after the loose raw coal 9 is mined out, the steep end slope 1 slope is exposed in the form of a trapezoid, and is supported by the working slope, the end slope 1 and the internal discharge material to ensure the safety of the slope.

[0035] Figure 8 S7: As shown in , after the raw coal 9 is mined out, the platforms reserved by the end slope 1 recovery steps 2 are reversely discharged to strip the stripping material 10 to press the slope, which improves the backfilling speed and reduces the falling height to reduce the impact, and the amount of material discharged by each step 2 gradually increases from bottom to top, and the stripping material 10 is discharged from the internal discharge dump to restore the transportation channel.

[0036] It will be apparent to those skilled in the art that the application is not limited to the details of the above-exemplified embodiments and that the present application can be implemented in other particular forms without departing from the spirit or essential characteristics of the present application. The presently disclosed embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. No reference to an item in the claims is to be construed as an admission that such item is admitted prior art.

[0037] The above description is only the preferred embodiment of the present application, and is not intended to limit the present application. Any slight modification, equivalent replacement and improvement made to the above embodiments according to the technical essence of the present application shall be included in the protection scope of the technical scheme of the present application.

Claims

1. A method for segmented blasting and side-mounted mining of end-wall coal seams with a thickness greater than 40 meters, characterized in that, Includes the following steps: S1: In the direction of the open-pit mine advance, the end wall (1) is divided into at least four steps (2) in the height direction. The uppermost step (2) is provided with an upper stripping step (6) on the side of the end wall (1) and the platform width of the uppermost step (2) meets the normal transportation layout of the end wall (1) in the open-pit mine. The platform width of the steps (2) of the other layers meets the single-lane transportation of the open-pit mine. S2: While the working side is being mined, the slope surface (4) of the end side (1) is trimmed so that the slope angle (3) of the step (2) increases from bottom to top. The uppermost step (2) of the side mining can adopt the maximum stable slope angle (3). S3: Multiple rows of throwing boreholes (5) are opened inside each step (2). The direction of the throwing boreholes (5) opened in each step is parallel to the slope surface (4) of that step, and the hole spacing is not less than 1.5 times the row spacing. The density of the throwing boreholes (5) opened in the lower step (2) is higher than that of the throwing boreholes (5) opened in the upper step (2), so that the amount of explosive in the lower step (2) is 1.0-1.3 times that in the upper step (2). Pre-splitting boreholes (7) are opened from the bottom line of the upper peeling step (6) into the uppermost step (2), and pre-splitting boreholes (7) are opened from the inner side of the platform of each other step (2) into the step (2). S4: Except for the top step (2), loose drill holes (8) are opened in the interior of each step (2) within 1 / 3 of the platform of the other steps (2) on the side close to the step (2). The direction of the loose drill holes (8) is vertically downward or opposite to the slope of the step (4) and at an angle of 10-30° with the vertical. The loose drill holes (8) are opened in multiple rows at intervals. S5: The detonation sequence is as follows: all pre-splitting boreholes (7) are detonated; the loosening boreholes (8) of the first step (2) are detonated simultaneously; the throwing boreholes (5) of the first step (2) are detonated row by row while the loosening boreholes (8) of the second step (2) are detonated simultaneously; the throwing boreholes (5) of the second step (2) are detonated row by row while the loosening boreholes (8) of the third step (2) are detonated simultaneously; and so on up to the top step (2). S6: After the blasting, at least two mining steps are arranged on the loose raw coal (9), and multiple channels are arranged through the inner spoil heap, working side and pit bottom to transport it out. Among them, the stripping material (10) that naturally slides onto the coal blast pile and the material that needs to be stripped a second time are transported out through the ramp arranged in the inner spoil heap; the loose coal blast pile is transported out through the nearest road on the side of the working side, forming a coal and rock separate mining and transportation system; the stripping material (10) mixed into the loose coal pile is removed by working face selection and subsequent washing and screening. S7: After the raw coal (9) is mined out, the end side (1) recovers the stripped material (10) reserved by each platform of the step (2) and presses it down. The amount of material discharged from each step (2) gradually increases from bottom to top. At the same time, the stripped material (10) is dumped from the inner dumping yard to restore the transportation channel.

2. The method for segmented blasting and side-mounted mining of end-wall coal with a thickness greater than 40 meters according to claim 1, characterized in that: In step S1, the two lowest steps (2) are connected to ensure the length of the charge.

3. The method for segmented blasting and side-mounted mining of end-wall coal with a thickness greater than 40 meters according to claim 1, characterized in that: In step S4, the loosening drill holes (8) and the throwing drill holes (5) are arranged alternately, with the spacing between the former being twice that between the latter.

4. The method for segmented blasting and side-mounted mining of end-wall coal with a thickness greater than 40 meters according to claim 1, characterized in that: In step S3, the hole mesh parameters of the throwing borehole (5) meet the requirement that the amount of throwing blasting explosive is not less than 1.5 times the single consumption of normal loosening blasting explosive.

5. The method for segmented blasting and side-mounted mining of end-wall coal with a thickness greater than 40 meters according to claim 1, characterized in that: The final positions of the throwing borehole (5), pre-splitting borehole (7) and loosening borehole (8) are all located on the bottom plate of the coal seam.

6. The method for segmented blasting and side-mounted mining of end-wall coal with a thickness greater than 40 meters according to claim 1, characterized in that: In step S4, the length of the explosive charge in the loosening borehole (8) is no more than 1 / 2 of the borehole length.

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