A method of blasting treatment of large triangular ore bodies

Abstract

The application relates to a blasting treatment method of a large triangular ore body and relates to the technical field of mine exploitation. The blasting treatment method of the large triangular ore body comprises the following steps: selecting one side surface of the triangular ore body as a first working surface, arranging three rows of fan-shaped holes which are arranged in a staggered mode on the first working surface in the height direction; selecting another surface of the triangular ore body as a second working surface, arranging three rows of fan-shaped holes which are arranged in a staggered mode on the second working surface in the height direction; the fan-shaped holes comprise deep holes and shallow holes; each row of fan-shaped holes forms a shallow hole away from the edge of the junction of the first working surface and the second working surface; the fan-shaped holes on the first working surface and the second working surface are projected, the projection surface is adapted to the shape of the bottom surface of the triangular ore body, and the projection line of the fan-shaped hole on the first working surface in the middle part of the bottom surface of the triangular ore body and the projection line of the fan-shaped hole on the second working surface in the middle part of the bottom surface of the triangular ore body cross each other to form a net shape. The blasting treatment method of the large triangular ore body has the effects of complete blasting and avoidance of explosive waste.

Description

Technical Field

[0001] This invention belongs to the field of open-pit mining, specifically relating to a method for blasting large triangular ore bodies. Background Technology

[0002] With the maturity of modern open-pit mining technology, the development of blasting materials, the properties of various explosives, rock and soil blasting technology, and mobile information networks, the solution for blasting isolated rocks at the edge has a certain foundation.

[0003] The Dazhaizi limestone mine is located in the Qilian Mountains, a mountainous region characterized by high mountains, deep valleys, and strong incision, resulting in a complex topography with crisscrossing gullies and ridges. The ore body consists of fine-grained limestone and pseudo-oolitic limestone, which is generally hard, dense, intact, and stable. Exposed sections of the ore layer often feature cliffs and precipices. Irregular triangular ore bodies, fish-ridge-shaped ridges, and isolated boulders are frequently formed along the eastern edge, creating east-west extending barriers. During horizontal layered mining, each section left behind strip-shaped or circular ring-shaped ore bodies that cannot be blasted out by conventional blasting. These ore bodies are called triangular ore bodies because of their triangular shape.

[0004] Clearing the triangular ore body is a prerequisite for developing new working faces. This triangular ore body is restricted by its external geometry and is open on three sides. Its bottom is triangular fan-shaped, with two perforation working faces on the west and north sides. The measurement center can reach a depth of 20 to 30 meters. The bottom width of the west side is 20 to 30 meters, and the bottom width of the north side is 20 to 30 meters, forming a triangular shape.

[0005] On the one hand, the triangular ore body is quite high, while the height of the drilling rig boom is limited, thus restricting the drilling height. On the other hand, the rock shape is irregular, making post-blast ore recovery difficult. Furthermore, the Zhongping Highway and Zhonglian Mine quarry are located directly below the edge of the ore body, making site clearing and warning before blasting a crucial task. Strict control of blasting risks is necessary, so a safe, reliable, and reasonable plan needs to be designed for the blasting of isolated boulders at the edge. Summary of the Invention

[0006] We aim to provide a method for joint blasting from two working faces of a triangular ore body, thereby enabling greater blasting coverage of the triangular ore body.

[0007] This application provides a blasting method for large triangular ore bodies, employing the following technical solution: A method for blasting a large triangular ore body, comprising the following steps: Select one side of the triangular ore body as the first working face, and arrange at least three rows of staggered fan-shaped holes along the height direction on the first working face; Select the second working face on the other side of the triangular ore body, and arrange at least three rows of staggered fan-shaped holes along the height direction on the second working face; The fan-shaped holes include deep holes and shallow holes, with shallow holes formed at the edge of each row of fan-shaped holes away from the junction of the first working surface and the second working surface; Projecting the fan-shaped holes on the first working face and the second working face onto the projection surface, the resulting projection surface is adapted to the bottom shape of the triangular ore body. The projection lines of the fan-shaped holes on the first working face at the middle of the bottom surface of the triangular ore body and the projection lines of the fan-shaped holes on the second working face at the middle of the bottom surface of the triangular ore body intersect to form a mesh.

[0008] By adopting the above technical solution, the projection lines of the fan-shaped holes on the first working face at the middle of the bottom surface of the triangular ore body and the projection lines of the fan-shaped holes on the second working face at the middle of the bottom surface of the triangular ore body intersect to form a network, which can make the blasting force distributed more evenly from top to bottom, and make the blasting more thorough during the layered blasting process.

[0009] Optionally, when three rows of fan-shaped holes are arranged along the height direction on the first working surface: The first row of holes is 1 to 2 meters above the horizontal plane of the ore body mining area, with an average hole spacing of 3.2 to 3.5 meters. One or two shallow holes are formed at the edge with a depth of 10.5 to 15.5 meters. Five to ten deep holes with a depth of 17 to 22 meters are arranged between the boundary and the edge. The second row of holes is 1.8 meters to 2 meters from the first row of holes, with an average hole spacing of 3.2 meters to 3.5 meters and an upward angle. Three or six shallow holes are formed at the edge with a depth of 12 meters to 17 meters, and five to ten deep holes with a depth of 17 meters to 22 meters are arranged between the junction and the edge. The distance between the third row of holes and the second row of holes is between 1.8 meters and 2 meters, with an average hole spacing between 3.2 meters and 3.5 meters. The holes are inclined upwards and the inclination angle is greater than that of the second row of holes. Three or six shallow holes with a depth between 12 meters and 17 meters are formed at the edge, and three to six deep holes with a depth between 15 meters and 20 meters are arranged between the junction and the edge. When three rows of fan-shaped holes are arranged along the height direction on the second working surface: The first row of holes is 1 to 2 meters above the horizontal plane of the ore body mining area, with an average hole spacing of 3.2 to 3.5 meters. Two or four shallow holes with a depth of 12 to 17 meters are formed at the edge, and four to eight deep holes with a depth of 15 to 20 meters are arranged between the boundary and the edge. The second row of holes is 1.8 meters to 2 meters from the first row of holes, with an average hole spacing of 3.2 meters to 3.5 meters and an upward angle. Two or four shallow holes are formed at the edge with a depth of 12 meters to 17 meters, and four to eight deep holes with a depth of 15 meters to 20 meters are arranged between the junction and the edge. The distance between the third row of holes and the second row of holes is between 1.8 meters and 2 meters, with an average hole spacing between 3.2 meters and 3.5 meters. The holes are inclined upwards and the inclination angle is greater than that of the second row of holes. Two or four shallow holes are formed at the edge with a depth between 12 meters and 17 meters. Five to ten deep holes with a depth between 15 meters and 20 meters are arranged between the junction and the edge.

[0010] By adopting the above technical solution, the upward tilt angle of each row of holes on the two working faces gradually increases with the increase of height. The first row of holes is parallel to the bottom surface of the triangular ore body and is not tilted, which makes it easier to crush the bottom of the triangular ore body and reduces the possibility that rock roots may remain at the bottom of the triangular ore body after blasting. The blasted rocks can be cleaned up later.

[0011] Optionally, the center height of the triangular ore body is H=23 meters, the bottom width of the first working face is 22 meters, and the bottom width of the second working face is 20 meters. When three rows of fan-shaped holes are arranged along the height direction on the first working surface: The first row of holes is 1 meter above the horizontal plane of the ore body mining area, with an average hole spacing of 3.2 meters. A shallow hole with a depth of 10.5 meters is formed at the edge, and five deep holes with a depth of 17 meters are arranged between the boundary and the edge. The second row of holes is 2 meters apart from the first row of holes, with an average hole spacing of 3.2 meters. The hole is slanted upward at an angle of 15°. Three shallow holes with a depth of 12 meters are formed at the edge, and five deep holes with a depth of 17 meters are arranged between the junction and the edge. The third row of holes is 2 meters apart from the second row of holes, with an average hole spacing of 3.2 meters. The upward drilling angle is 30°. Three shallow holes with a depth of 12 meters are formed at the edge, and three deep holes with a depth of 15 meters are arranged between the junction and the edge. When three rows of fan-shaped holes are arranged along the height direction on the second working surface: The first row of holes is 1 meter above the horizontal plane of the ore body mining area, with an average hole spacing of 3.2 meters. Two shallow holes with a depth of 12 meters are formed at the edge, and four deep holes with a depth of 15 meters are arranged between the boundary and the edge. The second row of holes is 2 meters apart from the first row of holes, with an average hole spacing of 3.2 meters. The hole is slanted upward at an angle of 15°. Two shallow holes with a depth of 12 meters are formed at the edge, and four deep holes with a depth of 15 meters are arranged between the junction and the edge. The third row of holes is 2 meters apart from the second row of holes, with an average hole spacing of 3.2 meters. The hole is slanted upward at an angle of 30°. Two shallow holes with a depth of 12 meters are formed at the edge, and five deep holes with a depth of 15 meters are arranged between the junction and the edge.

[0012] By adopting the above technical solution, each row is evenly dispersed inside the rock mass and forms a fan shape, with small resistance lines and densely distributed holes in a plum blossom pattern, which can complete the blasting and removal of the triangular ore body in one go.

[0013] Optionally, when three rows of fan-shaped holes are arranged along the height direction on the first working surface or the second working surface: The intersection of the middle hole length of the second row of holes on the same working face and the center height H of the triangular ore body is at the same horizontal height as the starting point of the third row of holes.

[0014] By adopting the above technical solution, the explosive extension point of the second row of holes in each working face can reach at least the entrance height of the third row of holes in the center of the triangular ore body, thereby reducing the possibility of ore body rock retention at the entrance height of the third row of holes.

[0015] Optionally, when the angle between any working face and the horizontal plane of the ore body stope is 'a', and 45° < a ≤ 60°: The end point of the middle hole length in the third row of holes is located on the center height H of the triangular ore body. The middle hole length in the second row of holes on the same working face passes through the center height H of the triangular ore body and ends on the line connecting the intersection point O of the middle hole length in the third row of holes and the center height H of the triangular ore body with the apex point of the triangular ore body facing the working face.

[0016] By adopting the above technical solution, when the dip angle of the triangular ore body is relatively small, the hole arrangement inside the triangular ore body forms a triangular pyramid with a larger apex angle than the apex angle of the triangular ore body. Moreover, the blasting surface of the triangular ore body is more widely affected, thereby reducing the situation where the bottom blasting is incomplete and rock layers remain when the dip angle of the triangular ore body is small.

[0017] Optionally, when the angle between any working face and the horizontal plane of the ore body stope is 'a', and 60° < a ≤ 75°: The first vertical plane is formed perpendicular to the horizontal plane of the ore body mining area. The first vertical plane is formed by the midpoint of the bottom width of the second working face, the line connecting the bottom edge of the non-working face of the triangular ore body, and the center height H of the triangular ore body. The projection of the three rows of deep holes on the first working face is located on the first vertical plane. A second vertical plane is formed that is perpendicular to the horizontal plane of the ore body mining area. The line connecting the midpoint of the bottom width of the first working face, the bottom edge of the non-working face of the triangular ore body, and the center height H of the triangular ore body constitute the second vertical plane. The projection of the three rows of deep holes on the second working face is located on the second vertical plane.

[0018] By adopting the above technical solution, when the triangular ore body is relatively steep, since the center of the triangular ore body is the most difficult to blast, a four-sided pyramidal hole-laying body is formed in the center of the triangular ore body. By arranging the blasting positions on the entire four-sided pyramid, the four-sided pyramid can be effectively blasted while ensuring the blasting effect of the triangular ore body, and at the same time avoiding the waste of explosives.

[0019] Optional, single-hole charge in deep holes: Q=q×a×b×H=0.41kg / m³×3.2m×2m×23m≈60kg; q represents the charge per explosive, a represents the hole spacing, b represents the row spacing, and H represents the center height of the triangular ore body; The charge per shallow hole is: Q = q × a × W × H = 0.41 kg / m³ × 3.2 m × 1.06 m × 23 m ≈ 33 kg; q represents the charge per unit of explosive, a represents the hole spacing, H represents the center height of the triangular ore body, and W represents the minimum resistance line, which is the minimum distance between the shallow hole and the free surface, and the free surface is the plane surrounding the triangular ore body.

[0020] By adopting the above technical solutions, the minimum safe distance for flying rocks in this blasting operation complies with the minimum safe distance for flying rocks stipulated in the "Safety Regulations for Blasting" (GB6722-2014).

[0021] Optionally, the first row of holes on the same working surface forms a detonation transmission row, and the second and third rows of holes form a control row; The micro-delay blasting is controlled in each hole of the first row of holes, with a micro-delay time of 17 milliseconds; The second row of holes is controlled to form a micro-delay blasting relative to the first row of holes, with a micro-delay time of 42 milliseconds; The third row of holes is controlled to form a micro-delay blast relative to the second row of holes, with a micro-delay time of 42 milliseconds.

[0022] By adopting the above technical solution, and by controlling the timing and point of detonation for each hole, large isolated rocks can be blasted away in one go.

[0023] Optionally, the arrangement of the rows of holes on the first working surface and the arrangement of the rows of holes on the second working surface are staggered vertically.

[0024] By adopting the above technical solution, the height of the explosive layout is more layered, avoiding the waste of explosives caused by blasting from the same height on two working faces.

[0025] In summary, this application includes at least one of the following beneficial technical effects: the intersecting holes on the two working faces form a mesh, which makes the blasting force more evenly distributed from top to bottom, and the blasting is more thorough during the layered blasting process; in addition, the inclination angle of each row of holes can be set according to the inclination of the triangular ore body to avoid incomplete blasting and root rock formation, while avoiding the excessive use of explosives, so as to make the explosives reasonably configured and effectively blasted. Attached Figure Description

[0026] Figure 1 This is a three-dimensional structural diagram illustrating a large triangular ore body as described in this application; Figure 2 This is a top view illustrating the hole layout of a large triangular ore body as described in this application; Figure 3This is a schematic diagram illustrating the micro-delay blasting of a large triangular ore body as described in this application; Figure 4 This is a structural schematic diagram illustrating yet another embodiment of a large triangular ore body according to this application; Figure 5 This is a schematic diagram illustrating the relationship between the first working face of a large triangular ore body and the center height H of the triangular ore body, as described in this application.

[0027] Explanation of reference numerals in the attached figures: 1. First working surface; 2. Second working surface; 3. First vertical surface; 4. Second vertical surface; L1, first row of holes; L10, first row of holes; L2, second row of holes; L20, second row of holes; L3, third row of holes; L30, third row of holes. Detailed Implementation

[0028] The following is in conjunction with the appendix Figures 1-5 This application will be described in further detail.

[0029] This application discloses a method for blasting a large triangular ore body.

[0030] Please see Figure 1 and Figure 2 A method for blasting a large triangular ore body, comprising: Step S1: Select one side of the triangular ore body as the first working face 1, and arrange at least three rows of staggered fan-shaped holes on the first working face 1 along the height direction. Specifically, the first working surface 1 includes three rows of holes. The first row of holes L1 includes holes L11, L12, L13, etc. arranged in sequence. The second row of holes L2 includes holes L21, L22, L23, etc. arranged in sequence. The third row of holes L3 includes holes L31, L32, L33, etc. arranged in sequence.

[0031] Taking the first row of holes L1 as an example, the projections of each hole in the same row onto the bottom surface of the triangular ore body are fan-shaped, indicating that the lengths of adjacent holes in the same row have an included angle and diverge at the bottom of the holes. Figure 2 In the middle, holes L11 and L12 are not parallel and have an included angle, and the distance between the bottoms of the two holes is larger than the distance between their openings. The projections of each hole in the second row L2 and the third row L3 onto the bottom surface of the triangular ore body are also fan-shaped, as can be seen from the first row L1. The fan-shaped hole layout can concentrate the blasting force on the bottom area of ​​the isolated rock ore body and cover the entire area, which helps to more comprehensively cover the blasting surface, resulting in better rock breaking effect and avoiding the occurrence of rock residue.

[0032] The three rows of holes are staggered, meaning that one of the third row holes is located above each pair of adjacent holes in the second row, and one of the first row holes is located below each pair of adjacent holes in the second row. This makes the overall hole arrangement on the working face resemble a quincunx, which allows the blasting force to be distributed more evenly on different parts of the boulder, reducing local stress concentration and thus breaking the rock more effectively.

[0033] Step S2: Select the second working face 2 on the other side of the triangular ore body, and arrange at least three rows of staggered fan-shaped holes on the second working face 2 along the height direction; Specifically, the second working surface 2 includes three rows of holes. The first row of holes L10 includes holes L101, L102, L103, etc. arranged in sequence. The second row of holes L20 includes holes L201, L202, L203, etc. arranged in sequence. The third row of holes L30 includes holes L301, L302, L303, etc. arranged in sequence.

[0034] Taking the first row of holes L10 as an example, the projections of each hole in the same row onto the bottom surface of the triangular ore body are fan-shaped. This is manifested in the fact that the lengths of adjacent holes in the same row have an included angle and diverge at the bottom of the holes. For details, please refer to the first row of holes L1 mentioned above, which will not be elaborated here. The fan-shaped hole layout can concentrate the blasting force in a specific area of ​​the boulder, avoiding the occurrence of rock erosion.

[0035] The three rows of holes on the second working surface 2 are also staggered, and the overall hole pattern on the working surface is also plum blossom-shaped. For details, please refer to step S1, which will not be repeated here.

[0036] Step S3: Each row of sector holes includes deep holes and shallow holes, and shallow holes are formed at the edge of each row of sector holes away from the junction of the first working surface 1 and the second working surface 2; Specifically, due to the irregular shape of the boulder, some parts are long and some parts have a corner, resulting in different perforation depths. The boulder is generally thinner on the side away from the junction of the first working face 1 and the second working face 2, so shallow holes are set.

[0037] Step S4: Project the fan-shaped holes on the first working face 1 and the second working face 2. The resulting projection surface is adapted to the bottom shape of the triangular ore body. The projection lines of the fan-shaped holes on the first working face 1 at the middle of the bottom surface of the triangular ore body and the projection lines of the fan-shaped holes on the second working face 2 at the middle of the bottom surface of the triangular ore body intersect to form a mesh. This makes the blasting force more evenly distributed from top to bottom, and the blasting more thorough during the layered blasting process.

[0038] The blasting method for large triangular ore bodies disclosed in this application is applicable to triangular ore bodies with a center height H between 21 meters and 28 meters, a bottom width of the second working face 1 between 18 meters and 25 meters, and a bottom width of the first working face 2 between 20 meters and 27 meters.

[0039] When three rows of sector holes are arranged on the first working face 1: The first row of holes L1 is 1 to 2 meters above the horizontal plane of the ore body mining area, with an average hole spacing of 3.2 to 3.5 meters. One or two shallow holes are formed at the edge with a depth of 10.5 to 15.5 meters. Five to ten deep holes with a depth of 17 to 22 meters are arranged between the boundary and the edge.

[0040] The distance between the second row of holes L2 and the first row of holes L1 is between 1.8 meters and 2 meters, with an average hole spacing between 3.2 meters and 3.5 meters. The upward perforation angle is between 15° and 29°. Three or six shallow holes with a depth between 12 meters and 17 meters are formed at the edge, and five to ten deep holes with a depth between 17 meters and 22 meters are arranged between the junction and the edge.

[0041] The distance between the third row of holes L3 and the second row of holes L2 is between 1.8 meters and 2 meters, with an average hole spacing between 3.2 meters and 3.5 meters. The upward perforation angle is between 30° and 45°. Three or six shallow holes with a depth between 12 meters and 17 meters are formed at the edge, and three to six deep holes with a depth between 15 meters and 20 meters are arranged between the junction and the edge.

[0042] When three rows of fan-shaped holes are arranged on the second working face 2: The first row of holes L10 is 1 to 2 meters above the horizontal plane of the ore body mining area, with an average hole spacing of 3.2 to 3.5 meters. Two or four shallow holes with a depth of 12 to 17 meters are formed at the edge, and four to eight deep holes with a depth of 15 to 20 meters are arranged between the boundary and the edge.

[0043] The second row of holes L20 is 1.8 meters to 2 meters away from the first row of holes L10, with an average hole spacing of 3.2 meters to 3.5 meters. The upward perforation angle is 15° to 29°. Two or four shallow holes with a depth of 12 meters to 17 meters are formed at the edge, and four to eight deep holes with a depth of 15 meters to 20 meters are arranged between the junction and the edge.

[0044] The distance between the third row of holes L30 and the second row of holes L20 is between 1.8 meters and 2 meters, with an average hole spacing between 3.2 meters and 3.5 meters. The upward perforation angle is between 30° and 45°. Two or four shallow holes with a depth between 12 meters and 17 meters are formed at the edge, and five to ten deep holes with a depth between 15 meters and 20 meters are arranged between the junction and the edge.

[0045] The upward inclination angle of each row of holes on both working faces gradually increases with height. The first row of holes is parallel to the bottom of the triangular ore body and is not inclined, which makes it easier to crush the bottom of the triangular ore body and reduces the possibility of rock roots remaining at the bottom of the triangular ore body after blasting, which can be easily cleaned up later. Since the triangular ore body is relatively high, reaching about 20 meters, the drilling height is limited, and drilling is difficult in higher areas. Therefore, the third row of holes is inclined upwards to allow blasting of the upper part of the triangular ore body. Because the third row of holes is inclined upwards, and the height of the hole opening is parallel to the horizontal plane of the ore body stope, there is a possibility of incomplete blasting of the rock in this area. Therefore, the second row of holes is inclined, but the inclination angle can be smaller than that of the third row of holes, thus allowing for blasting of both the upper and lower rock strata.

[0046] The following provides a specific method for blasting a large triangular ore body, as described in this application.

[0047] Example 1: Please refer to the following: Figure 3 Clearing the triangular ore body is a prerequisite for opening up new working faces. This triangular ore body is constrained by its external geometry, with three sides exposed. It has two perforation working faces, one to the west and one to the north. The highest point measured by the center is 23 meters, the bottom width of the north face is 22 meters, and the bottom width of the west face is 20 meters, forming a triangular shape. Post-blast ore recovery will be difficult. Furthermore, the Zhongping Highway and the Zhonglian Mine quarry are located directly below the edge of the ore body. Therefore, clearing and securing the site before blasting is crucial, and strict control of blasting risks is essential.

[0048] One KQ-110 tracked down-the-hole drill rig will be used for rock drilling. Based on the topographic features of the triangular ore body, the drilling area will be divided into two working faces, west and north. Besides the different drilling directions, the west and north working faces have a 1.5m height difference (the two working faces have different stope levels). However, the drilling methods on the two working faces are very similar, using a quincunx pattern, with each hole spaced 3.2m apart to prevent them from intersecting. Each working face will have three rows of drill holes, evenly distributed within the rock mass, forming a fan shape. The drilling depth of each hole will be determined based on the shape of the triangular ore body, with drilling angles between 0° and 45°. The borehole diameter will be 110mm, with a small resistance line and a dense quincunx pattern, totaling 39 holes. Continuous charging will be used inside the holes, with each hole having a minimum of 3m of mud plugging length, to complete the blasting and removal of the triangular ore body in one operation.

[0049] The center of the triangular ore body has a height H=23 meters, the bottom of the first working face 1 (north side bottom) is 22 meters wide, and the bottom of the second working face 2 (west side bottom) is 20 meters wide. When three rows of fan-shaped holes are arranged in the height direction on the first working face 1 (bottom of the north side): The first row of holes, L1, is a parallel drilling hole in a straight line, 1 meter above the horizontal plane of the ore body. The average hole spacing is 3.2 meters. Due to the irregular shape of the triangular ore body, a shallow hole with a depth of 10.5 meters is formed at the northeast edge. Five deep holes with a depth of 17 meters are arranged between the junction and edge of the two working faces, for a total of 6 holes.

[0050] The second row of holes L2 is 2 meters away from the first row of holes L1, with an average hole spacing of 3.2 meters. The holes are drilled in a straight line with an upward drilling angle of 15°. Three shallow holes with a depth of 12 meters are formed at the northeast edge. Five deep holes with a depth of 17 meters are arranged between the two working faces and the edge, for a total of 8 holes.

[0051] The distance between the third row of holes L3 and the second row of holes L2 is 2 meters, with an average hole spacing of 3.2 meters. The drilling is done in a straight line with an upward drilling angle of 30°. Due to the irregular shape of the triangular ore body, three shallow holes with a depth of 12 meters are formed at the northeast edge. Three deep holes with a depth of 15 meters are arranged between the two working faces and the edge, for a total of 6 holes.

[0052] When three rows of fan-shaped holes are arranged in the height direction on the second working face 2 (west bottom): The first row of holes L10 is a parallel drilling hole in a straight line, 1 meter above the horizontal plane of the ore body (due to the 1.5m height difference between the west and north drilling faces, the first row of holes L10 of the second working face 2 and the first row of holes L1 of the first working face 2 have an actual height difference due to the different heights of the horizontal plane of the mining area, forming a staggered arrangement, and the north face is higher than the west face). The average hole spacing is 3.2 meters. Due to the irregularity of the edge of the triangular ore body, two shallow holes with a depth of 12 meters are formed at the edge, and four deep holes with a depth of 15 meters are arranged between the boundary and the edge, for a total of 6 holes.

[0053] The second row of holes L20 is 2 meters away from the first row of holes L10, with an average hole spacing of 3.2 meters. The upward drilling angle is 15°. Due to the irregular edges of the triangular ore body, two shallow holes with a depth of 12 meters are formed at the edge. Four deep holes with a depth of 15 meters are arranged between the boundary and the edge, for a total of 6 holes.

[0054] The distance between the third row of holes L30 and the second row of holes L20 is 2 meters, with an average hole spacing of 3.2 meters. The drilling is done in a straight line with an upward angle of 30°. Two shallow holes with a depth of 12 meters are formed at the edge, and five deep holes with a depth of 15 meters are arranged between the junction and the edge, for a total of 7 holes.

[0055] The working plane of the first working face 1 is higher than the working plane of the second working face 2. The height of the first row of holes L1 on the first working face 1 is higher than the height of the first row of holes L10 on the second working face 2, but lower than the height of the second row of holes L20 on the second working face 2. The height of the second row of holes L2 on the first working face 1 is higher than the height of the second row of holes L20 on the second working face 2, but lower than the height of the third row of holes L30 on the second working face 2. The height of the third row of holes L3 on the first working face 1 is higher than the height of the third row of holes L30 on the second working face 2, thus causing the rows of holes on the two working faces to be vertically misaligned.

[0056] Furthermore, the angles of the holes in the same row on the first working face 1 and the second working face 2 are set in the same way, which can also prevent the first row of holes L10 on the second working face 2 from penetrating the first row of holes L1 on the first working face 1, prevent the second row of holes L20 on the second working face 2 from penetrating the second row of holes L2 on the first working face 1, and prevent the third row of holes L30 on the second working face 2 from penetrating the third row of holes L3 on the first working face 1. At the same time, the explosive force is placed in different positions, which also prevents the holes in different rows from penetrating each other, reducing the risk of the explosive in the penetrated hole breaking and failing to achieve effective blasting in the penetrated hole.

[0057] The charge per deep hole is: Q = q × a × b × H = 0.41 kg / m³ × 3.2 m × 2 m × 23 m ≈ 60 kg; q represents the charge per unit, a represents the hole spacing, b represents the row spacing, and H represents the center height of the triangular ore body.

[0058] The first and second working faces have a total of 26 deep holes (15-17 meters). The estimated amount of emulsion explosive in the deep holes is: the amount of explosive per hole multiplied by the number of deep holes 60kg × 26 ≈ 1560.

[0059] The charge per shallow hole is: Q = q × a × W × H = 0.41 kg / m³ × 3.2 m × 1.06 m × 23 m ≈ 33 kg; q represents the charge per unit of explosive, a represents the hole spacing, H represents the center height of the triangular ore body, and W represents the minimum resistance line, which is the minimum distance between the shallow hole and the free surface, and the free surface is the plane surrounding the triangular ore body.

[0060] The first and second working faces have a total of 13 deep holes (10-12 meters). The estimated amount of emulsion explosive in the shallow holes is: the amount of explosive per hole multiplied by the number of shallow holes 33kg × 13 ≈ 432kg.

[0061] Total charge: Q_total = 1560kg + 432kg = 1992kg.

[0062] Note: Ø70 emulsion explosives are used.

[0063] The triangular ore body at the edge of the ore body in the eastern mining area of ​​the 2595m section was measured and calculated to have a total ore volume of approximately 13,300 tons. Based on the routine rock-root blasting explosive consumption of q=0.151kg / t, the total explosive charge required to remove this triangular ore body in a single blast is approximately 13,300t × 0.151kg / t ≈ 2008kg, which is close to the actual total explosive charge of 1992kg in this blast, thus meeting the requirements for safe blasting operations (see the perforation diagram). Figure 2 (As shown).

[0064] Control of harmful effects of blasting (a) Vibration control measures: Construction must be carried out strictly in accordance with the designed blasting parameters, and the amount of explosive charge per hole and the maximum amount of explosive charge per single detonation must be strictly controlled to ensure the actual maximum amount of explosive charge per single detonation and to control vibration hazards.

[0065] (ii) Explosive debris: R = 20Kn²W, R is the safe distance for a flying rock (m). K is a coefficient related to rock properties, topography, geology and climate. It is generally taken as 0.1-1.5, with the maximum value taken when throwing into the wind and the minimum value taken when throwing away from the wind. In this case, the value is 1.0. n is the explosive force index of the largest explosive charge, which is generally taken as 1.2-2.5, and the value taken here is 1.4; The minimum resistance line for the largest W-type medicine pack is 4.5m.

[0066] R = 20 × 1.0 × 1.4 × 1.4 × 4.5 = 176.4m. According to the calculation, the minimum safe distance for flying rocks in this blasting is 176.4m, which complies with the minimum safe distance for flying rocks in the "Safety Regulations for Blasting" (GB6722-2014).

[0067] During construction, the plugging process must be carried out strictly in accordance with the design parameters to ensure the plugging length and quality. When loading explosives, pay attention to the changes in the free surface. If the free surface of the hole changes, remeasure the length of the resistance line. If the resistance line of the hole is too weak, it is necessary to discard the hole.

[0068] (III) Protection against toxic gases The blasting in this project uses expanded ammonium nitrate rock explosive as a positive oxygen balance explosive, and it is an open-pit blast. The amount of harmful gases generated by the blast is extremely small and easily dissipates. The harmful gases from the blast are basically not a concern. However, in order to minimize the harm, workers must wear protective masks before entering for inspection and wait for a sufficient time (5 minutes for open-pit blasting) before being allowed to enter for inspection.

[0069] Please refer to the following: Figure 3The first row of each working face is the control row, with a 17-millisecond delay difference between adjacent holes in the control row, and a 17-millisecond delay difference between adjacent holes in the upper and lower rows of the detonation train. This embodiment uses a fan-shaped hole layout with micro-delay blasting for blasting operations. The detonation time difference and detonation point for each hole are determined, allowing large isolated rocks to be removed in a single blast. The subsequent goal is to clear large isolated rocks from the slope, eliminate safety hazards to external roads, reduce ore loss, improve the appearance of the mining face and slope, and summarize a practical and feasible blasting construction technology scheme for clearing large isolated rocks with outward bulges on slopes.

[0070] Example 2: Please refer to the following: Figure 4 and Figure 5 The difference between this embodiment and Embodiment 1 is that when three rows of fan-shaped holes are arranged on the first working surface 1 or the second working surface 2 along the height direction: Taking the first working face 1 as an example, the intersection of the middle hole length L23 of the second row of holes L2 on the first working face 1 and the center height H of the triangular ore body is at the same horizontal height as the starting point of the length of the third row of holes L3.

[0071] The purpose of this is that, since the third row of holes L3 is inclined upwards to blast locations that the upper drilling rig cannot reach, there is a possibility that the triangular ore body at the same height as the entrance of the third row of holes L3 may be incompletely blasted and leave rock behind. In order to reduce the occurrence of this situation, the drilling depth of the second row of holes L2 can reach the center height H of the triangular ore body. This ensures that the explosive extension point of the second row of holes L2 reaches at least the entrance height of the third row of holes L3 or above in the center of the triangular ore body. This reduces the possibility of rock being left behind in the triangular ore body at the same height as the entrance of the third row of holes L3, thus avoiding secondary blasting.

[0072] Of course, the explosive extension point of any hole in the second row is relative to the adjacent hole in the third row (e.g., Figure 3 As shown, all planes should reach the plane containing the center height H of the triangular ore body, and this plane should be perpendicular to the bottom surface of the triangular ore body.

[0073] Example 3: Please refer to the following: Figure 4 and Figure 5 The difference between this embodiment and Embodiment 2 is that when the angle between any working face and the horizontal plane of the ore body mining area is 'a', and 45° < a ≤ 60°: At this time, the dip angle of the triangular ore body is relatively small and not steep. The end point of the middle hole length in the third row of holes on any working face is located on the center height H of the triangular ore body. Taking the first working face 1 as an example, the middle hole length in the second row of holes L2 on the same working face passes through the center height H of the triangular ore body and the end point is located on the line connecting the intersection point O of the middle hole length in the third row of holes L3 and the center height H of the triangular ore body with the apex angle c of the triangular ore body facing the working face. Other holes in the same row can still be arranged in a divergent fan shape relative to the middle hole, as long as the inclination follows the layout in Example 1.

[0074] Since the triangular ore body is not very steep, and the central part and bottom are relatively wide, it is not easy to blast it completely. By extending the depth of the second row of holes L2 beyond the center height H of the triangular ore body and reaching the triangular ore body on the other side of the center height H, the holes inside the triangular ore body form a cone with a relatively large apex angle d compared to the apex angle of the triangular ore body. Moreover, the blasting holes of the triangular ore body can at least reach the triangular cone, and the blasting surface is more affected. This reduces the situation where the bottom blasting is incomplete and rock layers are left when the dip angle of the triangular ore body is small.

[0075] Example 4: Please refer to the following: Figure 4 and Figure 5 The difference between this embodiment and Embodiment 3 is that when the angle between any working face and the horizontal plane of the ore body mining area is 'a', and 60° < a ≤ 75°: At this point, the triangular ore body is relatively steep, and the central area of ​​the triangular ore body is easier to blast than in Example 3. This can ensure the blasting effect while avoiding the excessive use of explosives and waste.

[0076] Specifically, a first vertical plane 3 is formed that is perpendicular to the horizontal plane of the ore body mining area. The midpoint of the bottom width of the second working face 2, the line connecting the bottom edge of the non-working face of the triangular ore body, and the center height H of the triangular ore body are located on the same plane and constitute the first vertical plane 3. The projection of the three rows of deep holes on the first working face 1 is located on the first vertical plane 3. A second vertical plane 4 is formed that is perpendicular to the horizontal plane of the ore body mining area. The midpoint of the bottom width of the first working face 1, the line connecting the bottom edge of the non-working face of the triangular ore body, and the center height H of the triangular ore body are located on the same plane and constitute the second vertical plane 4. The projection of the three rows of deep holes on the second working face 2 is located on the second vertical plane 4.

[0077] When the dip angle of the triangular ore body is relatively large, i.e., the triangular ore body is relatively steep, by adopting the setting method of this embodiment, the holes of the two working faces can be located on the square pyramid formed by the first vertical plane 3, the second vertical plane 4, and the fixed point of the triangular ore body. That is, a square pyramid hole-laying body is formed in the center of the triangular ore body. Since the center of the triangular ore body is the most difficult to blast, by arranging the blasting positions on the entire square pyramid, the square pyramid can be effectively blasted while ensuring the blasting effect of the triangular ore body, and at the same time, the waste of explosives is avoided, and the explosives are used rationally.

[0078] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A method for blasting a large triangular ore body, characterized in that: Including the following steps: Select one side of the triangular ore body as the first working face, and arrange at least three rows of staggered fan-shaped holes along the height direction on the first working face; Select the other side of the triangular ore body as the second working face, and arrange at least three rows of staggered fan-shaped holes along the height direction on the second working face; The fan-shaped holes include deep holes and shallow holes, with shallow holes formed at the edge of each row of fan-shaped holes away from the junction of the first working surface and the second working surface; Projecting the fan-shaped holes on the first working face and the second working face onto the projection surface, the resulting projection surface is adapted to the bottom shape of the triangular ore body. The projection lines of the fan-shaped holes on the first working face at the middle of the bottom surface of the triangular ore body and the projection lines of the fan-shaped holes on the second working face at the middle of the bottom surface of the triangular ore body intersect to form a mesh.

2. The blasting method for large triangular ore bodies according to claim 1, characterized in that: When three rows of fan-shaped holes are arranged along the height direction on the first working surface: The first row of holes is 1 to 2 meters above the horizontal plane of the ore body mining area, with an average hole spacing of 3.2 to 3.5 meters. One or two shallow holes are formed at the edge with a depth of 10.5 to 15.5 meters. Five to ten deep holes with a depth of 17 to 22 meters are arranged between the boundary and the edge. The second row of holes is 1.8 meters to 2 meters from the first row of holes, with an average hole spacing of 3.2 meters to 3.5 meters and an upward angle. Three or six shallow holes are formed at the edge with a depth of 12 meters to 17 meters, and five to ten deep holes with a depth of 17 meters to 22 meters are arranged between the junction and the edge. The distance between the third row of holes and the second row of holes is between 1.8 meters and 2 meters, with an average hole spacing between 3.2 meters and 3.5 meters. The holes are inclined upwards and the inclination angle is greater than that of the second row of holes. Three or six shallow holes with a depth between 12 meters and 17 meters are formed at the edge, and three to six deep holes with a depth between 15 meters and 20 meters are arranged between the junction and the edge. When three rows of fan-shaped holes are arranged along the height direction on the second working surface: The first row of holes is 1 to 2 meters above the horizontal plane of the ore body mining area, with an average hole spacing of 3.2 to 3.5 meters. Two or four shallow holes with a depth of 12 to 17 meters are formed at the edge, and four to eight deep holes with a depth of 15 to 20 meters are arranged between the boundary and the edge. The second row of holes is 1.8 meters to 2 meters from the first row of holes, with an average hole spacing of 3.2 meters to 3.5 meters and an upward angle. Two or four shallow holes are formed at the edge with a depth of 12 meters to 17 meters, and four to eight deep holes with a depth of 15 meters to 20 meters are arranged between the junction and the edge. The distance between the third row of holes and the second row of holes is between 1.8 meters and 2 meters, with an average hole spacing between 3.2 meters and 3.5 meters. The holes are inclined upwards and the inclination angle is greater than that of the second row of holes. Two or four shallow holes are formed at the edge with a depth between 12 meters and 17 meters. Five to ten deep holes with a depth between 15 meters and 20 meters are arranged between the junction and the edge.

3. The blasting method for large triangular ore bodies according to claim 2, characterized in that: The center of the triangular ore body has a height H=23 meters, the bottom width of the first working face is 22 meters, and the bottom width of the second working face is 20 meters. When three rows of fan-shaped holes are arranged along the height direction on the first working surface: The first row of holes is 1 meter above the horizontal plane of the ore body mining area, with an average hole spacing of 3.2 meters. A shallow hole with a depth of 10.5 meters is formed at the edge, and five deep holes with a depth of 17 meters are arranged between the boundary and the edge. The second row of holes is 2 meters apart from the first row of holes, with an average hole spacing of 3.2 meters. The hole is slanted upward at an angle of 15°. Three shallow holes with a depth of 12 meters are formed at the edge, and five deep holes with a depth of 17 meters are arranged between the junction and the edge. The third row of holes is 2 meters apart from the second row of holes, with an average hole spacing of 3.2 meters. The upward drilling angle is 30°. Three shallow holes with a depth of 12 meters are formed at the edge, and three deep holes with a depth of 15 meters are arranged between the junction and the edge. When three rows of fan-shaped holes are arranged along the height direction on the second working surface: The first row of holes is 1 meter above the horizontal plane of the ore body mining area, with an average hole spacing of 3.2 meters. Two shallow holes with a depth of 12 meters are formed at the edge, and four deep holes with a depth of 15 meters are arranged between the boundary and the edge. The second row of holes is 2 meters apart from the first row of holes, with an average hole spacing of 3.2 meters. The hole is slanted upward at an angle of 15°. Two shallow holes with a depth of 12 meters are formed at the edge, and four deep holes with a depth of 15 meters are arranged between the junction and the edge. The third row of holes is 2 meters apart from the second row of holes, with an average hole spacing of 3.2 meters. The hole is slanted upward at an angle of 30°. Two shallow holes with a depth of 12 meters are formed at the edge, and five deep holes with a depth of 15 meters are arranged between the junction and the edge.

4. The blasting method for large triangular ore bodies according to claim 2, characterized in that: When three rows of sector-shaped holes are arranged along the height direction on the first working surface or the second working surface: The intersection of the middle hole length of the second row of holes on the same working face and the center height H of the triangular ore body is at the same horizontal height as the starting point of the third row of holes.

5. The blasting method for large triangular ore bodies according to claim 4, characterized in that: When the angle between any working face and the horizontal plane of the ore body mining area is 'a', and 45° < a ≤ 60°: The end point of the middle hole length in the third row of holes is located on the center height H of the triangular ore body. The middle hole length in the second row of holes on the same working face passes through the center height H of the triangular ore body and ends on the line connecting the intersection point O of the middle hole length in the third row of holes and the center height H of the triangular ore body with the apex point of the triangular ore body facing the working face.

6. The blasting method for large triangular ore bodies according to claim 4, characterized in that: When the angle between any working face and the horizontal plane of the ore body mining area is 'a', and 60° < a ≤ 75°: The first vertical plane is formed perpendicular to the horizontal plane of the ore body mining area. The first vertical plane is formed by the midpoint of the bottom width of the second working face, the line connecting the bottom edge of the non-working face of the triangular ore body, and the center height H of the triangular ore body. The projection of the three rows of deep holes on the first working face is located on the first vertical plane. A second vertical plane is formed that is perpendicular to the horizontal plane of the ore body mining area. The line connecting the midpoint of the bottom width of the first working face, the bottom edge of the non-working face of the triangular ore body, and the center height H of the triangular ore body constitute the second vertical plane. The projection of the three rows of deep holes on the second working face is located on the second vertical plane.

7. The blasting method for large triangular ore bodies according to claim 3, characterized in that: The charge per deep hole is: Q = q × a × b × H = 0.41 kg / m³ × 3.2 m × 2 m × 23 m ≈ 60 kg; q represents the charge per unit of explosive, a represents the hole spacing, b represents the row spacing, and H represents the center height of the triangular ore body. The charge per shallow hole is: Q = q × a × W × H = 0.41 kg / m³ × 3.2 m × 1.06 m × 23 m ≈ 33 kg; q represents the charge per unit of explosive, a represents the hole spacing, H represents the center height of the triangular ore body, and W represents the minimum resistance line, which is the minimum distance between the shallow hole and the free surface, and the free surface is the plane surrounding the triangular ore body.

8. The blasting method for large triangular ore bodies according to any one of claims 1 to 7, characterized in that: On the same working face, the first row of holes forms the control row, and the second and third rows of holes form the detonation transmission row; The micro-delay blasting is controlled in each hole of the first row of holes, with a micro-delay time of 17 milliseconds; The second row of holes is controlled to form a micro-delay blasting relative to the first row of holes, with a micro-delay time of 42 milliseconds; The third row of holes is controlled to form a micro-delay blast relative to the second row of holes, with a micro-delay time of 42 milliseconds.

9. The blasting method for large triangular ore bodies according to claim 1, characterized in that: The arrangement of the rows of holes on the first working surface and the arrangement of the rows of holes on the second working surface are staggered vertically.

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