The charging method of long and short interval filling of fan-shaped blastholes in underground metal mines

Abstract

The present invention discloses a charging method for filling fan-shaped blastholes with long and short intervals in underground mining areas of metal mines, and the method steps are as follows: 1) determining the length of the minimum resistance line of blasting according to the rock firmness coefficient and the diameter of the blasthole; 2) determining the size of the tool circle with the length of the minimum resistance line as the radius; 3) using the tool circle to delineate the filling range in the middle and lower part of the fan-shaped blasthole according to the number of holes and the hole depth; 4) determining the filling length of the lower end of the blasthole according to the delineated range, and performing charging and blasting. This method not only reasonably utilizes the energy of explosives, controls the uniform size of the blasting caving ore, but also saves about 1 / 4 of the explosives, reducing the blasting cost; the charging method of this method is simple to operate, can reasonably utilize the energy of explosives, ensure the uniform size of the caving ore, improve the shoveling efficiency and crushing efficiency, save about 1 / 4 of the explosive consumption, and reduce the blasting cost.

Description

Technical Field

[0001] The invention relates to a mine blasting engineering method, in particular to a charging method for filling fan-shaped blast holes with long and short intervals in underground metal mines. Background Art

[0002] In my country's underground mining production, the fan-shaped blasthole arrangement method is widely used because of its advantages such as small drilling tunnel excavation engineering, flexible deep hole arrangement and less movement of rock drilling equipment. It is mostly used in mining methods such as stage caving method, segmented caving method and stage mine room method. The characteristic of fan-shaped hole arrangement is that in the same row, the deep holes are arranged radially, and the deep hole spacing gradually increases from the hole mouth to the bottom of the hole; however, since the fan-shaped deep holes are radial, the hole mouth spacing is small and the hole bottom spacing is large, the size of the collapsed ore is uneven, which is reflected in the high charge density at the hole mouth, excess blasting energy, small block size, and even powder, resulting in waste of explosives and low utilization rate of blastholes. The blasting effect of fan-shaped blastholes directly affects the blasting cost, mining efficiency and crushing efficiency. At present, the common charging method of fan-shaped blastholes is to charge all the blastholes, leaving a filling length of 0.8 to 1 meter at the hole mouth. The disadvantage of this charging method is that it causes uneven ore size after blasting and excessive charging density at the hole mouth, resulting in a waste of explosives. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a method for charging long and short intervals of fan-shaped blast holes in underground metal mines, which can save the amount of charge while ensuring the explosion effect.

[0004] In order to solve the above technical problems, the method steps adopted by the present invention are as follows: 1) determining the length of the minimum resistance line of blasting according to the rock solidity coefficient and the blasthole diameter;

[0005] 2) Determine the size of the tool circle with the length of the minimum resistance line as the radius;

[0006] 3) Use a tool circle to circle the filling range in the lower middle part of the fan-shaped blasthole according to the number of holes and hole depth;

[0007] 4) According to the designated range, determine the filling length of the lower end of the blast hole and carry out charging and blasting work.

[0008] Furthermore, in the step 2), the tool circle is determined as follows: Ⅰ) the tool circle determined for the first time is one, with the bottom end of the central blast hole as the center;

[0009] Ⅱ) The tool circles defined for the second time are two, both tangent to the central blast hole and tangent to the two side holes respectively;

[0010] III) There are three tool circles circled for the third time, one of which is tangent to the two blast holes separated by one blast hole from the center blast hole, and the other two are tangent to the two blast holes separated by one blast hole from the center blast hole and are tangent to the two blast holes adjacent to the side holes.

[0011] Furthermore, in the step 3), the filling length of each blast hole is as follows: Ⅰ) the central blast hole and two side holes are not filled, and two blast holes separated by two from the two side holes are filled to the position intersecting with the tool circle delineated for the first time;

[0012] Ⅱ) The two blast holes adjacent to the two side holes are filled to the position where they intersect with the tool circle delineated for the second time, and the two blast holes separated by one from the central blast hole are filled to the position where they intersect with the tool circle delineated for the second time;

[0013] III) The remaining blast holes are filled to the position where they intersect with the tool circle defined for the third time.

[0014] Furthermore, the diameter of the blasthole is greater than or equal to 50 mm, the row spacing between the blastholes is greater than or equal to 1500 mm, and the distance between the bottoms of the blastholes is greater than or equal to 1500 mm.

[0015] The beneficial effects of adopting the above technical scheme are: the present invention adopts the long and short interval filling charging method to uniformly control the blasting energy, and through reasonably defining the filling range and determining the length of the charge column in the blasthole, the explosives are evenly distributed on the fan-shaped blasthole surface, which not only reasonably utilizes the explosive energy and controls the uniform size of the blasting collapsed ore, but also saves about 1 / 4 of the explosives and reduces the blasting cost; the charging method of the present invention is simple to operate, can reasonably utilize the explosive energy, ensure the uniform size of the collapsed ore, improve the shoveling efficiency and crushing efficiency, save about 1 / 4 of the explosive consumption, and reduce the blasting cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0017] Figure 1 Schematic diagram of the scope of the present invention

[0018] Figure 2 It is a schematic diagram of the arrangement of the charge method of the present invention;

[0019] Figure 3 This is a schematic diagram of the original full-hole charge arrangement of the fan-shaped blasthole;

[0020] Figure 4 yes Figure 3 A top view of the charge and blasting funnel distribution of the blasthole at position 12 of the middle section;

[0021] Figure 5 yes Figure 2Top view of the blast hole charge and blasting funnel distribution at mid-section position 7.

[0022] The markings in the figure are as follows: upper segment blasting empty area 1; material pile after upper segment blasting 2; charge column 3; side hole blast hole 4; filling area 5; bottom tunnel in the mine room 6; cross-sectional position 7; blasting free face 8; blasting funnel 9; loaded blast hole 10; unloaded blast hole 11; cross-sectional position 12; center blast hole 13; tool circle circled for the third time 14; tool circle circled for the second time 15; tool circle circled for the first time 16; a, b, c, d, e, f, g, h, j, k, m, n, p, q, n are the blast hole numbers. DETAILED DESCRIPTION

[0023] Figure 1 , Figure 2 As shown, the charging method for long and short interval filling of fan-shaped blastholes in the underground mining area of ​​the metal mine adopts the following construction steps:

[0024] 1) Blast holes are set upward in the bottom tunnel 6 in the mine room, and the number of blast holes is determined according to the area of ​​the upper stage blasting empty area 1 and the material pile 2 after the upper stage blasting; the blast holes are set in a fan shape, the diameter of the blast holes is greater than or equal to 50mm, and the bottom hole distance and row distance between the blast holes are greater than or equal to 1500mm.

[0025] 2) According to the fact that the minimum resistance line of deep hole ore falling is generally 23 to 30 times the drill bit diameter d, the length of the minimum resistance line for blasting is determined, that is, W = (23 to 30) d, where W is the minimum resistance line and d is the drill bit diameter. Based on practical experience, a certain value is selected from (23 to 30) d as the value W of the minimum resistance line. With the minimum resistance line as the radius, the size of the tool circle is determined.

[0026] 3) Circle the tool circle. Figure 1-5 The 15 blast holes shown in the figure are used as an example for explanation. The blast hole numbers from one side blast hole 4 to another side blast hole 4 are: a, b, c, d, e, f, g, h, j, k, m, n, p, q, r, among which blast hole a and blast hole r are two side blast holes 4, and blast hole h is the center blast hole 13. The process of delineating the tool circle is as follows:

[0027] Ⅰ) The tool circle delineated for the first time is one, with the bottom end of the central blast hole as the center; that is, the tool circle delineated for the first time is 16 with the blast hole h (central blast hole 13) as the center;

[0028] II) There are two tool circles 15 circled for the second time, both of which are tangent to the central blast hole and to the two side holes respectively; that is, one of the tool circles 15 circled for the second time is tangent to the blast hole h and the blast hole a (the side hole blast hole 4), and the other tool circle 15 circled for the second time is tangent to the blast hole h and the blast hole r (the side hole blast hole 4);

[0029] III) There are three tool circles 14 circled for the third time, one of which is tangent to two blast holes separated by one blast hole from the center blast hole, and the other two are tangent to two blast holes separated by one blast hole from the center blast hole, and are tangent to two blast holes adjacent to the side holes; that is, one of the tool circles 14 circled for the third time is tangent to blast hole f and blast hole k, another is tangent to blast hole b and blast hole f, and the last one is tangent to blast hole k and blast hole q.

[0030] 4) The filling length of each blast hole is as follows: Ⅰ) The central blast hole and the two side holes are not filled, and the two blast holes separated by two blast holes are filled to the position intersecting with the tool circle delineated for the first time; that is, blast holes h, blast holes a and blast holes r are not filled and are fully charged; blast holes d and blast holes n are filled to the position where the lower end of the charge column 3 intersects with the tool circle 16 delineated for the first time; the unfilled part of the lower end of the charge column 3 is the filling area 5, and the filling material is a nylon bag;

[0031] II) The two blast holes adjacent to the two side holes are filled to the position where they intersect with the tool circle delineated for the second time, and the two blast holes separated by one from the central blast hole are filled to the position where they intersect with the tool circle delineated for the second time; that is, blast holes b and blast holes f, blast holes k and blast holes q are filled to the position where the lower end of the charge column 3 intersects with the tool circle 15 delineated for the second time; the unfilled portion at the lower end of the charge column 3 is the filling area 5, and the filling material is a nylon bag;

[0032] III) The remaining blast holes are filled to the position where they intersect with the tool circle delineated for the third time; that is, blast holes c and blast holes e, blast holes g and blast holes j, blast holes m and blast holes p are filled to the position where the lower end of the charge column 3 intersects with the tool circle 14 delineated for the third time; the unfilled portion of the lower end of the charge column 3 is the filling area 5, and nylon bags are used as the filling material.

[0033] 5) Figure 5 As shown, after charging, due to the different charging amounts, charged blast holes 10 with explosives at the cross-sectional position and uncharged blast holes 11 without explosives at the cross-sectional position will appear in different cross-sections, and blasting free surfaces 8 and blasting funnels 9 will be formed; after charging, blasting work is carried out. Figure 3 This is a schematic diagram of the original fan-shaped blasthole full-hole charge arrangement. Figure 3 , Figure 4 It can be seen that all blastholes are filled with explosives, rather than the long and short interval filling method of this method; it can be seen that this method rationally utilizes the energy of explosives, saves about 1 / 4 of the explosives, and reduces the blasting cost.

[0034] Embodiment: The charging method for filling the fan-shaped blastholes with long and short intervals in the underground mining area of ​​a metal mine is specifically described as follows.

[0035] 1) Figure 1 , Figure 2As shown, the width of the bottom tunnel 6 of the mine room is 4.5m and the height is 3.8m. Blast holes are set upward in the bottom tunnel 6 in the mine room. The number of blast holes is determined to be 15 blast holes according to the area of ​​the upper segment blasting empty area 1 and the material pile 2 after the upper segment blasting. The blast holes are set in a fan shape, the diameter of the blast holes is 64mm, and the bottom distance of the blast holes 5 is 1.8m.

[0036] 2) According to W=(23~30)d, the minimum resistance line is obtained at 1.47~1.92m. Based on practical experience, the minimum resistance line of blasting is determined to be 1.8m. The size of the tool circle is determined with the minimum resistance line of 1.8m as the radius.

[0037] 3) Circle the tool circle. Figure 1-2 As shown; the tool circle 16 is circled for the first time with the blast hole h (center blast hole 13) as the center; there are two tool circles 15 circled for the second time, one of which is tangent to the blast hole h and the blast hole a, and the other is tangent to the blast hole h and the blast hole r; there are three tool circles 14 circled for the third time, one of which is tangent to the blast hole f and the blast hole k, another is tangent to the blast hole b and the blast hole f, and the last one is tangent to the blast hole k and the blast hole q.

[0038] 4) The filling length of each blasthole is: blasthole h, blasthole a and blasthole r are not filled, fully charged, and the filling depth is the full length of the blasthole; blasthole d and blasthole n are filled to the position where the lower end of the charge column 3 intersects with the tool circle 16 delineated for the first time, and the filling depth is 18 meters; the part at the lower end of the charge column 3 that is not filled with charge is the filling area 5, which is filled with 1 meter;

[0039] The charge filling depths of the blast holes b, f, k and q are 10 meters, and the unfilled portion of the lower end of the charge column 3 is the filling area 5, which is filled by 3 meters.

[0040] Holes c and e, holes g and j, holes m and p are filled with explosives until the lower end of the charge column 3 intersects with the tool circle 14 which is circled for the third time, and the filling depth is 7 meters; the part of the lower end of the charge column 3 that is not filled with explosives is the filling area 5, which is filled for 7 meters.

[0041] 5) After charging, blasting work is carried out; the collapse effect after the explosion is good, and there is no uncollapsed area. The maximum single-side diameter of the collapsed ore block is within the range of 0.8 meters, and the block size is uniform.

[0042] Statistical case: 10 cases were blasted using the original fan-shaped blasthole full-hole charging arrangement. Among them, 9 cases required secondary blasting, and the single-side diameter of the collapsed ore block was within the range of 0.5m to 1.5m. After adopting this method, 10 cases were blasted, among which 2 cases required secondary blasting, and the single-side diameter of the collapsed ore block was within the range of 0.4m to 1m.

Claims

1. A method for charging long and short intervals of fan-shaped blast holes in underground metal mines, characterized in that: Includes steps: 1) Determine the minimum blasting resistance line length based on the rock strength coefficient and blasthole diameter; 2) Determine the size of the tool circle with the length of the minimum resistance line as the radius; the steps for determining the tool circle are: Ⅰ) The tool circle drawn for the first time is one, with the bottom of the central blast hole as the center; Ⅱ) The tool circles defined for the second time are two, both tangent to the central blast hole and tangent to the two side holes respectively; III) There are three tool circles circled for the third time, one of which is tangent to two blast holes separated by one blast hole from the center blast hole, and the other two are tangent to two blast holes separated by one blast hole from the center blast hole, and are tangent to two blast holes adjacent to the side holes; 3) Use a tool circle to circle the filling range in the lower middle part of the fan-shaped blasthole according to the number of holes and hole depth; 4) According to the designated range, determine the filling length of the lower end of the blast hole and carry out charging and blasting work.

2. The method for charging long and short intervals of fan-shaped blast holes in underground metal mines according to claim 1, characterized in that: In step 3), the filling length of each blast hole is: Ⅰ) The center blast hole and the two side holes are not filled, and the two blast holes separated by two from the two side holes are filled to the position intersecting with the tool circle circled for the first time; Ⅱ) The two blast holes adjacent to the two side holes are filled to the position where they intersect with the tool circle delineated for the second time, and the two blast holes separated by one from the central blast hole are filled to the position where they intersect with the tool circle delineated for the second time; III) The remaining blast holes are filled to the position where they intersect with the tool circle defined for the third time.

3. The method for charging long and short intervals of fan-shaped blast holes in underground metal mines according to claim 1 or 2, characterized in that: The diameter of the blast holes is greater than or equal to 50 mm, the row spacing between the blast holes is greater than or equal to 1500 mm, and the distance between the bottoms of the blast holes is greater than or equal to 1500 mm.

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