Powdered charge device and method for open pit water hole blasting

Abstract

The present application relates to a kind of powder charging device and charging method for open water hole blasting, belong to the field of blasting technology.The present application uses powder charging device to charge, inner shell is fixed in the center of outer shell along axial direction, the cavity formed between outer shell and inner shell is air buffer cavity;Support hollow piece is inserted to the bottom of the charging cavity of inner shell, detonating cord is inserted into the central cavity of support hollow piece and passes through the through hole at the bottom end of support hollow piece downward;The charging cavity of inner shell is filled with powder explosive, disc cover is fixed at the top of outer shell to form powder charging structure;Powder charging structure is inserted into open water hole, the bottom end of powder charging structure is inserted into the bottom of open water hole;Pull out disc cover limiting piece upward, compressed spring restores normal state under the action of elastic force, push movable gear horizontally and outward and be clamped in the hole wall of open water hole.The present application method can solve the application of powder explosive in water hole, reach the blasting effect of high efficiency, safety.

Description

Technical Field

[0001] This invention relates to a powdered explosive charging device for open-pit waterhole blasting, belonging to the field of blasting technology. Background Technology

[0002] With the increasing scale and rate of mining in open-pit metallurgical mines, many mines have shifted from hillside open-pit production to deep-pit open-pit production. This inevitably leads to water-bearing boreholes in open-pit bench drilling and blasting methods. During open-pit mining, factors such as rainwater, groundwater, and geological conditions often result in high water content in the boreholes after drilling, severely affecting blasting effectiveness and quality. This not only impacts mining costs but also brings more serious blasting hazards. Water is incompressible and has a detonation-transfer effect during blasting, greatly improving blasting quality. However, it also brings significant obstacles. Water-bearing cavities often result in a high proportion of large pieces and uneven bottoms after blasting, greatly hindering loading, transportation, and other operations, reducing overall mining efficiency, and directly lowering production levels. In water-bearing blasting of ores in mines, the presence of water not only causes poor blasting quality, but the main reason is that the explosive charge in the water-bearing borehole cannot meet design requirements. Either the explosive cartridge cannot be loaded to the bottom of the hole, or the water causes the explosive to become ineffective. Most powdered explosives are not waterproof and will become ineffective when exposed to water, seriously affecting the explosive's role in rock breaking, causing resource waste and increased costs, and leaving a large amount of residual explosive and casing, seriously affecting the safety of construction personnel. Summary of the Invention

[0003] To address the problems of difficulty in applying powdered explosives and inadequate loading in existing open-pit waterhole blasting methods, this invention proposes a powdered explosive loading device and method for open-pit waterhole blasting. The device delivers powdered explosives to the bottom of the borehole, achieving the designed loading effect while also providing a water-proof function, keeping the powdered explosives dry and ensuring the detonation effect is not affected. This device and method solve the problem of applying powdered explosives in waterholes, achieving efficient and safe blasting results. Simultaneously, it reduces losses due to explosive failure upon contact with water, thereby lowering costs. Most importantly, it brings enterprises a low-investment, high-return benefit.

[0004] A powdered explosive charging device for open-pit water-hole blasting includes an outer shell 5, an inner shell fixedly disposed axially at the center of the outer shell 5, a cavity formed between the outer shell 5 and the inner shell serving as an air buffer cavity, and an inner cavity within the inner shell serving as a charging cavity. Powdered explosive 6 is installed within the charging cavity. A hollow support member is axially disposed within the charging cavity, with its bottom end inserted into the bottom of the charging cavity. The bottom end of the hollow support member has a through hole communicating with the charging cavity. A detonating cord 1 is inserted into the hollow cavity of the hollow support member, with its bottom end passing through the through hole at the bottom end of the hollow support member and connecting to the powdered explosive 6. A disc cover 3 is disposed at the top of the outer shell 5, and the top end of the support member extends upward through the disc cover 3 and beyond the water surface. The outer edge of the disc cover 3 is evenly provided with several horizontal grooves 12 along the circumference. The outer edge of the groove 12 is vertically and downwardly movable with a limiting member. A movable gear 9 is provided in the groove 12. A horizontal cavity is provided in the center of the movable gear 9. A spring 13 is provided in the horizontal cavity. The two ends of the spring 13 are A end and B end, respectively. The A end of the spring 13 is close to the outer edge of the disc cover 3 and is connected to the inner wall of the horizontal cavity. The B end of the spring 13 is close to the center of the disc cover 3 and is fixedly connected to the inner wall of the groove 12. When not loaded with explosives, the movable gear 9 is located inside the limiting member and the spring 13 is in a compressed state. When the water hole is loaded with explosives and detonates, the limiting member is pulled out and the movable gear 9 slides horizontally outward past the position of the limiting member.

[0005] The powdered explosive device for water-hole blasting can ensure that the powdered explosive remains dry in the water hole, thereby ensuring the accuracy of the explosive detonation.

[0006] Preferably, the outer shell can be made of a thin metal foil that is waterproof and does not rust when exposed to water.

[0007] Preferably, the spring can be a helical spring with good elasticity and sensitivity.

[0008] Preferably, the movable gear can be a steel gear.

[0009] Preferably, the support member includes a first support rod 2 and a second support rod 7, and the detonating cord 1 is inserted into the hollow cavity of the first support rod 2 or the second support rod 7.

[0010] Preferably, the first support rod 2 and the second support rod 7 can be hollow aluminum alloy tubes that are rust-resistant when exposed to water. The outer diameter of the hollow aluminum alloy tube is 3 to 50 mm, the inner diameter is 0.1 to 3.0 mm, and the weight is relatively light.

[0011] Preferably, the disc cover 3 is fixedly mounted on the top of the outer casing 5 by fixing bolts 8.

[0012] Preferably, a sealing ring I is provided at the junction of the disc cover 3 and the outer shell 5.

[0013] Preferably, a sealing ring II4 is provided at the junction of the hollow support component and the disc cover 3.

[0014] Preferably, a washer 10 is provided at the junction of the fixing bolt 8 and the top of the outer shell 5.

[0015] Preferably, a hanging ring is fixedly provided on the inner side wall of the groove 12, and a hook 14 is fixedly provided on the B end of the spring 13. The B end of the spring 13 passes horizontally through the horizontal cavity and the hook of the B end of the spring 13 is hung on the hanging ring on the inner side wall of the groove 12.

[0016] Preferably, the bottom wall of the groove 12 is provided with a limiting bottom groove, and the top wall of the groove 12 is provided with a limiting through hole 15 corresponding to the limiting bottom groove. The limiting member passes vertically downward through the limiting through hole 15 and is inserted into the limiting bottom groove. When the explosion occurs, the limiting member is pulled out, and the movable gear 9 slides horizontally outward through the limiting bottom groove.

[0017] Preferably, the bottom end of the inner shell is fixedly connected to the bottom wall of the outer shell 5 by a snap nut 11.

[0018] A method for using powdered explosives in open-pit water-hole blasting, employing the aforementioned powdered explosive charging device, comprises the following specific steps:

[0019] S1. The inner shell is fixed axially at the center of the outer shell, and the cavity formed between the outer shell and the inner shell is an air buffer cavity; the hollow support is inserted into the bottom of the charging cavity of the inner shell, and the detonating cord is inserted into the central cavity of the hollow support and passes downward through the through hole at the bottom of the hollow support;

[0020] S2. The inner shell is filled with powdered explosives in the charging cavity, and the disc cover is fixed to the top of the outer shell to form a powdered explosives structure;

[0021] S3. Insert the powdered explosive charge structure into the open water hole, with the bottom end of the powdered explosive charge structure inserted to the bottom of the open water hole;

[0022] S4. Pull out the disc cover limiter upwards. The compressed spring returns to its normal state under the action of elasticity, pushing the movable gear to slide out horizontally and lock onto the hole wall of the open water hole. Fill the top of the powdered charge structure with water hole filling material to the opening of the open water hole, thus completing the powdered charge for the open water hole blasting.

[0023] Preferably, the water hole filling material is composed of coarse rock fragments, fine rock fragments and liquid shotcrete binder, wherein the particle size of the coarse rock fragments is >0.5mm and the particle size of the fine rock fragments is ≤0.5mm.

[0024] The filler material for water wells consists of 50-60% coarse rock fragments, 30-40% fine rock fragments, and 10-15% liquid stemming binder.

[0025] The liquid clay adhesive is a commercially available high-strength, toluene-free liquid adhesive.

[0026] The beneficial effects of this invention are:

[0027] (1) The powdered explosive device of the present invention can deliver powdered explosives to the bottom of the borehole to achieve the design requirements of the explosive loading effect, and also achieve the water-proof function, so that the powdered explosives can be kept dry and the explosion effect is not affected. This device and loading method can solve the application of powdered explosives in water holes, achieve efficient and safe blasting effect, and at the same time reduce the loss of explosives when they are exposed to water.

[0028] (2) Since the explosive power of powdered explosives is greater than that of waterproof rock emulsion explosives, and the cost of powdered explosives is lower than that of waterproof rock emulsions, this invention reduces costs and can bring enterprises the effect of low investment and high returns. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of a powder loading device;

[0030] Figure 2 This is a schematic diagram of the disc cover structure;

[0031] Figure 3 Schematic diagram of the arrangement of movable gears when not loaded with explosives;

[0032] In the figure, 1-detonating cord, 2-first support rod, 3-disc cover, 4-sealing ring II, 5-outer shell, 6-powdered explosive, 7-second support rod, 8-fixing bolt, 9-moving gear, 10-washer, 11-clamp nut, 12-groove, 13-spring, 14-hook, 15-limiting through hole. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the content described.

[0034] Overview of the Invention

[0035] This invention relates to a powdered explosive charging device that can deliver powdered explosives to the bottom of the borehole, achieving the designed charging effect while also providing a water-proof function, keeping the powdered explosives dry and not affecting the explosion effect. This device and charging method can solve the problem of using powdered explosives in water holes, achieving efficient and safe blasting effects. At the same time, it reduces the loss of explosives due to water inactivation, thereby reducing costs. Most importantly, it can bring enterprises a low-investment, high-return effect.

[0036] A powdered explosive charging device for open-pit waterhole blasting (see...) Figures 1-3The device includes an outer shell 5, an inner shell fixedly disposed axially at the center of the outer shell 5, an air buffer cavity formed between the outer shell 5 and the inner shell, and a charging cavity containing powdered explosive 6. A hollow support member is disposed axially within the charging cavity, with its bottom end inserted into the bottom of the charging cavity. The bottom end of the hollow support member has a through hole communicating with the charging cavity. A detonating cord 1 is inserted into the hollow cavity of the hollow support member, with its bottom end passing through the through hole at the bottom end of the hollow support member and connecting to the powdered explosive 6. A disc cover 3 is disposed at the top of the outer shell 5, and the top of the support member extends upward through the disc cover 3 and beyond the water surface. The outer edge of the disc cover 3 extends along... A plurality of horizontal grooves 12 are evenly distributed around the periphery. A limiting element is vertically and downwardly mounted on the outer edge of the groove 12. A movable gear 9 is installed inside the groove 12. A horizontal cavity is opened in the center of the movable gear 9. A spring 13 is installed inside the horizontal cavity. The two ends of the spring 13 are A end and B end, respectively. The A end of the spring 13 is close to the outer edge of the disc cover 3 and is connected to the inner wall of the horizontal cavity. The B end of the spring 13 is close to the center of the disc cover 3 and is fixedly connected to the inner wall of the groove 12. When not loaded with explosives, the movable gear 9 is located inside the limiting element and the spring 13 is in a compressed state. When the water hole is loaded with explosives and detonates, the limiting element is pulled out and the movable gear 9 slides horizontally outward past the position of the limiting element.

[0037] The powdered explosive device for water hole blasting can ensure that the powdered explosive remains dry in the water hole, thereby ensuring the accuracy of the explosive detonation;

[0038] A method for using powdered explosives in open-pit water-hole blasting, employing the aforementioned powdered explosive charging device, comprises the following specific steps:

[0039] S1. The inner shell is fixed axially at the center of the outer shell, and the cavity formed between the outer shell and the inner shell is an air buffer cavity; the hollow support is inserted into the bottom of the charging cavity of the inner shell, and the detonating cord is inserted into the central cavity of the hollow support and passes downward through the through hole at the bottom of the hollow support;

[0040] S2. The inner shell is filled with powdered explosives in the charging cavity, and the disc cover is fixed to the top of the outer shell to form a powdered explosives structure;

[0041] S3. Insert the powdered explosive charge structure into the open water hole, with the bottom end of the powdered explosive charge structure inserted to the bottom of the open water hole;

[0042] S4. Pull out the disc cover limiting piece upwards. The compressed spring returns to its normal state under the action of elastic force, pushing the movable gear to slide out horizontally and lock onto the hole wall of the open water hole. Fill the top of the powdered charge structure with water hole filling material to the opening of the open water hole, completing the powdered charge for the open water hole blasting. The water hole filling material is composed of coarse rock fragments, fine rock fragments and liquid stemming clay binder. The particle size of the coarse rock fragments is >0.5mm, and the particle size of the fine rock fragments is ≤0.5mm. The coarse rock fragments account for 50-60%, the fine rock fragments account for 30-40%, and the liquid stemming clay binder accounts for 10-15%. The liquid stemming clay binder is a commercially available high-strength toluene-free liquid binder.

[0043] Example 1: A water-rich open-pit lead-zinc mine in a plateau depression in Northwest China, with an altitude above 3780m. Snowfall generally begins in late October and lasts until the end of March of the following year. The mine has a large water inflow, averaging 899m³ per day. 3 / d, with a maximum inflow of 8490m³ 3 / d, all water holes in the blasting area are full, the mining bench height is 12m, the safety platform width is 3m, and the cleaning platform width is 8-10m; No. 2 rock emulsion explosive and powdered expanded ammonium nitrate explosive are used, and the detonating equipment mainly consists of 2-15 sections of ordinary millisecond detonating cord detonators. The rock hardness is f=8-12, and the fissures are moderately developed; the 3492m platform of this mine has severe fissure water. After each drilling, water overflows from the blast hole, making it difficult to load the explosive. The explosive cannot be loaded to the bottom of the blast hole or floats on the water surface. For mining areas with harsh conditions, it is very difficult to transport explosives in snowy weather. When only powdered explosives are left, the failure of powdered explosives after contact with water should be fully considered in water hole blasting, resulting in poor blasting effect;

[0044] The area to be detonated is measured, and the holes are laid out strictly according to the design requirements. A tracked down-the-hole drill with a diameter of 120mm, a drilling depth of 0-50m, and a climbing angle of 24° is used to drill the laid-out blast holes. All water holes in the area to be detonated are drilled. The drilled blast holes in the area to be detonated are inspected to check for any blockages. After the inspection is completed, the powder charging device can be used to charge the explosives.

[0045] A powdered explosive charging device for open-pit water-hole blasting includes an outer shell 5, an inner shell fixedly disposed axially at the center of the outer shell 5, a cavity formed between the outer shell 5 and the inner shell serving as an air buffer cavity, and an inner cavity of the inner shell serving as a charging cavity containing powdered explosive 6. A hollow support member is axially disposed within the charging cavity, with its bottom end inserted into the bottom of the charging cavity. The bottom end of the hollow support member has a through hole communicating with the charging cavity. A detonating cord 1 is inserted into the hollow cavity of the hollow support member, with its bottom end passing through the through hole at the bottom end of the hollow support member and connecting to the powdered explosive 6. A disc cover 3 is disposed at the top of the outer shell 5, and the top end of the support member extends upward through the disc cover 3 and beyond the water surface. Several horizontal grooves are evenly distributed circumferentially along the outer edge of the disc cover 3. 12. A limiting component is vertically and downwardly movable on the outer edge of the groove 12. A movable gear 9 is installed inside the groove 12. A horizontal cavity is opened in the center of the movable gear 9. A spring 13 is installed in the horizontal cavity. The two ends of the spring 13 are A end and B end, respectively. The A end of the spring 13 is close to the outer edge of the disc cover 3 and connected to the inner wall of the horizontal cavity. The B end of the spring 13 is close to the center of the disc cover 3 and fixedly connected to the inner wall of the groove 12. When not loaded with explosives, the movable gear 9 is located inside the limiting component, and the spring 13 is in a compressed state. When the water hole is loaded with explosives for detonation, the limiting component is pulled out, and the movable gear 9 slides horizontally outward past the position of the limiting component. The powdered explosive device for water hole detonation can ensure that the powdered explosives remain dry in the water hole, thereby ensuring the accuracy of the explosive detonation.

[0046] The outer casing can be made of waterproof and rust-resistant thin metal foil; the spring can be a coil spring with good elasticity and sensitivity; the moving gear can be a steel gear;

[0047] The support includes a first support rod 2 and a second support rod 7. The detonating cord 1 is inserted into the hollow cavity of the first support rod 2 or the second support rod 7. The first support rod 2 and the second support rod 7 can be hollow aluminum alloy tubes that are rust-resistant when exposed to water. The outer diameter of the hollow aluminum alloy tube is 3 to 50 mm, the inner diameter is 0.1 to 3.0 mm, and the weight is relatively light.

[0048] The disc cover 3 is fixedly mounted on the top of the outer casing 5 by fixing bolts 8;

[0049] A sealing ring I is provided at the junction of the disc cover 3 and the outer shell 5;

[0050] A sealing ring II4 is provided at the junction of the hollow support and the disc cover 3;

[0051] A washer 10 is provided at the junction of the fixing bolt 8 and the top of the outer shell 5; the sealing ring I, sealing ring II 4 and washer 10 can achieve a complete seal of the outer shell to prevent the powdered explosive from getting wet.

[0052] A hanging ring is fixedly provided on the inner side wall of the groove 12, and a hook 14 is fixedly provided on the B end of the spring 13. The B end of the spring 13 passes horizontally through the horizontal cavity and the hook of the B end of the spring 13 is hung on the hanging ring on the inner side wall of the groove 12.

[0053] The bottom wall of the groove 12 is provided with a limiting groove, and the top wall of the groove 12 is provided with a limiting through hole 15 corresponding to the limiting groove. The limiting member passes vertically downward through the limiting through hole 15 and is inserted into the limiting groove. When the explosion occurs, the limiting member is pulled out and the movable gear 9 slides horizontally outward through the limiting groove.

[0054] The bottom end of the inner shell is fixedly connected to the bottom wall of the outer shell 5 by a snap nut 11;

[0055] A method for using powdered explosives in open-pit water-hole blasting, employing the aforementioned powdered explosive charging device, comprises the following specific steps:

[0056] S1. The inner shell is fixed axially to the center of the outer shell by a snap nut, and the cavity formed between the outer shell and the inner shell is an air buffer cavity; the first support rod and the second support rod supporting the hollow component are inserted into the bottom of the charging cavity of the inner shell, and the detonating cord is inserted into the central cavity of the first support rod or the second support rod supporting the hollow component and passes downward through the through hole at the bottom end;

[0057] S2. The inner shell is filled with powdered explosives in the charging cavity, and the disc cover is fixed to the top of the outer shell by fixing bolts to form a powdered explosives structure;

[0058] S3. Insert the powdered explosive charge structure into the open water hole, with the bottom end of the powdered explosive charge structure inserted to the bottom of the open water hole;

[0059] S4. Pull out the disc cover limiting piece upwards. The compressed spring returns to its normal state under the action of elastic force, pushing the movable gear to slide out horizontally and lock onto the hole wall of the open water hole. Fill the top of the powdered charge structure with water hole filling material to the opening of the open water hole, completing the powdered charge for the open water hole blasting. The water hole filling material is composed of coarse rock fragments, fine rock fragments, and liquid stemming clay binder (commercially available high-strength toluene-free liquid binder). The particle size of the coarse rock fragments is >0.5mm, and the particle size of the fine rock fragments is ≤0.5mm. By mass percentage, the water hole filling material contains 60% coarse rock fragments, 30% fine rock fragments, and 10% liquid stemming clay binder.

[0060] After the blasting was completed, the blasting effect on the slope was analyzed and summarized. It was found that when using powdered explosives for water-hole blasting, the blasting effect was good, the blasted pieces were uniform in size, and there were basically no large pieces produced. There were also no residual explosives or tubes. This indicates that the powdered explosive charging device and charging method used in open-pit water-hole blasting are effective in water-rich open-pit mine blasting. This device can isolate water, keeping the powdered explosives dry and not affecting the blasting effect.

[0061] The specific embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for using powdered explosives in open-pit water-hole blasting, characterized in that: A powdered explosive charging device for open-pit water hole blasting is adopted. The powdered explosive charging device includes an outer shell (5), an inner shell fixedly arranged along the center of the outer shell (5) along the axial direction, a cavity formed between the outer shell (5) and the inner shell as an air buffer cavity, and an inner cavity of the inner shell as a charging cavity. Powdered explosive (6) is installed in the charging cavity. A supporting hollow component is arranged along the axial direction in the charging cavity. The bottom end of the supporting hollow component is inserted into the bottom of the charging cavity. The bottom end of the supporting hollow component is a through hole communicating with the charging cavity. A detonating cord (1) is inserted into the hollow cavity of the supporting hollow component. The bottom end of the detonating cord (1) passes through the through hole at the bottom end of the supporting hollow component and connects with the powdered explosive (6). A disc cover (3) is provided at the top of the outer shell (5). The top end of the supporting hollow component passes upward through the disc cover (3) and extends beyond the water surface. The outer edge of the cover (3) is evenly provided with several horizontal grooves (12) along the circumference. The outer edge of the groove (12) is vertically and downwardly provided with a limiting component. A movable gear (9) is provided in the groove (12). A horizontal cavity is provided in the center of the movable gear (9). A spring (13) is provided in the horizontal cavity. The two ends of the spring (13) are A end and B end, respectively. The A end of the spring (13) is close to the outer edge of the disc cover (3) and is connected to the inner wall of the horizontal cavity. The B end of the spring (13) is close to the center of the disc cover (3) and is fixedly connected to the inner wall of the groove (12). When not loaded with explosives, the movable gear (9) is located inside the limiting component, and the spring (13) is in a compressed state. When the water hole is loaded with explosives and detonates, the limiting component is pulled out, and the movable gear (9) slides horizontally outward past the position of the limiting component. The hollow support component includes a first support rod (2) and a second support rod (7), and the detonating cord (1) is inserted into the hollow cavity of the first support rod (2) or the second support rod (7); A hanging ring is fixedly provided on the inner side wall of the groove (12), and a hook (14) is fixedly provided on the B end of the spring (13). The B end of the spring (13) passes horizontally through the horizontal cavity and the hook of the B end of the spring (13) is hung on the hanging ring on the inner side wall of the groove (12). A limiting bottom groove is opened on the bottom wall of the groove (12), and a limiting through hole (15) corresponding to the limiting bottom groove is opened on the top wall of the groove (12). The limiting member passes vertically downward through the limiting through hole (15) and is inserted into the limiting bottom groove. When the explosion occurs, the limiting member is pulled out and the movable gear (9) slides horizontally outward through the limiting bottom groove. The specific steps of the powder loading method are as follows: S1. The inner shell is fixed axially at the center of the outer shell, and the cavity formed between the outer shell and the inner shell is an air buffer cavity; the hollow support is inserted into the bottom of the charging cavity of the inner shell, and the detonating cord is inserted into the central cavity of the hollow support and passes downward through the through hole at the bottom of the hollow support; S2. The inner shell is filled with powdered explosives in the charging cavity, and the disc cover is fixed to the top of the outer shell to form a powdered explosives structure; S3. Insert the powdered explosive charge structure into the open water hole, with the bottom end of the powdered explosive charge structure inserted to the bottom of the open water hole; S4. Pull out the disc cover limiter upwards. The compressed spring returns to its normal state under the action of elasticity, pushing the movable gear to slide out horizontally and lock onto the hole wall of the open water hole. Fill the top of the powdered charge structure with water hole filling material to the opening of the open water hole, thus completing the powdered charge for the open water hole blasting.

2. The method for using powdered explosives in open-pit waterhole blasting according to claim 1, characterized in that: A sealing ring I is provided at the junction of the disc cover (3) and the outer shell (5).

3. The method for using powdered explosives in open-pit waterhole blasting according to claim 1, characterized in that: The bottom end of the inner shell is fixedly connected to the bottom wall of the outer shell (5) by a snap nut (11).

4. The method for using powdered explosives in open-pit waterhole blasting according to claim 1, characterized in that: The water hole filling material consists of coarse rock fragments, fine rock fragments, and liquid shot put binder. The coarse rock fragments have a particle size > 0.5 mm, and the fine rock fragments have a particle size ≤ 0.5 mm.

5. The method for using powdered explosives in open-pit waterhole blasting according to claim 4, characterized in that: By mass percentage, the coarse rock cuttings in the water hole filling material account for 50-60%, the fine rock cuttings account for 30-40%, and the liquid stemming binder accounts for 10-15%.

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