A method for charging water-containing blastholes

Abstract

The present invention provides a method for charging water-containing blastholes. The method comprises measuring the blasthole depth, inclination angle, and water depth to design a charge height; determining the required number of sections of emulsion explosive A; stringing the emulsion explosives A sequentially with metal wire and pressing them into the bottom of the blasthole; and if the total height of all emulsion explosives A is less than the designed charge height, inserting an isolation gasket through the metal wire and laying it flat above the emulsion explosives A. Emulsion explosive B is then strung onto the metal wire, and a detonating cord is connected between emulsion explosive B and the topmost emulsion explosive A. A detonator is connected to emulsion explosive B, and ammonium nitrate fuel oil explosive is loaded around and above emulsion explosive B in the blasthole to the same level as the designed charge height. Finally, the blasthole is blocked with taphole mud. This method avoids the problem of poor blasting effect caused by explosives not being loaded to the bottom of the blasthole or gaps between emulsion explosives, while also reducing explosives costs. The charging method is simple and convenient, and the blasting effect is excellent.

Description

Technical Field

[0001] The invention relates to the technical field of blasting engineering, in particular to a method for charging water-containing blastholes. Background Art

[0002] Water can accumulate in blastholes due to rainfall, groundwater infiltration, or residual water left inside during wet rock drilling. When charging explosives into water-containing blastholes, the ammonium nitrate (ANN) explosive dissolves in the water, losing its explosive effectiveness. Currently, water can be removed from water-containing blastholes by using a blower or a hollow pump before charging. However, water can still seep into the blasthole during the charging process, affecting the blasting effect.

[0003] To prevent the impact of water in the blasthole on the explosives, emulsion explosives can be loaded directly into the blasthole. However, since emulsion explosives have a density similar to that of water, they will float in the water and cannot reach the bottom of the blasthole, resulting in poor blasting results. Furthermore, gaps between the emulsion explosives can easily cause explosive refusal to detonate if the gaps are larger than the explosive detonation distance, affecting the blasting effect. Furthermore, the cost of emulsion explosives is relatively high, leading to high blasting costs.

[0004] Currently, there are many methods for loading explosives into water-containing blastholes. For example, patent CN109443119A discloses a charging device and method for loading non-waterproof explosives into water-containing blastholes. The method uses a flexible delivery hose to deliver explosives into a charging tube. Water flowing into the charging tube from the blasthole is then continuously drained through a drain plug via the drain hole. After the water is drained, the drain hole is sealed and blocked. Pressure is then applied to break through the waterproof sealing membrane, allowing the explosives to flow through the discharge hole into the charging bag. This allows non-waterproof explosives to be loaded into water-containing blastholes, significantly reducing explosives costs during blasting operations. However, this charging method requires on-site pressurized delivery of the charge, resulting in poor construction safety. Furthermore, connecting and sealing the waterproof charging bag is difficult, making the charging method relatively complex. Summary of the Invention

[0005] In order to solve the above-mentioned shortcomings in the prior art, the present invention provides a method for charging water-containing blastholes, in which emulsion explosives are strung together by metal wires and then pressed into the bottom of the blasthole, thereby avoiding the problem of poor blasting effect caused by the explosives not being able to reach the bottom of the blasthole or gaps between the emulsion explosives. At the same time, a snakeskin bag is laid flat above the emulsion explosives above the water surface, and the snakeskin bag is filled with ammonium nitrate explosive and a section of emulsion explosive, thereby reducing the cost of explosives, simplifying and conveniently charging the explosives, and achieving good blasting effect.

[0006] The technical solution adopted to achieve the above-mentioned purpose of the present invention is:

[0007] A method for charging a water-containing blasthole comprises the following steps: (1) measuring the depth and inclination of the blasthole using a measuring rope and a borehole angle measuring instrument, measuring the water depth in the blasthole using a groundwater level monitor, and designing the charge height according to the size of the blasthole;

[0008] (2) The required number of sections of emulsion explosive A is determined according to the water depth in the blasthole. The method for determining the number of sections of emulsion explosive A is as follows:

[0009] a1. Calculate the volume of water in the blasthole:

[0010] a2. Calculate the volume of the gap between the emulsion explosive A and the blasthole wall: V 空隙 =π×(r 炮孔 -r 炸药 ) 2 ×n×h 炸药 ;

[0011] In the above formula, r 炮孔 is the diameter of the blasthole, r 炸药i is the diameter of emulsion explosive A, h 水深 is the water depth in the blasthole, h 炸药 is the height of each section of emulsion explosive A, and n is the number of sections of emulsion explosive A;

[0012] a3. According to V 水 Less than V 空隙 , determine the number of nodes n of emulsion explosive A;

[0013] (3) The emulsion explosive A is strung together in sequence along the length direction with a metal wire, and then the strung emulsion explosive A is pressed into the bottom of the blast hole with a stick, and the strung emulsion explosive A is positioned on the center line of the blast hole;

[0014] (4) If the total height of all emulsion explosives A in step (2) is less than the designed charge height, then after step (3) is completed, an isolation gasket is passed through the metal wire and laid flat on the top of the emulsion explosive A, then the emulsion explosive B is strung on the metal wire above the isolation gasket, and the emulsion explosive B is also located on the center line of the blasthole, a detonating cord is connected between the emulsion explosive B and the topmost emulsion explosive A, now the emulsion explosive B is connected with a detonator, the leg line on the detonator extends from the blasthole, and the ammonium nitrate fuel oil explosive is filled around and above the emulsion explosive B in the blasthole to the same level as the designed charge height, and finally the blasthole is blocked with taphole mud;

[0015] (5) If the total height of all emulsion explosives A in step (2) is greater than or equal to the designed charge height, the number of sections of emulsion explosives A is adjusted so that the total height of the emulsion explosives A strung together in step (3) matches the designed charge height. After step (3) is completed, detonators are connected to the strung together emulsion explosives A, and the leg wires on the detonators extend from the blasthole. Gravel is then loaded above the strung together emulsion explosives A to fill the blasthole.

[0016] The diameter of the metal wire is 0.3-0.5 cm.

[0017] The top end of the metal wire is 15 to 20 cm higher than the top of the emulsion explosive B, and the bottom end of the metal wire is bent into a fishhook shape or fixedly connected to a limiting block.

[0018] The metal wire is iron wire.

[0019] In the step (4), the isolation gasket is a discarded snakeskin bag containing ammonium nitrate explosive.

[0020] In the step (3), the stick is a PVC tube, and the outer diameter of the PVC tube is 2 to 4 cm smaller than the diameter of the blast hole.

[0021] The diameter of the gravel in step (5) is 1 to 2 cm.

[0022] Compared with the prior art, the technical solution provided by the present invention has the following advantages: 1. In the present invention, different charging schemes are determined according to the water depth in the blasthole, so that after the water-containing blasthole charging is completed, the best blasting effect is achieved, the charging method is simple and convenient, and the blasting cost is low; 2. In the present invention, the emulsion explosives are strung together by metal wires, and there is no gap between the emulsion explosives, so that the emulsion explosives are smoothly transmitted; 3. In the present invention, the emulsion explosives are pressed into the bottom of the blasthole with a PVC pipe, so as to avoid the problem of poor blasting effect caused by the explosives not being able to be loaded into the bottom of the blasthole, and the PVC pipe is light and inexpensive; 4. In the present invention, an isolation pad is laid above the emulsion explosive A above the water surface, and the isolation pad is filled with ammonium nitrate oil explosive and a section of emulsion explosive, so as to reduce the cost of explosives and isolate the ammonium nitrate oil explosive from the water in the blasthole to avoid the ammonium nitrate oil explosive from becoming ineffective when encountering water; in addition, the isolation pad is selected from discarded snakeskin bags filled with ammonium nitrate oil explosive, and the discarded snakeskin bags are reused. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of the charge of the water-containing blasthole provided in the present invention;

[0024] In the figure: 1-blast hole, 2-water, 3-emulsion explosive A, 4-metal wire, 5-snake skin bag, 6-emulsion explosive B, 7-detonating cord, 8-detonator, 9-foot line, 10-ammonium nitrate explosive, 11-blast mud. DETAILED DESCRIPTION

[0025] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] The method for charging a water-containing blasthole provided by the present invention comprises the following steps: (1) using a measuring rope and a borehole angle measuring instrument to measure the depth and inclination of the blasthole 1, using a groundwater level monitor to measure the depth of water 2 in the blasthole, and designing the charging height according to the size of the blasthole; determining whether the blasthole depth and inclination meet the design requirements, and if the hole collapses, re-drilling is required.

[0027] (2) The required number of sections of emulsion explosive A3 is determined according to the water depth in the blasthole. The method for determining the number of sections of emulsion explosive A is as follows:

[0028] a1. Calculate the volume of water in the blasthole:

[0029] a2. Calculate the volume of the gap between the emulsion explosive A and the blasthole wall: V 空隙 =π×(r 炮孔 -r 炸药 ) 2 ×n×h 炸药 ;

[0030] In the above formula, r 炮孔 is the diameter of the blasthole, r 炸药 is the diameter of emulsion explosive A, h 水深 is the water depth in the blasthole, h 炸药 is the height of each section of emulsion explosive A, and n is the number of sections of emulsion explosive A;

[0031] a3. According to V 水 Less than V 空隙 , determine the number of nodes n of emulsion explosive A;

[0032] (3) The emulsion explosive A is strung together in sequence along the length direction with a metal wire 4. Specifically, the metal wire is an iron wire with a diameter of 0.3 to 0.5 cm. The bottom end of the metal wire is bent into a fishhook shape. Figure 1 , or fixedly connected with a limited block, so as to prevent the emulsion explosive A from sliding from the bottom; then use a stick to press the strung emulsion explosive A into the bottom of the blasthole, and make the strung emulsion explosive A located on the center line of the blasthole. Specifically, the stick is a PVC tube. After the emulsion explosive A is pressed into the bottom of the blasthole, the PVC tube can be taken out. The outer diameter of the PVC tube is 2 to 4 cm smaller than the diameter of the blasthole. The PVC tube is lighter, which makes it easier to press the emulsion explosive A into the bottom.

[0033] In the present invention, different charging schemes are determined according to the water depth in the blasthole. If the water depth in the blasthole is shallow, so that the total height of all emulsion explosives A in step (2) is less than the designed charging height, the blasthole is filled with emulsion explosives and ammonium nitrate explosive.

[0034] At this moment, after step (3) is completed, the isolation spacer is passed through the metal wire and laid flat on the top of the emulsion explosive A. In the present embodiment, the isolation spacer is a discarded snakeskin bag 5 for filling ammonium nitrate oil explosive. Then the emulsion explosive B6 is strung on the metal wire above the isolation spacer. The top of the metal wire is 15~20cm higher than the top of the emulsion explosive B. This prevents the emulsion explosive B from sliding out from the top of the metal wire, and the emulsion explosive B is also located on the center line of the blasthole. Between the emulsion explosive B and the topmost emulsion explosive A, a detonating cord 7 is connected so that the emulsion explosive is smoothly detonated. The emulsion explosive B is connected with a detonator 8. The foot line 9 on the detonator stretches out in the blasthole. In the blasthole, the ammonium nitrate oil explosive 10 is filled above the emulsion explosive B to the same level as the designed charge height. Finally, the blasthole is blocked with taphole mud 11. Figure 1 shown.

[0035] If the depth of water in the blasthole is deep, so that the total height of all emulsion explosives A in step (2) is greater than or equal to the designed charging height, only emulsion explosives are loaded into the blasthole.

[0036] At this time, the number of sections of the emulsion explosive A is first adjusted so that the total height of the emulsion explosive A strung together in step (3) matches the designed charging height. After step (3) is completed, a detonator is connected to the strung together emulsion explosive A, and the leg line on the detonator extends from the blast hole. Gravel is then loaded above the strung together emulsion explosive A to fill the blast hole. The diameter of the gravel is 1 to 2 cm. The charging method is not shown in the accompanying drawings.

[0037] The present invention rationally designs different charging schemes to meet the needs of blastholes with different water contents, ensuring that the best blasting effect is achieved after the water-containing blastholes are charged. When the water content is high, all emulsion explosives are used; when the water content is low, the emulsion explosives A are strung together with metal wires and then pressed into the bottom of the blasthole with a stick (PVC tube), thereby avoiding the problem of poor blasting effect caused by the explosives not being able to be loaded into the bottom of the blasthole or gaps between the emulsion explosives. At the same time, a snakeskin bag is laid flat above the emulsion explosives A above the water surface, and the snakeskin bag is filled with ammonium nitrate oil explosive and a section of emulsion explosive, thereby reducing the cost of explosives and simplifying the charging method.

Claims

1. A method for charging a water-containing blasthole, characterized in that The following steps are involved: (1) Use a measuring rope and a borehole angle measuring instrument to measure the depth and inclination of the blasthole, use a groundwater level monitor to measure the water depth in the blasthole, and design the charge height according to the size of the blasthole; (2) The required number of sections of emulsion explosive A is determined according to the water depth in the blasthole. The method for determining the number of sections of emulsion explosive A is as follows: a1. Calculate the volume of water in the blasthole: V 水 =π×r 炮孔 2 ×h 水深 ; a2. Calculate the volume of the gap between the emulsion explosive A and the blasthole wall: V 空隙 =π×(r 炮孔 2 -r 炸药 2 )×n×h 炸药 ; In the above formula, r 炮孔 is the radius of the blasthole, r 炸药 is the radius of emulsion explosive A, h 水深 is the water depth in the blasthole, h 炸药 is the height of each section of emulsion explosive A, and n is the number of sections of emulsion explosive A; a3. According to V 水 Less than V 空隙 , determine the number of nodes n of emulsion explosive A; (3) Use metal wire to string the emulsion explosive A in sequence along the length direction, and then use a stick to press the strung emulsion explosive A into the bottom of the blast hole, and make the strung emulsion explosive A be located on the center line of the blast hole; (4) If the total height of all emulsion explosives A in step (2) is less than the designed charge height, after step (3) is completed, an isolation gasket is passed through the metal wire and laid flat on the top of the emulsion explosive A, and then the emulsion explosive B is strung on the metal wire above the isolation gasket, and the emulsion explosive B is also located on the center line of the blasthole, and a detonating cord is connected between the emulsion explosive B and the top emulsion explosive A. At this time, a detonator is connected to the emulsion explosive B, and the leg line on the detonator extends from the blasthole. Ammonium nitrate explosive is filled around and above the emulsion explosive B in the blasthole until it is flush with the designed charge height, and finally the blasthole is blocked with blasthole mud; (5) If the total height of all emulsion explosives A in step (2) is greater than or equal to the designed charge height, the number of sections of emulsion explosives A is adjusted so that the total height of the emulsion explosives A strung together in step (3) matches the designed charge height. After step (3) is completed, detonators are connected to the strung together emulsion explosives A, and the leg wires on the detonators extend from the blasthole. Gravel is then loaded above the strung together emulsion explosives A to fill the blasthole.

2. The method for charging a water-containing blasthole according to claim 1, characterized in that: The diameter of the metal wire is 0.3-0.5 cm.

3. The method for charging a water-containing blasthole according to claim 1, characterized in that: The top end of the metal wire is 15 to 20 cm higher than the top of the emulsion explosive B, and the bottom end of the metal wire is bent into a fishhook shape or fixedly connected to a limiting block.

4. The method for charging a water-containing blasthole according to claim 1, characterized in that: The metal wire is iron wire.

5. The method for charging a water-containing blasthole according to claim 1, characterized in that: The isolation gasket in step (4) is a discarded snakeskin bag containing ammonium nitrate explosive.

6. The method for charging a water-containing blasthole according to claim 1, characterized in that: In step (3), the stick is a PVC tube, and the outer diameter of the PVC tube is 4 cm smaller than the diameter of the blast hole.

7. The method for charging a water-containing blasthole according to claim 1, characterized in that: The diameter of the gravel in step (5) is 1 to 2 cm.

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