Strip mine platform blasting method based on water medium transduction blasting

Abstract

The invention discloses a strip mine platform blasting method based on water medium transduction blasting, which can scientifically determine the length, the position and the angle of a blasting hole group and the position of a water injection hole by accurately measuring the earth surface inclination degree, the mine depth and the position of a coal seam primary crack of a blasting area, thereby being beneficial to improving the blasting effect and reducing resource waste. Drilling and water injection hole drilling are performed according to measurement data, so that the blasting accuracy and safety can be ensured; in addition, the parameters of the blasting hole group are determined again, and drilling is carried out, so that the blasting accuracy is further improved; by means of the charging structure of the energy gathering pipe and the detonating cord, release of blasting energy can be effectively controlled, the influence on the surrounding environment is reduced, meanwhile, the detonating cord connected in parallel ensures the synchronism of blasting, and the blasting efficiency is improved. The whole process is strictly executed, so that the safety and efficiency of blasting operation are improved, and environmental protection and reasonable utilization of resources are facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of open-pit mine platform blasting, and more specifically, to an open-pit mine platform blasting method based on water medium energy conversion blasting. Background Art

[0002] Open-pit blasting is a blasting technology commonly used in open-pit mining. It mainly refers to the blasting operation carried out during the open-pit mining process to strip off the overburden, mine ore or expand the mine pit. Its purpose is to use the energy released instantly by the explosive material to break or move the rock for subsequent mining and transportation.

[0003] In open-pit coal mining, traditional blasting methods will produce a lot of dust and cause environmental pollution, which does not meet the current environmental protection requirements and therefore does not meet existing needs. In this regard, we propose an open-pit platform blasting method based on water medium energy conversion blasting. Summary of the invention

[0004] The purpose of the present invention is to provide an open-pit mine blasting method based on water medium energy conversion blasting to solve the problem that in the prior art, in open-pit coal mining, traditional blasting methods will generate a lot of dust, causing environmental pollution, which does not meet the current environmental protection requirements.

[0005] The above technical objectives of the present invention are achieved through the following technical solutions: an open-pit mine blasting method based on water medium energy conversion blasting, comprising: S1, confirming the blasting area of ​​the mining area according to the exploration situation, clearing the surface covering soil of the blasting area until the rock used for drilling is exposed, and also clearing a safe area with the blasting area as the center of the circle; S2, measuring the surface inclination of the blasting area, the mine depth of the blasting area and the position of the original cracks in the coal seam, dividing the blasting area into a high area and a low area according to the surface inclination of the blasting area, the mine depth of the blasting area and the position of the original cracks in the coal seam, and determining the length, position and angle of the surface blasting hole group of the blasting area, the blasting hole group includes several blasting holes arranged in the high area, the blasting hole group is arranged in the high area, and then the positions of several water injection holes are delineated according to the positions of the original cracks in the coal seam and the blasting holes near the boundaries adjacent to the high area and the low area, and the water injection holes are arranged in the low area; S3, low area blasting, according to the measurement data of S2, several water injection holes are drilled and water is injected to moisten them, and the first-level explosive blasting and the second-level water medium energy conversion blasting are carried out; S4, high area blasting, according to the surface inclination of the blasting area, the mine depth of the blasting area and the position of the original fracture of the coal seam after the blasting of S3, the length, position and angle of the surface blasting hole group in the blasting area are determined according to the re-measured measurement data, and then the corresponding drilling is carried out; S5, the detonating cord is pre-tied to the energy-gathering tube on the surface of the blasting area, and then the explosive roll is tied to the energy-gathering tube according to the conventional design of the charging structure and charging amount, and the energy-gathering tube and the explosive roll are placed in the third blasting hole together, the energy-gathering tube is backed against the side of the retained rock mass, and the blasting hole group is connected with the detonating cord in parallel as a whole; S6, all auxiliary equipment is evacuated, and after ensuring that all auxiliary equipment has been evacuated and confirming that the safety warning measures are in place, the ignition and detonation operation is performed.

[0006] By adopting the above technical scheme, firstly, the surface covering soil in the blasting area is removed to expose the rock, thereby ensuring the accuracy and efficiency of the drilling operation, and at the same time, a safe area is cleared with the blasting area as the center, thereby ensuring the safety of the operators; secondly, by accurately measuring the surface inclination, mine depth and position of the original cracks in the coal seam in the blasting area, the length, position and angle of the blasting hole group and the position of the water injection hole can be scientifically determined, which helps to improve the blasting effect and reduce the waste of resources; drilling and setting of the drilling holes and water injection holes according to the measured data can ensure the accuracy and safety of the blasting; in addition, the parameters of the blasting hole group are re-determined and the drilling is carried out, which further improves the accuracy of the blasting; finally, the charge structure of the energy-gathering tube and the detonating cord can effectively control the release of the blasting energy and reduce the impact on the surrounding environment. At the same time, the detonating cord connected in parallel ensures the synchronization of the blasting and improves the blasting efficiency. The strict implementation of the entire process not only improves the safety and efficiency of the blasting operation, but also helps to protect the environment and make rational use of resources.

[0007] The present invention is further configured as follows: after step S3, the following steps are included: S301, wetting, low-pressure water is injected into the original cracks of the coal body through the water injection holes to wet the coal body, and the water injection time and the holding time after water injection are both affected by the specific gas desorption rate, the maximum crack opening, the water injection flow rate and the fracturing time; S302, primary explosive blasting, after wetting, the water injection holes are loaded with blasting explosives, the holes are sealed, and the explosives are detonated. The explosion shock waves are released in the water-containing environment provided in step S301, the original cracks of the coal body are expanded, and new cracks are generated, and the safety area of ​​the water injection hole blasting does not exceed the range of the safety area cleared with the blasting area as the center; S303, secondary water medium transducer blasting, new blasting points and water injection paths are determined, and pulsating water with a certain frequency is continuously injected into the new cracks using a transducer.

[0008] By adopting the above technical scheme, the processing flow after step S3 of wetting, primary explosive blasting and secondary water medium energy conversion blasting can significantly improve the desorption efficiency of coalbed methane (gas) and the expansion effect of coal body cracks. First, the coal body is moistened by low-pressure water injection to create favorable conditions for subsequent blasting; then, the primary explosive blasting is released in a water-containing environment, effectively expanding the original cracks and generating new cracks, while ensuring the safety of blasting; finally, the secondary water medium energy conversion blasting injects pulsating water into the new cracks to further promote the expansion of the cracks. Overall, this process not only improves the gas desorption rate and coalbed methane mining efficiency, but also enhances the safety of operations and reduces the impact on the environment.

[0009] The present invention is further configured as follows: in step S301, water is injected to fill the pores and cracks to provide a medium with high conductivity for the detonation pressure.

[0010] By adopting the above technical solution, based on the principles of fluid mechanics and rock mechanics, as the water injection pressure increases, the pore water pressure in the center of the borehole also increases, which leads to an increase in the range and speed of water diffusion outward along the borehole. Specifically, when the water injection pressure increases, the water's permeability in the coal seam increases, allowing the water to penetrate deeper into the pores and cracks of the coal seam, thereby improving the wetting effect of the coal seam. In addition, the increase in water injection pressure also means that there is more energy to push water into the coal seam, which helps to open more cracks, increase the permeability of the coal seam, and further improve the water injection effect.

[0011] The present invention is further configured as follows: in step S301, the gas desorption rate is subjected to curve fitting by the Vent equation, wherein the calculation function expression of the optimal value of the gas desorption rate is as follows: V t =V 1 t -kt 【4】Wherein, V t V is the gas desorption rate; 1is the gas desorption rate in the first minute; kt is the gas desorption rate attenuation coefficient; it is used to analyze the gas desorption rate of the coal sample after water injection to determine the optimal wetting time; the maximum crack opening, water injection flow rate and fracturing time are curve fitted by the Vent equation, where the calculation function expression of the optimal value of the maximum crack opening, water injection flow rate and fracturing time is as shown in formula [5]: The relationship between the maximum opening of the fracturing crack W, the water injection flow rate Q and the fracturing time t can be expressed by the following fitting relationship: W = 0.02 + 3.21 * 10 -5 Q 1.04 t 0.80 【5】W is the maximum fracture opening, Q is the water injection flow rate, and t is the fracturing time. This formula is used to evaluate the effects of different water injection flow rates and fracturing times on the hydraulic fracturing effect of soft and low permeability coal seams.

[0012] By adopting the above technical solution, the optimal wetting time is determined by the attenuation coefficient of the gas desorption rate, thereby optimizing the gas desorption efficiency; and the formula evaluates the effect of hydraulic fracturing under different conditions through the relationship between water injection flow and fracturing time, and then guides the actual hydraulic fracturing operations to achieve effective transformation of soft and low-permeability coal seams and improve the development efficiency and safety of coalbed methane.

[0013] The present invention is further configured as follows: after the step S3 is completed, the moisture content of the coal seam is detected, and when the moisture content of the coal seam reaches a dry basis moisture content exceeding 10%, drainage and drying treatment are required on site.

[0014] By adopting the above technical solutions, firstly, it helps to improve the quality and utilization efficiency of coal, because high water content will reduce the energy density and combustion efficiency of coal. Secondly, by reducing the moisture content of coal seams, the risk of spontaneous combustion of coal during transportation and storage can be reduced, and safety can be improved. In addition, the dried coal is easier to handle and process, which can improve the efficiency of coal processing. The drainage and drying process can also help reduce the emission of pollutants generated during the combustion of coal, which is environmentally friendly. Finally, for coal mining enterprises, by improving the quality of coal, economic benefits can be increased and market competitiveness can be improved.

[0015] The present invention is further configured as follows: in step S2, the surface inclination degree of the blasting area includes: nearly horizontal coal seam: a coal seam with an inclination angle of less than 5° during open-pit mining; gently inclined coal seam: a coal seam with an inclination angle of 5° to 10° during open-pit mining; inclined coal seam: a coal seam with an inclination angle of 10° to 45° during open-pit mining; steeply inclined coal seam: a coal seam with an inclination angle of more than 45° during open-pit mining.

[0016] The present invention is further configured as follows: in step S1, the safety area includes the splashing area of ​​blasting flying rocks, the blasting vibration influence area and the air shock wave influence area, and the safety area takes the maximum value among the splashing area of ​​blasting flying rocks, the blasting vibration influence area and the air shock wave influence area.

[0017] By adopting the above technical solution, the maximum values ​​of the splashing area of ​​blasting flying rocks, the area affected by blasting vibration and the area affected by air shock waves can be used to ensure the safety of workers and equipment to the greatest extent.

[0018] The present invention is further configured such that a protective net is provided at the edge of the surface safety area of ​​the blasting area.

[0019] By adopting the above technical solution, a protective net is used to improve the safety of the workers.

[0020] The present invention is further configured such that each explosion hole is 10m-30m away from an adjacent water injection hole.

[0021] By adopting the above technical scheme, appropriate spacing can ensure that the impact between each hole during blasting is limited to the adjacent holes, which helps to reduce the number of blasting times and the time to avoid blasting, improve the utilization rate of mining equipment, and optimize the distance between holes, which can reduce the rate of large blocks and improve the quality of ore and rock crushing. The rate of large blocks is 40%-50% less than that of single-row hole blasting.

[0022] In summary, the present invention has the following beneficial effects: first, by removing the surface soil of the blasting area to expose the rock, the accuracy and efficiency of the drilling operation are ensured, and at the same time, a safe area is cleared with the blasting area as the center, ensuring the safety of the operators; second, by accurately measuring the surface inclination, mine depth and the position of the original cracks in the coal seam in the blasting area, the length, position and angle of the blasting hole group and the position of the water injection hole can be scientifically determined, which helps to improve the blasting effect and reduce resource waste; drilling and setting of the drilling holes and water injection holes according to the measurement data can ensure the accuracy and safety of the blasting; in addition, re-determining the parameters of the blasting hole group and drilling further improves the accuracy of the blasting; finally, the charge structure of the energy-gathering tube and the detonating cord can effectively control the release of the blasting energy and reduce the impact on the surrounding environment. At the same time, the detonating cord connected in parallel ensures the synchronization of the blasting and improves the blasting efficiency. The strict implementation of the entire process not only improves the safety and efficiency of the blasting operation, but also contributes to environmental protection and the rational use of resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a basic flow diagram of an open-pit mine platform blasting method based on water medium energy conversion blasting in an embodiment of the present invention;

[0024] Figure 2It is a structural schematic diagram of an open-pit mine blasting method based on water medium energy conversion blasting in an embodiment of the present invention.

[0025] In the figure: 1, first blast hole; 2, second blast hole; 3, third blast hole; 4, slope; 5, guide seam. DETAILED DESCRIPTION

[0026] The following is combined with Figure 1 and 2 The present invention is described in further detail.

[0027] Example

[0028] like Figure 1 and Figure 2 As shown, an open-pit mine platform blasting method based on water medium energy conversion blasting comprises:

[0029] S1, confirm the blasting area of ​​the mining area through exploration, remove the covering soil on the surface of the blasting area until the rock for drilling is exposed, and clear a safe area with the blasting area as the center;

[0030] S2, measuring the surface inclination of the blasting area, the depth of the mine in the blasting area, and the location of the original fractures of the coal seam, dividing the blasting area into a high area and a low area according to the surface inclination of the blasting area, the depth of the mine in the blasting area, and the location of the original fractures of the coal seam, and determining the length, position, and angle of the surface blasting hole group in the blasting area, wherein the blasting hole group includes a plurality of blasting holes arranged in the high area, and the blasting hole group is arranged in the high area, and then defining the positions of a plurality of water injection holes according to the locations of the original fractures of the coal seam and the blasting holes near the boundary between the high area and the low area, and the water injection holes are arranged in the low area;

[0031] The surface inclination of the blasting area in step S2 includes:

[0032] Nearly horizontal coal seam: a coal seam with an inclination of less than 5° during open-pit mining; gently inclined coal seam: a coal seam with an inclination of 5° to 10° during open-pit mining; inclined coal seam: a coal seam with an inclination of 10° to 45° during open-pit mining; steeply inclined coal seam: a coal seam with an inclination of more than 45° during open-pit mining.

[0033] S3, low area blasting, according to the measurement data of S2, several water injection holes are drilled and water is injected to moisten them, and the first-level explosive blasting and the second-level water medium energy conversion blasting are carried out:

[0034] The wetting step is followed by step S3, which specifically includes the following steps:

[0035] S301, wetting, low-pressure water injection is performed into the original fractures of the coal body through the water injection holes to wet the coal body. The water injection time and the holding time after water injection are both affected by the specific gas desorption rate, the maximum opening of the fractures, the water injection flow rate and the fracturing time. Water is injected to fill the holes and fractures to provide a high-conductivity medium for the detonation pressure;

[0036] S302, primary explosive blasting, after wetting, blasting explosives are loaded into the water injection holes, the holes are sealed, and the explosives are detonated. The explosion shock wave is released in the water-containing environment provided in step S301, expanding the original cracks in the coal body and generating new cracks. The safety area of ​​the water injection hole blasting does not exceed the scope of the safety area cleared with the blasting area as the center to prevent air leakage during the blasting stage. The sealing length is 8-9 meters to prevent air leakage during the blasting stage. The two ends are sealed and the middle is charged with explosives for blasting. A recyclable capsule sealer is used for sealing. The distance between the middle charging sections is 0.5 meters, and the pressure used by the capsule sealer is 10-15Mpa.

[0037] S303, secondary water medium transducer blasting, determining a new blasting point and water injection path, and using a transducer to continuously inject pulsating water with a certain frequency into the newly formed fractures.

[0038] After step S3 is completed, the moisture content of the coal seam needs to be tested. When the moisture content of the coal seam reaches a dry basis moisture content of more than 10%, the site needs to be drained and dried to reduce the impact of the wet environment on subsequent blasting operations. Before ground blasting, the stability of the coal seam needs to be assessed and reinforcement measures taken if necessary to ensure the safety of the blasting operation. Otherwise, it is not necessary.

[0039] In step S301,

[0040] The gas desorption rate is curve-fitted using the Vent equation, where the calculation function expression of the optimal gas desorption rate is as follows:

[0041] V t =V 1 t -kt 【4】

[0042] Among them, V t V is the gas desorption rate; 1 is the gas desorption rate in the first minute; kt is the gas desorption rate attenuation coefficient; it is used to analyze the gas desorption rate of coal samples after water injection to determine the optimal wetting time;

[0043] The maximum crack opening, injection flow rate and fracturing time are curve-fitted using the Vent equation, where the calculation function expression of the optimal maximum crack opening, injection flow rate and fracturing time is as follows:

[0044] The relationship between the maximum opening W of the fracturing crack, the injection flow rate Q and the fracturing time t can be expressed by the following fitting relationship:

[0045] W=0.02+3.21*10 -5 Q 1.04 t 0.80 【5】

[0046] Among them, W is the maximum opening of the fracture; Q is the water injection flow rate; t is the fracturing time. This formula is used to evaluate the impact of different water injection flow rates and fracturing times on the hydraulic fracturing effect of soft and low permeability coal seams.

[0047] S4, based on the measurement data of S2, re-determine the length, position and angle of the surface blasting hole group in the blasting area, and then conduct corresponding drilling.

[0048] S5, on the surface of the blasting area, the detonating cord is pre-tied to the shaped tube, and then the explosive roll is tied to the shaped tube according to the conventional design of the charging structure and charging amount, and the shaped tube and the explosive roll are put into the third blasting hole 3 together, with the shaped tube backing against the side of the retained rock mass, and the blasting hole group is connected with the detonating cord in parallel as a whole.

[0049] S6. Evacuate all auxiliary equipment. After ensuring that all auxiliary equipment has been evacuated and confirming that safety precautions are in place, perform ignition and detonation operations. Before starting blasting operations, conduct a comprehensive inspection of the equipment to ensure that it is in safe blasting operation conditions, thereby ensuring the safety of the operation.

[0050] According to the technical measures for safe construction of water injection holes, the construction safety of water injection holes should be ensured, including hole depth, sealing length, operating pressure of the sealer, etc., to prevent air leakage during the blasting stage, and use recyclable capsule sealers to seal the holes to ensure the safe construction of water injection holes.

[0051] According to the measurement data of S2, several blasting hole positions for blasting are determined, and the vertical direction or parallel direction of the blasting holes is set according to the surface inclination of the blasting area.

[0052] During high-pressure pulsating pressure and low-pressure pulsating fracturing water injection, the pressure and frequency should be strictly controlled to prevent equipment damage and personal injury.

[0053] If step S3 and step S4 are executed simultaneously, the working platform is required to be wider to accommodate the slag pile, which may affect the layout and efficiency of on-site operations; the height of the blasting pile is relatively large, which may affect the safety of the excavator operation; at the same time, there are many large blocks blasted, which will increase the workload of subsequent processing of large rocks. In addition, the vibration, air shock wave, flying rocks, harmful gases and noise generated during blasting are all major blasting hazard factors and will be difficult to calculate.

[0054] If step S3 is performed before step S4, surface blasting in open-pit coal mines may destroy the water-containing environment required for water-medium blasting, reduce the effect of the explosion shock wave released in the water-containing environment, and thus reduce the ability to expand the original cracks in the coal body and generate new cracks. In addition, the vibration and flying rocks generated by surface blasting may affect the subsequent water-medium blasting equipment and operation safety, increasing the operation risk. At the same time, surface blasting may cause disturbance of coal seam gas, increasing the risk of gas explosion during water-medium blasting.

[0055] If step S3 is performed before step S4, firstly, water medium blasting can increase the permeability coefficient of the coal seam, improve the coal seam gas extraction rate, and provide a solution for the rapid elimination of coal seam bursts. Secondly, compared with air medium, water pressure blasting has the characteristics of long stress wave action time and high energy utilization rate, high energy transfer efficiency, good safety, and significant permeability enhancement effect. In addition, this step fully utilizes the advantages of hydraulic fracturing and the characteristics of blasting shock waves to enhance the permeability and wetting of the coal body and the efficient exploitation of coalbed methane. Specifically, the shock wave expands the cracks of the coal body on a large scale, and the water pressure enhances the permeability and wetting, while fracturing and refining the cracks of the coal seam; water is injected to wet the coal body, and along with the above-mentioned fracturing pressure, water flow is supplemented and injected into the newly formed cracks, expanding the wetting range of the coal body, reducing the brittleness of the coal body, reducing the generation of coal mining dust and coal block collapse and splashing, increasing the moisture content of coal particles, and weakening the flying ability of coal particles.

[0056] Open-pit coal mines usually use a combination of technologies to confirm the location of primary cracks in coal seams, including using a water flow meter to monitor the uniformity of water flow distribution to determine the location of cracks, obtaining fracturing crack morphology parameters through underground observations, and using sky-air-ground coordinated intelligent monitoring technology, combined with three-dimensional laser scanning, thermal imaging, DI nSAR deformation field analysis, GNSS monitoring, and crack displacement meters to conduct stability analysis of the spoil dump and direct observation of cracks.

[0057] Energy-focused tube blasting can reduce the number of blastholes, reduce labor intensity, save drilling time, and increase single-cycle footage. In addition, energy-focused tube blasting technology can significantly reduce over-excavation and under-excavation, and reduce the amount of grouting used in the later stage.

[0058] When performing blasting operations, first, the detonating cord needs to be fixed to the energy-gathering tube on the surface. Next, according to the pre-designed charge structure and the required amount of explosives, the explosive roll is also fixed to the energy-gathering tube. Then, these assemblies containing the energy-gathering tube and the explosive roll are placed together in the pre-drilled third blast hole 3. In this process, the energy-gathering tube should be close to the side of the rock mass that needs to be retained. As for the specific amount, density, length of the charge and the type of detonator used, they all need to be flexibly adjusted according to the specific depth of the third blast hole 3 to ensure that the blasting effect meets expectations. Such operations are intended to achieve effective pre-cracking of the rock mass by precisely controlling the use of explosives, while protecting the parts that need to be retained from damage.

[0059] If the blast hole on the surface of the blasting area needs to be directly connected to the coal seam, the explosive barrel must be used for charging. When charging, each section of the barrel must be reliably connected one by one and pushed to the designed charging position. The charging section is laid with a coal mine permissible detonating cord in the barrel. At the end of the detonator, the detonating cord should be 1m to 2m longer than the charging section.

[0060] The minimum safe distance of the splashing area of ​​blasting flying rocks, where the calculation function expression of the optimal value M1 is as follows:

[0061] M1=20Kn2m【1】

[0062] In formula [1], M1 is the safe distance for flying rocks, K is a coefficient related to rock properties, topography, geology and meteorology, and is generally taken as 1.0-1.5; a larger value is taken when facing the throwing direction, and a smaller value is taken when facing away from the throwing direction; n is the explosive effect index of the largest explosive package; m is the minimum resistance line of the largest explosive package. To ensure absolute safety, the result calculated by the above formula is generally multiplied by a coefficient of 3-4; in windy weather, the flying distance in the downwind direction should be increased by 25%-50%.

[0063] The minimum safe distance of the blasting vibration affected area, where the calculation function expression of the optimal value M2 is as follows:

[0064] M2=(k / v)1 / a*Q【2】

[0065] In formula [2], M2 is the safe distance of the impact of blasting seismic waves on adjacent equipment or buildings; Q is the amount of explosives, the total amount for simultaneous blasting and the maximum amount for delayed blasting, the unit is kilograms, and the amount index is generally 1 / 3; v is the vibration speed of the safe particle, the unit is centimeters per second; k and a are coefficients and attenuation indexes related to the topography and geological conditions of the blasting site.

[0066] The minimum safe distance of the air shock wave impact area. When the throwing blasting effect index is greater than or equal to 2, the air shock wave has the greatest destructive power on adjacent equipment or buildings. The calculation function expression of the optimal value M3 is as follows:

[0067] M3=Gy*kB【3】

[0068] In formula [3], M3 is the safety distance; Gy is the total number of blastings during the same period; kB is the safety factor, which is determined by the throwing blasting index and the safety level of the equipment or building.

[0069] If the surface inclination of the blasting area is an inclined coal seam and a steeply inclined coal seam, the blasting hole group includes a plurality of first blasting holes 1, a plurality of second blasting holes 2, a plurality of guide seams 5 and a plurality of third blasting holes 3. The first blasting hole 1 is vertically arranged on the surface of the blasting area, and the hole depth of the end of the first blasting hole 1 extending toward the slope gradually decreases. The guide seam 5 is arranged on the side of the first blasting hole 1 close to the slope, and the seam depth of the guide seam 5 closest to the first blasting hole 1 is greater than that of the first blasting hole 1. The seam depth of the guide seam 5 arranged toward the side of the slope gradually shortens, and the measured hole positions and seam positions are surrounded by lime powder.

[0070] The guide seam 5, the second blast hole 2 and the third blast hole 3 are all parallel to the ground surface inclination of the blasting area.

[0071] Drill holes according to the corresponding hole diameter and hole depth. When drilling the guide seam 5 and the reserved hole of the slope, first use the weight principle to set the vertical correction rod in the vertical direction, then fix the horizontal correction rod on the vertical correction rod, and then lead out a slope rod from the right angle between the two. Use an angle measuring instrument to adjust the slope of the slope rod. The other end of the slope rod is fixed on the ground. Corresponding vertical correction rods, horizontal correction rods, and slope rods are set on each guide seam 5 and each row of pre-cracking nets in the same straight line. The horizontal correction rod is set on both sides of the guide seam 5 and the third blasting holes 3 on both sides of the same straight line. The horizontal correction rod is then connected by a transverse fixing rod. The transverse fixing rod maintains a horizontal state and corresponding slope rods are set at the drilling nodes of the guide seam 5 and the positions of the third blasting holes 3 and the second blasting holes 2, so that the parallelism of each guide seam 5 and the third blasting holes 3 and the second blasting holes 2 is equal to the slope surface.

[0072] A plurality of guide seams 5 are arranged between the first blast hole 1 and the second blast hole 2, and the apertures of the guide seams 5 from the ground to the underground are shortened successively, which can break the rock structure between the first blast hole 1 and the second blast hole 2, so that the rock between the two can be completely broken and accumulated after blasting, and a stable slope surface is formed after cleaning. In the later construction, the stability of the entire slope is stronger, and the upper end opening of the guide seam is larger, which can discharge the high-pressure gas formed by the explosives and the energy-gathering tube into the air during the explosion, preventing excessive impact on the pre-crack hole, avoiding damage to the contour surface of the slope, reducing the influence of blasting vibration on the entire final slope during blasting, improving the stability of the final slope, and ensuring construction safety.

[0073] The energy-focused tube can convert the detonation wave generated by the explosion of explosives into a high-pressure, high-speed, high-energy jet, effectively cutting the rock into seams, reducing the number of drill holes, expanding the hole spacing, and reducing the amount of detonating tubes used.

[0074] If there is a rough requirement for the degree of rock crushing, the degree of rock crushing after blasting can be effectively controlled by adjusting the blasting parameters and using numerical simulation technology, and whether the expected blasting shape has been achieved can be evaluated.

[0075] The blasting parameters include step height, chassis resistance line, single hole charge, hole spacing, row spacing, charge length, blockage length and line charge density.

[0076] A protective net is set up at the edge of the surface safety zone of the blasting area, and the protective net set up at the edge of the blasting area should have sufficient strength and area to ensure that falling objects can be effectively intercepted and reduce damage to personnel and equipment.

[0077] The distance between each blast hole and the adjacent water injection hole is 10m-30m.

[0078] If a blind shot occurs after the blast, the power supply should be cut off and short-circuited first. It is strictly forbidden to forcibly pull out or take out the explosive package. Check the integrity of the detonating cord or detonating tube and re-detonate after repair, or deal with it through methods such as induced explosion, water filling, parallel hole charging blasting, etc. Finally, gently take out the filling material to induce explosion, and carefully check the explosion pile after processing, collect the remaining blasting equipment and destroy it uniformly, and record the processing process and reasons.

[0079] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An open-pit mine blasting method based on water medium energy conversion blasting, characterized in that: include: S1, confirm the blasting area of ​​the mining area through exploration, remove the covering soil on the surface of the blasting area until the rock for drilling is exposed, and clear a safe area with the blasting area as the center; S2, measuring the surface inclination of the blasting area, the depth of the mine in the blasting area, and the location of the original fractures of the coal seam, dividing the blasting area into a high area and a low area according to the surface inclination of the blasting area, the depth of the mine in the blasting area, and the location of the original fractures of the coal seam, and determining the length, position, and angle of the surface blasting hole group in the blasting area, wherein the blasting hole group includes a plurality of blasting holes arranged in the high area, and the blasting hole group is arranged in the high area, and then defining the positions of a plurality of water injection holes according to the locations of the original fractures of the coal seam and the blasting holes near the boundary between the high area and the low area, and the water injection holes are arranged in the low area; S3, low area blasting, according to the measurement data of S2, several water injection holes are drilled and water is injected to moisten them, and primary explosive blasting and secondary water medium energy conversion blasting are carried out; S4, high area blasting, re-measure the surface inclination of the blasting area, the depth of the blasting area and the location of the original cracks in the coal seam according to the S3 blasting, determine the length, location and angle of the surface blasting hole group in the blasting area according to the re-measured measurement data, and then drill the corresponding holes; S5, pre-binding the detonating cord to the shaped tube on the surface of the blasting area, and then binding the explosive roll to the shaped tube according to the conventional design of the charge structure and charge amount, placing the shaped tube and the explosive roll together into the third blasting hole, with the shaped tube backing against one side of the retained rock mass, and the blasting hole group connected by the detonating cord in parallel; S6, evacuate all auxiliary equipment. After ensuring that all auxiliary equipment has been evacuated and confirming that safety precautions are in place, perform ignition and detonation operations.

2. The open-pit mine blasting method based on water medium energy conversion blasting according to claim 1 is characterized in that: The following steps are included after step S3: S301, wetting, low-pressure water injection is performed into the original fractures of the coal body through the water injection holes to wet the coal body. The water injection time and the holding time after water injection are affected by the specific gas desorption rate, the maximum fracture opening, the water injection flow rate and the fracturing time; S302, primary explosive blasting, after wetting, blasting explosives are loaded into the water injection hole, the hole is sealed, and the explosives are detonated, and the explosion shock wave is released in the water-containing environment provided in step S301, expanding the original cracks in the coal body and generating new cracks, and the safety area of ​​the water injection hole blasting does not exceed the scope of the safety area cleared with the blasting area as the center; S303, secondary water medium transducer blasting, determining a new blasting point and water injection path, and using a transducer to continuously inject pulsating water with a certain frequency into the newly formed fractures.

3. The open-pit mine blasting method based on water medium energy conversion blasting according to claim 2 is characterized in that: In step S301, The gas desorption rate is curve-fitted using the Vent equation, where the calculation function expression of the optimal gas desorption rate is as follows: In t =V1t -kt 【4】 Among them, V t is the gas desorption rate; V1 is the gas desorption rate in the first minute; kt is the gas desorption rate attenuation coefficient; it is used to analyze the gas desorption rate of coal samples after water injection to determine the optimal wetting time; The maximum crack opening, injection flow rate and fracturing time are curve-fitted using the Vent equation, where the calculation function expression of the optimal maximum crack opening, injection flow rate and fracturing time is as follows: The relationship between the maximum opening W of the fracturing crack, the injection flow rate Q and the fracturing time t can be expressed by the following fitting relationship: W=0.02+3.21*10 -5 Q 1.04 t 0.80 【5】 Among them, W is the maximum opening of the fracture; Q is the water injection flow rate; t is the fracturing time. This formula is used to evaluate the impact of different water injection flow rates and fracturing times on the hydraulic fracturing effect of soft and low permeability coal seams.

4. The open-pit mine blasting method based on water medium energy conversion blasting according to claim 2 is characterized in that: In step S301, water is injected to fill the pores and fissures to provide a medium with high conductivity for the bursting pressure.

5. The open-pit mine blasting method based on water medium energy conversion blasting according to claim 2 is characterized in that: In step S302, the sealing length is 8-9 meters to prevent air leakage during the blasting stage. The holes are sealed at both ends and charged in the middle for blasting. A recyclable capsule sealer is used for sealing. The distance between the charging sections is 0.5 meters and the pressure used by the capsule sealer is 10-15 MPa.

6. The open-pit mine blasting method based on water medium energy conversion blasting according to claim 2 is characterized in that: After the step S3 is completed, the moisture content of the coal seam is detected. When the moisture content of the coal seam reaches a dry basis moisture content exceeding 10%, drainage and drying treatment are required on site.

7. The open-pit mine blasting method based on water medium energy conversion blasting according to claim 1 is characterized in that: In step S1, the safety area includes the splashing area of ​​blasting flying rocks, the area affected by blasting vibration and the area affected by air shock waves, and the safety area is the maximum value among the splashing area of ​​blasting flying rocks, the area affected by blasting vibration and the area affected by air shock waves.

8. The open-pit mine blasting method based on water medium energy conversion blasting according to claim 1 is characterized in that: A protective net is arranged at the edge of the surface safety zone of the blasting area.

9. The open-pit mine blasting method based on water medium energy conversion blasting according to claim 1, characterized in that: The distance between each blast hole and the adjacent water injection hole is 10m-30m.

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