Fracturing and blasting collaborative mining method for underground hard ore

Abstract

The invention discloses a fracturing and blasting collaborative mining method for underground hard ores, and relates to the technical field of ore mining. Drilling parameters are determined, fracturing holes and blasting holes distributed in a fan shape are formed, high-pressure water is injected into the fracturing holes, staged fracturing operation is carried out, detonating devices are arranged in the blasting holes, the blasting holes and the fracturing holes are plugged respectively, and millisecond blasting is carried out on the blasting holes after the detonating network is checked to be correct. The hydraulic fracturing technology is adopted for advanced softening and crushing of the ore, the millisecond blasting technology is adopted for further crushing of the ore, hydraulic fracturing softening and crushing and blasting ore breaking control can be fully utilized, the technology is mature, the process is simple, operation is convenient, and the method has the remarkable advantages of being safe, environmentally friendly, efficient, economical and the like; the purposes of controlling the ore lumpiness, saving explosives, reducing the cost, reducing the environmental pollution and controlling the safety risk are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of ore mining, and in particular to a fracturing and blasting coordinated mining method for underground hard ores. Background Art

[0002] In the underground mining process of non-coal mineral resources, ore crushing is an indispensable core content. The efficiency and cost of ore crushing have an important impact on the production efficiency, output and economic indicators of the mine. Safe, efficient and low-cost ore crushing technology is an important guarantee for the sustainable and healthy development of mines. The current methods of crushing hard ores mainly include blasting, hydraulic fracturing, mechanical equipment, etc. Among them, blasting has high efficiency, but there are problems such as complex management, prone to safety accidents, generation of harmful gases, and high cost; mechanical equipment has advantages in long-distance mine mining, but there are problems such as high initial investment cost, large material consumption, and noise; hydraulic fracturing is to inject high-pressure water through drilling, and form a suitable fracture network by controlling the number and shape of fractures, thereby achieving softening and crushing of ore, which has significant advantages. How to use the existing technical advantages to achieve safe, efficient and low-cost crushing of hard ores is a scientific and technological problem that urgently needs to be studied and solved in underground mining.

[0003] In previous studies, the existing application publication number CN117703373A, entitled "A method for pre-treating ore with hydraulic fracturing and blasting in the same space", proposed a method for pre-treating ore with hydraulic fracturing and blasting in the same space, and its main steps are: 1. Constructing and excavating a borehole for fracturing according to the actual situation of the ore on site; 2. Installing a fracturing device for hydraulic fracturing in the borehole; 3. Dividing the depth of the borehole into multiple sections and performing segmented hydraulic fracturing operations; 4. Removing the fracturing equipment in the borehole and placing an explosive assembly for blasting; 5. Detonating the explosive assembly in the borehole; This method uses fracturing and blasting in the same borehole to pre-crush the ore rock, creating conditions for other mining methods (such as natural collapse under the action of gravity and stress).

[0004] The existing authorization announcement number CN114753844B is named "A hydraulic fracturing-mechanical cutting coordinated mining method based on the staged open-pit mining method" and provides a hydraulic fracturing-mechanical cutting coordinated mining method based on the staged open-pit mining method, which involves a mining method for gently inclined medium-thick non-coal mines. The main steps are: 1. Determine the length, density and distribution of hydraulic fracturing boreholes; 2. Carry out mining in stages or in stages from bottom to top, and use a tunneling machine to cut the ore body during mining; this method uses hydraulic fracturing to crush the ore rock in advance, and then crush it under mechanical cutting.

[0005] The above methods adopt hydraulic fracturing-blasting shared space, hydraulic fracturing and other methods to pre-treat and crush the ore rock, creating conditions for the natural collapse and mechanical cutting and crushing of the ore, but their scope of use is limited, and they cannot meet the requirements of safe and efficient mining in terms of hard ore crushing size and working space. It is particularly important to use the synergistic effect of hydraulic fracturing and blasting to achieve safe and efficient mining of hard ore. In summary, the existing underground ore blasting methods have the problems of large hard ore crushing size, limited working space, high blasting cost, high risk and great environmental pollution. Therefore, the present invention proposes a fracturing and blasting coordinated mining method for underground hard ore to solve the problems existing in the prior art. Summary of the invention

[0006] In view of the above problems, the purpose of the present invention is to propose a method for the coordinated mining of underground hard ores by hydraulic fracturing and blasting, so as to solve the problem that the existing method of using hydraulic fracturing and blasting to crush hard ores has a limited scope of use, cannot meet the requirements for safe and efficient mining of hard ores, and cannot effectively utilize the coordinated effect of hydraulic fracturing and blasting to achieve safe and efficient mining of hard ores.

[0007] In order to achieve the purpose of the present invention, the present invention is implemented by the following technical scheme: a method for fracturing and blasting coordinated mining of underground hard ore, comprising the following steps:

[0008] Step 1: In the ore mining area, the drilling parameters of the blasting holes and the fracturing holes are determined according to the specification parameters of the ore mining area, and then in the rock drilling access of the mine room of the ore mining area, starting from the end, the fracturing holes and the blasting holes distributed in a fan shape are opened according to the determined drilling parameters;

[0009] Step 2: Determine the position of the segment in the fracturing hole according to the ore properties, ground stress conditions, and ore crushing block size requirements, push the sealer into the designated sealing position in the fracturing hole, use a high-pressure water pump to inject high-pressure water into the sealing section of the fracturing hole for segmented fracturing, and retreat the segmented fracturing from the bottom of the hole to the hole mouth in sequence until all the segmented fracturing in the fracturing hole is completed, and then take out the sealer;

[0010] Step 3: After the fracturing operation of the fracturing hole is completed, the explosive package, the detonator and the wire are installed in the blasting hole, and then the blasting hole and the fracturing hole are respectively sealed with fillers to complete the sealing operation;

[0011] Step 4: Check the blasting network to ensure that the explosive packages, detonators and wires are connected correctly, then perform micro-difference blasting in the blasting holes to complete ore crushing and ore dropping.

[0012] A further improvement is that in step one, the drilling parameters are determined based on the ore properties, ground stress, mine size and stage height of the ore mine, and the hole spacing between the fracturing holes and the blasting holes is determined based on the fracturing crack expansion radius of the fracturing holes and the blasting crushing influence radius.

[0013] Further improvements are: the drilling parameters include drilling depth and hole spacing, the drilling depth is determined according to the ore mining area segment height, the drilling depth of the blasting hole exceeds the mining area segment height by 2 to 5 meters, and the drilling depth of the fracturing hole is 1 to 4 times the drilling depth of the blasting hole.

[0014] A further improvement is that in step 1, each stage in the ore mining area is composed of a plurality of sections, and the four groups of fracturing holes and five groups of blasting holes in each section in the ore mining area are distributed in a fan-shaped staggered manner.

[0015] A further improvement is that in step one, each stage in the ore mine is composed of several segments, the fracturing holes are provided in a group and the depth is greater than the height of the mine stage, and the blasting holes are provided in several groups and are distributed in a fan shape in each segment of the ore mine.

[0016] A further improvement is that in step 2, when the sealer is pushed into the fracturing hole, segmented fracturing sealing sections are formed in sequence from the hole bottom to the hole mouth according to the segmented fracturing requirements until all segmented fracturing is completed.

[0017] A further improvement is that in step 2, when performing staged fracturing, the staged fracturing position is determined from the bottom of the fracturing hole to the hole mouth according to the requirements of the ore crushing size, and then the fracturing is carried out backwards in sequence according to the staged fracturing position, using the blasting hole as an observation hole, and fracturing is stopped when water is observed to flow out, and then the next staged fracturing is carried out until all staged fracturing in the fracturing hole is completed.

[0018] A further improvement is that in step three, the filler is taphole mud, and the sealing length of the fracturing hole and the blasting hole is greater than or equal to the length of the minimum resistance line of the ore.

[0019] A further improvement is that in step 4, the vibration, dust and noise during the blasting process are monitored during the implementation of the micro-difference blasting, and the blasting effect is checked after the micro-difference blasting is completed, including the degree of ore crushing and the distribution of the blast pile.

[0020] The beneficial effects of the present invention are as follows: the present invention adopts hydraulic fracturing technology to pre-soften and crush the ore, and uses micro-difference blasting technology to further crush the ore, can make full use of hydraulic fracturing softening and crushing, blasting ore drop control, mature technology, simple process, easy operation, and has the remarkable characteristics of safety, environmental protection, high efficiency, economy, etc., to achieve the purpose of ore block size control, saving explosives, reducing costs, reducing environmental pollution, and controlling safety risks, and realize the safe, environmentally friendly, efficient, low-cost rapid mining of hard ore, and the vertical fracture size of the ore is controlled by the segmented fracturing of the fracturing holes, and the hole spacing between the fracturing holes and the blasting holes controls the horizontal fracture size of the ore, so as to achieve the coordinated control of the ore fracture block size by fracturing and blasting, which can effectively avoid the problems of large ore fragmentation block size, environmental pollution, blasting safety accidents, high cost, vibration hazards, etc. in the process of blasting mining of hard ore, and plays an important role in promoting the safe, environmentally friendly, efficient and low-cost mining of hard ore. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0022] Figure 1 It is a schematic diagram of the process of the fracturing and blasting coordinated mining method of underground hard ore of the present invention;

[0023] Figure 2 is a schematic diagram of the distribution of fracturing holes and blasting holes in the first embodiment of the present invention;

[0024] Figure 3 is a schematic diagram of the segmented structure of the fracturing hole in the first embodiment of the present invention;

[0025] Figure 4 It is a schematic diagram of the blast hole charging structure in Embodiment 1 and Embodiment 2 of the present invention;

[0026] Figure 5 is a schematic diagram of the segmented structure of the fracturing hole in the second embodiment of the present invention;

[0027] Figure 6 It is a schematic diagram of blasting hole distribution in the second embodiment of the present invention.

[0028] Among them: 1. blasting hole; 2. fracturing hole; 3. segmented fracturing position; 4. hole sealer position; 5. high-pressure water pump; 6. explosive package; 7. detonator; 8. filling material; 9. wire; 10. continuous charging section. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Embodiment 1

[0031] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 This embodiment provides a method for mining underground hard ores by fracturing and blasting, comprising the following steps:

[0032] Step 1: In an ore mine with a height of 100m and a burial depth of 300m, the height of the mine pillar is 100m, the width is 20m, and the length is the thickness of the ore body. The ore mine is divided into four sections within 100m of the mine height. The height of each section is 25m. The drilling parameters of blasting hole 1 and fracturing hole 2 are determined according to the specifications of the ore mine. Then, in the rock drilling access of the mine room of the ore mine, starting from the end, Drill upward fan-shaped holes in each segmented rock drilling route, drill four groups of fracturing holes 2 and five groups of blasting holes 1 in each segment, and the four groups of fracturing holes 2 and the five groups of blasting holes 1 are staggered in a fan-shaped distribution, where the diameter of blasting hole 1 is 80mm, the diameter of fracturing hole 2 is 90mm, the maximum distance between blasting hole 1 and fracturing hole 2 is 5m, the drilling depth of blasting hole 1 exceeds the segmented height of the stope by 2m, and the drilling depth of fracturing hole 2 is the same as that of blasting hole 1;

[0033] In this embodiment, the drilling parameters are determined according to the ore properties, ground stress, stope size and stage height of the ore stope. The drilling parameters include drilling depth and hole spacing. The drilling depth is determined according to the segmented height of the ore stope. The hole spacing between the fracturing hole 2 and the blasting hole 1 is determined according to the expansion radius of the fracturing crack of the fracturing hole 2 and the blasting crushing influence radius. The hole spacing is determined according to the ore crushing size.

[0034] Step 2: Determine the segmented position in the fracturing hole according to the ore properties, ground stress conditions, and ore crushing size requirements, i.e., segmented fracturing position 3. Push the double-headed sealer into the designated sealing position in the fracturing hole 2 for segmented sealing. The sealer position 4 is as follows: Figure 3 As shown, when the sealer is pushed into the fracturing hole 2, according to the staged fracturing requirements, staged fracturing plugging sections are formed from the bottom of the hole to the hole mouth in sequence, and the high-pressure water pump 5 is used to fractur e in sequence, with the blasting hole 1 as the observation hole, until fracturing is stopped when water is observed to flow out, and then the next staged fracturing is carried out, until all staged fracturing in the fracturing hole 2 is completed, and then the sealer is taken out;

[0035] Step 3: After the fracturing operation of the fracturing hole 2 is completed, the porous granular ammonium oil explosive is used as the detonating charge 6, and the non-electric differential detonator is used as the detonating detonator 7. The detonating charge 6, the detonating detonator 7 and the conductor 9 are installed in the blasting hole in sequence. The continuous charging section 10 is as follows: Figure 4 As shown, a detonation network is formed, and then the blasting hole 1 and the fracturing hole 2 are blocked respectively with taphole mud as the filler 8, and the blocking length is greater than or equal to the minimum resistance line length of the ore;

[0036] Step 4: Check the blasting network to ensure that the explosive package 6, blasting cap 7 and wire 9 are connected correctly, then carry out micro-difference blasting in the blasting hole 1, monitor the vibration, dust and noise during the micro-difference blasting, check the blasting effect after the micro-difference blasting, including the degree of rock fragmentation and the distribution of the blast pile, and carry out subsequent ore transportation after the blasting is completed.

[0037] Embodiment 2

[0038] See also Figure 1 , Figure 4 , Figure 5 , Figure 6 This embodiment provides a method for mining underground hard ores by fracturing and blasting, comprising the following steps:

[0039] Step 1: In an ore mine with a height of 100m and a burial depth of 300m, the height of the mine pillar is 100m, the width is 20m, and the length is the thickness of the ore body. The ore mine is divided into four sections within 100m of the mine height. The height of each section is 25m. The drilling parameters of blasting hole 1 and fracturing hole 2 are determined according to the specification parameters of the ore mine. A group of fracturing holes 2 are opened vertically through the four sections from top to bottom, and then in the mine room of the ore mine, a group of fracturing holes 2 are opened vertically through the four sections. In the rock drilling route, starting from the end, upward fan-shaped holes are drilled in each segmented rock drilling route as blasting holes 1. Five groups of blasting holes 1 are drilled in each segment, and the five groups of blasting holes 1 are staggered in a fan shape. The diameter of blasting hole 1 is 80 mm, the diameter of fracturing hole 2 is 90 mm, the hole bottom spacing of blasting hole 1 is 5 m, and the row spacing of blasting hole 1 is determined according to the size of ore crushing. The drilling depth of blasting hole 1 is 30 m, and the drilling depth of fracturing hole 2 is 4 times the drilling depth of blasting hole;

[0040] In this embodiment, the drilling parameters are determined according to the ore properties, ground stress, stope size and stage height of the ore stope. The drilling parameters include drilling depth and hole spacing. The drilling depth is determined according to the segmented height of the ore stope. The hole spacing between the fracturing hole 2 and the blasting hole 1 is determined according to the expansion radius of the fracturing crack of the fracturing hole 2 and the blasting crushing influence radius. The hole spacing is determined according to the ore crushing size.

[0041] Step 2: Determine the segmented position in the fracturing hole according to the ore properties, ground stress conditions, and ore crushing size requirements, i.e., segmented fracturing position 3. Push the double-headed sealer into the designated sealing position in the fracturing hole 2 for segmented sealing. The sealer position 4 is as follows: Figure 5 As shown, when the sealer is pushed into the fracturing hole 2, according to the requirements of staged fracturing, a plugging section is formed in sequence from the bottom of the hole to the hole mouth, and a high-pressure water pump 5 is used to inject high-pressure water into the plugging section of the fracturing hole 2 for staged fracturing. From the bottom of the fracturing hole 2 to the hole mouth, fracturing is performed backward in sequence, with the blasting hole 1 as an observation hole, until water is observed to flow out, the fracturing is stopped, and the next staged fracturing is performed, until all staged fracturing in the fracturing hole 2 is completed, and then the sealer is taken out;

[0042] Step 3: After the fracturing operation of the fracturing hole 2 is completed, the porous granular ammonium oil explosive is used as the detonating charge 6, and the non-electric differential detonator is used as the detonating detonator 7. The detonating charge 6, the detonating detonator 7 and the conductor 9 are installed in the blasting hole 1 in sequence, and the continuous charging section 10 is as follows: Figure 4 As shown, a detonation network is formed, and then the blasting hole 1 and the fracturing hole 2 are blocked respectively with taphole mud as the filler 8, and the blocking length is greater than or equal to the minimum resistance line length of the ore;

[0043] Step 4: Check the blasting network to ensure that the explosive package 6, blasting cap 7 and wire 9 are correctly connected, then carry out micro-difference blasting on the blocked blasting hole 1, monitor the vibration, dust and noise during the micro-difference blasting, check the blasting effect after the micro-difference blasting, including the degree of rock crushing and the distribution of the blast pile, and carry out subsequent ore transportation after the blasting is completed.

[0044] In this embodiment, upward fan-shaped medium-deep boreholes (including blasting holes 1 and fracturing holes 2) are arranged in the rock drilling access of the mine room of the ore mining area. The borehole size, borehole row spacing, borehole number, and fracturing borehole position and number are determined according to the mining area length, mine room width, and ore crushing block size requirements. The fracturing position of the fracturing borehole is determined according to the stage height of the ore mining area, and the drilling stage fracturing is implemented to control the fracture network in the ore. After achieving the expected effect of hydraulic fracturing, the drilling micro-difference blasting is implemented from the end of the rock drilling access to achieve effective crushing and ore dropping, which effectively integrates The technical advantages of hydraulic fracturing and blasting overcome the shortcomings of existing technologies, effectively utilize the crack network formed in the ore by hydraulic fracturing to pre-soften and crush the ore, create more free surfaces for subsequent blasting, and then further crush and drop the ore through micro-difference blasting, achieving effective control of ore fragmentation, reducing blasting drilling by more than 50%, saving more than 50% of explosives and blasting equipment, reducing dust concentration in the workplace by more than 30%, significantly reducing the harm of blasting vibration, significantly reducing safety risks, and effectively reducing CO2 emissions. It is in line with the country's "dual carbon" policy and has great promotion and application value.

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for mining underground hard ores by fracturing and blasting, characterized in that: The following steps are involved: Step 1: In the ore mining area, the drilling parameters of the blasting holes and the fracturing holes are determined according to the specification parameters of the ore mining area, and then in the rock drilling access of the mine room of the ore mining area, starting from the end, the fracturing holes and the blasting holes distributed in a fan shape are opened according to the determined drilling parameters; Step 2: Determine the position of the segment in the fracturing hole according to the ore properties, ground stress conditions, and ore crushing block size requirements, push the sealer into the designated sealing position in the fracturing hole, use a high-pressure water pump to inject high-pressure water into the sealing section of the fracturing hole for segmented fracturing, and retreat the segmented fracturing from the bottom of the hole to the hole mouth in sequence until all the segmented fracturing in the fracturing hole is completed, and then take out the sealer; Step 3: After the fracturing operation of the fracturing hole is completed, the explosive package, the detonator and the wire are installed in the blasting hole, and then the blasting hole and the fracturing hole are sealed with fillers to complete the sealing operation; Step 4: Check the blasting network to ensure that the explosive packages, detonators and wires are connected correctly, then perform micro-difference blasting in the blasting holes to complete ore crushing and ore dropping.

2. The method for mining underground hard ores by fracturing and blasting according to claim 1, characterized in that: In step 1, the drilling parameters are determined based on the ore properties, ground stress, stope size and stage height of the ore mine, and the hole spacing between the fracturing holes and the blasting holes is determined based on the fracturing crack expansion radius of the fracturing holes and the blasting crushing influence radius.

3. The method for mining underground hard ores by fracturing and blasting according to claim 2, characterized in that: The drilling parameters include drilling depth and hole spacing. The drilling depth is determined according to the ore mining field segment height. The drilling depth of the blasting hole exceeds the mining field segment height by 2 to 5 meters. The drilling depth of the fracturing hole is 1 to 4 times the drilling depth of the blasting hole.

4. The method for mining underground hard ores by fracturing and blasting according to claim 1, characterized in that: In the step 1, each stage in the ore mining area is composed of a plurality of sections, and the four groups of fracturing holes and the five groups of blasting holes in each section in the ore mining area are distributed in a fan-shaped staggered manner.

5. The method for mining underground hard ores by fracturing and blasting according to claim 1, characterized in that: In the step 1, each stage in the ore mine is composed of several sections, the fracturing holes are provided in a group and the depth is greater than the height of the mine stage, and the blasting holes are provided in several groups and are distributed in a fan shape in each section of the ore mine.

6. The method for mining underground hard ores by fracturing and blasting according to claim 1, characterized in that: In the step 2, when the sealer is pushed into the fracturing hole, segmented fracturing sealing sections are formed in sequence from the hole bottom to the hole mouth according to the segmented fracturing requirements until all segmented fracturing are completed.

7. The method for mining underground hard ores by fracturing and blasting according to claim 1, characterized in that: In the step 2, when performing staged fracturing, the staged fracturing position is determined from the bottom of the fracturing hole to the hole mouth according to the ore crushing size requirement, and then the fracturing is carried out backwards in sequence according to the staged fracturing position, with the blasting hole as the observation hole, until fracturing is stopped when water is observed to flow out, and then the next staged fracturing is carried out until all staged fracturing in the fracturing hole is completed.

8. The method for mining underground hard ores by fracturing and blasting according to claim 1, characterized in that: In the step three, the filler is cannon mud, and the sealing length of the fracturing hole and the blasting hole is greater than or equal to the minimum resistance line length of the ore.

9. The method for mining underground hard ores by fracturing and blasting according to claim 1, characterized in that: In the step 4, the vibration, dust and noise during the blasting process are monitored during the micro-difference blasting process, and the blasting effect is checked after the micro-difference blasting is completed, including the degree of ore crushing and the distribution of the blast pile.

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