An intelligent process method suitable for supercritical CO2 jetting rock fracturing in mines

Abstract

This invention discloses an intelligent process method for supercritical CO2 jet fracturing of rock in mines. The method includes dividing the target ore body into several layers, dividing the current mining layer into several mining areas, and further dividing the current mining area into several strips; designing the process parameters for supercritical CO2 jet fracturing, including intake airway, return airway, working face dimensions, slotting process parameters, and drilling process parameters; arranging the supercritical CO2 jet equipment, intelligent drilling rig, intelligent sealing device, conveyor, and intelligent monitoring and control system; performing intermittent mining and backfilling operations on each strip within the current mining area; and after completing the mining and backfilling of the current layer, proceeding to the next layer, repeating the cycle until the ore body is completely mined. This invention, through an integrated process of supercritical CO2 jet fracturing of non-blasting rock, intelligent sorting, CO2 recovery, and goaf backfilling, significantly improves mining safety and efficiency while achieving an organic combination of efficient resource utilization and environmental protection.

Description

Technical Field

[0001] This invention relates to the field of mining technology, and in particular to an intelligent process method for supercritical CO2 jet-induced rock fracturing applicable to non-metallic mines such as coal mines. Background Technology

[0002] With the gradual depletion of shallow mineral resources, deep mining has become an inevitable trend. Currently, mining mainly employs blasting and mechanical rock breaking methods, which have the following problems: blasting methods have poor safety, easily leading to gas explosions and roof collapses; mechanical rock breaking has low efficiency, severe tool wear, and high costs; traditional methods cause serious environmental pollution, with prominent issues such as dust and noise; and they have low automation levels, high labor intensity, and are difficult to achieve unmanned mining. Supercritical CO2 jet technology has advantages such as high energy density, good environmental friendliness, and strong controllability, and has shown promising application prospects in the field of rock breaking in recent years.

[0003] However, existing technologies are mostly focused on hard rock breaking in metal mines, and lack integrated system processes that combine backfilling mining, CO2 recovery and mineralization. In particular, there is a lack of intelligent and unmanned implementation plans for non-metallic mines such as coal mines. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide an intelligent process method for supercritical CO2 jet fracturing and rock breaking in mines, in order to solve the problems of poor safety, low efficiency and serious pollution of traditional mining methods mentioned in the background art, and to realize a non-explosive, continuous, intelligent and green mining method.

[0005] This invention relates to an intelligent process method for supercritical CO2 jet-induced rock fracturing in mines, comprising the following steps: S1. The upward layered filling mining method is adopted to divide the target ore body into several layers; the current mining layer is divided into several mining areas, and the strip filling mining method is adopted to divide the current mining area into several strips.

[0006] S2. Design the process parameters of supercritical CO2 jet based on the occurrence conditions of the target ore body, and design the intake airway, return airway, working face size parameters, grooving process parameters and drilling process parameters for the current mining area.

[0007] S3. Excavate and construct intake and return airways in the current mining area. Arrange supercritical CO2 jet equipment, intelligent drilling rigs, intelligent sealing devices, and conveyors in the roadways where the working face is located. Arrange intelligent identification devices for identifying solid waste and automatic sorting devices for sorting solid waste next to the conveyors. Arrange a carbon dioxide recovery system in the return airway. Arrange an intelligent monitoring and control system for monitoring and controlling the supercritical CO2 jet equipment, intelligent drilling rigs, intelligent sealing devices, conveyors, intelligent identification devices, automatic sorting devices, and carbon dioxide recovery system. S4. Conduct intermittent mining and backfilling operations in each strip of the current mining area, including: 1) First, control the supercritical CO2 jet equipment to perform grooving operations on the working surface to form a free surface according to the grooving process parameters; then, control the intelligent drilling rig to perform drilling operations to form CO2 injection holes according to the drilling process parameters; then, control the intelligent sealing device to insert a sealing device into the CO2 injection hole according to the sealing process parameters; then, control the supercritical CO2 jet equipment to connect with the sealing device to implement supercritical CO2 jet fracturing and rock breaking; finally, control the conveyor to output ore and the carbon dioxide recovery system to collect CO2 gas. 2) Prepare filling material and fill the strip space left by the mining in step 1) with the filling material; 3) Repeat steps 1) and 2) until the mining and backfilling of the current mining area is completed; S5. Repeat step S4 to complete the mining and backfilling of the current mining layer; S6. Based on the upward layered filling mining method, after completing the current layer mining and filling, the next layer operation is carried out, and the cycle continues until the ore body is mined out.

[0008] Furthermore, in step S2, one intake airway is arranged in the current mining area, and the intake airway is located in the middle of the mining area; two return airways are arranged in the current mining area, and the return airways are arranged on both sides of the mining area.

[0009] Furthermore, the supercritical CO2 jet process parameters designed in step S1 include: jet pressure 30-40 MPa, jet temperature 50-60℃, jet flow rate 50-70 L / min, and single-hole jet action time 2-5 minutes.

[0010] Furthermore, the working surface dimensions designed in step S2 are: length 10-15m, width 1.0-1.5m, and height 1.5-2.0m.

[0011] Furthermore, the grooving process parameters designed in step S2 include: grooving height 1.6m and grooving depth 0.8m.

[0012] Furthermore, the drilling process parameters designed in step S2 include: a single-hole arrangement for drilling, a drilling diameter of 45-55mm, a drilling depth of 2.5-3.5m, a drill bit rotation speed of 200-400r / min, a propulsion speed of 0.5-1.0m / min, and a drilling inclination angle consistent with the coal seam inclination angle.

[0013] Furthermore, the sealing process parameters designed in step S2 include: sealing depth of 0.8m and sealing pressure of 40MPa.

[0014] Furthermore, the intermediate tube of the sealing device mentioned in step 1) is a Laval tube.

[0015] Further, the preparation of the filling material in step 2) includes: using mining solid waste as the filling raw material, adding a mineralizing agent to the mining solid waste, and obtaining the filling material through a mineralization reaction; the amount of mineralizing agent added in the mineralization reaction is 10%-30% of the mining solid waste, the pH value of the mineralization reaction is controlled between 8 and 10, the mineralization reaction temperature is 50-80℃, the reaction pressure is 1-3MPa, and the reaction time is 2-4 hours.

[0016] Furthermore, the supercritical CO2 jet equipment, intelligent drilling rig, intelligent sealing device, conveyor, intelligent identification device, automatic sorting device, and carbon dioxide recovery system are connected to the intelligent control system via a 5G network.

[0017] The beneficial effects of this invention are: Compared with existing technologies, this invention utilizes an integrated process of supercritical CO2 jet non-explosive rock breaking, intelligent sorting, CO2 recovery, and goaf backfilling. This significantly improves mining safety and efficiency while organically combining efficient resource utilization with environmental protection. Specifically, it maximizes the elimination of blasting accidents by significantly reducing safety risks through real-time monitoring and remote operation; continuous operation and parallel operation of dual equipment significantly improve mining efficiency; CO2 recovery and mineralized backfilling effectively reduce greenhouse gas emissions and achieve solid waste resource utilization, resulting in good environmental performance; the intelligent control system supports unmanned operation and adaptive parameter optimization; and this invention can improve resource recovery rates while reducing energy consumption and labor costs, providing a comprehensive solution for green, intelligent, efficient, and safe mining. Attached Figure Description

[0018] Figure 1 This is a schematic flowchart of the intelligent process method for supercritical CO2 jet-induced rock fracturing of the present invention.

[0019] Figure 2 This is a schematic diagram of the working section of the intelligent process for fracturing and breaking rocks using supercritical CO2 jets according to the present invention.

[0020] Figure 3This is a schematic diagram of the control system architecture for the intelligent process method of supercritical CO2 jet fracturing and rock breaking of the present invention.

[0021] Attached diagram labels: 1-Coal and rock mass; 2-Return airway; 3-Drill hole; 4-Intake airway; 5-Working face; 6-Belt conveyor; 7-Coal ore; 8-Mining area. Detailed Implementation

[0022] The present invention will be further described below with reference to embodiments.

[0023] The intelligent process method for supercritical CO2 jet-induced rock fracturing in mines, as described in this embodiment, includes the following steps: S1. The upward layered filling mining method is adopted to divide the target ore body into several layers; the current mining layer is divided into several mining areas, and the strip filling mining method is adopted to divide the current mining area into several strips.

[0024] S2. Design the process parameters of supercritical CO2 jet based on the occurrence conditions of the target ore body, and design the intake airway, return airway, working face size parameters, grooving process parameters and drilling process parameters for the current mining area.

[0025] In practical implementation, based on the actual geological conditions of the coal mine, a combination of numerical simulation and experimental methods can be used to design the process parameters for supercritical CO2 jet fracturing. This embodiment, targeting a coal seam thickness of 3.5m, compressive strength of 28MPa, tensile strength of 2.8MPa, ground stress of 15MPa, and ground temperature of 38℃, designs the following supercritical CO2 jet process parameters: jet pressure 30-40MPa, jet temperature 50-60℃, jet flow rate 50-70L / min, and single-hole jet action time 2-5 minutes.

[0026] The specific cross-sectional dimensions of the intake airway designed in this step are 4.0×3.5m, and the cross-sectional dimensions of the return airway are 3.5×3.0m.

[0027] The specific dimensions of the working surface designed in this step are: length 10-15m, width 1.0-1.5m, and height 1.5-2.0m.

[0028] The specific grooving process parameters designed in this step include: grooving height 1.6m and grooving depth 0.8m.

[0029] The specific drilling process parameters designed in this step include: a single-hole layout, a borehole diameter of 45-55mm, a borehole depth of 2.5-3.5m, a drill bit rotation speed of 200-400r / min, a propulsion speed of 0.5-1.0m / min, a borehole inclination angle consistent with the coal seam inclination angle, and a borehole deviation controlled within 1°.

[0030] The specific sealing process parameters designed for this step include: sealing depth 0.8m and sealing pressure 40MPa.

[0031] S3. Excavate and construct intake and return airway in the current mining area. Arrange supercritical CO2 jet equipment, intelligent drilling rigs, intelligent sealing devices, and conveyors in the roadways where the working face is located. Next to the conveyors, arrange intelligent identification devices for identifying solid waste and automatic sorting devices for sorting solid waste. Arrange a carbon dioxide recovery system in the return airway, and install an intelligent monitoring and control system to monitor and control the supercritical CO2 jet equipment, intelligent drilling rig, intelligent sealing device, conveyors, intelligent identification devices, automatic sorting devices, and carbon dioxide recovery system. The carbon dioxide recovery system includes a negative pressure collection device, a purification system for removing dust and purifying the gas collected by the negative pressure collection device, and a compression storage device for compressing and storing the carbon dioxide gas output from the purification system. The compression storage device is connected to the supercritical CO2 jet equipment via pipeline. The intelligent monitoring and control system includes sensors, an industrial computer, and communication network equipment deployed at the work site. The sensors are connected to the industrial computer, and the industrial computer is also connected to a remote control center through the communication network equipment. The remote control center understands the on-site work situation based on the sensor detection data and sends control commands to the industrial computer.

[0032] S4. Conduct intermittent mining and backfilling operations in each strip of the current mining area, including: 1) First, control the supercritical CO2 jet equipment to perform grooving operations on the working surface to form a free surface according to the grooving process parameters; then, control the intelligent drilling rig to perform drilling operations to form CO2 injection holes according to the drilling process parameters; then, control the intelligent sealing device to insert the sealing device into the CO2 injection hole according to the sealing process parameters; then, control the supercritical CO2 jet equipment to connect with the sealing device to implement supercritical CO2 jet fracturing and rock breaking; finally, control the conveyor to output ore and the carbon dioxide recovery system to collect CO2 gas.

[0033] 2) Prepare filling material and fill the strip space left by the mining in step 1) with the filling material.

[0034] 3) Repeat steps 1) and 2) until the mining and filling of the current mining area is completed.

[0035] S5. Repeat step S4 to complete the mining and filling of the current mining layer.

[0036] S6. Based on the upward layered filling mining method, after completing the current layer mining and filling, the next layer operation is carried out, and the cycle continues until the ore body is mined out.

[0037] As an improvement to the above embodiment, in step S3, one intake airway is arranged in the current mining area, and the intake airway is located in the middle of the mining area; two return airways are arranged in the current mining area, and the return airways are arranged on both sides of the mining area. In this way, the same mining area has two working faces, and the two working faces can carry out mining operations simultaneously, which can improve mining efficiency.

[0038] As a modification to the above embodiment, the intermediate tube of the sealing device in step 1) is a Laval tube. In this embodiment, the throat diameter of the Laval nozzle is 1.5 mm, and the outlet velocity reaches 220 m / s. Pressure changes are monitored in real time during the jetting process, and the jetting parameters can be adjusted according to the acoustic emission signal of rock fracture.

[0039] As an improvement to the above embodiment, the preparation of the filling material in step 2) includes: using mining solid waste as the filling raw material, adding a mineralizing agent to the mining solid waste, and obtaining the filling material through a mineralization reaction; the amount of mineralizing agent added in the mineralization reaction is 10%-30% of the mining solid waste, the pH value of the mineralization reaction is controlled between 8 and 10, the mineralization reaction temperature is 50-80℃, the reaction pressure is 1-3 MPa, and the reaction time is 2-4 hours. Using solid waste generated from mining as the filling raw material realizes the resource utilization of solid waste, has good environmental protection, and reduces filling costs.

[0040] As an improvement to the above embodiments, the supercritical CO2 jet equipment, intelligent drilling rig, intelligent sealing device, conveyor, intelligent identification device, automatic sorting device, and carbon dioxide recovery system are connected to the intelligent control system via a 5G network. The intelligent control system remotely controls the mining face, goaf filling, and CO2 recovery, achieving unmanned operation and high operational safety.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A smart process method for fracturing and breaking rocks using supercritical CO2 jets in mines, characterized in that: Includes the following steps: S1. The upward layered filling mining method is adopted to divide the target ore body into several layers; the current mining layer is divided into several mining areas, and the strip filling mining method is adopted to divide the current mining area into several strips; S2. Design the process parameters of supercritical CO2 jet based on the occurrence conditions of the target ore body, and design the intake airway, return airway, working face size parameters, grooving process parameters and drilling process parameters for the current mining area. S3. Excavate and construct intake and return airways in the current mining area. Arrange supercritical CO2 jet equipment, intelligent drilling rigs, intelligent sealing devices, and conveyors in the roadways where the working face is located. Arrange intelligent identification devices for identifying solid waste and automatic sorting devices for sorting solid waste next to the conveyors. Arrange a carbon dioxide recovery system in the return airway. Arrange an intelligent monitoring and control system for monitoring and controlling the supercritical CO2 jet equipment, intelligent drilling rigs, intelligent sealing devices, conveyors, intelligent identification devices, automatic sorting devices, and carbon dioxide recovery system. S4. Conduct intermittent mining and backfilling operations in each strip of the current mining area, including: 1) First, control the supercritical CO2 jet equipment to perform grooving operations on the working surface to form a free surface according to the grooving process parameters; then, control the intelligent drilling rig to perform drilling operations to form CO2 injection holes according to the drilling process parameters; then, control the intelligent sealing device to insert a sealing device into the CO2 injection hole according to the sealing process parameters; then, control the supercritical CO2 jet equipment to connect with the sealing device to implement supercritical CO2 jet fracturing and rock breaking; finally, control the conveyor to output ore and the carbon dioxide recovery system to collect CO2 gas. 2) Prepare filling material and fill the strip space left by the mining in step 1) with the filling material; 3) Repeat steps 1) and 2) until the mining and backfilling of the current mining area is completed; S5. Repeat step S4 to complete the mining and backfilling of the current mining layer; S6. Based on the upward layered filling mining method, after completing the current layer mining and filling, the next layer operation is carried out, and the cycle continues until the ore body is mined out.

2. The intelligent process method for supercritical CO2 jet-induced rock fracturing in mines according to claim 1, characterized in that: In step S2, one intake airway is arranged in the current mining area, and the intake airway is located in the middle of the mining area; two return airways are arranged in the current mining area, and the return airways are arranged on both sides of the mining area.

3. The intelligent process method for supercritical CO2 jet-induced rock fracturing in mines according to claim 1, characterized in that: The supercritical CO2 jet process parameters designed in step S1 include: jet pressure 30-40MPa, jet temperature 50-60℃, jet flow rate 50-70L / min, and single-hole jet action time 2-5 minutes.

4. The intelligent process method for supercritical CO2 jet-induced rock fracturing in mines according to claim 1, characterized in that: The working surface dimensions designed in step S2 are: length 10-15m, width 1.0-1.5m, and height 1.5-2.0m.

5. The intelligent process method for supercritical CO2 jet-induced rock fracturing in mines according to claim 1, characterized in that: The grooving process parameters designed in step S2 include: grooving height 1.6m and grooving depth 0.8m.

6. The intelligent process method for supercritical CO2 jet-induced rock fracturing in mines according to claim 1, characterized in that: The drilling process parameters designed in step S2 include: a single-hole arrangement for drilling, a drilling diameter of 45-55mm, a drilling depth of 2.5-3.5m, a drill bit rotation speed of 200-400r / min, a propulsion speed of 0.5-1.0m / min, and a drilling inclination angle consistent with the coal seam inclination angle.

7. The intelligent process method for supercritical CO2 jet-induced rock fracturing in mines according to claim 1, characterized in that: The sealing process parameters designed in step S2 include: sealing depth 0.8m and sealing pressure 40MPa.

8. The intelligent process method for supercritical CO2 jet-induced rock fracturing in mines according to claim 1, characterized in that: The intermediate tube of the sealing device mentioned in step 1) is a Laval tube.

9. The intelligent process method for supercritical CO2 jet-induced rock fracturing in mines according to claim 1, characterized in that: The preparation of the filling material in step 2) includes: using mining solid waste as the filling raw material, adding a mineralizing agent to the mining solid waste, and obtaining the filling material through a mineralization reaction; the amount of mineralizing agent added in the mineralization reaction is 10%-30% of the mining solid waste, the pH value of the mineralization reaction is controlled between 8 and 10, the mineralization reaction temperature is 50-80℃, the reaction pressure is 1-3MPa, and the reaction time is 2-4 hours.

10. The intelligent process method for supercritical CO2 jet-induced rock fracturing in mines according to claim 1, characterized in that: The supercritical CO2 jet equipment, intelligent drilling rig, intelligent sealing device, conveyor, intelligent identification device, automatic sorting device, and carbon dioxide recovery system are connected to the intelligent control system via a 5G network.

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