Sandstone uranium mine pulse permeation increasing device and method

Abstract

The invention provides a sandstone uranium mine pulse permeation enhancing device and method, and relates to the technical field of sandstone type uranium mine in-situ leaching mining, and the sandstone type uranium mine pulse permeation enhancing device comprises a ground system, a shock wave generator and a cable. The ground system comprises an alternating current power supply, a boosting component, an energy storage capacitor and a discharge switch which are electrically connected in sequence; the shock wave generator is placed in a uranium mine hole; the two ends of the cable are fixedly connected with the ground system and the shock wave generator respectively, and the shock wave generator is electrically connected with the ground system through the cable. The controllable shock waves generated by pulse discharge can effectively excite vibration of pores of the ore bed and generate cracks, and promote falling of blockages in the pores, so that the permeability of the sandstone uranium ore bed is remarkably improved; according to the method, corresponding process parameters are set according to the geologic characteristics of the sandstone uranium ore, and a good permeation enhancing effect is ensured to be achieved under different ore bed conditions.

Description

Technical Field

[0001] The invention relates to the technical field of in-situ leaching of sandstone-type uranium mines, and in particular to a device and method for increasing permeability and removing blockage in a near-wellbore zone of a sandstone stratum. Background Art

[0002] In the current sandstone uranium mining technology, in-situ leaching uranium has become the main mining process for sandstone uranium mines in my country. This process relies on the in-situ reaction of the leaching agent with the ore through flow diffusion in the formation environment to leach the metals in the uranium ore and transport them to the surface with the leachate. Due to the migration of particles and chemical precipitation in the sandstone uranium ore layer, the ore layer is prone to blockage during the leaching process, which leads to a significant decrease in the amount of pumped liquid, thus seriously affecting the production capacity and economic benefits of the uranium mine. Technicians have done a lot of research on the permeability enhancement of sandstone uranium ore layers, such as negative pressure or pulse well washing, chemical permeability enhancement, ultrasonic or blasting blockage removal, fracturing permeability enhancement and other physical and chemical permeability enhancement processes. However, there are still problems such as unsatisfactory results, complex processes, high costs or secondary damage to the ore layer.

[0003] As an emerging technology for mineral transformation, controlled shock wave permeability enhancement technology uses instantaneous shock waves generated by repeated pulse discharge to cause intense vibration of dirt and fluid in the mineral pores, causing the dirt blocking the pores to fall off, extending the original cracks and generating new micro-cracks in the mineral strata, achieving the effect of unblocking and increasing permeability. However, existing pulse discharge devices are mainly used for fracturing and permeability enhancement in coal seams and oil and gas wells. The discharge energy, frequency, size and other parameters of existing devices are not suitable for the geological characteristics and wellbore structure of sandstone uranium mines.

[0004] Based on the above shortcomings of the prior art, there is an urgent need for a sandstone uranium ore pulse permeability device and method. Summary of the invention

[0005] The purpose of the present invention is to provide a pulse permeability device and method for sandstone uranium ore to solve the above problems. In order to achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] In the first aspect, the present application provides a sandstone uranium mine pulse permeability device, comprising: a ground system, a shock wave generator and a cable. The ground system comprises an AC power supply, a boost component, an energy storage capacitor and a discharge switch electrically connected in sequence; a shock wave generator, which is arranged in a uranium mine wellbore; the two ends of the cable are respectively fixedly connected to the ground system and the shock wave generator, and the shock wave generator is electrically connected to the ground system through the cable.

[0007] Furthermore, the boost component includes a boost transformer and a rectifier electrically connected to each other, the boost transformer is electrically connected to the AC power supply, and the rectifier is electrically connected to the energy storage capacitor.

[0008] Furthermore, the cable consists of a copper core conductor, an insulating layer, a copper wire twisted layer, an outer conductor shielding layer and a steel armor from inside to outside.

[0009] Furthermore, the shock wave generator includes a metal shell, an electrode head assembly, an elastic water-blocking insulating filler, a copper conductor and a clamping column. The electrode head assembly, the elastic water-blocking insulating filler and the copper conductor are arranged inside the metal shell, the two ends of the electrode head assembly are fixedly connected to the copper conductor and the metal shell respectively, the other end of the copper conductor is fixedly connected to the copper core conductor, the opening of the metal shell is threadedly connected to the end of the cable, the elastic water-blocking insulating filler is fixedly arranged between the electrode head assembly and the insulating layer, and the clamping column is arranged on the inner side of the metal shell.

[0010] Furthermore, the electrode head combination includes a first electrode, a second electrode, a first bayonet and a second bayonet, the first electrode and the second electrode are coaxially arranged, the first electrode is fixedly connected to the copper conductor through the first bayonet, the second electrode is fixedly connected to the metal shell through the second bayonet, and the end of the first electrode facing the second electrode is conical.

[0011] Furthermore, the first electrode and the second electrode are made of copper-tungsten alloy.

[0012] Furthermore, the diameter of the shock wave generator is 66-102 mm.

[0013] Furthermore, the diameter of the copper core conductor is 8 mm.

[0014] Furthermore, the insulating layer is made of cross-linked polyethylene.

[0015] In a second aspect, the present application provides a pulse permeability enhancement method for sandstone uranium ore, comprising:

[0016] Obtaining geological parameters of the target ore layer of the sandstone uranium mine and physical parameters of the wellbore casing, wherein the geological parameters include the degree of rock and ore cementation, pore cementation, mechanical property parameters, and resonance frequency;

[0017] Calculating the discharge parameters of the shock wave generator according to the geological parameters and the physical parameters of the wellbore casing, wherein the discharge parameters include discharge energy, frequency and number of times;

[0018] The pulse permeability enhancement device for sandstone uranium ore is set based on the discharge parameters, and shock waves are excited. When the shock waves act on the ore layer, the shock wave generator is intermittently lifted or lowered. The interval between the action layer positions is 0.1m to 0.5m. The number of discharges in each operation section is 20 to 50 times, covering all target layers.

[0019] After the shock wave operation is completed, the shock wave generator is taken out and conventional well washing operations are carried out to wash out the blockages caused by the ore layer.

[0020] The beneficial effects of the present invention are:

[0021] The controllable shock wave generated by pulse discharge in the present invention can effectively stimulate the vibration of the pores of the ore layer, promote the falling off of blockages in the pores, and significantly improve the permeability of sandstone uranium ore; the present invention is flexibly set and adjusted according to actual geological parameters to ensure the best permeability enhancement effect under different ore layer conditions.

[0022] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or be understood by implementing the embodiments of the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 It is a schematic structural diagram of a pulse permeability enhancement device for sandstone uranium ore described in an embodiment of the present invention;

[0025] Figure 2 is an internal schematic diagram of a cable described in an embodiment of the present invention;

[0026] Figure 3 is a schematic structural diagram of a shock wave generator described in an embodiment of the present invention;

[0027] Figure 4 The figure is a flow chart of the pulse permeability enhancement method for sandstone uranium ore described in an embodiment of the present invention.

[0028] Markings in the figure: 1. Ground system; 11. AC power supply; 12. Boosting component; 121. Boosting transformer; 122. Rectifier; 13. Energy storage capacitor; 14. Discharge switch; 2. Shock wave generator; 21. Metal shell; 22. Electrode head assembly; 221. First electrode; 222. Second electrode; 223. First bayonet; 224. Second bayonet; 23. Elastic water-blocking insulating filler; 24. Copper conductor; 25. Column; 3. Cable; 31. Copper core conductor; 32. Insulation layer; 33. Copper wire twisted layer; 34. Outer conductor shielding layer; 35. Steel armor. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. At the same time, in the description of the present invention, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0031] Embodiment 1:

[0032] This embodiment provides a pulse permeability enhancement device for sandstone uranium ore, such as Figure 1As shown, it includes: a ground system 1, a shock wave generator 2 and a cable 3. The ground system 1 includes an AC power supply 11, a boost component 12, an energy storage capacitor 13 and a discharge switch 14 which are electrically connected in sequence. The AC power supply 11 provides basic power; the energy storage capacitor 13 is used to store the boosted electric energy so that it can be quickly released when needed; the discharge switch 14 is used to control when the electric energy in the capacitor is released to the shock wave generator 2; the shock wave generator 2, the shock wave generator 2 is arranged in the uranium mine wellbore; the two ends of the cable 3 are fixedly connected to the ground system 1 and the shock wave generator 2 respectively, and the shock wave generator 2 is electrically connected to the ground system 1 through the cable 3. The shock wave generator 2 is the core actuator of the device and is directly located in the uranium mine wellbore. Its main function is to generate pulse discharge by receiving electric energy from the ground system 1, and then generate shock waves to stimulate the pores of the ore layer to achieve the effect of increasing permeability and unblocking. The transformer, capacitor and switch of the existing pulse discharge device are all located underground, resulting in a large volume of the underground part, which cannot be lowered into the uranium mine wellbore. The modular design of the surface system 1 allows all heavy and bulky components to be operated above the well, reducing the burden on the downhole equipment. This design allows the shock wave generator 2 to be easily lowered to the target layer through the wellbore, ensuring the operability and flexibility of the equipment. Furthermore, after most of the equipment is placed above the well, it can be deployed and adjusted more flexibly according to process requirements. The volume and energy adjustment range of the equipment are significantly expanded, allowing it to be quickly adjusted to meet various needs under different mining conditions, improving operating efficiency.

[0033] Preferably, if Figure 1 As shown, the boost component 12 includes a boost transformer 121 and a rectifier 122 which are electrically connected to each other, the boost transformer 121 is electrically connected to the AC power source 11, and the rectifier 122 is electrically connected to the energy storage capacitor 13. The boost transformer 121 boosts the AC power to a required voltage level, and the rectifier 122 converts the boosted AC power into DC power so as to be stored in the capacitor.

[0034] Preferably, if Figure 2 As shown, the cable 3 is composed of a copper core conductor 31, an insulating layer 32, a copper wire twisted layer 33, an outer conductor shielding layer 34 and a steel armor 35 from the inside to the outside. The copper core conductor 31 and the copper wire twisted layer 33 are together as components of the discharge circuit, and their cross-sectional area is adjusted according to the actual required current carrying capacity. Due to the existence of the copper wire twisted layer 33, the discharge circuit does not pass through the ground around the borehole, and does not cause safety hazards such as the rise of the ground potential, thereby ensuring the safety of high-voltage discharge. The outer conductor shielding layer 34 is used to protect the copper stranded wire layer and is also an external shielding layer. The steel armor 35 is an aluminum wire steel armor 35, which plays a major role in mechanical protection, mechanical support and tensile resistance.

[0035] Preferably, if Figure 3As shown, the shock wave generator 2 includes a metal shell 21, an electrode head assembly 22, an elastic water-blocking insulating filler 23, a copper conductor 24 and a clamping column 25. The metal shell 21 provides mechanical protection to prevent the external environment from damaging the internal electrodes and conductors. At the same time, the metal shell 21 has good sealing to prevent moisture from intruding and ensure the normal operation of the equipment. The electrode head assembly 22 is the core part of the shock wave generator 2, and its function is to generate shock waves. The electrode head assembly 22, the elastic water-blocking insulating filler 23 and the copper conductor 24 are arranged inside the metal shell 21, and the two ends of the electrode head assembly 22 are fixedly connected to the copper conductor 24 and the metal shell 21 respectively, and the other end of the copper conductor 24 is fixedly connected to the copper core conductor 31. The opening of the metal shell 21 is threadedly connected to the end of the cable 3, the elastic water-blocking insulating filler 23 is fixedly arranged between the electrode head assembly 22 and the insulating layer 32, and the clamping column 25 is arranged on the inner side of the metal shell 21. The elastic water-blocking insulating material can effectively prevent moisture from entering the device, ensuring safe operation in a humid environment, while the elastic filler provides good electrical insulation to protect the connection between the electrode and the copper conductor 24. The copper conductor 24 is responsible for transmitting electrical energy from the ground system 1 to the shock wave generator 2. The design of the clamping column 25 enhances the structural stability of the internal components of the shock wave generator 2 and improves the overall reliability of the device.

[0036] Preferably, the electrode head assembly 22 includes a first electrode 221, a second electrode 222, a first bayonet 223 and a second bayonet 224. The first electrode 221 and the second electrode 222 are coaxially arranged. The first electrode 221 is fixedly connected to the copper conductor 24 through the first bayonet 223, and the second electrode 222 is fixedly connected to the metal shell 21 through the second bayonet 224. The end of the first electrode 221 facing the second electrode 222 is conical. The first electrode 221 is used as the main electrode for discharge. By being fixedly connected to the copper conductor 24, the effective transmission and discharge of electric energy are ensured. The second bayonet 224 is fixedly connected to the metal shell 21, and plays the role of grounding or returning current. The two bayonet pins are used to firmly fix the electrodes in the corresponding positions to ensure that the electrodes do not loosen during operation. At the same time, the bayonet connection structure is smaller in size, which plays the role of saving space.

[0037] Preferably, the first electrode 221 and the second electrode 222 are made of copper-tungsten alloy, wherein the weight of copper and tungsten account for 20% and 80% respectively, so that the alloy has both the toughness of copper and the ablation resistance of tungsten.

[0038] Preferably, the diameter of the shock wave generator 2 is 66-102 mm.

[0039] Preferably, the diameter of the copper core conductor 31 is 8 mm. That is, the cable 3 is an 8 mm single-core cable 3, the maximum working voltage is 650 V AC, the maximum instantaneous current is 7 A, the long-term working average current is 3 A, and the breaking force of the cable 3 is 55 KN.

[0040] Preferably, the material of the insulating layer 32 is cross-linked polyethylene, which is a commonly used insulating material for high-voltage cables 3 and has both insulation and heat resistance.

[0041] Embodiment 2:

[0042] This embodiment provides a pulse permeability enhancement method for sandstone uranium ore.

[0043] like Figure 4 As shown, the method includes steps S100 to S400.

[0044] Step S100, obtaining geological parameters of the target ore layer of the sandstone uranium mine and physical parameters of the wellbore casing, wherein the geological parameters include the degree of rock and ore cementation, pore cement, mechanical property parameters and resonance frequency;

[0045] It is understandable that the degree of cementation of rock ores reflects the softness of the ore layer and affects its adaptability to shock waves; the distribution of porous cement is directly related to the fluidity and permeability of the fluid. At the same time, mechanical performance parameters (such as compressive strength and elastic modulus) will help determine the safe operating range when applying shock waves to avoid excessive damage to the ore layer, and the determination of resonance frequency ensures that the shock wave frequency can match the natural frequency of the ore layer to maximize the energy transfer efficiency. In addition, the physical parameters of the wellbore casing need to be obtained. Specifically, the shock wave energy it withstands is less than 10KJ, the device length is between 2.0 and 8.0m, and the device weight is 50 to 100Kg. By comprehensively considering geological and physical parameters, it can provide a scientific basis for the adjustment of subsequent shock wave discharge parameters, thereby achieving the best permeability effect and improving the mining efficiency and economic benefits of sandstone uranium mines.

[0046] Step S200, calculating the discharge parameters of the shock wave generator 2 according to the geological parameters and the physical parameters of the wellbore casing, the discharge parameters including discharge energy, frequency and number;

[0047] It can be understood that the calculation and setting process of this step ensures that the shock wave generator 2 can operate efficiently in actual operation. According to different geological conditions, timely adjustment of discharge parameters can not only improve the effectiveness of permeability enhancement, but also avoid equipment failure and secondary damage to the ore layer. The specific range of discharge parameters is: single discharge energy is 0.3~5.0KJ, discharge frequency is 10~600 times / min, and discharge voltage is 10~12KV;

[0048] Step S300, setting the pulse permeability enhancement device for sandstone uranium ore based on the discharge parameters, and exciting the shock wave. While the shock wave acts on the ore layer, the shock wave generator is intermittently lifted or lowered. The interval between the action layer positions is 0.1m to 0.5m. The number of discharges in each operation section is 20 to 50 times, covering all target layers.

[0049] Specifically, the working mode of the shock wave generator 2 is first set to ensure that it operates effectively at the predetermined discharge frequency and energy. When the shock wave is excited, the device will quickly release the stored electrical energy to generate a shock wave to act on the ore layer. The shock wave generator 2 is intermittently raised or lowered to ensure that the shock wave evenly covers different positions of the ore layer and that each area is affected. In addition, each operation section enhances the shock effect through multiple discharges, further improving the permeability efficiency.

[0050] Step S400, after the shock wave operation is completed, the shock wave generator 2 is taken out and a conventional well washing operation is performed to wash out the blockages generated by the ore layer.

[0051] This cleaning process not only improves the fluidity of the ore layer, but also creates good conditions for subsequent leaching operations, ensuring the efficiency of uranium mining.

[0052] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A pulse permeability device for sandstone uranium ore, characterized in that: include: A ground system (1), the ground system (1) comprising an AC power source (11), a voltage boost component (12), an energy storage capacitor (13) and a discharge switch (14) electrically connected in sequence; A shock wave generator (2), the shock wave generator (2) being placed in a uranium mine borehole; A cable (3), wherein both ends of the cable (3) are fixedly connected to the ground system (1) and the shock wave generator (2), respectively; and the shock wave generator (2) is electrically connected to the ground system (1) via the cable (3).

2. The pulse permeation device for sandstone uranium ore according to claim 1, characterized in that: The boost component (12) comprises a boost transformer (121) and a rectifier (122) which are electrically connected to each other; the boost transformer (121) is electrically connected to the AC power source (11); and the rectifier (122) is electrically connected to the energy storage capacitor (13).

3. The pulse permeation device for sandstone uranium ore according to claim 2, characterized in that: The cable (3) is composed of, from inside to outside, a copper core conductor (31), an insulating layer (32), a copper wire twisted layer (33), an outer conductor shielding layer (34) and a steel armor (35).

4. The pulse permeation device for sandstone uranium ore according to claim 3, characterized in that: The shock wave generator (2) comprises a metal shell (21), an electrode head assembly (22), an elastic water-blocking insulating filler (23), a copper conductor (24) and a clamping column (25); the electrode head assembly (22), the elastic water-blocking insulating filler (23) and the copper conductor (24) are arranged inside the metal shell (21); the two ends of the electrode head assembly (22) are fixedly connected to the copper conductor (24) and the metal shell (21) respectively; the other end of the copper conductor (24) is fixedly connected to the copper core conductor (31); the opening of the metal shell (21) is threadedly connected to the end of the cable (3); the elastic water-blocking insulating filler (23) is fixedly arranged between the electrode head assembly (22) and the insulating layer (32); and the clamping column (25) is arranged on the inner side of the metal shell (21).

5. The pulse permeation device for sandstone uranium ore according to claim 4, characterized in that: The electrode head assembly (22) comprises a first electrode (221), a second electrode (222), a first bayonet (223) and a second bayonet (224); the first electrode (221) and the second electrode (222) are coaxially arranged; the first electrode (221) is fixedly connected to the copper conductor (24) via the first bayonet (223); the second electrode (222) is fixedly connected to the metal shell (21) via the second bayonet (224); and the end of the first electrode (221) facing the second electrode (222) is conical.

6. The pulse permeation device for sandstone uranium ore according to claim 5, characterized in that: The first electrode (221) and the second electrode (222) are made of copper-tungsten alloy.

7. The pulse permeation device for sandstone uranium ore according to claim 1, characterized in that: The diameter of the shock wave generator (2) is 66-102 mm.

8. The pulse permeation device for sandstone uranium ore according to claim 3, characterized in that: The diameter of the copper core conductor (31) is 8 mm.

9. The pulse permeation device for sandstone uranium ore according to claim 3, characterized in that: The material of the insulating layer (32) is cross-linked polyethylene.

10. A pulse permeability enhancement method for sandstone uranium ore, characterized in that: The method uses the sandstone uranium ore pulse permeability enhancement device according to any one of claims 1 to 9, and the method comprises: Obtaining geological parameters of the target ore layer of the sandstone uranium mine and physical parameters of the wellbore casing, wherein the geological parameters include the degree of rock and ore cementation, pore cementation, mechanical property parameters, and resonance frequency; Calculating the discharge parameters of the shock wave generator (2) according to the geological parameters and the physical parameters of the wellbore casing, wherein the discharge parameters include discharge energy, frequency and number of times; The pulse permeability enhancement device for sandstone uranium ore is set based on the discharge parameters, and shock waves are excited. When the shock waves act on the ore layer, the shock wave generator is intermittently lifted or lowered. The interval between the action layer positions is 0.1m to 0.5m. The number of discharges in each operation section is 20 to 50 times, covering all target layers. After the shock wave operation is completed, the shock wave generator (2) is removed and conventional well washing operations are carried out to wash out the blockages generated by the ore layer.

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