A method for in-situ leaching of ionic rare earth ore based on eddy current heating

Abstract

The present invention belongs to the field of solution mining technology and discloses an eddy current heating-based in-situ leaching method for ionic rare earth ore. The method comprises: arranging injection wells according to the rare earth ore body; arranging a liquid collecting pipe on the bottom surface of the rare earth ore body; arranging heating monitoring wells between the injection wells, wherein a coil assembly and an infrared thermal imaging detector are placed in the heating monitoring wells; injecting a leaching solution containing iron-nickel alloy particles; when the leaching solution flows into the collecting tank, activating a high-voltage alternating current box, causing the temperature of the iron-nickel alloy particles to rise under the action of an alternating magnetic field, heating the leaching solution; and displaying the captured infrared image on an infrared thermal imaging display through analog-to-digital conversion and image processing circuitry by the infrared thermal imaging detector. By observing the image on the infrared thermal imaging display, the scope of the leaching solution impregnation area in the ore body can be determined. The present invention solves the problem of being unable to confirm the seepage range and leakage location of the leaching solution during in-situ leaching of ionic rare earth ore, and can be used for ionic rare earth mining.

Description

Technical Field

[0001] The present invention relates to the technical field of solution leaching mining, and in particular to an ionic rare earth in-situ leaching mining method based on eddy current heating. Background Art

[0002] my country is the nation richest in rare earth resources, ranking first in the world in both reserves and production. Ionic rare earths are a new type of rare earth mineral resource unique to my country and a key strategic resource. Therefore, the efficient extraction of ionic rare earth ores is currently a crucial task for my country.

[0003] In-situ leaching is currently the most advanced method for extracting rare earth minerals. Leaching fluid is injected through a network of shallow wells distributed on the surface of the ore body. The leaching fluid then seeps into the ore body, extracting and recovering the rare earth elements. This process has the advantages of eliminating the need to extract the ore body to the surface, maintaining a stable structure, minimizing environmental damage, and achieving high resource utilization.

[0004] However, ion-based rare earth in-situ leaching (ISL) mining processes often suffer from leaching losses, significantly reducing both ISL efficiency and rare earth resource recovery. During the injection process, factors such as permeability, osmotic pressure, and injection well layout can prevent the leaching solution from reaching the entire ore body, creating "blind spots" and causing leaching losses. Furthermore, mother liquor recovery is lost, as the mother liquor leaks through cracks in the ore layer, preventing full recovery and resulting in losses. Summary of the Invention

[0005] The present invention aims to provide an ionic rare earth in-situ leaching mining method based on eddy current heating to solve the problem that the seepage range and leakage location of the leaching solution cannot be confirmed during the ionic rare earth in-situ leaching mining process.

[0006] In order to achieve the above object, the present invention provides the following technical solution: an ionic rare earth in-situ leaching mining method based on eddy current heating, comprising the following steps:

[0007] S1. Arrange injection wells according to the size, distribution and burial depth of the rare earth ore body in the area. The injection wells are circular and 2 meters deeper than the top surface of the rare earth ore body. At the same time, insert injection pipes into the injection wells. The size and depth of the injection pipes match the injection wells.

[0008] S2. Arrange a liquid collecting pipe at an appropriate position below the bottom surface of the rare earth ore body, and connect the liquid collecting pipe to an external liquid collecting tank;

[0009] S3. After the injection wells and liquid collecting pipes are arranged, heating monitoring wells are evenly spaced between the injection wells. The depth of the heating monitoring wells is 1-2 meters from the bottom of the rare earth ore body. The heating monitoring wells are provided with well casings. A coil group and an infrared thermal imaging detector are placed in the heating monitoring wells. The coil group is placed in the middle of the rare earth ore body and is connected to the high-voltage AC box via a high-voltage cable. The infrared thermal imaging detector is connected to the power supply and the infrared thermal imaging display via wires. At the same time, an infrared thermal imaging detector is placed vertically every 2-4 meters in the heating monitoring wells to ensure that all monitoring wells are within the detection range of the detector.

[0010] S4. Determine the depth and spacing of the heating monitoring wells based on the range of the alternating magnetic field and the detection range of the infrared thermal imaging detector to ensure that the eddy current heating caused by the alternating magnetic field can cover the rare earth ore body area and that the detection range of the infrared thermal imaging detector can cover the rare earth ore body area.

[0011] S5. Mixing the iron-nickel alloy particles with the leaching solution in the mixed liquid pool, injecting the leaching solution containing the iron-nickel alloy particles through the injection well and the mixed liquid pool; when the leaching solution flows into the liquid collecting pool, starting the high-voltage alternating current box, and causing the coil to generate an alternating magnetic field. Under the action of the alternating magnetic field, the temperature of the iron-nickel alloy particles rises, thereby heating the leaching solution; and simultaneously turning on the power supply of the infrared thermal imaging detector and the infrared thermal imaging display. The infrared thermal imaging detector displays the collected infrared image on the infrared thermal imaging display after analog-to-digital conversion and image processing circuitry. By observing the image on the infrared thermal imaging display, the range of the area impregnated by the leaching solution in the ore body is obtained, and the area not impregnated by the leaching solution is delineated;

[0012] S6. Increase the injection volume of the injection pipe near the unimpregnated area. If the leaching liquid still cannot reach the area, arrange a new injection well and its matching injection pipe above the area, and inject the leaching liquid into it to impregnate the unimpregnated area.

[0013] Furthermore, in step S1, the arrangement of the injection wells is based on the principle of being arranged along the contour lines, and the well depth is 1-5 meters.

[0014] Furthermore, in step S3, the interval between adjacent heating monitoring wells is 10-20 meters, and the depth of the heating monitoring wells is 4-15 meters.

[0015] Through the above-mentioned setting, it is ensured that the hot leaching solution can be effectively monitored by the infrared thermal imaging detector during the seepage process.

[0016] Furthermore, the well casing in step S3 is an infrared-transmitting plastic pipe with a sealed bottom.

[0017] Through the above arrangement, the well casing can be used to prevent the well wall from collapsing and the infiltration of leaching liquid, and the use of infrared penetrating plastic material can avoid affecting infrared detection.

[0018] Furthermore, in step S4, the vertical spacing of the infrared thermal imaging detectors arranged in the heating monitoring well is 2-4 meters.

[0019] Furthermore, in step S5, the iron-nickel alloy particles are spherical and have a particle size of 4000-8000 mesh.

[0020] The above-mentioned setting ensures that the iron-nickel alloy particles can be transported into the interior of the ore body along with the leaching solution, which is the premise and key to the successful eddy current heating.

[0021] Furthermore, in step S5, the high voltage AC box outputs 40KHz-200KHz high voltage AC power, and the heating rate of the leaching solution is adjusted by controlling the output frequency and the temperature thereof is controlled to be 40-80°C.

[0022] With this setup, during the heating process, temperatures decrease at greater distances from the eddy current heating source and increase at closer locations. The normal temperature is 25°C, and the lower temperature limit is set at 40°C to ensure the hydrothermal fluid can be detected by infrared imaging. The upper temperature limit is set at 80°C to ensure the proper chemical reaction between the hydrothermal fluid and the ore body and to avoid energy waste. This also accelerates the ion exchange rate between the leaching solution and the rare earth elements, improving the leaching rate and reducing the leaching time.

[0023] Furthermore, in step S5, the infrared image is used to find abnormal permeability areas or permeability areas outside the ore body, that is, areas where cracks are located, and the areas where cracks are located are sealed, thereby achieving the purpose of monitoring fluid infiltration.

[0024] Through the above arrangement, the loss of leaching solution can be reduced, thus saving costs.

[0025] Compared with the existing technical solutions, the present invention has the following beneficial effects:

[0026] 1. This solution solves the engineering problem of being unable to confirm the seepage range of the leaching solution during the in-situ leaching of ionic rare earth minerals, and promptly discovers the blind spots of leaching.

[0027] 2. This solution solves the engineering problem of being unable to confirm the location of leaching liquid leakage during the in-situ leaching mining of ionic rare earth minerals, and promptly discovers the stratum fissures that cause leaching liquid leakage.

[0028] 3. This solution solves the engineering problems of low rare earth leaching rate and long leaching time during in-situ leaching of ionic rare earths, and to a certain extent improves the leaching rate of rare earths and reduces the leaching time of rare earths. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic structural diagram of an ionic rare earth in-situ leaching mining method based on eddy current heating (without an alternating magnetic field) according to the present invention;

[0030] Figure 2 This is a structural schematic diagram of an ionic rare earth in-situ leaching mining method (including an alternating magnetic field) based on eddy current heating of the present invention.

[0031] The names of the corresponding marks in the accompanying drawings are: liquid collecting tank 1, liquid collecting pipe 2, rare earth ore body 3, high-voltage AC box 4, heating monitoring well 5, coil group 6, alternating magnetic field 7, injection pipe 8, infrared thermal imaging detector 9, crack 10, injection well 11, injection control valve 12, mixed liquid tank 13, power supply 14, infrared thermal imaging display 15, well protection casing 16. DETAILED DESCRIPTION

[0032] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments:

[0033] like Figure 1 and 2 As shown, an ionic rare earth in-situ leaching mining method based on eddy current heating includes the following steps:

[0034] S1. Arrange injection wells based on the size, distribution, and burial depth of the rare earth ore body 3 in the area. The injection wells are circular and approximately 2 meters deeper than the top surface of the rare earth ore body 3. The wells are arranged along contour lines and have a depth of 1-5 meters. Insert injection pipes 8, with the size and depth of the pipes matching the wells.

[0035] S2. Arrange liquid collecting pipes 2 at appropriate positions below the bottom surface of the rare earth ore body 3. The number and spacing of the liquid collecting pipes 2 depend on the scale of the ore body. The liquid collecting pipes 2 are connected to the external liquid collecting pool 1.

[0036] After the injection wells and the liquid collection pipe 2 are laid out, heating monitoring wells 5 are evenly spaced between the injection wells. The depth of the heating monitoring wells 5 is preferably 1-2 meters from the bottom of the rare earth ore body 3. Adjacent heating monitoring wells 5 are spaced 10-20 meters apart, and the depth of the heating monitoring wells 5 is 4-15 meters. The heating monitoring wells 5 are protected by protective well casings 16, which are infrared-transmissive plastic pipes with sealed bottoms. A coil group 6 and an infrared thermal imaging detector 9 are installed in the heating monitoring well 5. The coil group 6 is placed in the middle of the rare earth ore body 3. The coil group 6 is covered with a box for protecting the coil group 6. The box is made of silicone. The box is used to avoid adverse effects of external factors on the coil group 6. It is connected to the high-voltage AC box 4 on the ground through a high-voltage cable. The coil group 6 is used to generate an alternating magnetic field 7. The infrared thermal imaging detector 9 is connected to the power supply 14 and the infrared thermal imaging display 15 on the ground through wires. At the same time, an infrared thermal imaging detector 9 is placed at a vertical interval of 2-4 meters in the heating monitoring well 5 to ensure that all monitoring wells are within the detection range of the detector.

[0037] S4. Set the depth and spacing of the heating monitoring wells 5 according to the range of action of the alternating magnetic field 7 and the detection range of the infrared thermal imaging detector 9 to ensure that the eddy current heating caused by the alternating magnetic field 7 can cover the rare earth ore body 3 area and that the detection range of the infrared thermal imaging detector 9 can cover the rare earth ore body 3 area. The vertical spacing of the infrared thermal imaging detectors 9 in the heating monitoring wells 5 is 2-4 meters.

[0038] S5. Mix the iron-nickel alloy particles with the leaching solution in the mixed liquid tank 13, wherein the iron-nickel alloy particles are spherical and have a particle size of 4000-8000 mesh. Open the injection control valve 12 of the injection well 11, and inject the leaching solution containing the iron-nickel alloy particles into the injection pipe 8 through the injection well 11 and the mixed liquid tank 13. When the leaching solution flows into the liquid collection tank 1, the high-voltage AC box 4 is started, and the coils generate an alternating magnetic field 7. Under the action of the alternating magnetic field 7, the temperature of the iron-nickel alloy particles rises, heating the leaching solution. In this embodiment, the high-voltage AC box 4 outputs high-voltage AC power of 40 kHz to 200 kHz. By controlling the output frequency, the heating rate of the leaching solution is adjusted and its temperature is controlled to 40-80°C. Simultaneously, the power supply 14 of the infrared thermal imaging detector 9 and the infrared thermal imaging display 15 are turned on. After analog-to-digital conversion and image processing, the infrared thermal imaging detector 9 displays the captured infrared image on the infrared thermal imaging display 15. By observing the image on the infrared thermal imaging display 15, the scope of the leaching liquid impregnation area within the ore body is determined. Based on the impregnation area, areas not impregnated by the leaching liquid are delineated, and abnormal infiltration areas or areas of infiltration outside the ore body, i.e., areas where cracks 10 are located, are identified. Furthermore, the infrared image is used to locate abnormal infiltration areas or areas of infiltration outside the ore body, i.e., areas where cracks 10 are located, and these areas are sealed, thereby monitoring fluid infiltration.

[0039] S6. Increase the injection volume of the injection pipe 8 near the unimpregnated area. If the leaching liquid still cannot reach the area, arrange a new injection well and its corresponding injection pipe 8 above the area, inject the leaching liquid into it to impregnate the above-mentioned unimpregnated area, and at the same time seal the leakage area, that is, the area where the crack 10 is located, so as to achieve the purpose of monitoring fluid impregnation and improving the recovery rate of rare earth resources.

[0040] The above is only an embodiment of the present invention, and common knowledge such as the specific technical solutions or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several variations and improvements can be made, which should also be regarded as the scope of protection of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the description can be used to interpret the content of the claims.

Claims

1. An ionic rare earth in-situ leaching mining method based on eddy current heating, characterized by: The steps include: S1. Arrange injection wells according to the size, distribution and burial depth of the rare earth ore body in the area. The injection wells are circular and 2 meters deeper than the top surface of the rare earth ore body. At the same time, insert injection pipes into the injection wells. The size and depth of the injection pipes match the injection wells. S2. Arrange a liquid collecting pipe at an appropriate position below the bottom surface of the rare earth ore body, and connect the liquid collecting pipe to an external liquid collecting tank; S3. After the injection wells and liquid collecting pipes are arranged, heating monitoring wells are evenly spaced between the injection wells. The depth of the heating monitoring wells is 1-2 meters from the bottom of the rare earth ore body. The heating monitoring wells are provided with well casings. A coil group and an infrared thermal imaging detector are placed in the heating monitoring wells. The coil group is placed in the middle of the rare earth ore body and is connected to the high-voltage AC box via a high-voltage cable. The infrared thermal imaging detector is connected to the power supply and the infrared thermal imaging display via wires. At the same time, an infrared thermal imaging detector is placed vertically every 2-4 meters in the heating monitoring wells to ensure that all monitoring wells are within the detection range of the detector. S4. Determine the depth and spacing of the heating monitoring wells based on the range of the alternating magnetic field and the detection range of the infrared thermal imaging detector to ensure that the eddy current heating caused by the alternating magnetic field can cover the rare earth ore body area and that the detection range of the infrared thermal imaging detector can cover the rare earth ore body area. S5. Mixing the iron-nickel alloy particles with the leaching solution in the mixed liquid pool, injecting the leaching solution containing the iron-nickel alloy particles through the injection well and the mixed liquid pool; when the leaching solution flows into the liquid collecting pool, starting the high-voltage alternating current box, and causing the coil to generate an alternating magnetic field. Under the action of the alternating magnetic field, the temperature of the iron-nickel alloy particles rises, thereby heating the leaching solution; and simultaneously turning on the power supply of the infrared thermal imaging detector and the infrared thermal imaging display. The infrared thermal imaging detector displays the collected infrared image on the infrared thermal imaging display after analog-to-digital conversion and image processing circuitry. By observing the image on the infrared thermal imaging display, the range of the area impregnated by the leaching solution in the ore body is obtained, and the area not impregnated by the leaching solution is delineated; S6. Increase the injection volume of the injection pipe near the unimpregnated area. If the leaching liquid still cannot reach the area, arrange a new injection well and its matching injection pipe above the area, and inject the leaching liquid into it to impregnate the unimpregnated area.

2. The ionic rare earth in-situ leaching mining method based on eddy current heating according to claim 1, characterized in that: In step S1, the arrangement of the injection wells is based on the principle of arranging along the contour lines, and the well depth is 1-5 meters.

3. The method for in-situ leaching of rare earth ore using eddy current heating according to claim 1, characterized in that: In step S3, the interval between adjacent heating monitoring wells is 10-20 meters, and the depth of the heating monitoring wells is 4-15 meters.

4. The method for in-situ leaching of rare earth ore using eddy current heating according to claim 1, wherein: The well casing in step S3 is an infrared-transmitting plastic pipe with a sealed bottom.

5. The method for in-situ leaching of rare earth ore using eddy current heating according to claim 1, characterized in that: In step S4, the vertical spacing of the infrared thermal imaging detectors arranged in the heating monitoring well is 2-4 meters.

6. The ionic rare earth in-situ leaching mining method based on eddy current heating according to claim 1, characterized in that: In step S5, the iron-nickel alloy particles are spherical and have a particle size of 4000-8000 mesh.

7. The method for in-situ leaching of ionic rare earth ore based on eddy current heating according to claim 1, characterized in that: In step S5, the high-voltage AC box outputs 40KHz-200KHz high-voltage AC power, and adjusts the heating rate of the leaching solution and controls its temperature to 40-80°C by controlling the output frequency.

8. The ionic rare earth in-situ leaching mining method based on eddy current heating according to claim 1, characterized in that: In step S5, the infrared image is used to find abnormal permeability areas or permeability areas outside the ore body, that is, areas where cracks are located, and the areas where cracks are located are sealed, thereby achieving the purpose of monitoring fluid infiltration.

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