A method for reconstructing the leaching environment in mining areas

Abstract

The present invention mainly belongs to the technical field of in-situ leaching of uranium deposits, and specifically relates to a method for reconstructing the leaching environment of a mining area. Generally, the longer the service time of an acid in-situ leaching uranium mine, the uranium concentration of the leaching solution in the mining area will show a decreasing trend year by year. Therefore, it is necessary to study a new method to increase the uranium concentration of the leaching solution to achieve lean mining of uranium resources. The present invention is a method for reconstructing the leaching environment of a mining area, including obtaining geophysical exploration and interpretation information of an in-situ leaching mining area, obtaining production and operation parameter information of an in-situ leaching mining area, determining whether to enter a circulation module in the mining area, forming a new leaching unit, and finding a high-increment area assisted by independent and precise acid distribution measures for the unit. After the overall uranium concentration of the leaching solution in the mining area is increased, it is incorporated into the water metallurgical system for operation. The leaching environment of the acid in-situ leaching uranium mine mining area is optimized, the uranium concentration of the leaching solution in the well site is increased, and thus the good effect of improving resource utilization and economic benefits is achieved.

Description

Technical Field

[0001] The invention mainly belongs to the technical field of in-situ leaching mining of uranium deposits, and in particular relates to a method for reconstructing the leaching environment of a mining area. Background Art

[0002] In-situ uranium leaching is a uranium mining method that integrates mining and metallurgy. Under natural burial conditions, chemical reagents are injected into the ore layer to selectively dissolve the uranium in it, and then the uranium-containing solution is lifted to the surface for uranium extraction. Uranium deposits are not isotropic homogeneous bodies. For the same mining area, there will be a certain degree of difference in occurrence, mineral occurrence form, ore composition, permeability, etc., and the conditions required for leaching in each area are also different. Generally, the longer the service time of the acid in-situ leaching uranium mining area, the uranium concentration of the leachate in the mining area will show a decreasing trend year by year. In a certain in-situ leaching uranium mine in Inner Mongolia, there is a threshold for the processing capacity of the water metallurgy system. Due to long-term service in some mining areas, the uranium concentration of the leachate has decreased year by year, resulting in a continuous decrease in the amount of metal recovery per unit time. In view of this, it is necessary to study a new method to increase the uranium concentration of the leachate to achieve lean mining of uranium resources. Summary of the invention

[0003] 1. Purpose

[0004] The purpose of the present invention is to optimize the leaching environment of the acid in-situ leaching uranium mining area, increase the uranium concentration of the well site leaching solution through an internal circulation operation mode and environmental reconstruction, thereby improving resource utilization and economic benefits.

[0005] 2. Technical solution

[0006] A method for reconstructing a leaching environment in a mining area includes a circulation operation mode in the mining area and reconstruction of the leaching environment in the mining area; the circulation operation mode in the mining area includes:

[0007] Step 1: Obtain geophysical and interpretation information of the in-situ leaching mining area;

[0008] Step 2: Obtaining production operation parameter information of the in-situ leaching mining area;

[0009] Step 3: Determine whether to enter the circulation module in the mining area;

[0010] The reconstruction of the leaching environment in the mining area includes:

[0011] Step 4: forming a new leaching unit;

[0012] Step 5: Discover high-increment areas and use independent and precise acid allocation measures for each unit;

[0013] Step 6: After the uranium concentration of the entire leaching solution in the mining area is increased, it is incorporated into the hydrometallurgical system for operation.

[0014] The step 1 is to obtain geophysical and interpretation information of the in-situ leaching mining area, specifically including the drilling hole number, coordinate value, quantity, lithology, grade, and uranium content per square meter.

[0015] The second step is to obtain the production operation parameter information of the in-situ leaching mining area, including the operating water volume of the pumping hole, the concentration of the leaching solution; the operating water volume of the injection hole, and the leaching agent preparation parameters. When the uranium concentration of the leaching solution reaches 15 mg / L, the mining area is directly incorporated into the water metallurgy system to recover metals; the mining area with a uranium concentration of the leaching solution below 10 mg / L is operated in an internal circulation mode and is temporarily not incorporated into the water metallurgy system to recover metals. The leaching agent preparation range is 8 to 15 g / L, preferably 12 g / L.

[0016] The step 3 determines whether to enter the internal circulation module of the mining area, specifically including: if the water volume of the pumping hole is less than 5-6 cubic meters / hour, it will not enter the internal circulation module of the mining area; if the water volume of the injection hole is less than 5-6 cubic meters / hour, it will not enter the internal circulation module of the mining area. After the internal circulation mode of the mining area is running, the overall leachate concentration of the mining area reaches 15mg / L and can be incorporated into the water metallurgical system for operation.

[0017] The fourth step is to form a new leaching unit, specifically including: according to the results of the first and second steps, calculating the area of ​​the extraction unit, the unit resource volume, and the unit leaching rate in the mining area, superimposing the contour map of the unit leaching rate, uranium concentration, and the square meter uranium volume, and forming a new leaching unit after the well pattern adjustment; the unit operating water volume reaches ≥5m 3 / h, the operation is maintained by the remaining resources in the unit, and the remaining pumping holes are converted into injection holes or shut down, thereby forming a new well network.

[0018] The fifth step is to find high increment areas and independently and accurately prepare acid for each unit, including: arranging the reconstruction of the leaching environment, circulating the acid through the whole mining area, screening the whole mining area when the unit cannot effectively identify the potential point, and finding the extraction unit with a concentration higher than the overall average concentration of the mining area, and then preparing acid separately.

[0019] 3. Effect

[0020] The method for reconstructing the leaching environment of a mining area for in-situ leaching uranium provided by the present invention can reconstruct the operation mode inside the mining area without adding additional drilling holes. When a certain degree of uranium metal is enriched inside the mining area, incorporating it into the water metallurgy system can effectively avoid the water metallurgy treatment load and achieve an overall uranium concentration increase. In a test mining area of ​​a uranium mine in Inner Mongolia, the internal circulation operation was carried out according to this mode for 27 days, and the system was incorporated for operation for 30 days. The cumulative leaching of metal was 1.394 tons, the average daily leaching metal improvement rate reached 37.7%, and the economic benefits reached 715,000 yuan. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1This is a schematic diagram of the operation of a pumping unit in a mining area before the leaching environment is reconstructed according to an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of the overall operation of the mining area before the leaching environment reconstruction according to an embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the overall operation of the mining area after the leaching environment is reconstructed according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The injection holes and extraction holes of the in-situ leaching mine are distributed in a five-point pattern, that is, the four injection holes are distributed in a square, located at the four corners of the square, and the extraction hole is located at the center of the square. Every four injection holes and one extraction hole are collectively referred to as an extraction unit (leaching unit). Each mining area usually consists of more than 30 extraction units. Each mining area has a centralized control room to centrally control the extraction and injection flow of the mining area.

[0025] As the mining area is put into operation for an increasing period of time, differences in ore permeability, ore distribution, ore lithology, etc. will lead to differences in the uranium concentration of the leachate, the injection flow rate, and the unit leaching rate of each leaching unit.

[0026] like Figure 1 As shown, before the leaching environment was reconstructed, a pumping unit in the mining area was designed with a pumping hole in the center and four injection holes around it.

[0027] like Figure 1 As shown in FIG. 1 , before the leaching environment is reconstructed, the underground solution flow field of a pumping unit in the mining area is that the injection holes on the surrounding sides converge toward the pumping hole in the middle.

[0028] like Figure 2 As shown, before the leaching environment was reconstructed, the overall operation of the mining area was that the underground solution converged to the extraction holes of each extraction unit.

[0029] like Figure 2 As shown, before the leaching environment is reconstructed, there are areas between each pumping unit that cannot be reached by the leaching liquid.

[0030] like Figure 3 As shown, under the condition of leaching environment reconstruction, the injection holes in the mining area are closed, the extraction holes are changed to injection holes, and the flow field of the underground solution is changed to achieve the purpose of reducing the leaching dead corners.

[0031] like Figure 3 A method for reconstructing the leaching environment of a mining area is shown, comprising the following steps:

[0032] (1) Obtaining geophysical and interpretation information of the in-situ leaching mining area: the geophysical and interpretation information at least includes: drilling hole number, coordinate value, quantity, lithology, grade, and uranium content per square meter;

[0033] (2) Obtaining production operation parameter information of the in-situ leaching mining area: operating water volume of the pumping hole, leaching solution concentration; operating water volume of the injection hole, leaching agent preparation parameters;

[0034] (3) Calculate the unit area, unit resource volume, and unit leaching rate of the mining area based on the above drilling information and operating parameters;

[0035] (4) The unit leaching rate, uranium concentration and square meter uranium content contour map are superimposed, and the new leaching unit formed after the well pattern adjustment is adjusted. The unit operating water volume reaches the set value requirement (≥5m 3 / h), and the remaining resources of the unit are maintained in operation, and the remaining pumping holes are changed into injection holes or shut down, thereby forming a new well pattern;

[0036] (5) The arrangement of leaching environment reconstruction is carried out through the internal circulation of acid extraction in the whole mining area. When the unit cannot effectively identify the potential point, the whole mining area is screened to find the high increment area and assist with the independent and precise acid distribution measures of the unit.

[0037] (6) After the circulation mode in the mining area has been running for a certain period of time and the uranium concentration of the overall leaching solution in the mining area has increased, it will be incorporated into the hydrometallurgical system to achieve a more efficient and economic recovery model.

[0038] The specific embodiments are as follows:

[0039] A mining area leaching environment reconstruction method includes designing an operation mode of a circulation within the mining area and reconstructing the mining area leaching environment.

[0040] (1) Circulation operation mode within the mining area

[0041] Normally, the mining area of ​​in-situ uranium mines is developed and invested year by year. In the early stage of the service of the mining area, the uranium concentration of the leachate is high, and the metal recovery per unit time is high, which decreases year by year with the service time. Because there is an upper limit to the processing capacity of the water metallurgical system, in the internal circulation operation mode, the mining area with a uranium concentration of 15 mg / L in the leachate is directly incorporated into the water metallurgical system to recover metals. The mining area with a uranium concentration of less than 10 mg / L in the leachate is operated in accordance with the internal circulation mode and is temporarily not incorporated into the water metallurgical system to recover metals. The concentration is increased and enriched to more than 20% and incorporated into the water metallurgical system. At the same time, the mining area with a lower uranium concentration of 10 mg / L in the leachate is switched to enter the internal circulation mode. This method can effectively increase the metal concentration of the solution entering the water metallurgical system for treatment.

[0042] The operation mode of internal circulation in the mining area refers to the circulation of solution in the mining area through the main pump of the mining area control room and the submersible pumps of each pumping hole. The uranium metal concentration of the solution enrichment > the concentration of the collective sample (15 mg / L and above) is used to determine whether to merge into the water metallurgy system for operation. The internal circulation operation time is more than 30 days. Through the intermittent internal circulation, enrichment, and incorporation operation mode of multiple mining areas, the uranium concentration of the leaching solution in the mining area is increased, and the amount of recovered metal is increased.

[0043] (2) Reconstruction of the leaching environment in the mining area

[0044] By analyzing the mining area data, the unit leaching rate, uranium concentration and square meter uranium content contour map are superimposed. According to the new leaching unit formed after the well pattern adjustment, the unit operating water volume reaches the set value requirement (≥5m 3 / h), and the remaining resources of the unit are maintained in operation, and the remaining pumping holes are changed into injection holes or shut down, and a new well network is formed accordingly. For some pumping units with concentrations higher than the overall average concentration of the mining area, stable operation is continued, that is, a new large five-point well pattern is formed with the pumping holes as the center, and the leaching environment is reconstructed and adjusted accordingly to form a new well pattern layout, shut down low-concentration drilling holes, activate inefficient units, and reduce leaching dead corners.

[0045] The reconstruction of the leaching environment does not require new land acquisition, new drilling holes and equipment facilities. It provides an efficient operation mode for the mid- and late-stage mining areas, enriches the operation paradigm of the mining areas throughout their life cycle, and provides a reference for subsequent mining areas and units to tap potential and increase efficiency.

Claims

1. A method for reconstructing the leaching environment of a mining area, characterized by: Including the circulation operation mode within the mining area and the reconstruction of the leaching environment in the mining area; The circulation operation modes within the mining area include: Step 1: Obtain geophysical and interpretation information of the in-situ leaching mining area; Step 2: Obtaining production operation parameter information of the in-situ leaching mining area; Step 3: Determine whether to enter the circulation module in the mining area; The reconstruction of the leaching environment in the mining area includes: Step 4: forming a new leaching unit; Step 5: Discover high-increment areas and use independent and precise acid allocation measures for each unit; Step 6: After the uranium concentration of the entire leaching solution in the mining area is increased, it is incorporated into the hydrometallurgical system for operation.

2. A method for reconstructing the leaching environment of a mining area according to claim 1, characterized in that: The step 1 is to obtain geophysical and interpretation information of the in-situ leaching mining area, specifically including the drilling hole number, coordinate value, quantity, lithology, grade, and uranium content per square meter.

3. A method for reconstructing the leaching environment of a mining area according to claim 1, characterized in that: The second step is to obtain the production operation parameter information of the in-situ leaching mining area, specifically including the operating water volume of the pumping hole, the concentration of the leaching solution; the operating water volume of the injection hole, and the preparation parameters of the leaching agent.

4. A method for reconstructing the leaching environment of a mining area according to claim 1, characterized in that: The step three determines whether to enter the circulation module in the mining area, specifically including: if the water volume of the pumping hole is lower than 5-6 cubic meters / hour, it will not enter the circulation module in the mining area; if the water volume of the injection hole is lower than 5-6 cubic meters / hour, it will not enter the circulation module in the mining area.

5. A method for reconstructing the leaching environment of a mining area according to claim 3, characterized in that: When the uranium concentration of the leachate in step 2 reaches 15 mg / L, the mining area is directly incorporated into the water metallurgy system to recover metals; the mining area where the uranium concentration of the leachate is below 10 mg / L is operated in an internal circulation mode and is temporarily not incorporated into the water metallurgy system to recover metals.

6. A method for reconstructing the leaching environment of a mining area according to claim 1, characterized in that: The fourth step is to form a new leaching unit, specifically including: according to the results of the first and second steps, calculating the area of ​​the extraction unit, the unit resource volume, and the unit leaching rate in the mining area, superimposing the contour map of the unit leaching rate, uranium concentration, and the square meter uranium volume, and forming a new leaching unit after the well pattern adjustment; the unit operating water volume reaches ≥5m 3 / h, the operation is maintained by the remaining resources in the unit, and the remaining pumping holes are converted into injection holes or shut down, thereby forming a new well network.

7. A method for reconstructing the leaching environment of a mining area according to claim 4, characterized in that: The fifth step is to find high increment areas and independently and accurately prepare acid for each unit, including: arranging the reconstruction of the leaching environment, circulating the acid through the whole mining area, screening the whole mining area when the unit cannot effectively identify the potential point, and finding the extraction unit with a concentration higher than the overall average concentration of the mining area, and then preparing acid separately.

8. A method for reconstructing the leaching environment of a mining area according to claim 3, characterized in that: The preparation range of the leaching agent is 8-15 g / L, preferably 12 g / L.

9. A method for reconstructing the leaching environment of a mining area according to claim 1, characterized in that: The sixth step: after the uranium concentration of the overall leaching solution in the mining area is increased, it is incorporated into the water metallurgical system for operation, specifically including the operation of the circulation mode in the mining area. After the overall leaching solution concentration in the mining area reaches 15 mg / L, it can be incorporated into the water metallurgical system for operation.

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