Test method and device for determining uranium metallogenic fluid components

Abstract

The invention provides a test method and device for determining uranium metallogenic fluid components, a rock core sample is selected and put into a sealed beaker, a pH-Eh test is carried out for multiple days, after the test is finished, leachate is filtered through ICP-MS, the chemical components of the leachate are determined, and the uranium metallogenic fluid components are determined. The method comprises the following steps: calculating an asphalt uranium ore dissolution precipitation mechanism (mineral saturation index SI), an asphalt uranium ore dissolved uranium concentration boundary value and an oxidation reduction boundary value through hydrogeochemical simulation PHREEQC software, and approximately representing chemical components of ore-forming fluid as well as pH and Eh values of the chemical components by using the measured values; uranium metallogenic conditions and environments are determined through hydrogeochemical simulation calculation, basic data are provided for uranium metallogenic prospective area prediction, experimental data objectively explains the relationship between uranium migration and activation and metallogenic fluid, and the test device can achieve a certain effect for sandstone type uranium ore exploration and prediction.

Description

Technical Field

[0001] The present invention relates to the technical field of mining detection, in particular to a test method and device for determining the composition of uranium mineralization fluid. Background Art

[0002] Uranium usually migrates in an oxidizing environment and precipitates in a reducing environment. The Eh-pH value and chemical composition of the mineralizing fluid water are particularly important for the dissolution, migration and precipitation of uranium.

[0003] During uranium exploration, hydrogeological boreholes are rarely deployed. In some prospecting or prospecting areas, no dedicated hydrogeological boreholes are deployed at all, while a large number of geological exploration holes are deployed. This makes it difficult to quantitatively determine the Eh-pH value and chemical composition of ore-forming fluids. Furthermore, research on water-rock interactions during mineralization has primarily focused on qualitative theoretical inferences, lacking data support. To address the challenges of prospecting for sandstone-type uranium deposits, the difficulty in obtaining ore-forming fluids during uranium exploration, and the difficulty in clarifying the relationship between fluids and uranium mineralization, laboratory-based water-rock reaction experiments can better reconstruct the interactions between ore-forming fluids and geological bodies during the mineralization period, playing a crucial role in revealing the formation mechanism of interlayer oxidation zone-type uranium deposits.

[0004] In view of this, the inventors specially designed an experimental method and device for determining the composition of uranium mineralization fluids, which led to the present case. Summary of the Invention

[0005] In order to solve the above problems, the technical solutions of the present invention are as follows:

[0006] For the test sample collection and preliminary processing, complete columnar sealed sandstone core samples from sandstone-type uranium geological exploration holes were selected, and the surface mud skin was removed until the uneven fresh core layer was exposed for the experiment;

[0007] The sandstone samples were crushed to natural particle size by beating with a rubber hammer;

[0008] Add deionized water while adding the unoxidized sandstone sample and stir thoroughly until it becomes a paste and no bubbles are generated.

[0009] Conduct pH-Eh test on its seal, and measure pH value and Eh value by pH instrument and Eh instrument;

[0010] After the test, the leachate was filtered and the chemical composition of the leachate was determined. The U, K + 、Na + , Ca 2+ Mg 2+ 、SO4 2- 、Cl - 、Al3+ concentration.

[0011] Preferably, the pH-Eh test comprises the following steps:

[0012] Seal with sealing wax;

[0013] Monitor pH and Eh values once every fixed time and record them;

[0014] The test can be terminated when the recorded Eh and pH values remain stable for several consecutive days.

[0015] Preferably, this solution also provides a test device for determining the composition of uranium mineralizing fluid, including a cup body, a rubber stopper, a platinum electrode, a glass electrode, a reference electrode, a pH instrument, an Eh instrument and an ICP-MS. The rubber stopper is sealed with the cup body, the platinum electrode, the glass electrode and the reference electrode are inserted into the cup body through the rubber stopper, the pH instrument and the Eh instrument are respectively connected to one end of the platinum electrode and the reference electrode, and the ICP-MS is used to determine the chemical composition of the leachate.

[0016] Preferably, the platinum electrode, glass electrode and reference electrode are respectively a 213-01 model platinum electrode, a 231-01 model glass electrode and a 232-01 model reference electrode.

[0017] Preferably, the cup body is a 200ml spoutless beaker.

[0018] Preferably, the rubber stopper is a cylinder, and the diameter of the rubber stopper is the same as the outer diameter of the cup body.

[0019] The technical solution provided by the present invention has the following beneficial effects:

[0020] According to the principle of water-rock interaction, the indoor water-rock system Eh-pH test device is used to obtain the pH and Eh values of the chemical composition when the rock and water are mixed to reach water-rock equilibrium, and these measured values are used to approximately represent the chemical composition of the mineralizing fluid and its pH and Eh values. The chemical composition, uranium concentration and measured ion concentration of the water-rock equilibrium mineralizing fluid in the prospecting target layer are determined, and these data are used to approximately represent the fluid geochemical characteristics of the uranium mineralization period, which has achieved certain results in the exploration and prediction of sandstone-type uranium deposits. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings described herein are used to provide further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0022] in:

[0023] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0024] Figure 2 This is the characteristic diagram of pH value of the water-rock system of core ZKY1546-1 changing with time;

[0025] Figure 3 This is the characteristic diagram of the Eh value of the water-rock system of core ZKY1546-1 changing with time;

[0026] Figure 4 is a graph of the pitchblende saturation index under different Eh values of different core leachates in this embodiment;

[0027] Figure 5 It is the Eh boundary value of pitchblende dissolution and precipitation under different uranium concentration conditions in different cores in this example.

[0028] Description of labels:

[0029] 1. Cup; 2. Rubber stopper; 3. Platinum electrode; 4. Glass electrode; 5. Reference electrode. DETAILED DESCRIPTION

[0030] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer and more understandable, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0031] The present invention provides a test method for determining the composition of uranium mineralization fluid, comprising the following steps:

[0032] For the collection and preliminary processing of test samples, complete columnar sealed sandstone core samples were selected from sandstone-type uranium geological exploration holes, and the surface mud skin was removed until the uneven fresh core layer was exposed for the experiment. The complete columnar sealed core was used and the surface mud skin was removed to maximize the preservation of the original pore structure and fluid environment, avoiding the interference of drilling pollution on the redox state; at the same time, the weathering layer was removed by mechanical treatment to ensure that the experimental object was a deep primary mineral-water interface system that was not affected by surface oxidation. In this embodiment, a total of five sandstone core samples were tested, numbered ZKY1546-1, ZKY1546-2, ZKY1546-3, ZKY1546-5 and ZKY1546-7. The lithology of the above five sandstone cores was different. The specific sampling locations and lithology are shown in the following table:

[0033] Table 1 Drill cores and sampling locations

[0034]

[0035] Before the test, the platinum electrode 3, glass electrode 4, and reference electrode 5 need to be inserted into the standard solution to calibrate the Eh instrument and pH instrument. The three-electrode system consisting of the platinum electrode 3, glass electrode 4, and reference electrode 5, combined with standard solution calibration, can simultaneously eliminate electrode drift errors and ensure the absolute reliability of Eh-pH data.

[0036] The pH-Eh test is carried out on its seal. The sealing experiment can simulate the closed environment of the underground aquifer, avoid the false high Eh value caused by oxygen interference, and truly reflect the redox balance process;

[0037] After the test, the leachate was filtered and the chemical composition of the leachate was determined by ICP-MS. The pH, Eh, U, and K of the mineral water were determined. + 、Na + , Ca 2+ Mg 2+ 、SO4 2- 、Cl - 、Al 3+ concentration, Table 2 shows the chemical composition of the leachate from each core in this experiment;

[0038] Table 2 Chemical composition of leachate

[0039]

[0040] The dissolution and precipitation mechanism of pitchblende (mineral saturation index SI) and the boundary value of dissolved uranium concentration and redox boundary value of pitchblende were calculated by hydrogeochemical simulation software PHREEQC. The mineral saturation index (SI) was used to quantitatively characterize the dissolution / precipitation tendency of pitchblende (SI>0 indicates precipitation state, SI<0 indicates dissolution state).

[0041] The process of selecting sandstone samples includes the following steps:

[0042] The sandstone samples were broken into natural particle size by beating with a rubber hammer. Using a rubber hammer (rather than a metal tool) to beat the sandstone samples can avoid contamination by iron debris and prevent the accumulation of metal ions (such as Fe 2+ / Fe 3+ ) interferes with subsequent Eh-pH testing and analysis of uranium redox processes. At the same time, crushing to a "natural particle size" retains the original pore structure of the sandstone and the contact relationship between mineral particles, simulating the migration conditions of groundwater in a real fracture network, avoiding the abnormal increase in reaction surface area caused by ultra-fine grinding, and ensuring that the dissolution dynamics are close to the actual geological process.

[0043] Place the unoxidized sandstone sample in the cup 1, add the ore sample and deionized water while stirring, and stir it thoroughly with a glass rod until it becomes a paste. Until no bubbles are generated in the cup 1, the oxidation effect of atmospheric oxygen on the sample is reduced by eliminating bubbles, and a closed reducing environment is maintained. At the same time, it is fully stirred into a paste to ensure full contact between solid particles and liquid, simulate the slow diffusion process of minerals and fluids in the aquifer, promote the steady-state balance of ion exchange and complexation reaction, and provide initial homogeneous conditions for subsequent sealing experiments.

[0044] The PH-EH test includes the following steps:

[0045] The cup body 1 is sealed with sealing wax; the extremely low permeability of the sealing wax can completely isolate the infiltration of atmospheric oxygen, inhibit the oxidation and dissolution of uranium minerals, and truly simulate the anoxic conditions of deep aquifers, thereby avoiding an artificially high Eh value caused by oxidation interference in the experimental system.

[0046] The pH and Eh values were monitored and recorded every 12 hours. The 12-hour interval was based on the uranium mineral dissolution reaction rate. This allowed for both rapid initial changes in Eh-pH (e.g., a sudden increase in Eh caused by pyrite oxidation) and the subsequent slow equilibrium process. In this experiment, the interval was set to record at 9:00 AM and 9:00 PM.

[0047] The test can be terminated when the recorded Eh and pH values remain stable for 7 consecutive days. Stability for 7 consecutive days indicates that the system has reached thermodynamic equilibrium. The subsequent leachate composition can be directly used to calculate the saturation index (SI), such as Figure 4 and Figure 5 As shown in Table 3, the pitchblende saturation index for different core leachates under different Eh values and the Eh boundary values for pitchblende dissolution and precipitation under different uranium concentrations in various water-rock systems were obtained in this example. The dissolution and precipitation characteristics of pitchblende are characterized by the saturation index (SI). When SI = 0, the water and mineral are saturated, and no precipitation or dissolution occurs. When SI > 0, the mineral can precipitate and precipitate from the water. When SI < 0, the mineral dissolves, releasing more dissolved substances. The calculated saturation index results for all water-rock system leachates under actual Eh values and actual U concentrations are shown in Table 3. As can be seen from the table, the pitchblende saturation index (SI) for each borehole sample leachate is greater than zero, indicating that the pitchblende is in a precipitating state. This is because the low Eh of the leachate results in a strongly reducing state, which favors the reduction of U(+6) to U(+4), resulting in the formation of pitchblende precipitation. Therefore, the pitchblende saturation index is positive.

[0048] For details, please refer to Figure 1, including a cup body 1, a rubber stopper 2, a platinum electrode 3, a glass electrode 4, a reference electrode 5, a pH instrument, an Eh instrument and an ICP-MS. The rubber stopper 2 is sealed with the cup body 1. The cup body 1 contains deionized water and a sandstone sample. The platinum electrode 3, the glass electrode 4 and the reference electrode 5 are inserted into the deionized water in the cup body 1 through the rubber stopper 2. The interference fit design of the rubber stopper 2 and the cup body 1 ensures airtightness while allowing the electrode group to be stably inserted, avoiding oxidation disturbances caused by repeated unsealing of traditional sealing wax. The platinum electrode 3, the glass electrode 4 and the reference electrode 5 are fixed on the same plane by the rubber stopper 2, eliminating the solution resistance difference caused by the electrode spacing in traditional split measurement, and ensuring the accuracy of Eh-pH synchronous detection.

[0049] For details, please refer to Figure 1 The platinum electrode 3, glass electrode 4, and reference electrode 5 are model 213-01 platinum electrode 3, model 231-01 glass electrode 4, and model 232-01 reference electrode 5, respectively. The 213-01 platinum electrode 3, model 231-01 glass electrode 4, and model 232-01 reference electrode 5 have high sensitivity, good stability, and low noise. These characteristics enable them to perform well in experiments to determine the composition of uranium mineralization fluids, enabling more accurate detection and analysis of the chemical composition and electrochemical signals in the fluids.

[0050] For details, please refer to Figure 1 The cup body 1 is a 200ml spoutless beaker. The spoutless beaker has a simple design and no additional structure (such as a beaker spout). This can avoid problems such as liquid splashing, volatilization, or uneven heating caused by the presence of the beaker spout. This design helps to reduce human errors during the experiment and improve the accuracy of the experimental results.

[0051] For details, please refer to Figure 1 The rubber stopper is cylindrical, and its diameter is the same as the outer diameter of the cup body 1, ensuring a tight fit between the rubber stopper and the cup body 1. This design can effectively prevent liquid leakage or the ingress of external gas, thereby ensuring the sealing of the experimental environment and avoiding the influence of oxidation, volatilization or the ingress of external impurities on the experimental results.

[0052] In summary, based on the principle of water-rock interaction, the present invention uses an indoor water-rock system Eh-pH test device to obtain the pH and Eh values of the chemical composition when the rock and water are mixed to reach water-rock equilibrium, and uses ICP-MS to measure the U and K of the mineral water. + 、Na + , Ca 2+ Mg 2+ 、SO4 2- 、Cl - 、Al 3+concentration, and these measured values approximately represent the chemical composition of the mineralizing fluid and its pH and Eh values. Through hydrogeochemical simulation calculations, the uranium mineralization conditions and environment are determined to provide basic data for the prediction of uranium mineralization prospect areas. This experimental device can achieve certain results for the exploration and prediction of sandstone-type uranium deposits.

[0053] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the scope of protection of the present invention.

Claims

1. An experimental method for determining the composition of uranium mineralization fluids, characterized in that: The following steps are involved: For the test sample collection and preliminary processing, complete columnar sealed sandstone core samples from sandstone-type uranium geological exploration holes were selected, and the surface mud skin was removed until the uneven fresh core layer was exposed for the experiment; The sandstone samples were crushed to natural particle size by beating with a rubber hammer; Add deionized water while adding the unoxidized sandstone sample and stir thoroughly until it becomes a paste and no bubbles are generated. Conduct pH-Eh test on its seal, and measure pH value and Eh value by pH instrument and Eh instrument; After the test, the leachate was filtered and the chemical composition of the leachate was determined. The U, K + 、Na + , Ca 2+ Mg 2+ 、SO4 2- 、Cl - 、Al 3+ concentration.

2. The experimental method for determining the composition of uranium mineralization fluid according to claim 1, characterized in that: The pH-Eh test comprises the following steps: Seal with sealing wax; Monitor pH and Eh values once every fixed time and record them; The test can be terminated when the recorded Eh and pH values remain stable for several consecutive days.

3. A test device for determining the composition of uranium ore-forming fluids, based on the test method for determining the composition of uranium ore-forming fluids according to any one of claims 1 to 4, characterized in that: The invention comprises a cup body (1), a rubber stopper (2), a platinum electrode (3), a glass electrode (4), a reference electrode (5), a pH instrument, an EH instrument and an ICP-MS. The rubber stopper (2) is sealed and connected to the cup body (1). The platinum electrode (3), the glass electrode (4) and the reference electrode (5) pass through the rubber stopper (2) and are inserted into the cup body (1). The pH instrument and the EH instrument are respectively connected to one end of the platinum electrode (3) and the reference electrode (5). The ICP-MS is used to determine the chemical composition of the leachate.

4. The test device for determining the composition of uranium mineralization fluid according to claim 3, characterized in that: The platinum electrode (3), glass electrode (4) and reference electrode (5) are respectively a 213-01 model platinum electrode (3), a 231-01 model glass electrode (4) and a 232-01 model reference electrode (5).

5. The test device for determining the composition of uranium mineralization fluid according to claim 3, characterized in that: The cup body (1) is a 200ml spoutless beaker.

6. The test device for determining the composition of uranium mineralization fluid according to claim 3, characterized in that: The rubber stopper is a cylinder, and the diameter of the rubber stopper is the same as the outer diameter of the cup body (1).

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