Method for selecting thermal modeling subclasses from unconventional uranium resources

Abstract

The invention belongs to the technical field of uranium resource prospecting, and particularly relates to a method for selecting a thermal modeling subclass from unconventional uranium resources, which comprises the following steps of: 1, collecting an unconventional uranium resource sample; 2, sample manufacturing and processing; 3, performing optical microscope pulse body statistics; 4, observing apatite through an optical microscope; and 5, heavy sand screening statistics. The method has the characteristics of process, intuition, easiness in operation and the like, the thermal modeling subclass with higher economic value and mining value can be efficiently and conveniently selected from the widely developed unconventional uranium resources, the method is particularly suitable for regions with backward technical equipment, and the economical efficiency and the effectiveness in the aspect of prospecting of the unconventional uranium resources are greatly improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of uranium resource prospecting, and particularly relates to a method for selecting a thermomorphous subclass from unconventional uranium resources. BACKGROUND

[0002] Unconventional uranium resources are widely distributed in the world, and are widely distributed in Asia, Africa, Europe, North America, South America and Oceania. Since they are originally of sedimentary origin, the development horizon is stable, the extension is wide, and the thickness is large. Unconventional uranium resources can be divided into three subclasses of sedimentary diagenetic type, thermomorphous type and leaching type. The thermomorphous type is based on the initial enrichment of uranium elements in the sedimentary diagenetic stage, and is further reformed by hydrothermal alteration. Therefore, the enrichment degree of uranium elements is higher, and under the action of hydrothermal alteration, multiple metal elements such as nickel, molybdenum, vanadium and barium are also enriched. Therefore, it has higher economic value and exploitation value. SUMMARY

[0003] The purpose of the present application is to provide a method for selecting a thermomorphous subclass from unconventional uranium resources. The method has the characteristics of flow, intuition and easy operation, and can efficiently and conveniently select a thermomorphous subclass with higher economic value and exploitation value from widely developed unconventional uranium resources. It is especially suitable for areas with backward technology and equipment, and greatly improves the economy and effectiveness of unconventional uranium resource prospecting.

[0004] The technical scheme for achieving the purpose of the present application is as follows:

[0005] A method for selecting a thermomorphous subclass from unconventional uranium resources, comprising:

[0006] Step 1: unconventional uranium resource sample collection;

[0007] Step 2: sample processing;

[0008] Step 3: optical microscope vein statistics;

[0009] Step 4: optical microscope apatite observation;

[0010] Step 5: heavy sand screening statistics.

[0011] Further, the step 1 comprises: carrying out sampling work on the unconventional uranium resource strata of the target area, and collecting samples vertically to the strata bedding surface. At least one group of samples is collected from each stratum, and each group of samples is composed of A and B samples.

[0012] Further, the weight of each sample in the step 1 is not less than 300 grams.

[0013] Further, the step 2 comprises: making optical thin sections for the A sample in each group of samples collected in the step 1, and the corresponding B sample is reserved.

[0014] Furthermore, in step 2, the thickness of the optical sheet is 0.3 mm.

[0015] Further, step 3 includes: observing the thin film prepared in step 2 under an optical microscope; if the number of quartz veins + calcite veins observed in the thin film is greater than 3 or the total width of quartz veins + calcite veins is greater than 0.5 cm, then the sample continues to perform the operation of step 4; samples that do not meet the above conditions are excluded.

[0016] Furthermore, in step 3, when observing with an optical microscope, the objective lens uses a 5x field of view and cross-polarized light.

[0017] Furthermore, step 4 includes: continuing optical microscopic observation of the selected sample thin sections from step 3.

[0018] Step 4.1: Randomly select 3 apatite particles from each thin slice. If the number of apatite particles in the thin slice is less than 3, then exclude the sample corresponding to that thin slice.

[0019] Step 4.2: Perform individual statistics on each optical thin slice selected in Step 4.1, and count the corner angles of the selected apatite particles in the optical thin slice. If the proportion of acute corner angles is ≥30%, the sample corresponding to the optical thin slice will continue to the work in Step 5. The samples corresponding to other optical thin slices that do not meet the conditions will be excluded.

[0020] Further, step 5 includes: weighing and recording the B sample corresponding to the sample selected in step 4, crushing the sample, and then performing heavy sand washing and screening to separate pyrite particles from the heavy sand sample of each sample, and weighing and recording the pyrite; when the weight of pyrite screened from a B sample is ≥ 0.1% of the weight of its B sample, the unconventional uranium resource corresponding to the sample is finally determined to be a thermomorphic subclass, which has high economic and mining value; conversely, when the weight of pyrite screened from a B sample is < 0.1% of the weight of its B sample, the stratum corresponding to the sample is determined to not meet the preferred conditions, is not a thermomorphic subclass, and has low economic value.

[0021] Furthermore, in step 5, when the B sample is crushed, the particle size is 120 mesh.

[0022] The beneficial technical effects of this invention are as follows:

[0023] 1. The present invention provides a method for selecting thermomorphic subclasses from unconventional uranium resources. This method can be completed using relatively simple and portable laboratory equipment. It can easily and efficiently select more economically valuable thermomorphic unconventional uranium resource areas for many third-world countries and remote areas of my country, reduce the investment in large-scale scientific research equipment, save the expensive costs and lengthy process of large-scale scientific research equipment analysis and testing, save scientific research funds, save money and time, and improve mineral exploration efficiency and economy.

[0024] 2. This invention provides a method for selecting thermomorphic subclasses from unconventional uranium resources. This method is broad in scope, highly effective, and widely applicable, and can be effectively extended to the entire geosciences field. Its innovation lies in extracting key elements such as marker products of the hydrothermal alteration stage of unconventional uranium resources, mineralogy characteristics, and typical hydrothermal alteration minerals as selection criteria, leading to convenient, rapid, and streamlined conclusions. The simplified method for selecting thermomorphic subclasses from unconventional uranium resources constructed using this invention was validated in a large-scale unconventional uranium resource area in central Angola from 2022 to 2024, identifying four thermomorphic unconventional uranium resource layers covering a total area of ​​620 km². 2 Later, it was found that the highest content reached n000×10 in the selected layers. -6 (several thousand × 10) -6 The discovery of uranium in these unconventional uranium resources, along with the discovery of vanadium, molybdenum, barium, and other mineral elements that can be comprehensively utilized, has greatly enhanced the comprehensive economic value of uranium resources in the region, marking a significant breakthrough in unconventional uranium resource exploration in this area. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the embodiments.

[0026] This invention provides a method for selecting thermomorphic subclasses from unconventional uranium resources. It is based on extensive work conducted in technologically underdeveloped countries such as Namibia, Niger, and Angola. A total of 3700 rock samples were collected from 36 unconventional uranium resource sampling sites in these countries, and the results were obtained by combining local research conditions. The method includes steps such as unconventional uranium resource sample collection, sample processing, optical microscopy vein counting, optical microscopy apatite observation, and heavy sand sieving and counting. Specifically, it includes the following steps:

[0027] Step 1: Sample Collection of Unconventional Uranium Resources

[0028] Sampling work shall be carried out on unconventional uranium resource strata in the target area. The samples shall be collected perpendicular to the bedding plane of the strata. At least one set of samples shall be collected from each stratum. Each set of samples shall consist of two samples, A and B. Each sample shall weigh no less than 300 grams and shall be fresh and intact.

[0029] Step 2: Sample making and processing

[0030] For each sample A collected in step 1, a thin film is prepared. The thickness of the thin film is required to be 0.3 mm. The corresponding sample B is ready for use.

[0031] Step 3: Pulse count using optical microscope

[0032] Observe the thin section prepared in step 2 using an optical microscope. The objective lens should have a 5x field of view and cross-polarized light. If more than 3 quartz veins + calcite veins are observed in the thin section, or if the total width of the quartz veins + calcite veins is greater than 0.5 cm, proceed to step 4 for that sample. Samples that do not meet the above conditions should be excluded, as further work is unnecessary.

[0033] Step 4: Observation of apatite under an optical microscope

[0034] The thin sections of samples selected in step 3 were further observed under an optical microscope:

[0035] Step 4.1: Randomly select 3 apatite particles from each thin film. If the number of apatite particles in the thin film is less than 3, then exclude the sample corresponding to that thin film.

[0036] Step 4.2: Perform individual statistics on each optical thin section selected in Step 4.1, and count the corner angles of the selected apatite particles in the optical thin section. If the proportion of acute corner angles is ≥30%, the sample corresponding to the optical thin section will continue to the work in Step 5. The samples corresponding to other optical thin sections that do not meet the conditions will be excluded, and there is no need to carry out further work.

[0037] Step 5: Heavy sand screening statistics

[0038] Identify the B sample to be used in step 2. Weigh and record the B sample corresponding to the sample selected in step 4, and crush it to a particle size of 120 mesh. Then, perform heavy sand washing and screening to separate pyrite particles from the heavy sand of each sample, and weigh and record the pyrite. When the weight of pyrite screened from a B sample is ≥ 0.1% of its B sample weight, the unconventional uranium resource corresponding to the sample is ultimately determined to be a thermomorphic subclass, with high economic and mining value. Conversely, when the weight of pyrite screened from a B sample is < 0.1% of its B sample weight, the formation corresponding to the sample does not meet the preferred conditions, is not a thermomorphic subclass, and has low economic value.

[0039] Example 1

[0040] Taking the unconventional uranium resources developed in the Sautar region of central Angola as an example, this embodiment provides a method for selecting thermomorphic subclasses from unconventional uranium resources, specifically including the following steps:

[0041] Step 1: Large-scale unconventional uranium resources exist in the Sautar region of central Angola. However, due to the wide age range and complex formation conditions, the genesis of unconventional uranium resources in different strata varies greatly, belonging to different subclasses, and are difficult to distinguish in the field based solely on rock texture and appearance. Therefore, in order to select strata with higher economic value, one set of samples was collected from each stratum of unconventional uranium resources in the Sautar region. A total of 37 sets of samples were collected from bottom to top in a direction perpendicular to the rock bedding in this region. Each set of samples contained two pieces, A and B, and each sample weighed more than 400 grams.

[0042] Step 2: Prepare optical thin films for sample A from the 37 collected samples. One optical thin film will be prepared for each sample A, with a thickness of 0.3 mm. A total of 37 optical thin films will be prepared for the 37 samples. Sample B from the 37 samples will be used later.

[0043] Step 3: Observe the veins in the thin films prepared in Step 2 under an optical microscope. Since the observation is of veins formed by hydrothermal modification, a low magnification and wide field of view are required. Therefore, a 5x field of view and orthogonal polarized light are used for statistical observation. Among the 37 thin films, 18 films have more than 3 quartz veins + calcite veins. Although 5 films have fewer than 3 veins, the width of the quartz veins + calcite veins is greater than 0.5 cm. Therefore, they also meet the selection criteria of this step. Continue to the operation of Step 4 for the samples corresponding to these 23 thin films. The remaining samples that were not selected do not need to be further processed because the hydrothermal modification was not strong and the traces of hydrothermal activity left behind were weak.

[0044] Step 4: Continue to perform optical microscopic observation and statistical analysis on the selected samples from Step 3:

[0045] Step 4.1: Observe and count the apatite in the 23 thin sections. Four of the 23 thin sections have fewer than 3 apatite particles, so the operation in Step 4.2 cannot be carried out. Therefore, the sample corresponding to the thin section is excluded. For the remaining 19 thin sections, 3 apatite particles are randomly selected from each thin section. The 3 apatite particles selected from each thin section are not fixed and can be changed arbitrarily during the process of Step 4.2.

[0046] Step 4.2: Individually observe and statistically analyze each of the 19 thin sections selected in Step 4.1. Analyze the angles of the three selected apatite crystals in each section. Of the 19 thin sections, 8 sections have a ≥30% proportion of acute apatite angles. The apatite in these 8 sections has been damaged by hydrothermal alteration, resulting in incomplete crystal structures and sharp angles. The apatite in the remaining thin sections, having not undergone strong hydrothermal alteration, retains its original, more rounded crystal structure, with most angles remaining obtuse. Continue with Step 5 on the 8 selected samples from this step; the remaining samples are excluded.

[0047] Step 5: Take out the B samples corresponding to the 8 samples selected in Step 4. First, weigh and record the weight of each of the 8 B samples. Then, crush each B sample to 120 mesh. Next, perform heavy sand washing and sieving on each sample to separate pyrite particles from the heavy sand. Weigh and record the pyrite in each sample. Pyrite is not only the most common metallic mineral formed in hydrothermal alteration, but it also indicates the reducing environment required for polymetallic uranium mineralization. Finally, divide the weight of pyrite in each B sample by the weight of the B sample itself. If the weight of pyrite in 4 of the 8 samples is ≥0.1% of the weight of their B sample, then the formation corresponding to these 4 samples is determined to be a hydrothermal unconventional uranium resource with high economic and mining value. The formations corresponding to the remaining samples are excluded.

[0048] The numerical results of the parameters measured in the above steps are shown in Table 1.

[0049] Table 1. Parameter numerical results (those excluded in each step are highlighted in bold).

[0050]

[0051]

[0052] Based on the above steps and using simple laboratory equipment, four stratigraphic layers in the Sautar region of central Angola were identified as high-value hot-formed unconventional uranium resources. Subsequent analysis of samples from this region using large-scale domestic experimental instruments such as scanning electron microscopes, electron probe microscopes, and energy dispersive spectroscopy confirmed the effectiveness of this method. Furthermore, during the exploration of the four selected stratigraphic layers according to specifications, the highest U content was found to be n000×10⁻⁶. -6 (several thousand × 10) -6 The highest vitamin content was 7726 × 10⁻⁶. -6 The highest Mo content was 3625×10. -6 The highest Ba content was 32215×10. -6 This demonstrates that the unconventional uranium resources in this region have extremely high value for comprehensive utilization of uranium polymetallic resources.

[0053] The present invention has been described in detail above with reference to the embodiments. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. All contents not described in detail in the present invention can be derived from existing technologies.

Claims

1. A method for selecting thermally shaped subclasses from unconventional uranium resources, characterized in that, include: Step 1: Sample collection of unconventional uranium resources; Step 2: Sample preparation and processing; Step 3: Pulse count using optical microscope; Step 4: Observe the apatite under an optical microscope; Step 5: Heavy sand screening statistics.

2. The method for selecting thermally shaped subclasses from unconventional uranium resources according to claim 1, characterized in that, Step 1 includes: conducting sampling work on unconventional uranium resource strata in the target area, collecting samples perpendicular to the bedding plane of the strata, collecting at least one set of samples for each stratum, and each set of samples consists of two samples, A and B.

3. The method for selecting thermally shaped subclasses from unconventional uranium resources according to claim 2, characterized in that, In step 1, the weight of each sample shall not be less than 300 grams.

4. The method for selecting thermally shaped subclasses from unconventional uranium resources according to claim 2, characterized in that, Step 2 includes: preparing optical thin films from sample A in each group of samples collected in step 1, and keeping the corresponding sample B ready for use.

5. The method for selecting thermally shaped subclasses from unconventional uranium resources according to claim 4, characterized in that, The thickness of the thin film in step 2 is 0.3 mm.

6. The method for selecting thermally shaped subclasses from unconventional uranium resources according to claim 4, characterized in that, Step 3 includes: observing the thin section prepared in step 2 using an optical microscope; if the number of quartz veins + calcite veins observed in the thin section is greater than 3 or the total width of quartz veins + calcite veins is greater than 0.5 cm, then proceed to step 4 for the sample; samples that do not meet the above conditions are excluded.

7. The method for selecting thermally shaped subclasses from unconventional uranium resources according to claim 6, characterized in that, In step 3, when observing with an optical microscope, the objective lens uses a 5x field of view and cross-polarized light.

8. A method for selecting thermally shaped subclasses from unconventional uranium resources according to claim 6, characterized in that, Step 4 includes: continuing optical microscopic observation of the thin film samples selected in step 3. Step 4.1: Randomly select 3 apatite particles from each thin slice. If the number of apatite particles in the thin slice is less than 3, then exclude the sample corresponding to that thin slice. Step 4.2: Perform individual statistics on each optical thin slice selected in Step 4.1, and count the corner angles of the selected apatite particles in the optical thin slice. If the proportion of acute corner angles is ≥30%, the sample corresponding to the optical thin slice will continue to the work in Step 5. The samples corresponding to other optical thin slices that do not meet the conditions will be excluded.

9. A method for selecting thermally shaped subclasses from unconventional uranium resources according to claim 8, characterized in that, Step 5 includes: weighing and recording the B sample corresponding to the sample selected in step 4, crushing the sample, and then performing heavy sand washing and screening to separate pyrite particles from the heavy sand sample of each sample, and weighing and recording the pyrite; when the weight of pyrite screened from a B sample is ≥ 0.1% of the weight of the B sample, the unconventional uranium resource corresponding to the sample is finally determined to be a thermomorphic subclass, which has high economic and mining value; conversely, when the weight of pyrite screened from a B sample is < 0.1% of the weight of the B sample, the strata corresponding to the sample are determined to not meet the preferred conditions, are not a thermomorphic subclass, and have low economic value.

10. A method for selecting thermally shaped subclasses from unconventional uranium resources according to claim 9, characterized in that, In step 5, when crushing sample B, the particle size is 120 mesh.

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