Method and system for determining mineralization age of sandstone type uranium

Abstract

The embodiment of the invention relates to the technical field of uranium mineralization chronology and uranium mineralization mechanism research, in particular to a method and system for determining sandstone type uranium mineralization age, and the method comprises the steps: collecting a sandstone type uranium mineralization sample, and making the sandstone type uranium mineralization sample into a polished thin sheet; performing scanning electron microscope analysis on the polished thin section, and determining ferrodolomite minerals having a predetermined relationship with uranium mineralization; performing U-Pb isotope analysis on the ferrodolomite minerals; and determining the ore-forming age of the sandstone type uranium according to the result of the U-Pb isotope analysis. According to the embodiment of the invention, U-Pb isotope analysis is carried out on the ferrodolomite minerals having the predetermined relationship with uranium mineralization in the polished flakes to determine the formation age of the ferrodolomite minerals, and the ferrodolomite minerals and uranium mineralization have the predetermined relationship, so that the sandstone type uranium mineralization age can be determined according to the formation age of the ferrodolomite minerals, and the uranium mineralization age can be determined according to the formation age of the sandstone type uranium mineralization. The influence of interference factors on the determination result of the uranium mineralization age is avoided, and the accuracy and reliability of the sandstone type uranium mineralization age are improved.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of uranium mineralization chronology and uranium mineralization mechanism research, and specifically to a method for determining the sandstone-type uranium mineralization age and a system for determining the sandstone-type uranium mineralization age. Background Art

[0002] The statements herein merely provide background information related to the present application and do not necessarily constitute prior art.

[0003] Sandstone-type uranium deposits occupy an important position in uranium resources. Accurate determination of their mineralization age is of great significance for understanding the mineralization mechanism and guiding prospecting practice. The mineralization of sandstone-type uranium deposits is mainly affected by multiple factors such as fluid action, sedimentary environment and tectonic background. In the process of sandstone-type uranium deposit mineralization, the generation and migration of fluids, the transfer and enrichment of fluids in sandstones, and the physical and chemical effects of fluids are involved. Under the joint action of these links, sandstone-type uranium deposits can be formed.

[0004] Since the mineralization process of sandstone-type uranium deposits is usually very complex and involves a variety of geological processes and fluid activities, the results of the determination of the mineralization age are affected by many factors, making it difficult to accurately reflect the true mineralization age. The current method for determining the mineralization age of sandstone-type uranium is not ideal. Summary of the invention

[0005] A brief overview of the present application is provided below in order to provide a basic understanding of certain aspects of the present application. It should be understood that this overview is not an exhaustive overview of the present application. It is not intended to identify the key or important parts of the present application, nor is it intended to limit the scope of the present application. Its purpose is merely to present certain concepts in a simplified form as a prelude to a more detailed description discussed later.

[0006] In a first aspect, an embodiment of the present application provides a method for determining the age of sandstone-type uranium mineralization, which comprises the following steps: S10: collecting a sample of the sandstone-type uranium mineralization to be determined; S20: making a light slice of the sample collected in step S10, and determining the ankerite mineral in the light slice; S30: performing a scanning electron microscope analysis on the light slice prepared in step S20, and determining the ankerite mineral having a predetermined relationship with uranium mineralization; S40: performing a U-Pb isotope analysis on the ankerite mineral having a predetermined relationship with uranium mineralization determined in step S30; S50: determining the age of sandstone-type uranium mineralization according to the result of the U-Pb isotope analysis on the ankerite mineral in step S40.

[0007] The method provided in the embodiment of the present application collects samples of sandstone-type uranium mineralization to be determined and makes them into optical thin sections, so as to determine the iron dolomite mineral in the optical thin section that has a predetermined relationship with uranium mineralization and perform U-Pb isotope analysis on it. In this way, the formation age of the iron dolomite mineral can be determined based on the result of the U-Pb isotope analysis. Furthermore, since the iron dolomite mineral has a predetermined relationship with uranium mineralization, the sandstone-type uranium mineralization age can be determined based on the formation age of the iron dolomite mineral. This method is beneficial to avoiding the influence of interference factors on the determination results of the uranium mineralization age, improving the accuracy and reliability of the determined sandstone-type uranium mineralization age, and has a relatively wide range of applications.

[0008] In the second aspect, an embodiment of the present application also provides a system for determining the age of sandstone-type uranium mineralization, which includes: a collection module, the collection module is configured to collect samples of sandstone-type uranium mineralization to be determined; a sample preparation module, the sample preparation module is configured to make the collected samples into optical thin sections; an analysis module, the analysis module is configured to determine the iron dolomite minerals in the optical thin sections, and perform scanning electron microscopy analysis on the iron dolomite minerals to determine the iron dolomite minerals that have a predetermined relationship with uranium mineralization, and perform U-Pb isotope analysis on the determined iron dolomite minerals that have a predetermined relationship with uranium mineralization, and determine the sandstone-type uranium mineralization age based on the results of the U-Pb isotope analysis of the iron dolomite minerals.

[0009] These and other advantages of the present application will become more apparent through the following detailed description of the preferred embodiments of the present application in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to further illustrate the above and other advantages and features of the present application, the specific embodiments of the present application are further described in detail below in conjunction with the accompanying drawings. The accompanying drawings together with the following detailed description are included in this specification and form a part of this specification. Elements with the same function and structure are represented by the same reference numerals. It should be understood that these drawings only describe typical examples of the present application and should not be regarded as limiting the scope of the present application.

[0011] Figure 1 is a schematic flow chart of a method for determining the sandstone-type uranium mineralization age according to an embodiment of the present application;

[0012] Figure 2 This is a schematic diagram of the U-Pb isochron age of an ankerite mineral according to an embodiment of the present application;

[0013] Figure 3 is a schematic diagram of U-Pb isochron age of ankerite mineral according to another embodiment of the present application;

[0014] Figure 4It is a schematic block diagram of a system for determining the sandstone-type uranium mineralization age according to an embodiment of the present application.

[0015] It should be noted that the drawings are not necessarily drawn to scale, but are merely shown in a schematic manner that does not affect the reader's understanding.

[0016] Description of reference numerals:

[0017] 10. Acquisition module; 20. Sample preparation module; 30. Analysis module. DETAILED DESCRIPTION

[0018] Exemplary embodiments of the present application will be described below in conjunction with the accompanying drawings. For the sake of clarity and conciseness, not all features of the actual implementation are described in the specification. However, it should be understood that many implementation-specific decisions must be made in the process of developing any such actual implementation in order to achieve the developer's specific goals, such as meeting those constraints related to the system and business, and these constraints may vary from implementation to implementation. In addition, it should be understood that although the development work may be very complex and time-consuming, it is only a routine task for those skilled in the art who benefit from the content of this application.

[0019] It is also necessary to explain here that, in order to avoid obscuring the present application due to unnecessary details, only the device structure and / or processing steps closely related to the scheme according to the present application are shown in the accompanying drawings, while other details that are not very relevant to the present application are omitted.

[0020] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in this application should have the common meanings understood by persons with ordinary skills in the field to which this application belongs.

[0021] In the description of the embodiments of the present application, “plurality” means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0022] There are many shortcomings in the current methods for determining the age of sandstone-type uranium mineralization. There are many difficulties in determining the U-Th-Pb apparent age (also known as "apparent age" or "surface age") of uranium minerals. For example, it is difficult to select uranium mineral samples in sandstone-type uranium deposits, and there is great uncertainty in deducting the initial lead isotope composition mixed in when the samples are formed. This leads to different apparent age data for a group of samples from the same deposit. For the determination of the mineralization age of uranium deposits using laser ablation inductively coupled plasma mass spectrometry, it is suitable for application scenarios with smaller uranium mineral diameters, and there are many inconveniences in the application process.

[0023] In view of the above technical problems, the embodiments of the present application provide a method for determining the age of sandstone-type uranium mineralization (hereinafter referred to as the determination method). Figure 1 is a schematic flow chart of a method for determining the sandstone-type uranium mineralization age according to an embodiment of the present application, such as Figure 1 As shown, the determination method includes the following steps S10 to S50.

[0024] S10: Collect samples of sandstone-type uranium mineralization to be determined.

[0025] S20: Prepare a thin optical section from the sample collected in step S10, and determine the ankerite mineral in the thin optical section.

[0026] S30: Performing scanning electron microscopy analysis on the optical thin section produced in step S20 to determine the ankerite minerals having a predetermined relationship with uranium mineralization.

[0027] S40: Performing U-Pb isotope analysis on the ankerite minerals having a predetermined relationship with uranium mineralization determined in step S30.

[0028] S50: Determine the sandstone-type uranium mineralization age according to the result of U-Pb isotope analysis of the ankerite mineral in step S40.

[0029] The method provided in the embodiment of the present application collects samples of sandstone-type uranium mineralization to be determined and makes them into optical thin sections, so as to determine the iron dolomite mineral in the optical thin section that has a predetermined relationship with uranium mineralization and perform U-Pb isotope analysis on it. In this way, the formation age of the iron dolomite mineral can be determined based on the result of the U-Pb isotope analysis. Furthermore, since the iron dolomite mineral has a predetermined relationship with uranium mineralization, the sandstone-type uranium mineralization age can be determined based on the formation age of the iron dolomite mineral. This method is beneficial to avoiding the influence of interference factors on the determination results of the uranium mineralization age, improving the accuracy and reliability of the determined sandstone-type uranium mineralization age, and has a relatively wide range of applications.

[0030] In some embodiments, in step S10, the radioactivity intensity of the uranium ore is measured using a radioactivity measuring instrument such as a core logger and an energy spectrometer, and uranium ores of different radioactivity intensities are collected as samples.

[0031] In some embodiments, step S20 further includes the following steps: S21: making a light slice from the sample collected in step S10; S22: staining the light slice; S23: determining the type of carbonate cement in the light slice; S24: determining the ankerite mineral in the light slice based on the type of carbonate cement.

[0032] The method provided in the embodiment of the present application can determine the ankerite mineral in the optical thin section according to the staining result by making the collected sample into an optical thin section and staining it. The operation is relatively simple and efficient, and the reliability of the determined ankerite mineral is also relatively high.

[0033] In some embodiments, in step S21, the sample collected in step S10 is ground into a light slice.

[0034] In such an embodiment, the optical sheet has dimensions of 2 cm x 3 cm and a thickness of 0.03 mm.

[0035] In some embodiments, in step S22, a mixed solution of potassium ferrocyanide and alizarin red is used to dye the optical slice, so as to improve the accuracy and efficiency of determining the ankerite mineral in the optical slice.

[0036] In some embodiments, in step S23, the occurrence forms of different types of carbonate cements in the optical slice are observed under a polarizing microscope.

[0037] In some embodiments, the types of carbonate cements in sandstone-type uranium mineralization include calcite, dolomite, ankerite and siderite. After dyeing the light slice, calcite is orange-red, iron-containing calcite is purple-dark purple, ankerite is light blue, and dolomite is not dyed. The type of carbonate cement in the uranium ore can be determined by observing the colors of different areas in the dyed light slice using a polarizing microscope.

[0038] In some embodiments, in step S24, the ankerite mineral in the light slice can be determined by circling and marking the light blue area in the stained light slice.

[0039] In some embodiments, in step S30, the following steps are also included: S31: determining that the ankerite mineral has a symbiotic relationship with the uranium mineralization; S32: determining that the ankerite mineral and the uranium mineralization are distributed along its edges.

[0040] The method provided in the embodiment of the present application can determine the ankerite mineral by determining that the ankerite mineral has a symbiotic relationship with uranium mineralization, thereby ensuring the reliability and accuracy of determining the age of uranium mineralization based on the formation age of the ankerite mineral.

[0041] In some embodiments, the predetermined relationship in step S30 is a symbiotic relationship.

[0042] In some embodiments, by performing scanning electron microscopy analysis on optical thin sections, the symbiotic relationship between the marked ankerite minerals and uranium mineralization is observed. If a large amount of uranium mineralization is seen growing along the edge of the ankerite mineral, that is, the uranium mineralization forms a "border" structure along the edge of the ankerite mineral, it means that the formation time of the current ankerite mineral is close to the formation time of the uranium mineralization.

[0043] In such an embodiment, at least 30 ankerite particles may be marked and identified as ankerite mineral having a predetermined relationship to uranium mineralization.

[0044] In some embodiments, in step S32, the ankerite mineral having a particle size greater than a predetermined value is determined, thereby facilitating testing using a laser ablation inductively coupled plasma mass spectrometer.

[0045] In some embodiments, the predetermined value is 100 μm.

[0046] In some embodiments, in step S50, U-Pb isotope analysis is performed on the ankerite mineral multiple times and correction is performed to further improve the accuracy of the determined uranium mineralization age.

[0047] In some embodiments, laser ablation inductively coupled plasma mass spectrometry is used to perform U-Pb isotope analysis on ankerite minerals. During the U-Pb isotope analysis, five sets of standard samples are repeatedly measured for every ten sample test points in the ankerite minerals to calibrate the results of the U-Pb isotope analysis, thereby ensuring the reliability of the results of the U-Pb isotope analysis.

[0048] In some embodiments, Figure 2 is a schematic diagram of the U-Pb isochron age of ankerite mineral according to an embodiment of the present application, such as Figure 2 As shown, a represents the harmonic curve obtained by fitting the analysis test data, and b represents the analysis test points, wherein the major axis of some ellipses is parallel to the horizontal axis, and the major axis of some ellipses is perpendicular to the horizontal axis, and both represent the errors of the analysis test data; Figure 3 is a schematic diagram of the U-Pb isochron age of ankerite mineral according to another embodiment of the present application, such as Figure 3 As shown, c is the harmonic curve obtained by fitting the analysis test data, and d represents the analysis test points, among which the major axes of some ellipses are parallel to the horizontal axis, and the major axes of some ellipses are perpendicular to the horizontal axis, all of which analyze the errors of the test data.

[0049] like Figure 2 and Figure 3As shown, the two samples were collected from the Hailijin sandstone-type uranium deposit in the Songliao Basin. Through the determination method provided in the embodiment of the present application, U-Pb isotope analysis was performed on the iron dolomite mining area of ​​40 test points in the two samples, and the results of the U-Pb isotope analysis were fitted to determine that the uranium mineralization ages of the two periods were 14.8±5.7Ma and 2.94±0.18Ma, respectively. Figure 2 The mean squared weighted deviation (MSWD) of the determined uranium mineralization age is 3. Figure 3 The average standard weighted deviation of the determined uranium mineralization ages is 3.1. Figure 2 and Figure 3 It represents two uranium mineralization events of the Hailijin uranium deposit in the Miocene and Pliocene, which is consistent with the uranium mineralization age obtained by previous researchers.

[0050] The embodiment of the present application also provides a system for determining the sandstone-type uranium mineralization age (hereinafter referred to as the determination system). Figure 4 is a schematic block diagram of a system for determining the sandstone-type uranium mineralization age according to an embodiment of the present application, such as Figure 4 As shown, the determination system includes a collection module 10 , a sample preparation module 20 and an analysis module 30 .

[0051] The collection module 10 is configured to collect samples of sandstone-type uranium mineralization to be determined.

[0052] The sample preparation module 20 is configured to prepare the collected samples into optical slices.

[0053] The analysis module 30 is configured to determine the ankerite minerals in the optical thin section, and perform scanning electron microscopy analysis on the ankerite minerals to determine the ankerite minerals having a predetermined relationship with uranium mineralization, and perform U-Pb isotope analysis on the determined ankerite minerals having a predetermined relationship with uranium mineralization, and determine the sandstone-type uranium mineralization age based on the results of the U-Pb isotope analysis on the ankerite minerals.

[0054] The embodiment of the present application utilizes the sample preparation module 20 to make the sample collected by the collection module 10 into an optical slice, and then utilizes the analysis module 30 to determine the iron dolomite mineral having a predetermined relationship with uranium mineralization in the optical slice and conducts a U-Pb isotope analysis on it, so that the formation age of the iron dolomite mineral can be determined according to the result of the U-Pb isotope analysis. Furthermore, since the iron dolomite mineral has a predetermined relationship with uranium mineralization, the analysis module 30 can be used to determine the sandstone-type uranium mineralization age according to the formation age of the iron dolomite mineral, which is beneficial to avoid the influence of interference factors on the determination results of the uranium mineralization age, improve the accuracy and reliability of the determined sandstone-type uranium mineralization age, and has a relatively wide range of applications.

[0055] In some embodiments, the sample preparation module 20 is also configured to dye the optical thin section; the analysis module 30 is also configured to analyze the dyed optical thin section to determine the type of carbonate cement in the optical thin section, and the type of carbonate cement to determine the ankerite mineral in the optical thin section.

[0056] The embodiment of the present application utilizes the sample preparation module 20 to dye the optical slice, and then utilizes the analysis module 30 to analyze the dyed optical slice to determine the ankerite mineral in the optical slice. The operation is relatively simple and efficient, and the reliability of the determined ankerite mineral is also relatively high.

[0057] In some embodiments, the analysis module 30 is further configured to determine that the ankerite mineral has a paragenetic relationship with the uranium mineralization; and determine that the ankerite mineral has uranium mineralization distributed along its edges.

[0058] The embodiment of the present application uses the analysis module 30 to determine that the ankerite mineral has a symbiotic relationship with the uranium mineralization, thereby ensuring the reliability and accuracy of determining the age of the uranium mineralization based on the formation age of the ankerite mineral.

[0059] In some embodiments, the sample preparation module 20 is configured to dye the uranium ore thin sections with a mixed solution of potassium ferrocyanide and alizarin red, so as to improve the accuracy and efficiency of determining the ankerite minerals in the thin sections.

[0060] Regarding the embodiments of the present application, it should also be noted that, in the absence of conflict, the embodiments of the present application and the features therein can be combined with each other to obtain new embodiments.

[0061] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. The protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for determining the age of sandstone-type uranium mineralization, characterized in that: It includes the following steps: S10: Collect samples of sandstone-type uranium mineralization to be determined; S20: preparing a light slice from the sample collected in step S10, and determining ankerite minerals in the light slice; S30: performing scanning electron microscope analysis on the optical slice prepared in step S20 to determine the ankerite mineral having a predetermined relationship with the uranium mineralization; S40: performing U-Pb isotope analysis on the ankerite mineral having a predetermined relationship with the uranium mineralization determined in step S30; S50: Determine the sandstone-type uranium mineralization age according to the result of U-Pb isotope analysis on the ankerite mineral in step S40.

2. The method according to claim 1, characterized in that In step S20, the following steps are also included: S21: making the sample collected in step S10 into a light slice; S22: dyeing the optical slice; S23: determining the type of carbonate cement in the optical thin section; S24: Determine the ankerite mineral in the optical thin section according to the type of the carbonate cement.

3. The method according to claim 1, characterized in that In step S30, the following steps are also included: S31: Determining that the ankerite mineral has a symbiotic relationship with the uranium mineralization; S32: Determine the ankerite mineral and the uranium mineralization is distributed along its edge.

4. The method according to claim 3, characterized in that In step S32, the ankerite mineral having a particle size greater than a predetermined value is determined.

5. The method according to claim 2, characterized in that: In step S22, the optical slice is stained with a mixed solution of potassium ferrocyanide and alizarin red.

6. The method according to claim 1, characterized in that In step S50, the U-Pb isotope analysis of the ankerite mineral is performed multiple times and calibrated.

7. A system for determining the age of sandstone-type uranium mineralization, characterized in that: It includes: A collection module, the collection module is configured to collect samples of sandstone-type uranium mineralization to be determined; A sample preparation module, wherein the sample preparation module is configured to prepare a light sheet from the collected sample; An analysis module, wherein the analysis module is configured to determine the ankerite mineral in the optical thin section, and perform a scanning electron microscope analysis on the ankerite mineral to determine the ankerite mineral having a predetermined relationship with the uranium mineralization, and perform a U-Pb isotope analysis on the determined ankerite mineral having the predetermined relationship with the uranium mineralization, and determine the sandstone-type uranium mineralization age based on the result of the U-Pb isotope analysis on the ankerite mineral.

8. The system according to claim 7, characterized in that The sample preparation module is also configured to dye the optical sheet; The analysis module is also configured to analyze the stained optical slice to determine the type of carbonate cement in the optical slice, and the type of carbonate cement determines the ankerite mineral in the optical slice.

9. The system according to claim 8, characterized in that The analysis module is also configured to determine that the ankerite mineral has a symbiotic relationship with the uranium mineralization; and to determine that the ankerite mineralization has the uranium mineralization distributed along its edges.

10. The system according to claim 8, characterized in that The sample preparation module is configured to dye the uranium ore thin slice using a mixed solution of potassium ferrocyanide and alizarin red.

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