Method for researching mineralization process of interlayer oxidation zone sandstone type uranium deposit by using clay minerals

Abstract

The invention provides a method for researching the mineralization process of an interlayer oxidation zone sandstone type uranium deposit by using clay minerals, and belongs to the technical field of geological exploration. The method comprises the following steps: collecting clay minerals in an interlayer oxidation zone sandstone type uranium deposit area; the collected clay minerals are divided into medium-coarse-grain sandstone and medium-fine-grain sandstone according to the granularity; analyzing the mineral composition of the medium-coarse-grain sandstone and the medium-fine-grain sandstone; based on the analysis, summarizing the fraction distribution of clay minerals in the sandstone; analyzing the relationship between the total amount of clay and the mass fraction of uranium; according to the method, the mass fraction and distribution characteristics of the clay minerals of the interlayer oxidation zone sandstone type uranium ore deposit are comprehensively analyzed, the adsorption effect of the clay minerals on uranium is determined, the mineralization mechanism of the sandstone type uranium ore is analyzed, and the method has the advantages that the method is simple and convenient to operate, and the application prospect is wide. And a reference basis is provided for guiding general survey prospecting and carrying out uranium deposit ore composition research.

Description

Technical Field

[0001] The invention relates to the technical field of geological exploration, and in particular to a method for studying the mineralization process of interlayer oxidation zone sandstone-type uranium deposits by using clay minerals. Background Art

[0002] Interlayer oxidation zone sandstone uranium deposits refer to uranium deposits that are formed in permeable sandstones sandwiched between impermeable rock layers (such as mudstone). As uranium-containing oxygen-containing pressurized groundwater migrates downward along the permeable sandstones, uranium is reduced and precipitated at the front of the oxidation zone.

[0003] The mineralization process of uranium is a complex water-rock process. When oxygen-containing uranium-containing water enters the sand body, Fe 2+ The organic matter begins to be oxidized. As the water body moves farther or the degree of oxidation increases, the dissolved oxygen (free O2) in the water will gradually be consumed until the oxygen is completely consumed near the front line of the oxidation zone. The anaerobic bacteria in the unoxidized gray rock zone produce H2 and H2S. These reducing agents lower the pH of the formation water, which is beneficial to U 6+ Convert to U 4+ , U 4+ It precipitates to form uranium ore.

[0004] Clay minerals can change during the process of sedimentation and burial. Their formation and transformation are closely related to the environment in which they are located. Therefore, by deeply studying the changes in the combination and content of clay minerals, the structural characteristics and transformation laws, and the particle size distribution, we can infer the weathering type and climate evolution laws of their formation and source areas. Many scholars at home and abroad have long noticed the existence of clay minerals in interlayer oxidation zone sandstone-type uranium deposits, but the behavior of clay minerals in the uranium mineralization process is limited to qualitative understanding. Summary of the invention

[0005] The purpose of the present invention is to provide a method for studying the mineralization process of interlayer oxidation zone sandstone type uranium deposits by using clay minerals, to explore the relationship between clay minerals and the mineralization process of interlayer oxidation zone type sandstone uranium deposits, to help subsequent mining and prospecting, to provide a reference basis for guiding general prospecting and conducting research on uranium deposit ore composition.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a method for studying the mineralization process of interlayer oxidation zone sandstone-type uranium deposits using clay minerals, comprising the following steps:

[0008] (1) Collect clay minerals in the interlayer oxidation zone sandstone-type uranium deposit area;

[0009] (2) The collected clay minerals are divided into medium-coarse-grained sandstone and medium-fine-grained sandstone according to their particle size;

[0010] (3) Analyze the mineral composition of medium-coarse-grained sandstone and medium-fine-grained sandstone;

[0011] (4) Based on the above analysis, summarize the distribution of clay mineral fractions in sandstone;

[0012] (5) Analyze the relationship between the total amount of clay and the mass fraction of uranium;

[0013] (6) Infer the interaction between clay minerals and groundwater and mineralization hydrothermal fluids during the sedimentary evolution process.

[0014] Preferably, the interlayer oxidation zone in step (1) is a strong oxidation zone, a weak oxidation zone, a transition zone, a quasi-reduction zone and a reduction zone.

[0015] Preferably, the medium-coarse-grained sandstone in step (2) includes medium-grained sandstone, medium-coarse sandstone, coarse sandstone and gravelly coarse sandstone;

[0016] The medium-fine grained sandstone includes fine sandstone, silty fine sandstone and medium-fine sandstone.

[0017] Preferably, the analysis method in step (3) comprises one or more of X-ray powder diffraction analysis, X-ray fluorescence spectroscopy analysis, plasma mass spectrometry analysis, and solid mass spectrometry analysis.

[0018] The present invention has the following beneficial effects

[0019] The present invention comprehensively analyzes the mass fraction and distribution characteristics of clay minerals in interlayer oxidation zone sandstone-type uranium deposits, clarifies the adsorption effect of clay minerals on uranium, analyzes the mineralization mechanism of sandstone-type uranium deposits, and provides a reference for guiding prospecting and conducting research on uranium deposit ore composition. DETAILED DESCRIPTION

[0020] The present invention provides a method for studying the mineralization process of interlayer oxidation zone sandstone-type uranium deposits using clay minerals, comprising the following steps:

[0021] (1) Collect clay minerals in the interlayer oxidation zone sandstone-type uranium deposit area;

[0022] (2) The collected clay minerals are divided into medium-coarse-grained sandstone and medium-fine-grained sandstone according to their particle size;

[0023] (3) Analyze the mineral composition of medium-coarse-grained sandstone and medium-fine-grained sandstone;

[0024] (4) Based on the above analysis, summarize the distribution of clay mineral fractions in sandstone;

[0025] (5) Analyze the relationship between the total amount of clay and the mass fraction of uranium;

[0026] (6) Infer the interaction between clay minerals and groundwater and mineralization hydrothermal fluids during the sedimentary evolution process.

[0027] In the present invention, the interlayer oxidation zone in step (1) is preferably a strong oxidation zone, a weak oxidation zone, a transition zone, a quasi-reduction zone and a reduction zone.

[0028] In the present invention, the medium-coarse-grained sandstone in step (2) preferably includes medium-grained sandstone, medium-coarse sandstone, coarse sandstone and gravelly coarse sandstone;

[0029] The medium-fine grained sandstone preferably includes fine sandstone, silty fine sandstone and medium-fine sandstone.

[0030] In the present invention, the analysis method in step (3) preferably includes one or more of X-ray powder diffraction analysis, X-ray fluorescence spectroscopy analysis, plasma mass spectrometry analysis, and solid mass spectrometry analysis.

[0031] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0032] Example 1

[0033] Taking the 512 uranium deposit on the gently inclined slope belt on the southern edge of the Yili Basin as an example, clay minerals in the interlayer oxidation zones (strong oxidation zone, weak oxidation zone, transition zone, quasi-reduction zone and reduction zone) of the deposit were collected;

[0034] The collected clay minerals are divided into medium-coarse-grained sandstone and medium-fine-grained sandstone according to their particle size;

[0035] The clay mineral compositions of medium-coarse-grained sandstone and medium-fine-grained sandstone were determined by X-ray powder diffraction (XRD), and the results are shown in Table 1;

[0036] Table 1 Clay mineral composition of medium-coarse-grained sandstone and medium-fine-grained sandstone

[0037]

[0038]

[0039] Note: I / S is illite-montmorillonite mixed layer, C / S is chlorite-montmorillonite mixed layer; S% is the mixed layer ratio of montmorillonite in the mixed layer clay mineral.

[0040] Based on the above analysis, the distribution of clay mineral fractions in sandstone is summarized;

[0041] As can be seen from Table 1, the main components of clay minerals in the 512 uranium deposit are kaolinite and illite; followed by smectite, chlorite, and a small amount of illite-smectite (I / S) and chlorite-smectite mixed layer (C / S) minerals. The clay mineral mass fractions of sandstones with different particle sizes are significantly different. The total amount of clay minerals in medium-fine grained sandstone is higher than that in medium-coarse grained sandstone in each sub-zone of the interlayer oxidation zone, which is about 2 to 3 times that of medium-coarse grained sandstone; there is no analytical data of quasi-reduction zone and reduction zone for medium-coarse grained sandstone, but its change trend from strong oxidation zone to transition zone is similar to that of medium-fine sandstone, and its overall change trend is also similar; through the changes in the clay mineral mass fractions of medium-fine grained sandstone in the primary zone and other sub-zones, it can be seen that the clay minerals in each sub-zone of the interlayer oxidation zone of the 512 uranium deposit were mainly formed during the diagenetic period, and are mainly kaolinite and illite, indicating that kaolinite and illite are closely related to the formation of uranium ore. In general, the total amount of clay minerals and the mass fraction of quartz show a decreasing relationship. The quartz particles are dissolved in the strong oxidation zone and re-precipitated from the weak oxidation zone to the transition zone, indicating that there are obvious differences in the pH values ​​of the subzones in the interlayer oxidation zone, that is, the strong oxidation zone is weakly alkaline, which becomes moderately acidic in the transition zone, and the quasi-reduction zone and the reduction zone become weakly alkaline environments, which is similar to the change in the Eh value (from the strong oxidation zone to the transition zone).

[0042] According to the comparison between the total amount of clay and the mass fraction of uranium, except for the transition zone, the change trend of the mass fraction of uranium in the remaining zones is basically consistent with the change trend of the total amount of clay minerals w(TC), which shows that the role of clay minerals on uranium is mainly adsorption enrichment, but not in all zones. The mass fraction of uranium in the transition zone and w(TC) show a decreasing relationship, indicating that uranium is not only adsorbed by clay minerals, but also by underwater environmental factors. Therefore, the interaction between clay minerals and groundwater and mineralization hydrothermal fluids during the sedimentary evolution process is further inferred, that is, the method of using clay minerals to study the mineralization process of interlayer oxidation zone sandstone-type uranium deposits is completed.

[0043] As can be seen from the above embodiments, the present invention provides a method for studying the mineralization process of interlayer oxidation zone sandstone-type uranium deposits using clay minerals, comprising the following steps: (1) collecting clay minerals in the interlayer oxidation zone sandstone-type uranium deposit area; (2) dividing the collected clay minerals into medium-coarse-grained sandstone and medium-fine-grained sandstone according to particle size; (3) analyzing the mineral composition of medium-coarse-grained sandstone and medium-fine-grained sandstone; (4) summarizing the distribution of clay mineral fractions in sandstone based on the above analysis; (5) analyzing the relationship between the total amount of clay and the mass fraction of uranium; (6) estimating the interaction between clay minerals and groundwater and mineralization hydrothermal fluids during the sedimentary evolution process. The present invention comprehensively analyzes the mass fraction and distribution characteristics of clay minerals in interlayer oxidation zone sandstone-type uranium deposits, clarifies the adsorption of clay minerals on uranium, analyzes the mineralization mechanism of sandstone-type uranium deposits, and provides a reference for guiding prospecting and conducting research on uranium deposit ore composition.

[0044] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for studying the mineralization process of interlayer oxidation zone sandstone-type uranium deposits using clay minerals, characterized in that: It includes the following steps: (1) Collect clay minerals in the interlayer oxidation zone sandstone-type uranium deposit area; (2) The collected clay minerals are divided into medium-coarse-grained sandstone and medium-fine-grained sandstone according to their particle size; (3) Analyze the mineral composition of medium-coarse-grained sandstone and medium-fine-grained sandstone; (4) Based on the above analysis, summarize the distribution of clay mineral fractions in sandstone; (5) Analyze the relationship between the total amount of clay and the mass fraction of uranium; (6) Infer the interaction between clay minerals and groundwater and mineralization hydrothermal fluids during the sedimentary evolution process.

2. The method for studying the mineralization process of interlayer oxidation zone sandstone-type uranium deposits using clay minerals as claimed in claim 1, characterized in that: The interlayer oxidation zones in step (1) are strong oxidation zones, weak oxidation zones, transition zones, quasi-reduction zones and reduction zones.

3. The method for studying the mineralization process of interlayer oxidation zone sandstone-type uranium deposits using clay minerals as claimed in claim 1 or 2, characterized in that: The medium-coarse-grained sandstone in step (2) includes medium-grained sandstone, medium-coarse sandstone, coarse sandstone and gravelly coarse sandstone; The medium-fine grained sandstone includes fine sandstone, silty fine sandstone and medium-fine sandstone.

4. The method for studying the mineralization process of interlayer oxidation zone sandstone-type uranium deposits using clay minerals as claimed in claim 3, characterized in that: The analysis method described in step (3) includes one or more of X-ray powder diffraction analysis, X-ray fluorescence spectroscopy analysis, plasma mass spectrometry analysis, and solid mass spectrometry analysis.

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