Method for determining distribution of hydrothermal uranium deposit based on iron valence state ratio

Abstract

The application relates to a method for analyzing a geological body by means of physical and chemical properties of the geological body, and particularly relates to a method for determining distribution of a hydrothermal uranium deposit based on an iron valence ratio, which comprises the following steps: collecting ore samples at different depths in an exploration area; fitting a functional relationship between the iron valence ratio of the ore samples and the depths of the ore samples; determining a vertical variation trend of the iron valence ratio of the hydrothermal uranium deposit in the exploration area based on the functional relationship; determining the iron valence ratio at a point to be explored in the exploration area; and determining the vertical distribution of the hydrothermal uranium deposit at the point to be explored based on the iron valence ratio at the point to be explored and the vertical variation trend. The method provided in the application embodiment can effectively predict the vertical distribution of the hydrothermal uranium deposit, so that the exploration efficiency of the hydrothermal uranium deposit is improved and the cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to a method for analyzing a geological body by means of physical and chemical properties of the geological body, and in particular to a method for determining distribution of a hydrothermal uranium deposit based on a ratio of iron valence states. BACKGROUND

[0002] Preliminary prediction of the distribution of uranium deposits before exploration can effectively reduce the difficulty and cost of exploration. However, in related technologies, the distribution of hydrothermal uranium deposits in the plane is usually predicted, and the distribution of hydrothermal uranium deposits in the vertical direction is rarely predicted, which leads to the inability to determine whether there is uranium deposit in the deep part in the actual drilling exploration process, resulting in an increase in the difficulty of exploration and an increase in the cost. SUMMARY

[0003] In view of the above problems, the present application is proposed in order to provide a method for determining the distribution of a hydrothermal uranium deposit based on a ratio of iron valence states, which overcomes the above problems or at least partially solves the above problems.

[0004] Embodiments of the present application provide a method for determining the distribution of a hydrothermal uranium deposit based on a ratio of iron valence states, comprising: collecting ore samples at different depths in an exploration area; fitting a functional relationship between the ratio of iron valence states of the ore samples and the depths of the ore samples, the ratio of iron valence states being a ratio between the content of trivalent iron and the content of divalent iron of the ore samples; determining a vertical variation trend of the ratio of iron valence states of the hydrothermal uranium deposit in the exploration area based on the functional relationship; determining the ratio of iron valence states at a point to be explored in the exploration area; and determining the vertical distribution of the hydrothermal uranium deposit at the point to be explored based on the ratio of iron valence states at the point to be explored and the vertical variation trend.

[0005] The method for determining the distribution of a hydrothermal uranium deposit based on a ratio of iron valence states according to the embodiments of the present application can effectively predict the distribution of a hydrothermal uranium deposit in the vertical direction, thereby improving the efficiency of exploration of a hydrothermal uranium deposit and reducing the cost. BRIEF DESCRIPTION OF DRAWINGS

[0006] Figure 1 A flowchart of the method for determining the distribution of a hydrothermal uranium deposit based on a ratio of iron valence states according to the embodiments of the present application;

[0007] Figure 2 A schematic diagram of the functional relationship fitted according to the embodiments of the present application. DETAILED DESCRIPTION

[0008] In order to make the purposes, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described clearly and completely below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are one embodiment of the present application, rather than all the embodiments. Based on the described embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without any creative effort belong to the scope of protection of the present application.

[0009] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present application should be understood as the common meanings understood by those of ordinary skill in the art to which the present application belongs. If the descriptions of “first”, “second”, etc. are involved throughout the text, the descriptions of “first”, “second”, etc. are only used to distinguish similar objects, and cannot be understood as indicating or implying the relative importance, the order of precedence or implicitly indicating the number of the indicated technical features, and it should be understood that the data of “first”, “second”, etc. can be interchanged under appropriate circumstances. If “and / or” appears throughout the text, it means that three parallel schemes are included, for example, “A and / or B” includes A scheme, or B scheme, or A and B schemes are satisfied at the same time.

[0010] The embodiments of the present application provide a method for determining the distribution of hydrothermal uranium ore based on iron valence ratio, referring to Figure 1 , which comprises:

[0011] Step S102: Collecting ore samples at different depths in the exploration area.

[0012] Step S104: Fitting the functional relationship between the iron valence ratio of the ore sample and the depth of the ore sample, the iron valence ratio being the ratio between the content of trivalent iron and the content of divalent iron of the ore sample.

[0013] Step S106: Determining the vertical variation trend of the iron valence ratio of the hydrothermal uranium ore body in the exploration area based on the functional relationship.

[0014] Step S108: Determining the iron valence ratio at the point to be explored in the exploration area.

[0015] Step S110: Determining the vertical distribution of the hydrothermal uranium ore body at the point to be explored based on the iron valence ratio at the point to be explored and the vertical variation trend.

[0016] The valence of iron in nature includes divalent and trivalent, and the valence of iron will change under the influence of oxidation-reduction potential, medium acidity and alkalinity, temperature, pressure, ion concentration, etc. Therefore, the iron valence ratio can reflect the change of the environmental conditions when it is formed. The iron valence ratio in the present embodiment refers to the ratio between trivalent iron and divalent iron (Fe 3+ / Fe 2+), specifically, if the content of ferric iron is high, it indicates an oxidizing environment, and if the content of ferrous iron is high, it indicates a reducing environment.

[0017] The present application proposes that hematitization, magnetitization, pyritization and the like related to hydrothermal uranium deposits have regular variation trends in vertical space. Generally, the content of ferrous iron will increase with the increase of depth. Based on this variation trend, the distribution of hydrothermal uranium deposits can be determined by the iron valence state ratio. Specifically, based on the variation trend of the iron valence state ratio and the iron valence state ratio at a certain point, the depth position of the point in the entire hydrothermal uranium deposit can be determined, and thus the vertical distribution of the hydrothermal uranium deposit can be determined.

[0018] However, the present application further proposes that the variation trend of the iron valence state ratio in the vertical direction may be changed or destroyed due to the change of geological conditions after mineralization, and directly using the iron valence state ratio to determine the vertical distribution of the hydrothermal uranium deposit may not be accurate. Therefore, in the method provided in the embodiments of the present application, the variation trend of the iron valence state ratio of the hydrothermal uranium deposit in the exploration area is first determined by sampling analysis and function fitting.

[0019] Specifically, in step S102, ore samples at different depths in the exploration area are collected, then in step S104, a functional relationship between the iron valence state ratio of the ore samples and the depth of the ore samples is fitted, and finally in step S106, the variation trend of the iron valence state ratio of the hydrothermal uranium deposit in the vertical direction is determined based on the functional relationship.

[0020] The exploration area in step S102 can refer to an area where hydrothermal uranium exploration is being or is about to be carried out. Those skilled in the art can use any suitable method to determine the hydrothermal uranium exploration area, and no limitation is made thereto.

[0021] It is necessary to collect ore samples at different depths in the exploration area. It should be noted that, since the variation trend of the iron valence state ratio of the hydrothermal uranium deposit in the vertical direction is expected to be determined in the present application, the different depths here are with respect to the same hydrothermal uranium deposit. The collection of ore samples can be carried out by means of existing drillings or ore deposits in the exploration area. The specific sampling method will be described in detail in the relevant part below, and will not be described here. The number of samples and the depth interval of the samples can be determined by those skilled in the art according to the actual situation, as long as the number of samples collected can meet the data requirement of function fitting.

[0022] After the ore samples at different depths are collected, the iron valence ratio of the ore samples needs to be determined, so as to obtain the corresponding data between the iron valence ratio of the ore samples and the depth, so as to fit the function relationship in step S104. The divalent iron content and the trivalent iron content in the ore samples can be obtained by means of the related iron element analysis method in the art, and then the iron valence ratio of the ore samples is calculated. Some methods for calculating the iron valence ratio will be described in detail in the related part below, and will not be repeated here.

[0023] After the calculation of the iron valence ratio is completed, the function relationship between the iron valence ratio and the depth can be fitted. The person skilled in the art can complete the fitting of the function relationship by means of linear regression analysis and the like, and the fitting of the function relationship is not limited.

[0024] Figure 2 FIG. 2 shows a schematic diagram of the fitted function relationship in an embodiment, wherein the upper left corner is the origin, the horizontal axis is the iron valence ratio (Fe 3+ / Fe 2+ ), the iron valence ratio gradually increases from left to right, the vertical axis is the depth, the depth gradually increases from top to bottom, the discrete data points 21 in the figure indicate a plurality of ore samples obtained by sampling, and the curve 22 indicates the function relationship obtained by fitting.

[0025] In step S106, the vertical variation trend of the iron valence ratio of the hydrothermal uranium ore body can be determined based on the function relationship. Obviously, Figure 2 The function relationship in FIG. 2 indicates that the vertical variation trend of the iron valence ratio of the hydrothermal uranium ore body in the exploration area is that the iron valence ratio gradually decreases as the depth increases.

[0026] After the vertical variation trend is determined, in step S108, the iron valence ratio at the point to be explored can be determined, and then in step S110, the vertical distribution of the hydrothermal uranium ore body at the point to be explored can be determined based on the iron valence ratio at the point to be explored and the vertical variation trend. The point to be explored here can refer to any point in the exploration area that needs to be explored.

[0027] Still referring to Figure 2 , which indicates that the variation trend of the iron valence ratio in the hydrothermal uranium ore body is that the iron valence ratio gradually decreases as the depth increases. If it is determined that the iron valence ratio at the point to be explored is relatively small, it can be determined that the point to be explored is close to the root of the hydrothermal uranium ore body in the vertical direction, and the hydrothermal uranium ore body can continue to extend only within a relatively small depth range below the point to be explored. It can be selected not to continue to explore below the point to be explored, or to continue to explore only within a small depth range. If it is determined that the iron valence ratio at the point to be explored is relatively large, it can be determined that the point to be explored is located in the middle or upper section of the hydrothermal uranium ore body, and the hydrothermal uranium ore body can continue to extend below the point to be explored. Therefore, it can be continued to explore below the point to be explored.

[0028] The method according to the embodiments of the present application can predict the vertical distribution of the hydrothermal uranium ore body, and further reasonably determine the depth range of exploration based on the vertical distribution of the hydrothermal uranium ore body, thereby improving the efficiency of exploration and reducing the cost of exploration.

[0029] In some embodiments, the plurality of mineralization sections can be pre-divided, and the plurality of mineralization sections correspond to the plurality of numerical intervals of the iron valence state ratio. When the vertical distribution of the hydrothermal uranium ore body at the point to be explored is determined based on the iron valence state ratio and the vertical variation trend at the point to be explored in step S110, the vertical positional relationship between the mineralization sections can be determined based on the vertical variation trend first, and then the mineralization section in which the point to be explored is located in the hydrothermal uranium ore body can be determined based on the numerical interval in which the iron valence state ratio at the point to be explored is located, so that whether there is another mineralization section of the hydrothermal uranium ore body vertically below the point to be explored can be determined based on the vertical positional relationship.

[0030] As an example, the plurality of mineralization sections divided can include an oxidation section, an oxidation-reduction excessive section, and a reduction section, the numerical interval of the iron valence state ratio corresponding to the reduction section is less than 0.5, the numerical interval of the iron valence state ratio corresponding to the oxidation-reduction transition section is greater than or equal to 0.5 and less than or equal to 1, and the numerical interval of the iron valence state ratio corresponding to the oxidation section is greater than 1.

[0031] Still taking the vertical variation trend indicated by the function relationship in Figure 2 As an example, the vertical positional relationship can be determined as the oxidation-reduction transition section being distributed below the oxidation section, and the reduction section being distributed below the oxidation-reduction excessive section. If the iron valence state ratio at the point to be explored indicates that the point to be explored is in the oxidation section, it can be determined that the oxidation-reduction transition section and the reduction section are also distributed below the point to be explored, if the iron valence state ratio at the point to be explored indicates that the point to be explored is in the oxidation-reduction transition section, it can be determined that the reduction section is also distributed below the point to be explored, and if the iron valence state ratio at the point to be explored indicates that the point to be explored is in the reduction section, it can be determined that there is no other mineralization section below the point to be explored.

[0032] By pre-dividing the plurality of mineralization sections, the person skilled in the art can more intuitively and efficiently determine the vertical distribution of the hydrothermal uranium ore body, and further determine whether it is necessary to continue to explore the deep part and the specific depth range to be explored downward according to the number of mineralization sections below the point to be explored. In some embodiments, the person skilled in the art can also divide more detailed mineralization sections according to the actual situation, not limited to the above three mineralization sections.

[0033] In some other embodiments, it can also be selected not to divide the mineralization sections, and it can be selected to directly determine the vertical distribution of the hydrothermal uranium ore body at the point to be explored based on the iron valence state ratio and the vertical variation trend at the point to be explored. Figure 2The function relationship is shown in the figure, and the position of the iron valence state ratio at the to-be-explored point in the function relationship is determined, and the extension range of the hydrothermal uranium ore body under the to-be-explored point is estimated.

[0034] In some embodiments, before determining the vertical variation trend of the iron valence state ratio of the hydrothermal uranium ore body in the exploration area based on the function relationship, it is necessary to confirm that the correlation coefficient of the function relationship is greater than a preset value. It can be understood that if the correlation coefficient of the fitted function relationship is small, it may indicate that the correlation between the iron valence state ratio and the depth is poor, and the vertical variation trend indicated based on the function relationship may not accurately predict the vertical distribution of the hydrothermal uranium ore body. At this time, the person skilled in the art can choose to increase the number of samples to obtain more data for fitting. If a correlation coefficient that meets the expectations cannot be fitted, it may mean that the vertical variation trend of the iron valence state ratio in the hydrothermal uranium ore body in the exploration area may have been destroyed by post-mineralization geological activities, and the method provided in the embodiment is not applicable.

[0035] In some embodiments, if the fitted function relationship does not indicate a significant vertical variation trend, it also means that the hydrothermal uranium ore body in the exploration area is not suitable for the method provided in the embodiment.

[0036] In some embodiments, when collecting ore samples at different depths in the exploration area in step S102, the collection can be performed in the drilling profile of the exploration area. Specifically, ore samples at different elevations of the drilling profile in the uranium exploration area can be collected.

[0037] In some other embodiments, when collecting ore samples at different depths in the exploration area in step S102, the collection can also be performed in the ore deposit in the exploration area. Specifically, ore samples at different sections of the ore deposit in the exploration area can be collected. The section here refers to that according to the different elevations of the ore body in the direction of inclination, the full length of the ore deposit along the strike is divided into several strips, and one of the strips is a section.

[0038] As described above, attention should be paid to collecting samples for the same hydrothermal uranium ore body when sampling. The sampling interval can be determined by the person skilled in the art according to the actual situation. The sampling interval can be the same or different.

[0039] In some embodiments, when collecting the sample, it is required to collect ore samples at different depths in the exploration area with uranium grade in a preset range. Specifically, the uranium content of the collected ore sample can be determined in the process of sampling by means of a directional radiation instrument, a gamma spectrometer, etc., and if the uranium content is not in the preset range, the ore sample is discarded. Collecting ore samples with uranium grade in the preset range can avoid the interference of abnormal data, so that the fitted function relationship is more accurate. The preset range of uranium grade can be set by a person skilled in the art according to the actual situation, for example, the preset range can be determined based on the commercial grade, so that the collected ore sample can better represent the commercial ore body. As an example, it can be set to 400x10 -6 900x10 -6 .

[0040] In some embodiments, when determining the iron valence ratio of the point to be explored, the uranium grade at the point to be explored can also be determined, and if the uranium grade is not in the preset range, the point to be explored can need to be reselected.

[0041] In some embodiments, it is required to pay attention to the mineralization type of the uranium deposit in the exploration area, and if there are uranium deposits of multiple mineralization types, in the process of collecting samples, it is required to pay attention to collecting ore samples of different types at each depth, and subsequently fitting function relationships for ore samples of different mineralization types respectively. In these embodiments, it is further required to determine the mineralization type at the point to be explored, and select the function relationship corresponding to the mineralization type at the point to be explored to determine the vertical variation trend and determine the vertical distribution of the hydrothermal uranium deposit.

[0042] It can be understood that different mineralization types of uranium deposits indicate that the ore-forming hydrothermal fluid has changed, so fitting respectively for different mineralization types helps to improve the accuracy of prediction. However, the vertical distribution trend of these different mineralization types of uranium ore bodies is roughly the same, so even if the mineralization types are not distinguished and the fitting of the vertical variation trend is directly performed, the vertical distribution of the uranium deposit can still be predicted, but the accuracy is relatively poor.

[0043] In some embodiments, when determining the iron valence ratio of the ore sample, the total iron content and the divalent iron content of the ore sample can be determined first, and then the trivalent iron content of the ore sample is determined based on the total iron content and the divalent iron content of the ore sample, and the iron valence ratio of the ore sample is determined.

[0044] Specifically, the total iron content (TFe2O3) of the rock sample can be determined by means of an X-ray fluorescence spectrometer, the content of ferrous oxide (FeO) in the rock sample can be determined by means of a chemical titration method, Fe 2+ = 0.757*FeO, Fe 3+=0.675*Fe2O3= 0.675*(TFe2O 3(测定) -1.1* FeO (测定) The determination of total iron content and ferrous oxide content can be carried out by referring to the relevant testing standards in this field, which will not be elaborated here.

[0045] The following will use the applicant's investigation into the distribution of hydrothermal uranium deposits in the Zhuguangnan Yangtze River region as an example to provide a more detailed description and supplement to one or more of the embodiments mentioned above.

[0046] The deepest industrial borehole in the area, the Changjiang No. 1 profile, was selected. Based on well logging and geophysical survey results, the uranium grade was found to be between 400 and 900 × 10⁻⁶. -6 Representative ore samples were collected from all depth ranges within the area. During sampling, the location, depth, size, and mineralization type of the samples were recorded in detail, with the size generally controlled between 150 and 200g.

[0047] After cleaning the collected samples, they were manually ground to 200 mesh using a ball mill and an agate mortar and pestle, and then sent to the analytical testing laboratory for analysis.

[0048] The sample was dried in an oven at 105℃ for 2 hours, then calcined and melted at 1000℃ to form a glass slide. The total iron content (TFe₂O₃) was determined using X-ray fluorescence spectrometry. The FeO content was determined by chemical titration (CA) (range: >0.5%). The contents of ferrous and ferric ions were then calculated. 3+ =0.675*Fe2O3= 0.675*(TFe2O 3(测定) -1.1* FeO (测定) ), Fe 2+ =0.757*FeO, and then the iron valence state ratio was calculated. The calculation results are shown in Table 1.

[0049] Table 1. Iron valence state and uranium content in the Yangtze No. 1 deep drilling and verification optimization holes.

[0050]

[0051] Next, the functional relationship between depth (elevation) and iron valence ratio in the table above was fitted, and the fitting result was h=174.43r. 2 +665.63r-1359.8, where h is the depth and r is the iron valence ratio, the R² of this function is 0.8021, which is within the preset range. Based on this function, the vertical trend of the iron valence ratio in hydrothermal uranium deposits is determined to be that the iron valence ratio decreases with increasing depth.

[0052] Next, the same mineralization type of the area to be explored point sampling analysis, obtain its uranium content and iron valence ratio, based on iron valence ratio and the above vertical variation trend to the vertical distribution of the hydrothermal uranium ore body at the point of exploration to be confirmed.

[0053] The application is described in detail above in combination with the drawings and examples, but the application is not limited to the above examples, and various changes can be made within the knowledge possessed by those skilled in the art without departing from the purpose of the application.

Claims

1. A method for determining the distribution of hydrothermal uranium deposits based on iron valence ratio, comprising: Collect ore samples from different depths in the exploration area; Fit the functional relationship between the iron valence ratio of the ore sample and the depth of the ore sample, where the iron valence ratio is the ratio between the trivalent iron content and the divalent iron content of the ore sample; Based on the aforementioned functional relationship, the vertical variation trend of the iron valence state ratio in the hydrothermal uranium ore body in the exploration area is determined; Determine the iron valence state ratio at the points to be explored in the exploration area; The vertical distribution of the hydrothermal uranium ore body at the site to be explored is determined based on the iron valence ratio at the site to be explored and the vertical variation trend. The vertical positional relationship between multiple mineralization sections of the hydrothermal uranium ore body is determined based on the vertical variation trend, wherein multiple mineralization sections correspond to multiple numerical ranges of iron valence state ratio; Based on the numerical range of the iron valence ratio at the point to be explored, the mineralization section of the point to be explored in the hydrothermal uranium ore body is determined, and based on the vertical positional relationship, it is determined whether there are other mineralization sections of the hydrothermal uranium ore body vertically below the point to be explored. The method further includes: Determine the mineralization type of the ore sample; The functional relationship was fitted to the ore samples with different mineralization types.

2. The method according to claim 1, wherein, The multiple mineralization sections include: a reduction section, a redox transition section, and an oxidation section. The iron valence ratio corresponding to the reduction section is less than 0.5, the iron valence ratio corresponding to the redox transition section is greater than or equal to 0.5 and less than or equal to 1, and the iron valence ratio corresponding to the oxidation section is greater than 1.

3. The method according to claim 1, further comprising: Before determining the vertical variation trend of the iron valence state ratio of hydrothermal uranium ore bodies in the exploration area based on the aforementioned functional relationship, it is confirmed that the correlation coefficient of the functional relationship is greater than a preset value.

4. The method according to claim 1, wherein, The ore samples collected from different depths in the exploration area include: Ore samples were collected from different elevations of the borehole profile in the exploration area.

5. The method according to claim 1, wherein, The ore samples collected from different depths in the exploration area include: Ore samples were collected from different sections of the mining deposit in the exploration area.

6. The method according to any one of claims 1, 4, and 5, wherein, The ore samples collected from different depths in the exploration area include: Collect ore samples from different depths in the exploration area, with uranium grades within a preset range.

7. The method according to claim 1, wherein, Determining the iron valence ratio of the ore sample includes: Determine the total iron content and ferrous iron content of the ore sample; The ferric iron content of the ore sample is determined based on the total iron content and ferrous iron content, so as to determine the iron valence ratio of the ore sample.

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