How to select ore, how to create a calibration curve, how to update the calibration curve, and how to analyze ore

Abstract

To quicken a series of tasks accompanying confirmation of validity of XRF.SOLUTION: A method for selecting a plurality of ores to be used for obtaining a new analytical curve to be replaced by an analytical curve used for obtaining actually measured XRF analytical value as data whose first relative error is beyond an allowable range is obtained by a prescribed ore M, from respective ores related to respective data in a database in the database prepared for data having chemical analysis value for element A and first relative error for each ore has: a virtual analytical curve creation step which creates from a prescribed data group among data in the database a virtual analytical curve in the relations between theoretical XRF strength and chemical analysis value; a determining step which determines whether or not a second relative error is beyond an allowable range; and an ore selection step which selects as a material for obtaining a new analytical curve a plurality of ores to form a data group when it is determined at the determining step that it is within the allowable range. A related technique for the same method is provided.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for selecting an ore, a method for creating a calibration curve, a method for updating the calibration curve, and a method for analyzing an ore. [Background technology]

[0002] A fluorescent X-ray analysis method is known in which a sample is irradiated with primary X-rays and the content of components (elements or compounds) contained in the sample is quantitatively analyzed based on the detected X-ray intensity of secondary X-rays emitted from the sample.

[0003] It is known to calculate the theoretical intensity of fluorescent X-rays of each analytical component using the fundamental parameter method (FP method) (see Patent Document 1).

[0004] ).

[0004] It is known that the FP method determines the element content from an initial value of the element content that is appropriately set based on the results of qualitative analysis, by successive approximation convergence calculation using theoretical strength (Patent Document 2,

[0003] ).

[0005] For the calculation of the theoretical intensity of fluorescent X-rays, the content described in Non-Patent Document 1, for example, may be adopted, and the details of the calculation are omitted in this specification. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2021-128027 [Patent Document 2] JP 2002-181740 A [Non-patent literature]

[0007] [Non-Patent Document 1] Practical application of X-ray fluorescence analysis, 2nd edition (X-ray analysis research roundtable of the Japan Society for Analytical Chemistry), pp. 108-109, Asakura Publishing Co., Ltd. Summary of the Invention [Problem to be solved by the invention]

[0008] By performing X-ray fluorescence analysis (XRF) on the ore, the intensity due to each element contained in the ore can be obtained. This intensity is also called the measured XRF intensity. A calibration curve showing the relationship between the measured XRF intensity and the chemical analysis value of a specific element (element A in this specification) is prepared in advance. By using this calibration curve, the content of element A can be obtained from the measured XRF intensity.

[0009] It has been found that, depending on the ore to be collected, even if the above calibration curve is used, the content of element A cannot be correctly obtained from the actually measured XRF intensity. In other words, depending on the ore to be collected (ore M in this specification), it has been found that the actually measured XRF analysis value, which is the content of element A from the actually measured XRF intensity using the above calibration curve, is significantly different from the chemical analysis value, which is the content of a predetermined element A obtained by chemical analysis involving dissolution.

[0010] It is necessary to confirm the validity of XRF, including the validity of the above calibration curve. On the other hand, it takes about one week to obtain the above chemical analysis values ​​of each element from one sample. This means that it takes about one week to confirm the validity of XRF.

[0011] Even if the validity of XRF is confirmed, if it turns out that XRF is not valid (for example, it is determined that the calibration curve needs to be updated), a new calibration curve must be prepared. Tests are required to create a new calibration curve. Furthermore, even if a new calibration curve is created, the validity of XRF for the above ore M (validity of the new calibration curve) must be confirmed. If XRF is not valid, the calibration curve must be remade. Even if it is valid, it may be determined that XRF is not valid (the new calibration curve is not valid) for another ore that is collected. In that case, the work described in this paragraph must be performed again.

[0012] An object of the present invention is to expedite the sequence of steps involved in confirming the validity of XRF. [Means for solving the problem]

[0013] In order to achieve the object of the present invention, the present inventors have focused on utilizing the theoretical intensity of fluorescent X-rays. In this specification, the theoretical intensity of fluorescent X-rays is also referred to as theoretical XRF intensity.

[0014] The inventors have come up with a method of creating a provisional calibration curve in the relationship between theoretical XRF intensity and chemical analysis values ​​in order to confirm the validity of XRF. The inventors have come up with a method of utilizing data on ores for which chemical analysis values ​​have been obtained in the past in order to create this provisional calibration curve. The inventors have come up with a method of selecting, after confirming the validity of this provisional calibration curve (i.e., the validity of XRF), a number of ores that are the source of the data used to create the provisional calibration curve as materials for obtaining a new calibration curve (in other words, a so-called main calibration curve for obtaining actual XRF analysis values). In other words, the inventors have found that by creating the provisional calibration curve, it is possible to confirm the validity of XRF and select a number of ores that will be materials for the creation of the main calibration curve to be obtained after the confirmation, all at once.

[0015] The first aspect of the present invention is A chemical analysis value, which is the content of a predetermined element A obtained by chemical analysis involving dissolution; and A first relative error is an error of the measured XRF analysis value, which is the content of element A obtained from the measured XRF intensity, relative to the chemical analysis value of element A; In a database in which data having the above-mentioned first relative error is prepared for each ore, when data for a specific ore M is obtained in which the first relative error exceeds an allowable range, a method for selecting a plurality of ores to be used for obtaining a new calibration curve to replace the calibration curve used to obtain the actual XRF analysis value from among the ores related to each data in the database, The chemical analysis value of the element A; the mass absorption coefficient of the ore M calculated from the mass absorption coefficients of each element including the element a in the irradiated X-ray; The efficiency of fluorescent X-ray generation of element A, a provisional calibration curve creation step of creating a provisional calibration curve showing the relationship between the theoretical XRF intensity of element A obtained by using a chemical analysis value of said element A from a predetermined data group of data in said database; a determination step of determining whether a second relative error, which is an error of a theoretical XRF analysis value, which is the content of element A obtained from a theoretical XRF intensity of element A in the ore M using the provisional calibration curve, with respect to a chemical analysis value of element A in the ore M, exceeds the allowable range; an ore selection step of selecting a plurality of ores that are the source of the data group as materials for obtaining the new calibration curve when the determination step determines that the data group is within the allowable range; having If it is determined in the determination step that the tolerance is exceeded, the method for selecting an ore comprises reselecting the data group from the database and repeating the provisional calibration curve creation step and the determination step until it is determined that the tolerance is within the tolerance.

[0016] A second aspect of the present invention is This is a method for selecting an ore according to a first aspect, in which the data group is a data group having a first relative error of the same sign as the first relative error for the ore M among the data in the database.

[0017] A third aspect of the present invention is A second aspect of the present invention is a method for selecting an ore, wherein the data group is a data group in which the absolute value of a first relative error is equal to or exceeds the absolute value of a threshold value that determines the acceptable range.

[0018] A fourth aspect of the present invention is In the method for selecting an ore according to any one of first to third aspects, the data group is a data group having a mass absorption coefficient within the allowable range.

[0019] A fifth aspect of the present invention is The theoretical XRF intensity is at least one of intensity 1, which is the theoretical XRF intensity itself, intensity 2 obtained by normalizing intensity 1 with Compton scattering intensity, and intensity 3 obtained by normalizing intensity 1 with Rayleigh scattering intensity, and this is the ore selection method according to any one of the first to fourth aspects, in which the provisional calibration curve having the determination coefficient closest to 1 is adopted among the provisional calibration curves.

[0020] A sixth aspect of the present invention is a method for producing a composition comprising the steps of: Each data in the database further includes: the incidence angle of the incident X-rays and the take-off angle of the fluorescent X-rays of the X-ray fluorescence analyzer used to obtain the measured XRF intensity, and the angle at which the incidence angle and the take-off angle intersect; K-edge jump ratio of element A, The fluorescence yield of element A, The spectral ratio of Kα line in the fluorescent X-ray of element A, having The method for selecting an ore according to any one of the first to fifth aspects, wherein the efficiency of generation of fluorescent X-rays of the element a is obtained from the chemical analysis value of the element a, the mass absorption coefficient, the K-absorption edge jump ratio, the fluorescence yield, and the Kα ray spectral ratio.

[0021] A seventh aspect of the present invention is a method for producing a composition comprising the steps of: The ore selection method according to any one of the first to sixth aspects, further comprising a theoretical XRF intensity calculation step of calculating the theoretical XRF intensity before the tentative calibration curve creation step.

[0022] An eighth aspect of the present invention is a method for producing a composition comprising the steps of: The ore selection method according to any one of the first to seventh aspects, further comprising a data group selection step of selecting the data group from the database prior to the provisional calibration curve creation step.

[0023] A ninth aspect of the present invention is a method for producing a composition comprising the steps of: This is a calibration curve creation method, comprising a calibration curve creation step of creating a calibration curve showing the relationship between the measured XRF intensity of the element A and the chemical analysis value of the element A for a plurality of ores selected by the ore selection method described in any one of items 1 to 8.

[0024] A tenth aspect of the present invention is a method for producing a composition comprising the steps of: The theoretical XRF intensity is at least one of intensity 1, which is the theoretical XRF intensity itself, intensity 2 obtained by normalizing the intensity 1 with the Compton scattering intensity, and intensity 3 obtained by normalizing the intensity 1 with the Rayleigh scattering intensity. When the provisional calibration curve having the determination coefficient closest to 1 is used among the provisional calibration curves, In the calibration curve creating step, a calibration curve is created by setting any one of the intensities 1 to 3 used in the tentative calibration curve as the X-axis or Y-axis.

[0025] An eleventh aspect of the present invention is a method for producing a composition comprising the steps of: The calibration curve updating method includes a calibration curve replacement step of replacing a calibration curve used to obtain an actual XRF analysis value from the actual XRF intensity of element A in ore M with a calibration curve created by the calibration curve creation method described in the ninth or tenth aspect.

[0026] A twelfth aspect of the present invention is a method for producing a composition comprising the steps of: This is a method for analyzing an ore, in which an actual XRF analysis value of element A in an ore is periodically obtained while employing the method for updating the calibration curve described in the eleventh aspect. Effect of the Invention

[0027] The present invention can expedite the sequence of steps involved in validating XRF. [Brief description of the drawings]

[0028] [Figure 1] FIG. 1 is a flowchart of the ore selection method according to this embodiment. [Diagram 2] FIG. 2 is a plot showing tentative calibration curves (R2 is the coefficient of determination) with the chemical analysis value (wt%) of transition metal A on the horizontal axis and the theoretical XRF intensity (au) of transition metal A on the vertical axis, where (a) corresponds to intensity 1, (b) corresponds to intensity 2, and (c) corresponds to intensity 3. [Diagram 3]FIG. 3 is a plot (R2 is the coefficient of determination) with the first relative error (%) of transition metal A on the vertical axis. (a) shows the mass absorption coefficient of the theoretical XRF intensity corresponding to intensity 1 on the horizontal axis, (b) shows the mass absorption coefficient of the Compton scattering intensity corresponding to intensity 2 on the horizontal axis, and (c) shows the mass absorption coefficient of the Rayleigh scattering intensity corresponding to intensity 3 on the horizontal axis. [Figure 4] Figure 4 is a plot showing tentative calibration curves (R2 is the coefficient of determination) with the chemical analysis value (wt%) of transition metal A on the horizontal axis and the theoretical XRF intensity (au) of transition metal A on the vertical axis, where (a) corresponds to intensity 1, (b) corresponds to intensity 2, and (c) corresponds to intensity 3. The solid line shows the tentative calibration curve. The tentative calibration curve is an approximation line obtained using only the data group selected in Figure 3. For reference, the dotted line shows a provisional calibration curve. The provisional calibration curve is an approximation line obtained using all the data in the database. [Diagram 5] FIG. 5 is a flowchart of a method for updating a calibration curve according to this embodiment. [Figure 6] FIG. 6 is a block diagram of the ore analyzing system according to this embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] This embodiment will be described in the following order: "-" indicates a value greater than or equal to a given value and less than or equal to a given value. 1. Ore selection method 1-1. Preparation process 1-2. First judgment process 1-3. Provisional calibration curve creation process 1-4.Second judgment process 1-5. Ore selection process 2. How to create a calibration curve 2-1. Calibration curve creation process 2-2. Third judgment process 2-3. Calibration curve update process (method of updating calibration curve) 3.Ore Analysis Method 4. A system for carrying out each method.

[0030] FIG. 1 is a flowchart of the ore selection method according to this embodiment.

[0031] <1. How to select ores> (1-1. Preparation process) Preparations are made to carry out the method for selecting an ore according to the present embodiment. Specifically, a database is prepared. The database contains the following data: - Chemical analysis value, which is the content of a given element A obtained by chemical analysis involving dissolution The first relative error is the error of the measured XRF analysis value, which is the content of element A obtained from the measured XRF intensity, relative to the chemical analysis value of element A.

[0032] The chemical analysis value is the content (mass%) of the elements constituting the ore, obtained by gravimetric analysis. For example, the content of each element is obtained by drying, crushing, weighing, acid decomposition, titration, etc. of the ore.

[0033] The first relative error is a value expressed by the following formula (1).

number

[0034] Element A is any one of the elements contained in the ore. Element A may be a transition metal element, or may be an element other than a transition metal (light element). Of course, this embodiment may be carried out for element A while carrying out this embodiment separately for other elements. In this embodiment, a case where element A is a transition metal is illustrated. Hereinafter, unless otherwise specified, element A refers to a transition metal. Element A is also referred to as transition metal A.

[0035] The database preferably also includes the following data: Actual XRF Intensity Actual XRF analysis value The incidence angle of the X-rays incident on the X-ray fluorescence analyzer used to obtain the measured XRF intensity, the take-off angle of the X-rays fluorescent, and the angle at which the incidence angle and the take-off angle intersect K-edge jump ratio of element A (also called K-line jump ratio) Fluorescence yield of element A Spectral ratio of Kα line in fluorescent X-ray of element A The angle of intersection can be determined from the instrument conditions of the X-ray fluorescence analyzer. The K-absorption edge jump ratio, the fluorescence yield, and the Kα line spectrum ratio of element A may be values ​​found in literature.

[0036] The above data is prepared for each ore. Each ore is classified according to the date, time and place of collection. There is no limit to the number of ores that serve as the source of the data, but the more samples there are, the more accurately the provisional calibration curve described below can be created, and the more accurately a new calibration curve (main calibration curve) can be created. The number of ores that serve as the source of the data that makes up the database may be 10 to 3,000.

[0037] (1-2. First judgment step) In this step, it is determined whether or not data in which the first relative error exceeds the allowable range is obtained in the database.

[0038] There is no limitation on the threshold of the tolerance range. The tolerance range can be appropriately set depending on whether the first relative error involving only one ore (ore M) is adopted, or the average value of the first relative errors of ores continuously collected (for example, ore K collected two times before last, ore L collected previously, and ore M collected this time).

[0039] In this embodiment, merely as an example, a case will be illustrated in which, in regular ore collection, if the first relative error (in the above example, each of the first relative errors of ore L and ore M) falls outside the allowable range twice consecutively, the first determination step will consider that the "first relative error has exceeded the allowable range." Hereinafter, this case will also be simply referred to as "outside the allowable range." As an example, the first relative error may be within ±3.0% within the allowable range, and a value exceeding +3.0% or a value below -3.0% may be outside the allowable range.

[0040] In addition, Ore L and Ore M (i.e., the ores deemed to require the calibration curve update) do not have to be the most recent examples of regular sampling. For example, if the ore to be sampled in the future is expected to have a composition similar to that of the ore sampled in the past (e.g., several years ago), it is not necessary to update the calibration curve in the most recent example.

[0041] In addition, "periodically" in this embodiment is not necessarily limited to strictly at regular intervals.

[0042] One of the features of this embodiment is the work performed after the database is prepared in the preparation step and the first determination step determines that the value is outside the allowable range. This embodiment relates to a method for selecting, from the ores related to each data in the database, a plurality of ores to be used for obtaining a new calibration curve to replace the calibration curve used to obtain the actual XRF analysis value, when data in which the first relative error exceeds the allowable range is obtained for a specific ore M in a database in which the data is prepared for each ore.

[0043] (1-3. Provisional calibration curve creation process) In this step, a provisional calibration curve is created from a predetermined group of data from the database. To create the provisional calibration curve, the theoretical XRF intensity of element A is obtained. The theoretical XRF intensity is calculated using the method described in Non-Patent Document 1. The theoretical XRF intensity is obtained from the following data. Chemical analysis value of element A Mass absorption coefficient of ore M calculated from the mass absorption coefficients of each element, including element a, in irradiated X-rays - Efficiency of fluorescent X-rays from element A

[0044] The chemical analysis value of element A can be found by referring to the data for ore M in the above database.

[0045] The mass absorption coefficient is an index of the degree to which an X-ray of interest (e.g., fluorescent X-ray of element A, Rh(tube)-Compton scattering radiation (see below), Rh(tube)-Rayleigh scattering radiation (see below)) is absorbed by a matrix component.

[0046] The mass absorption coefficient of ore M is as follows. Mass absorption coefficients are additive, and the mass absorption coefficient of a certain ore is the sum of the mass absorption coefficients of its component elements multiplied by the mass fraction of that component (mass%, wt%).

[0047] The mass absorption coefficient of ore M can be calculated if the chemical analysis values ​​of each element are available. In more detail, the mass absorption coefficient μ(λ) of ore M in the Kα ray of the irradiated X-ray tube (Rh) and the mass absorption coefficient μ(ip) of element A in the Kα ray can be calculated if the chemical analysis values ​​of each element are available. The formula for calculating the theoretical XRF intensity from Non-Patent Document 1 (formula (2) below) is shown below.

number

[0048] The mass absorption coefficient of the ore M may be included as one item of each data in the database.

[0049] The efficiency of fluorescent X-ray generation of element A is the efficiency of fluorescent X-ray generation per unit weight of the sample, and is expressed as a function of the mass absorption coefficient and the concentration of element A.

[0050] Efficiency of fluorescent X-ray generation of element A Q ip (λ) can be calculated from the chemical analysis value of element A, the mass absorption coefficient, the K absorption edge jump ratio, the fluorescence yield, and the Kα line spectrum ratio (the above items are also referred to as "physical parameters"). The generation efficiency may be included as one item of each data in the database.

[0051] The physical parameters are summarized in Table 1 below. [Table 1]

[0052] The theoretical XRF intensity calculation step for calculating the theoretical XRF intensity may be performed before the provisional calibration curve creation step. In FIG. 1, for convenience of explanation, the theoretical XRF intensity calculation step is performed between the first judgment step and the data group selection step described later, but the present invention is not limited thereto. Before carrying out this embodiment, that is, during the preparation step, the theoretical XRF intensity calculation step may be performed in advance for each ore that is the source of each data in the database. Then, the resulting theoretical XRF intensity may be stored as one item of data in the database.

[0053] In this step, a provisional calibration curve showing the relationship between the theoretical XRF intensity of element A and the chemical analysis value of element A is created from a predetermined data group among the data in the database. The selection of this predetermined data group is called a data group selection step. The data group selection step may be performed before the provisional calibration curve creation step.

[0054] The data group may be a data group in the database having a first relative error with the same sign as the first relative error for the ore M. In other words, a data group having a value relatively close to the first relative error for the ore M may be used. For example, if the first relative error for the ore M is a negative value of -5.0%, a data group of ores having a first relative error with a negative value may be used.

[0055] In addition, the data group may be a data group in which the absolute value of the first relative error is equal to or exceeds the absolute value of a threshold value that determines the tolerance range. For example, if the first relative error for ore L and ore M is -5.0%, a data group of ores having a first relative error in a range from -5.0% to -12.0% may be selected from the database.

[0056] The data group may be a data group having a mass absorption coefficient within the above-mentioned allowable range (for example, a data group having a mass absorption coefficient between the lower limit and the upper limit of the X-axis in the region of the dashed line in each of the figures in FIG. 3 shown below). The mass absorption coefficient reflects information about the matrix of the ore. For data, and therefore for ores, whose mass absorption coefficients are within the above-mentioned allowable range, it can be determined that the influence of the matrix is ​​relatively small. For this reason, a data group having a mass absorption coefficient within the above-mentioned allowable range may be selected.

[0057] There is no limit to the number of data constituting the selected data group (and thus the number of ores selected). However, actual XRF intensities will be obtained for all ores later to create a new calibration curve (main calibration curve). Even if it takes only a few tens of minutes to obtain the actual XRF intensity from one ore, it is more efficient if the number of ores selected is not excessive. Also, although it is possible to create the main calibration curve with two or more ores, it is preferable to be accurate. Therefore, the number of ores selected may be about 5 to 100 (a suitable example of the lower limit is 10, and a suitable example of the upper limit is 50 or 30).

[0058] The provisional calibration curve in this specification (and the actual calibration curve and provisional calibration curve described later) is exemplified as an approximate straight line (or an approximate line) obtained from a predetermined data group (coordinate point group). The approximate straight line is obtained using a function attached to commercially available software.

[0059] (1-4.Second judgment step) In this step, it is determined whether or not a second relative error, which is an error between a theoretical XRF analysis value, which is the content of element A obtained from the theoretical XRF intensity of element A in ore M using the provisional calibration curve, with respect to the chemical analysis value of element A in ore M, exceeds the allowable range. The second determination step is also simply referred to as the "determination step."

[0060] The second relative error is a value expressed by the following formula (3).

number

[0061] The "theoretical XRF analysis value" in this embodiment is a value specialized for performing the second judgment step to confirm the validity of XRF. In detail, the "theoretical XRF analysis value" in this embodiment is a value specialized for confirming the validity of the provisional calibration curve, and further, the validity of selecting the multiple ores used in creating the provisional calibration curve when creating the actual calibration curve.

[0062] If it is determined in the second determination step that the data exceeds the allowable range, the data group is reselected from the database (i.e., the data group selection step is performed again) and the provisional calibration curve creation step and the determination step are repeated until the data group is determined to be within the allowable range. There is no limitation on the method of reselecting the data group.

[0063] If the CPU of a computer existing at the time of filing the present application is used, it does not take much time to reselect the data group. In particular, by narrowing down the data conditions using the above-mentioned exemplary data group selection method, i.e., first relative error of the same sign, mass absorption coefficient that is equal to or greater than the absolute value of the threshold value, or that is within the allowable range, and the like, and then selecting each data from the remaining data group, a provisional calibration curve that is considered to be within the allowable range in the second judgment step can be obtained without taking a long time.

[0064] If a data group satisfies all of the above conditions but is nonetheless judged to be outside the above-mentioned acceptable range in the second judgment step, in accordance with the above example, the upper and / or lower limits of the value of the first relative error in the range of -5.0% to -12.0% may be changed by 0.1% to select each piece of data belonging to the data group until a provisional calibration curve that is deemed to be within the acceptable range in the second judgment step is obtained.

[0065] (1-5. Ore selection process) If it is determined in the second determination step that the result is within the allowable range, the multiple ores that are the source of the data group are selected as materials for obtaining the new calibration curve.

[0066] The method for selecting ores according to the present embodiment can expedite a series of tasks associated with confirming the validity of XRF. Specifically, multiple ores can be appropriately selected to obtain a new calibration curve. In addition, a separate test (e.g., an actual test involving the addition of a known amount of element A) is not required to obtain a new calibration curve.

[0067] An improved example of the ore selection method according to this embodiment is as follows.

[0068] The theoretical XRF intensity may be at least one of intensity 1, which is the theoretical XRF intensity itself, intensity 2 obtained by normalizing intensity 1 with Compton scattering intensity, and intensity 3 obtained by normalizing intensity 1 with Rayleigh scattering intensity. Of the provisional calibration curves, the provisional calibration curve having the determination coefficient closest to 1 may be used. Normalization refers to dividing intensity 1 by Compton scattering intensity or Rayleigh scattering intensity.

[0069] To carry out the above, the intensities 2 and 3 may be obtained along with the intensity 1 obtained in the theoretical XRF intensity calculation step. Then, a provisional calibration curve showing the relationship between each of the intensities 1 to 3 and the chemical analysis value of element A may be created from the data group in the database (multiple intensity types preparation step).

[0070] In addition, a provisional calibration curve (in other words, a provisional calibration curve) may be created using all data in the database just to determine which of the intensities 1 to 3 to select. Then, among the provisional calibration curves, the intensity type of the provisional calibration curve with the coefficient of determination closest to 1 may be adopted (intensity type selection step). In this embodiment, the coefficient of determination (R 2 ) is closest to 1. The type of intensity adopted may also be used when creating a provisional calibration curve. In addition, when creating a new calibration curve (main calibration curve) after the ore selection step, the type of intensity adopted may continue to be used as the X-axis or Y-axis.

[0071] In order to obtain the Compton scattering intensity and the Rayleigh scattering intensity, it is necessary to obtain the following atomic scattering factor, which is expressed by the following formula (4).

number

number

number

[0072] The database may include atomic scattering factors, Compton scattering intensities and / or Rayleigh scattering intensities as data items.

[0073] The multiple intensity type preparation step and the intensity type selection step may be performed before the provisional calibration curve creation step. For convenience of explanation, FIG. 1 illustrates the multiple intensity type preparation step and the intensity type selection step being performed between the first judgment step and the provisional calibration curve creation step, but the present invention is not limited to this. For example, the multiple intensity type preparation step and the intensity type selection step may be performed in advance using all data before the first judgment step, and one intensity among the intensities 1 to 3 whose coefficient of determination is close to 1 may be grasped in advance, and only the one intensity may be handled after the first judgment step.

[0074] An example of the multiple strength type preparation step and the strength type selection step will be described below. FIG. 2 is a plot (R 2 is the coefficient of determination), where (a) corresponds to intensity 1, (b) to intensity 2, and (c) to intensity 3. All data in the database are used for each plot.

[0075] Of the plots in FIG. 2, (b), i.e., intensity 2, has the coefficient of determination closest to 1, so intensity 2 is used in this example.

[0076] Subsequently, a data group selection step is performed. An example of the data group selection step will be described below. Figure 3 shows the mass absorption coefficient (cm 2 / g) on ​​the horizontal axis and the first relative error of transition metal A (%) on the vertical axis (R 2 is the coefficient of determination), where (a) is the mass absorption coefficient of the theoretical XRF intensity corresponding to intensity 1 on the horizontal axis, (b) is the mass absorption coefficient of the Compton scattering intensity corresponding to intensity 2 on the horizontal axis, and (c) is the mass absorption coefficient of the Rayleigh scattering intensity corresponding to intensity 3 on the horizontal axis. All data in the database is used in each plot. In this example, intensity 2 is used, but plots for intensity 1 and intensity 3 are also shown for reference. Note that each mass absorption coefficient related to (a) to (c) may be included as an item of data in the database. The dotted straight line in the figure is an approximation straight line obtained from the data group (coordinate point group) in the figure.

[0077] As a method for selecting the data group in the above example, in this example, a data group that is equal to or greater than the absolute value of the threshold value is selected. The data group that satisfies this condition is a coordinate point group that exists within the area surrounded by the dotted line in each diagram of Figure 3. In other words, on the premise that it is recognized as being within the allowable range in the second judgment process, the multiple ores corresponding to this coordinate point group will be the multiple ores selected in the subsequent ore selection process.

[0078] Subsequently, a provisional calibration curve creating step is performed. An example of the provisional calibration curve creating step will be described below.

[0079] FIG. 4 is a plot (R 2is the coefficient of determination), where (a) corresponds to intensity 1, (b) corresponds to intensity 2, and (c) corresponds to intensity 3. The solid line shows the tentative calibration curve. The tentative calibration curve is an approximation line obtained using only the data group selected in Figure 3. For reference, the dotted line shows the provisional calibration curve. The provisional calibration curve is an approximation line obtained using all data in the database.

[0080] A second judgment step was performed to judge whether the second relative error obtained using the provisional calibration curve of strength 2 (Fig. 4(b)) exceeded the above allowable range, and it was found to be within the allowable range. As a result, all ores corresponding to the coordinate points existing within the area surrounded by the dotted lines in each diagram of Fig. 3 should be selected for creating the actual calibration curve. Then, the calibration curve should be created using the selected ores.

[0081] <2. How to create a calibration curve> FIG. 5 is a flowchart of a method for updating a calibration curve according to this embodiment.

[0082] (2-1. Calibration curve creation process) In this process, a calibration curve (this calibration curve) is created showing the relationship between the measured XRF intensity of element A and the chemical analysis value of element A for multiple ores selected by the ore selection method of this embodiment.

[0083] The method for creating the calibration curve may be performed by an entity other than the entity that performed the method for selecting the ore. In this case, the entity that performs the method for selecting the ore is referred to as the "ore selection side," and the entity that performs the method for creating the calibration curve (this calibration curve) is referred to as the "ore collection side."

[0084] This calibration curve obtains the measured XRF intensity for each selected ore. If the measured XRF intensity is included in the data for each ore, it may be used, but it is more accurate to measure the measured XRF intensity for each selected ore (each saved ore) separately and use the measured XRF intensity.

[0085] The theoretical XRF intensity is at least one of the intensities 1 to 3. When a provisional calibration curve having a coefficient of determination closest to 1 is adopted among the provisional calibration curves, a calibration curve may be created in the calibration curve creation step by setting any one of the intensities 1 to 3 adopted in the provisional calibration curve as the X-axis or Y-axis.

[0086] (2-2. Third judgment step) In this step, the actual XRF analysis value is obtained using the created calibration curve, and the same judgment as in the first judgment step is performed. The third judgment step may be performed by the ore collecting side or the ore selecting side. In the first place, as long as the ore selection method according to this embodiment is carried out, the calibration curve obtained from the selected ore is accurate. Therefore, the third judgment step is not essential to the present invention.

[0087] (2-3. Calibration curve update process (method of updating calibration curve)) In this step, the calibration curve used to obtain the measured XRF analysis value from the measured XRF intensity of element A in the ore M is replaced with the calibration curve created by the calibration curve creation method according to this embodiment. This step can be considered as an invention of a calibration curve updating method.

[0088] The method for creating and updating a calibration curve according to the present embodiment can expedite a series of operations associated with confirming the validity of XRF. Specifically, a new calibration curve can be created without performing a separate test (e.g., an actual test involving the addition of a known amount of element A) to obtain a new calibration curve, and the validity of the new calibration curve can also be quickly confirmed.

[0089] <3. Analytical methods for minerals> Another aspect of the present invention is an ore analysis method in which an actual XRF analysis value of element A in an ore is periodically obtained while employing the calibration curve update method according to this embodiment.

[0090] The method for analyzing ores according to the present embodiment can expedite a series of operations for confirming the validity of XRF. Specifically, multiple ores can be appropriately selected to obtain a new calibration curve. Furthermore, a new calibration curve can be created without performing a separate test (e.g., an actual test involving the addition of a known amount of element A) to obtain a new calibration curve, and the validity of the new calibration curve can be quickly verified.

[0091] <4. Systems for implementing each method.> This embodiment relates to a method for selecting an ore, a method for creating a calibration curve, a method for updating a calibration curve, and a method for analyzing an ore, and each method can be realized by a system or a program that causes a computer to execute the contents of the system.

[0092] FIG. 6 is a block diagram of the ore analyzing system according to this embodiment.

[0093] An example of the configuration of the ore selection system is as follows. Contents that overlap with the contents of the ore selection method will be omitted. A provisional calibration curve creating unit that creates a provisional calibration curve representing the relationship between the theoretical XRF intensity of element A and the chemical analysis value of element A from a predetermined group of data in the database. a (second) judgment unit that judges whether or not a second relative error, which is an error between a theoretical XRF analysis value, which is the content of element A obtained from a theoretical XRF intensity of element A in the ore M using the provisional calibration curve, with respect to a chemical analysis value of element A in the ore M, exceeds the allowable range. an ore selection unit that selects the plurality of ores that are the source of the data group as materials for obtaining the new calibration curve when the determination step determines that the data group is within the allowable range;

[0094] A preferred configuration is as follows. -Ore selection recorder that records the database A first judgment unit that performs the first judgment process -Theoretical XRF intensity calculation section for calculating theoretical XRF intensity A data group selection section for selecting data groups for creating a provisional calibration curve A multiple strength type preparation unit that performs a multiple strength type preparation process and a strength type selection unit that performs a strength type selection process

[0095] The above configuration may be included in the ore selection computer. The above preferred configuration may be included in another computer, or may exist in cloud data via a network line.

[0096] An example of the configuration of a calibration curve update (creation) system is as follows. Contents that overlap with the contents of the calibration curve update (creation) method will be omitted. a calibration curve creation unit that creates a calibration curve showing the relationship between the measured XRF intensity of the element A and the chemical analysis value of the element A in the multiple ores selected by the ore selection unit; A calibration curve replacement section that replaces the calibration curve used to obtain the actual XRF analysis value from the actual XRF intensity of element A in the ore M with the calibration curve created by the calibration curve creation section.

[0097] A preferred configuration is as follows. - At least a part of the database (especially the measured XRF intensities) and the calibration curve are stored in the ore extraction side recorder A third judgment section for performing the third judgment process

[0098] The above configuration may be included in the ore extraction computer. The above preferred configuration may be included in another computer, or may exist in cloud data via a network.

[0099] Each of the above components is controlled by a control unit of each of the above systems. In this embodiment, the components are mounted on a computer. However, some of the components described in this embodiment may be separate components connected to a network, rather than being mounted on a computer.

[0100] Each recording unit may be a recording unit (such as a HDD) of a computer. In this case, the data is stored in the HDD. On the other hand, each recording unit may be other than a HDD, and may be configured to have a function of reading the data stored in a cloud connected to a network.

[0101] There is no limitation on the XRF device as long as it can perform XRF analysis on a sample. An existing XRF device may be used.

[0102] The technical scope of the present invention is not limited to the above-described embodiments, but also includes forms in which various modifications and improvements are made within the scope that can derive specific effects obtained by the constituent elements of the invention and their combinations.

Claims

1. A chemical analysis value, which is the content of a predetermined element A obtained by chemical analysis involving dissolution; and a first relative error, which is an error of an actual XRF analysis value, which is the content of element A obtained from the actual XRF intensity, relative to a chemical analysis value of element A; In a database in which data having the above-mentioned first relative error is prepared for each ore, when data in which the first relative error exceeds an allowable range is obtained for a specific ore M, a method for selecting a plurality of ores to be used for obtaining a new calibration curve to replace the calibration curve used to obtain the actual XRF analysis value from among the ores related to each data in the database, comprising: A chemical analysis value of the element A; The mass absorption coefficient of the ore M calculated from the mass absorption coefficients of each element including the element a in the irradiated X-rays; The generation efficiency of fluorescent X-rays of element A, a provisional calibration curve creation step of creating a provisional calibration curve showing the relationship between the theoretical XRF intensity of element A obtained by using a predetermined data group among the data in the database, and the chemical analysis value of the element A; a determination step of determining whether a second relative error, which is an error of a theoretical XRF analysis value, which is the content of element A obtained from a theoretical XRF intensity of element A in the ore M using the provisional calibration curve, with respect to a chemical analysis value of element A in the ore M, exceeds the allowable range; an ore selection step of selecting a plurality of ores that are the source of the data group as materials for obtaining the new calibration curve when the determination step determines that the data group is within the allowable range; having When it is determined in the determination step that the tolerance is exceeded, the data group is reselected from the database and the provisional calibration curve creation step and the determination step are repeated until it is determined that the tolerance is within the tolerance.

2. 2. The method for selecting an ore according to claim 1, wherein the data group is a data group having a first relative error of the same sign as the first relative error for the ore M among the data in the database.

3. The ore selection method according to claim 2 , wherein the data group is a data group in which the absolute value of the first relative error is equal to or exceeds an absolute value of a threshold value that determines the tolerance range.

4. 4. The method for selecting an ore according to claim 1, wherein the data group is a data group having a mass absorption coefficient within the allowable range.

5. The theoretical XRF intensity is at least one of intensity 1, which is the theoretical XRF intensity itself, intensity 2 obtained by normalizing intensity 1 with Compton scattering intensity, and intensity 3 obtained by normalizing intensity 1 with Rayleigh scattering intensity, and the provisional calibration curve having the coefficient of determination closest to 1 among the provisional calibration curves is adopted. The method for selecting an ore according to any one of claims 1 to 4.

6. Each data in the database further includes: the incidence angle of the incident X-rays and the take-off angle of the fluorescent X-rays of the X-ray fluorescence analyzer used to obtain the measured XRF intensity, and the angle at which the incidence angle and the take-off angle intersect; The K-edge jump ratio of element A; The fluorescence yield of element A, The spectral ratio of Kα ray in the fluorescent X-ray of element A, having The method for selecting an ore according to any one of claims 1 to 5, wherein the efficiency of generation of fluorescent X-rays of the element a is obtained from the chemical analysis value of the element a, the mass absorption coefficient, the K-absorption edge jump ratio, the fluorescence yield, and the Kα ray spectrum ratio.

7. The ore selection method according to any one of claims 1 to 6, further comprising a theoretical XRF intensity calculation step of calculating the theoretical XRF intensity before the provisional calibration curve creation step.

8. The ore selection method according to any one of claims 1 to 7, further comprising a data group selection step of selecting the data group from the database prior to the provisional calibration curve creation step.

9. A method for creating a calibration curve, comprising a calibration curve creation step of creating a calibration curve showing the relationship between the measured XRF intensity of the element A and the chemical analysis value of the element A in a plurality of ores selected by the ore selection method according to any one of claims 1 to 8.

10. The theoretical XRF intensity is at least one of intensity 1, which is the theoretical XRF intensity itself, intensity 2 obtained by normalizing the intensity 1 with the Compton scattering intensity, and intensity 3 obtained by normalizing the intensity 1 with the Rayleigh scattering intensity. When the provisional calibration curve having the determination coefficient closest to 1 is used among the provisional calibration curves, 10. The method for creating a calibration curve according to claim 9, wherein in the calibration curve creating step, a calibration curve is created by setting any one of the intensities 1 to 3 used in the tentative calibration curve as an X-axis or a Y-axis.

11. A calibration curve updating method comprising a calibration curve replacement step of replacing a calibration curve used to obtain an actual XRF analysis value from the actual XRF intensity of element A in the ore M with a calibration curve created by the calibration curve creation method described in claim 9 or 10.

12. A method for analyzing an ore, comprising periodically obtaining an actual XRF analysis value of element A in an ore while employing the method for updating the calibration curve according to claim 11.

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