JP2011089953A - Fluorescent x-ray analyzer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluorescent X-ray analyzer, capable of correcting a weight variation of an oxidizing agent with respect to a sample converted to a glass bead by the addition of the oxidizing agent and capable of properly calculating the concentrations of respective components. <P>SOLUTION: The fluorescent X-ray analyzer is equipped with a calculation means 10A for calculating the concentrations of the respective components in the sample 3a by an SFP method. In the calculation means 10A, the theoretical matrix correction constant related to the weight ratio of the oxidizing agent 3c and the sample 3a is contained in a theoretical matrix correction constant and, at the time of adaptation of a calibration curve, the respective weights of the sample 3a related to the glass bead 3, which is the analyzing target input to an input means 11A, and the oxidizing agent 3c are used to perform correction with respect to the variation of the weight ratio of the oxidizing agent 3c and the sample 3a. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a fluorescent X-ray analyzer for determining the concentration (content ratio) of each component in a sample prepared in a glass bead.

  Conventionally, in a fluorescent X-ray analysis, when a sample is powdery or granular, in order to uniformly distribute the elements in the sample, the sample and the flux are heated and melted to prepare a glass bead. The glass beads are irradiated with primary X-rays, and the intensity of the generated fluorescent X-rays is measured. In such fluorescent X-ray analysis using the glass bead method, a calibration curve method is employed, and the semi-linear matrix correction constant is calculated based on the theoretical intensity calculation of the fundamental parameter method (FP method) in the calibration curve method. The fundamental parameter method (SFP method) is also employed.

  The relationship between the measured strength of the glass beads and the concentration of each component in the sample varies depending on the dilution rate of the sample during glass beading. For example, the weight of the sample and the weight of the flux are predetermined targets. It is conceivable that the sample and the flux are precisely weighed so that the value is the same, but in actuality, in order to improve the weighing efficiency, an error of about ± several% with respect to the target value is set as an allowable range for the weighing value. The dilution rate is calculated for each sample from the measured value of the sample and the measured value of the flux, and by using the diluted rate, an error in the measured value with respect to the target value is corrected in the quantitative calculation (see Patent Document 1).

Here, when the sample is iron ore or ferroalloy, it is necessary to add an oxidizing agent such as NaNO ₃ during the glass beading, and the weight of the oxidizing agent also affects the dilution rate of the sample. For example, a flux and an oxidizer are mixed in advance at a certain ratio, and the mixture is regarded as a kind of flux, and the dilution rate is calculated for each sample from the measured value of the sample and the measured value of the mixture as described above. By using the dilution ratio, an error in the weighing value with respect to the target value is corrected in the quantitative calculation (hereinafter, such a mixture is referred to as a mixed flux).

Japanese Patent No. 2626857

  However, when changing the weight of the oxidizer or the type of oxidizer depending on the sample type, it is necessary to prepare many kinds of mixed fluxes. In order to save this trouble, even when trying to correct the error of the measured value with respect to the target value including the oxidizing agent by weighing each of the sample, the flux, and the oxidizing agent, in calculating the theoretical matrix correction constant in the conventional SFP method, The weight of the oxidant cannot be handled, and therefore the concentration of each component in the sample prepared in the glass bead by adding the oxidant cannot be appropriately determined. The same problem arises when the FP method is employed for fluorescent X-ray analysis using the glass bead method in which an oxidizing agent is added.

  The present invention has been made in view of the above-mentioned conventional problems, and for a sample prepared in a glass bead by adding an oxidant, the variation in the weight of the oxidant can be corrected, and the concentration of each component can be determined appropriately. An object of the present invention is to provide an X-ray fluorescence analyzer capable of performing

  In order to achieve the above object, the X-ray fluorescence analyzer of the first configuration of the present invention first irradiates a glass bead prepared by heating and melting a sample, a flux and an oxidant with X-rays irradiated with primary X-rays. A radiation source, a detection means for measuring the intensity of fluorescent X-rays generated from the glass bead, the concentration of each component assumed for the sample, the dilution rate, the weight ratio of the oxidizing agent to the sample, and the glass bead to be analyzed And an input means for inputting the weight of each of the flux and glass beads and the oxidizer.

  Further, the theoretical intensity of fluorescent X-rays generated from each component in the glass bead is calculated using the concentration, dilution rate and weight ratio of the oxidant and the sample assumed for the sample input to the input means. Calculating and calculating theoretical matrix correction constants related to absorption and excitation of fluorescent X-rays based on the theoretical intensity, and measuring intensities measured by the detection means for a plurality of standard glass beads having different compositions and different samples And the concentration of the component in the sample, for each component, obtained and stored as a calibration curve corrected using the theoretical matrix correction constant, measured intensity measured by the detection means for the glass beads to be analyzed And a calculation means for calculating the concentration of each component in the sample by applying the calibration curve.

  The theoretical matrix correction constant includes a theoretical matrix correction constant for the weight ratio of the oxidant to the sample, and the calculation means uses the analysis object input to the input means when applying the calibration curve. Each weight of sample and oxidant for a glass bead is used to correct for variations in the weight ratio of oxidant to sample.

  The X-ray fluorescence analyzer of the first configuration includes a calculating means for calculating the concentration of each component in the sample by the SFP method. In the calculating means, the theoretical matrix correction constant includes the weight ratio of the oxidant to the sample. A theoretical matrix correction constant is included, and when the calculation means applies the calibration curve, using the weight of the sample and the oxidant for the glass bead that is the analysis target input to the input means, Because corrections are made for variations in the weight ratio of the oxidizer to the sample, corrections are made for variations in the weight of the oxidizer, and therefore the concentration of each component in the sample prepared in the glass bead with addition of the oxidizer should be determined appropriately Can do.

  The X-ray fluorescence analyzer of the second configuration of the present invention first comprises an X-ray source for irradiating a glass bead prepared by heating and melting a sample, a flux and an oxidant with primary X-rays, and the glass bead. Detection means for measuring the intensity of the generated fluorescent X-rays, and input means for inputting each weight of the sample, one of the fluxing agent and the glass bead, and the oxidizing agent.

  Furthermore, each component in the glass bead is calculated based on the concentration of each component assumed for the sample using the weight of each of the sample, the flux and the glass bead, and the oxidant input to the input means. The theoretical intensity of fluorescent X-rays generated from the sample is calculated, and the theoretical intensity of each component assumed for the sample is matched so that the measured intensity measured by the detection means matches the converted measured intensity converted to the theoretical intensity scale. And a calculating means for calculating the concentration of each component in the sample by correcting the concentration sequentially and approximately.

  Then, when the calculation means calculates the theoretical intensity of the fluorescent X-rays generated from each component in the glass bead, the weight of the sample and the oxidant input to the input means is used, and the oxidant And correct for variations in the weight ratio of the sample.

  The X-ray fluorescence analyzer of the second configuration is provided with a calculation means for calculating the concentration of each component in the sample by the FP method, and the calculation means is for the fluorescent X-ray generated from each component in the glass bead. When calculating the theoretical intensity, the weight of the oxidant and the sample is corrected using the weight of the sample and the oxidant input to the input means, so that the change in the weight of the oxidant is corrected. Therefore, the concentration of each component in the sample prepared in the glass bead by adding the oxidizing agent can be appropriately determined.

It is the schematic which shows the X-ray-fluorescence analyzer of 1st and 2nd embodiment of this invention.

  The X-ray fluorescence analyzer according to the first embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, this apparatus includes a sample stage 8 on which a glass bead 3 prepared by heating and melting a sample 3a, a flux 3b, and an oxidant 3c is placed, and a primary X-ray on the glass bead 3. 2, an X-ray source 1 such as an X-ray tube, detection means 9 for measuring the intensity of fluorescent X-rays 4 generated from the glass beads 3, and a sample 3 a (the apparatus of the first embodiment that embodies the SFP method) Then, the concentration (concentration ratio) of each component, the dilution ratio, the weight ratio of the oxidizing agent 3c and the sample 3a, and the glass bead that is the analysis target, which are assumed for the sample to be analyzed and have a typical composition) 3, input means 11 </ b> A such as a mouse, a keyboard, a touch panel, or the like, to which the weight of any one of the sample 3 a, the flux 3 b and the glass bead 3, and the oxidizer 3 c is input.

  Although not shown in detail, the glass bead 3 is prepared by heating and melting the sample 3a, the flux 3b, and the oxidizing agent 3c by a known method. The detecting means 9 is composed of a spectroscopic element 5 that splits fluorescent X-rays 4 generated from the glass beads 3 and a detector 7 that measures the intensity of each spectroscopic fluorescent X-ray 6. In addition, it is good also as a detection means not using the spectroscopic element 5, but a detector with high energy resolution. That is, the fluorescent X-ray analysis apparatus of this embodiment may be a wavelength dispersion type or an energy dispersion type.

  This device further uses the concentration, dilution rate, and weight ratio of the oxidizing agent 3c and the sample 3a assumed for the sample 3a input to the input means 11A to generate fluorescence generated from each component in the glass bead 3. A glass bead that calculates the theoretical intensity of the X-ray 4 and calculates a theoretical matrix correction constant for absorption and excitation of the fluorescent X-ray 4 based on the theoretical intensity, as well as a plurality of different standards having different compositions in the sample 3a. 3, the correlation between the measured intensity measured by the detection means 9 and the concentration of the component in the sample 3a is obtained and stored for each component as a calibration curve corrected using the theoretical matrix correction constant, and is the glass to be analyzed. A calculating means 10A for calculating the concentration of each component in the sample 3a by applying the calibration curve to the measured intensity measured by the detecting means 9 for the bead 3. It is provided. That is, a calculation means 10A for calculating the concentration of each component in the sample 3a prepared on the glass bead 3 by the SFP method is provided.

  In the calculation means 10A, the theoretical matrix correction constant includes the theoretical matrix correction constant for the weight ratio of the oxidizer 3c and the sample 3a. When the calculation means 10A applies the calibration curve, the input means 11A Using the weights of the sample 3a and the oxidant 3c for the glass bead 3 that is the analysis target input to, the variation in the weight ratio of the oxidant 3c and the sample 3a is corrected.

  The calculation means 10A will be described more specifically, in particular, a theoretical matrix correction constant and a calibration curve corrected using the theoretical matrix correction constant. In the first place, conventionally, variations in the weight of the sample and the flux were corrected by using the dilution rate as in the following equation (1).

Here, the reference dilution rate R _F ^A is a target predetermined dilution rate, and the dilution rate R _F is an actual dilution rate, but there are two methods of handling the dilution rate, The ratio F / S between the weight F of the flux and the weight S of the sample is defined as a dilution rate. In this case, to correct for the so-called ignition loss (the weight obtained by subtracting the weight of the glass beads from the total weight of the sample and the flux, also referred to as Iglos), the mass absorption coefficient of the ignition loss component corresponding to the ignition loss Is treated as 0.

  In another method, the value B / S-1 using the ratio between the weight of the glass beads and the weight of the sample is used as the dilution rate. In this case, in order to correct the ignition loss, the mass absorption coefficient of the flux is used as the mass absorption coefficient of the ignition loss component.

Calibration curve formula corrected using the theoretical matrix correction constant in the calculation means 10A of the first embodiment, corresponding to the conventional formula (1), to be applied to a sample prepared in a glass bead by adding an oxidizing agent. Is derived as follows. First, an approximate expression of the fluorescent X-ray intensity I _i of the analysis component is shown in the following expression (2).

When the ratio F1 / S between the weight F1 of the flux and the weight S of the sample is used as the dilution ratio, the following equation (3) is obtained by rewriting the equation (2) using the concentration ratio W _j of each component in the sample. Is obtained.

For example, when NaNO ₃ is used as the oxidizing agent, it remains as Na ₂ O in the glass bead. Therefore, as the weight F2 of the oxidizing agent, a coefficient of 0.3646 is added to the weight of the actually weighed NaNO _3. Use the remaining weight as Na ₂ O multiplied.

(3) Rewriting equation, concentration ratio W _i of the analysis element is expressed by the following equation (4).

Here, μ _j can be used as a matrix correction constant as it is, but if it is further rewritten, the following equation (5) is obtained.

Here, regarding the concentration ratio W _L of ignition loss (corresponding to ignition loss component), W _L + ΣW _j = 1.0, which is 100% including the ignition loss component. The reference weight ratio R _F2 ^A is a predetermined weight ratio between the target oxidant and the sample, and the weight ratio R _F2 is the actual weight ratio between the oxidant and the sample. When the equation (5) is rewritten into a quadratic equation of the fluorescent X-ray intensity I _i of the analytical element in correspondence with the conventional equation (4), the following equation (6) is obtained.

^{_{W i = (AI i 2 +}} BI i + C) (1 + α 1 W 1 + ... + α n W n + α F1 W L + α F1 ΔR F1 + α F2 ΔR F2) (6)

  This is an example of an equation showing a calibration curve corrected using the theoretical matrix correction constant in the calculation means 10A of the apparatus of the first embodiment.

On the other hand, when the glass bead weight B is used instead of the flux F1, that is, when the dilution rate is expressed by using the glass bead weight B and the sample weight S, the equation (2) is expressed as follows. rewritten using the concentration ratio _{W j,} the following (7), the formula (8) is obtained.

Rewriting equation (8), the concentration ratio W _i of the analysis element can be expressed by the following equation (9).

Equation (7) may be rewritten using (B-F2) / S-1 as the dilution rate, but since the term of the dilution rate becomes complicated, Equation (9) was obtained from Equation (8). When the equation (9) is rewritten into a quadratic equation of the fluorescent X-ray intensity I _i of the analytical element in correspondence with the conventional equation (4), the following equation (10) is obtained.

W _i = (AI _i ² + BI _i + C) (1 + α ₁ W ₁ +... + Α _n W _n + α _L W _L + α _F1 ΔR _F1 + α _F2 ΔR _F2 ) (10)

  This is another example of the equation showing the calibration curve corrected using the theoretical matrix correction constant in the calculation means 10A of the apparatus of the first embodiment.

The theoretical matrix correction constant α (α _{1 to} α _n , α _F1 , α _F2 , α _L ) in the equations (6) and (10) is assumed to be the sample 3a (sample to be analyzed) input to the input means 11A. Fluorescence X generated from each component in the glass bead 3 using the concentration W _{j of} each component assumed for the sample having a representative composition), the dilution ratio R _F1, and the weight ratio R _F2 of the oxidizing agent 3c and the sample 3a The theoretical strength of the line 4 is calculated by the FP method, and is obtained based on the theoretical strength. Then, for each component i, the correlation between the measured intensity I _i measured by the detection means 9 and the concentration W _i of the component in the sample 3a for a plurality of different standard glass beads 3 with known compositions in the sample 3a is The calibration curve corrected using the theoretical matrix correction constant α is obtained as equations (6) and (10) including calibration curve constants A, B, and C, and stored in the calculation means 11A.

As described above, the apparatus according to the first embodiment includes the calculation unit 10A that calculates the concentration W _i of each component in the sample 3a by the SFP method. In the calculation unit 10A, the theoretical matrix correction constant α is set to the oxidation matrix 10A. Analysis included in the input means 11A when the calculation means 10A applies the calibration curve (6) or (10), including the theoretical matrix correction constant α _F2 for the weight ratio of the agent 3c and the sample 3a. Using the respective weights S and F2 of the sample 3a and the oxidant 3c for the target glass bead 3, the variation ΔR _{F2 in} the weight ratio between the oxidant 3c and the sample 3a is corrected, so the variation in the weight F2 of the oxidant 3c correction is performed, therefore, it is possible to determine the concentration W _i of each component in the sample 3a was prepared in a glass bead 3 with an oxidizing agent added 3c appropriately.

Next, a fluorescent X-ray analyzer according to the second embodiment of the present invention will be described. As shown in FIG. 1, this apparatus is different from the apparatus of the first embodiment only in the contents input to the input means 11B and the configuration and operation contents of the calculation means 10B. Specifically, the input means 11B receives the sample 3a, one of the flux 3b and the glass bead 3, and one of the weights S, F1 and B of the oxidant 3c, and F2. The calculation means 10B uses the sample 3a, the flux 3b and the glass bead 3 input to the input means 11B, and the respective weights S, F1 and B of the oxidant 3c, F2, and the sample. 3a based on the concentration W _i of each component is assumed for the theoretical strength of the fluorescent X-rays 4 emitted from each of the components in the glass beads 3 is calculated, theoretical strength measurement strength measured by the detection means 9 and its theoretical strength as the conversion measured intensity in terms of the scale matches the concentration W _i of each component assumed by successive approximation to modify calculated for samples 3a, it calculates the concentration W _i of each component in the sample 3a. That is, the concentration W _i of each component in the sample 3a was prepared in a glass bead 3 is calculated by FP method.

  Then, when the calculating means 10B calculates the theoretical intensity of the fluorescent X-ray 4 generated from each component in the glass bead 3, the weights S and F2 of the sample 3a and the oxidant 3c input to the input means 11B are calculated. It is used to correct for variations in the weight ratio between the oxidant 3c and the sample 3a.

In the calculation means 10B that performs quantitative calculation by the FP method, when calculating the assumed initial concentration (initial content ratio) from the measured intensity, the calculation means 10B is an expression corresponding to the expressions (3) and (7), and the ignition loss component When calculating the theoretical strength using a formula including the concentration ratio W _i of each component in the sample 3a, the concentration ratio W _L of the ignition loss component, the dilution rate, etc. 3 is converted into the concentration ratio C _{i of} each component, the concentration ratio C _{F1 of the} flux, and the concentration ratio C _F2 of the oxidizing agent, and a stricter theoretical strength equation corresponding to the equation (2) is used.

When the ratio F1 / S of the weight F1 of the flux and the weight S of the sample is used as the dilution rate, when calculating the assumed initial concentration from the measured intensity, the equation corresponding to the equation (3) is used and the sample 3a The concentration ratio W _{i of} each component, the concentration ratio W _L of the ignition loss component, the dilution rate F1 / S, and the weight ratio of the oxidizing agent 3c and the sample 3a are used. When calculating the theoretical strength, the ignition loss L can be negative. Therefore, using the following equations (11) to (14), the respective concentration ratios C _i and C in the glass beads from which the ignition loss L has been removed. _F1 and _CF2 are obtained.

On the other hand, when the glass bead weight B is used instead of the flux F1, that is, when the dilution rate is expressed using the glass bead weight B and the sample weight S, when calculating the assumed initial concentration from the measured intensity, In the theoretical strength calculation of the FP method, since it is necessary to divide by the component, the following formulas (15) to (17) are used when calculating the theoretical strength using formula (7) instead of formula (8). Thus, the respective concentration ratios C _i , C _F1 , C _F2 in the glass beads from which the ignition loss L is removed are obtained. Since the ignition loss component is calculated as a flux, the ignition loss L is included in the dilution rate.

Thus, apparatus of the second embodiment is provided with the calculating means 10B for calculating the concentration W _i of each component in the sample 3a by FP method, the calculating means 10B is, from each component in the glass beads 3 When calculating the theoretical intensity of the generated fluorescent X-ray 4, the weight ratio between the oxidant 3c and the sample 3a is changed using the weights S and F2 of the sample 3a and the oxidant 3c input to the input unit 11B. is corrected, the correction for variations in the weight F2 oxidant 3c made, therefore, it is possible to determine the concentration W _i of each component in the sample 3a was prepared in a glass bead 3 with an oxidizing agent added 3c appropriately. In the apparatus of the first and second embodiments, the fluctuation of the weight F2 of the oxidizer 3c is appropriately corrected for the sample 3a in which the apparent ignition loss L is negative.

DESCRIPTION OF SYMBOLS 1 X-ray source 2 Primary X-ray 3 Glass bead 3a Sample 3b Fusing agent 3c Oxidizing agent 4 Fluorescent X-ray 9 Detection means 10A, 10B Calculation means 11A, 11B Input means

Claims (2)

An X-ray source for irradiating a primary bead to a glass bead prepared by heating and melting a sample, a flux and an oxidizing agent;
Detection means for measuring the intensity of fluorescent X-rays generated from the glass beads;
The concentration of each component assumed for the sample, the dilution rate, and the weight ratio of the oxidant to the sample, and the sample for the glass bead to be analyzed, either the flux or glass bead, and the weight of the oxidant are input. Input means,
The theoretical intensity of fluorescent X-rays generated from each component in the glass bead is calculated using the concentration of each component assumed for the sample input to the input means, the dilution rate, and the weight ratio of the oxidizing agent to the sample. , Calculating theoretical matrix correction constants related to absorption and excitation of fluorescent X-rays based on the theoretical intensity, and measuring intensity measured by the detection means for a plurality of different standard glass beads whose compositions in the sample are known and different from each other The correlation with the concentration of the component in the sample is obtained and stored as a calibration curve corrected using the theoretical matrix correction constant for each component, and the measured intensity measured by the detection means for the glass bead to be analyzed is A fluorescent X-ray analyzer comprising: a calculating means for calculating a concentration of each component in the sample by applying a calibration curve;
The theoretical matrix correction constant includes a theoretical matrix correction constant for the weight ratio of the oxidant to the sample, and the calculation means uses the calibration curve to apply the glass that is the analysis target input to the input means. A fluorescent X-ray analyzer that corrects for variations in the weight ratio of the oxidant to the sample by using the weight of the sample and the oxidant for the bead. An X-ray source for irradiating a primary bead to a glass bead prepared by heating and melting a sample, a flux and an oxidizing agent;
Detection means for measuring the intensity of fluorescent X-rays generated from the glass beads;
Input means for inputting the weight of each of the sample, the flux and the glass bead, and the oxidizing agent,
Generated from each component in the glass bead based on the concentration of each component assumed for the sample, using each weight of the sample, flux or glass bead and oxidizer input to the input means The concentration of each component assumed for the sample is calculated so that the theoretical intensity of the fluorescent X-ray is calculated and the theoretical intensity matches the measured intensity measured by the detection means and converted to the theoretical intensity scale. A fluorescent X-ray analysis apparatus comprising a calculation means for calculating the concentration of each component in the sample by performing correction calculation in a successive approximation,
When the calculation means calculates the theoretical intensity of fluorescent X-rays generated from each component in the glass bead, each weight of the sample and the oxidant input to the input means is used to calculate the oxidant and the sample. X-ray fluorescence analyzer that corrects for fluctuations in the weight ratio.

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