JP2014206515A - Method for measuring chlorine concentration in solid fuel, method for preparing calibration curve, and method for manufacturing fluorescent x-ray intensity measuring sample - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for more simply, promptly and accurately than before measuring a chlorine concentration in solid fuel, to provide a method for preparing a calibration curve, and to provide a method for manufacturing a fluorescent X-ray intensity measuring sample.SOLUTION: A method for more simply, promptly and accurately than before measuring a chlorine concentration in solid fuel, comprises: a measuring target sample preparation step of drying and pulverizing the solid fuel having an unknown chlorine concentration and pressure-molding the obtained granular pulverized material by a pressure device to prepare the measuring target sample; and a chlorine concentration measurement step of measuring a chlorine concentration in the measuring target sample on the basis of: a fluorescent X-ray intensity obtained by measuring fluorescent X-ray intensity for the prepared measuring target sample; and a calibration curve in which the fluorescent X-ray intensity is associated with the chlorine concentration in the solid fuel.

Description

  The present invention relates to a method for measuring a chlorine concentration in a solid fuel containing waste plastic such as vinyl chloride, a method for preparing a calibration curve, and a method for producing a sample for measuring fluorescent X-ray intensity.

  From the viewpoint of protecting the global environment, attempts have been made to use the waste that is originally discarded for another use. For example, refuse paper & plastic fuel (hereinafter referred to as “RPF”) is made of waste paper, wood waste, and waste plastic that are difficult to reuse and must be burned. Attempts are also being made. Since RPF contains abundant carbon elements, it is easy to burn, and RPF is suitable as a fuel for driving a boiler.

  However, RPF may contain, for example, chlorine derived from waste plastic. Therefore, when RPF is burned, ash containing chlorine is generated. And when this ash accumulates in a boiler, corrosion of the structure in a boiler may advance with the contained chlorine, and the durability of a boiler may be reduced. Therefore, it is preferable that the RPF to be burned has a chlorine concentration as low as possible.

  In order to select a low chlorine concentration RPF, a technique for measuring the chlorine concentration in a solid fuel such as RPF is known. Specifically, the chlorine content (chlorine concentration) in the RPF can be measured based on JIS Z7302-6. However, in this method, since measurement is performed using an ion chromatograph, the measurement is troublesome and takes time. Therefore, in order to solve such problems, Patent Document 1 discloses that solid fuel is burned in an oxygen bomb combustion container, and hydrogen chloride and chlorine generated by this combustion are absorbed in an alkaline aqueous solution housed in the combustion container. A method for measuring the chlorine concentration in a solid fuel is described in which the amount of chlorine in the absorbing solution is measured with fluorescent X-rays.

JP 2012-21797 A

  However, the technique described in Patent Document 1 uses a special container that is kept airtight, such as an oxygen bomb combustion container. In addition, for example, if measurement is performed in an open system such as in the atmosphere, measurement results may vary, or measurement with good accuracy may not be performed. Therefore, the technique described in Patent Document 1 still has a problem that it is difficult to perform simple and rapid measurement.

  Therefore, a technique that replaces Patent Document 1 is desired in order to perform simple and rapid measurement. For example, it is conceivable that the measurer independently creates a calibration curve, and uses the calibration curve to measure the chlorine concentration of a sample made of solid fuel of unknown concentration that is uniquely created by the measurer. According to this, the chlorine concentration may be easily and quickly measured.

  However, if the measurement conditions such as the calibration curve preparation method and the sample preparation method are different for each measurer, even if the sample is made of the same solid fuel, the same measurement result (chlorine concentration) may not be obtained. Therefore, according to the above method, simple and quick measurement can be performed, but there is still a problem in terms of good accuracy.

  The present invention has been made in view of the above problems, and the problems to be solved by the present invention include a method for measuring the chlorine concentration in a solid fuel more easily and quickly than before, a method for preparing a calibration curve, And it is providing the manufacturing method of the sample for a fluorescent X ray intensity measurement.

  The present inventors have intensively studied to solve the above problems. As a result, the following knowledge was found and the present invention was completed. That is, the gist of the present invention is as follows.

(1)
A method for measuring chlorine concentration in a solid fuel,
A measurement target sample preparation step of drying and pulverizing a solid fuel of unknown chlorine concentration, and pressurizing and molding the obtained granular pulverized product with a pressure device;
Based on the fluorescent X-ray intensity obtained by performing fluorescent X-ray intensity measurement on the prepared sample to be measured, and a calibration curve in which the fluorescent X-ray intensity and the chlorine concentration in the solid fuel are associated with each other. And a chlorine concentration measuring step for measuring the chlorine concentration in the sample to be measured.
(2)
A standard sample preparation step of drying and pulverizing a solid fuel having a known chlorine concentration, and pressure-molding the obtained granular pulverized product with a pressurizing device;
A calibration curve creating step of creating a calibration curve by performing fluorescence X-ray intensity measurement under the same conditions as the measurement conditions in the fluorescence X-ray intensity measurement for the prepared standard sample,
The method for measuring a chlorine concentration in a solid fuel according to (1), wherein the chlorine concentration measuring step is performed using the calibration curve created in the calibration curve creating step.
(3)
The method for measuring a chlorine concentration in a solid fuel according to (1) or (2), wherein the solid fuel is a waste solidified fuel.
(4)
Any one of (1) to (3), wherein the solid fuel is pulverized in at least one of the measurement sample preparation step and the standard sample preparation step until the solid fuel has a diameter of less than 10 mm. The measuring method of the chlorine concentration in the solid fuel as described in the item.
(5)
In at least one of the measurement sample preparation step and the standard sample preparation step, the dried and pulverized solid fuel is filled in a mold, and the whole solid fuel filled in the mold is filled The solid fuel according to any one of (1) to (4) above, wherein pressure molding is performed by applying a force of 1000 kg or more using the pressurizing device. Measuring method of chlorine concentration.
(6)
A standard sample preparation step of drying and pulverizing a solid fuel having a known chlorine concentration, and pressure-molding the obtained granular pulverized product with a pressurizing device;
A calibration curve creating step of performing a fluorescence X-ray intensity measurement on the prepared standard sample and creating a calibration curve in which the fluorescence X-ray intensity and the chlorine concentration in the solid fuel are associated with each other. A characteristic calibration curve creation method.
(7)
Production of a fluorescent X-ray intensity measurement sample characterized by drying and pulverizing a solid fuel, and pressure-molding the obtained granular pulverized product with a pressure device to produce a fluorescent X-ray intensity measurement sample Method.

  According to the present invention, it is possible to provide a method for measuring a chlorine concentration in a solid fuel, a method for preparing a calibration curve, and a method for producing a fluorescent X-ray intensity measurement sample more easily and quickly than in the past. .

It is a production flow of an RPF standard board. It is a creation flow of a calibration curve. It is an example of a calibration curve that can be created. It is a measurement flow of the chlorine concentration of a RPF sample. It is a calibration curve created in Example 1 3 is a graph showing the accuracy of Example 1. 5 is a graph showing the accuracy of Comparative Example 1. 10 is a graph showing the accuracy of Example 3.

  Hereinafter, a mode for carrying out the present invention (this embodiment) will be described.

  The method for measuring the chlorine concentration in the solid fuel according to the present embodiment measures the chlorine concentration in the solid fuel such as waste solidified fuel (RPF) by fluorescent X-ray intensity measurement. The measuring method of the chlorine concentration in the solid fuel of this embodiment mainly includes four steps (processes). Specifically, (1) a standard sample preparation step in which a solid fuel having a known chlorine concentration is dried and pulverized, and the obtained granular pulverized product is pressure-molded by a pressure device to prepare a standard sample; ) A calibration curve creating step for creating a calibration curve by measuring fluorescent X-ray intensity on the prepared standard sample, and (3) drying and pulverizing the solid fuel whose chlorine concentration is unknown, and pulverizing the resulting granules A measurement target sample preparation step for preparing a measurement target sample by press molding an object with a pressure device; and (4) the same conditions as the measurement conditions in the fluorescent X-ray intensity measurement for the prepared measurement target sample The concentration of chlorine in the sample to be measured based on the fluorescent X-ray intensity obtained by measuring the fluorescent X-ray intensity in 1 and the calibration curve in which the fluorescent X-ray intensity and the chlorine concentration in the solid fuel are associated with each other And chlorine concentration measurement step to measure Steps are included. Here, a calibration curve can be created through at least the (1) standard sample preparation step and (2) the calibration curve creation step.

  Among these, the chlorine concentration in the solid fuel is measured more easily and more quickly and accurately than in the past by passing through at least two steps of (3) a measurement target sample preparation step and (4) a chlorine concentration measurement step. A method can be provided. However, in order to obtain a further effect, it is preferable to go through these four steps. Therefore, in the following description, each step will be described on the assumption that these four steps are performed. In addition, since the measuring method of this embodiment is especially suitable with respect to chlorine in RPF, in the following description, RPF will be described as an example of solid fuel.

<Description of each step>
(1) Standard sample preparation step In this step, a solid fuel with a known chlorine concentration is dried and pulverized, and the resulting granular pulverized material is pressure-molded with a pressure device, and then an RPF standard plate (standard sample, fluorescent X-rays). Strength measurement sample) is prepared. The produced RPF standard plate is used when creating a calibration curve to be described later. This step will be described with reference to the flow shown in FIG. FIG. 1 is a flowchart for manufacturing an RPF standard plate.

  First, the chlorine concentration in the RPF is measured according to the method of JIS Z 7302-6 (so-called JIS method). This measurement is performed on a plurality of RPFs, and a plurality (for example, about 20 samples) of RPFs with known concentrations are prepared. Then, each of the RPFs having known concentrations is dried (step S101). In addition, drying may be performed after the grinding | pulverization (step S102) mentioned later. This drying is preferably performed sufficiently, and more preferably so-called “absolutely dry”. By sufficiently drying the RPF, there is an advantage that more accurate fluorescent X-ray intensity can be easily obtained.

  The drying method is not particularly limited, but since it varies depending on the size of the RPF and the like, it cannot be generally stated. However, in the case of a cylindrical RPF having a diameter of about 30 mm, for example, it is preferably set at 105 ° C. for 1 hour or longer. Natural drying may be used, but when a drying apparatus is used, for example, a constant temperature dryer DV 600 manufactured by Yamato Scientific Co., Ltd. can be used.

  The dried RPF is then pulverized (step S102). However, as described above, the RPF may be dried after pulverization. The pulverization is performed to such an extent that a pulverized product of granular RPF is obtained. The other grinding conditions are not particularly limited. For example, the grinding is preferably performed until the particle size (diameter) is less than 10 mm, more preferably 5 mm or less, and particularly preferably 2 mm or less. The smaller the particle size, the finer the chlorine-containing material such as vinyl chloride in the RPF can be dispersed throughout, and a more accurate measurement result can be obtained. The pulverization may be performed only once or a plurality of times. Moreover, you may use the sieve which has a predetermined hole diameter as needed so that RPF of a desired particle size may be obtained.

  Any pulverizer may be used. For example, for the pulverization, an arbitrary pulverization apparatus such as a cutter, a mixer, or a Willet mill can be used. As the cutter, for example, PIP-19 manufactured by MERRY can be used, for example, WDL-1 manufactured by Osaka Chemical Co., Ltd. can be used as the mixer, and for example, 1029 type (φ2 mm) manufactured by Yoshida Seisakusho can be used. Furthermore, if necessary, the RPF may be crushed manually.

  Next, the granular pulverized product of RPF is filled in a mold or the like and is pressure-molded by a pressure device (step S103). Molding is performed using a pressure device. Further, other molding conditions are not particularly limited, but it is preferable to perform molding using a pressure device capable of applying a large force so as to be as dense as possible. Since the molded product (RPF standard plate) to be obtained is as dense as possible, it is possible to suppress irregular reflection of X-rays due to the included voids and obtain a more accurate measurement result. Further, by applying as much force as possible, the surface roughness of the molded product (RPF standard plate) can be reduced to a high smooth state, and the fluorescent X-ray intensity measurement described later can be performed well.

  Therefore, as the molding conditions, specifically, for example, a circular mold (for example, an inner diameter of 30 mm) is filled with RPF granular pulverized material, and then, for example, 1000 kg ( A force having a magnitude of about 1 t) to 20000 kg (20 t), preferably about 10,000 kg (10 t) can be applied. Thereby, a plate (RPF standard plate) made of a disc-shaped RPF having a thickness of, for example, about 3 mm and a weight of, for example, about 2 g can be produced. As such a mold, for example, N1246-00 manufactured by Sansho Industry Co., Ltd. can be used.

  The pressure device for applying force is not particularly limited, but it is preferable to use a pressure device capable of applying as much force as possible. Accordingly, examples of such means include a manual press machine and an electric press machine, but it is preferable to use an electric press machine from the viewpoint that a larger force can be applied. However, a manual press machine may be used from the viewpoint of easier molding. Examples of such a manual press machine include a hand press SSP-10A manufactured by Shimadzu Corporation.

  Further, the molding is not limited to molding using a mold. That is, any means or method other than the mold may be used as long as the same molded product as that obtained using the mold can be molded.

  Through the above steps S101 to S103, an RPF standard plate with a known density is obtained (step S104). This RPF standard plate with a known concentration is used when a calibration curve to be described later is created (calibration curve creation step).

(2) Calibration curve creation step In this step, a calibration curve is created by performing fluorescent X-ray intensity measurement on the RPF standard plate (standard sample) produced in the above (1) standard sample production step. By using the prepared calibration curve, the chlorine concentration of RPF whose concentration is unknown can be measured quickly and simply with high accuracy.

  Specifically, first, the fluorescent X-ray intensity is measured for each RPF standard plate produced in the (1) standard sample production step (step S201). Here, the fluorescent X-ray analysis method is based on the energy and intensity of fluorescent X-rays generated when X-rays are irradiated on a sample (RPF standard plate, RPF sample plate described later, etc.). This is a technique for analyzing concentration and the like. For chlorine, Kα radiation is measured. The specific type of the X-ray fluorescence analyzer is not particularly limited. For example, Spectris wavelength-dispersion X-ray fluorescence PW2404, Oxford Twin-X, SII Nanotechnology SEA1200VX, Techno-X ED05S, SII SEA1000AII manufactured by Nanotechnology, Inc. can be used. Although details will be described later, the fluorescent X-ray intensity measurement for the RPF standard plate and the fluorescent X-ray intensity measurement for the RPF sample are performed under the same conditions using the same type of apparatus.

  And since the density | concentration of each RPF standard plate is known about the measured fluorescence X-ray intensity, the graph which made the x-axis the known chlorine density | concentration and the y-axis the fluorescence X-ray intensity is created (step S202). Then, for each plot on the graph, an approximate straight line is drawn using the least square method. The approximate straight line drawn in this way is used as a calibration curve used for measuring the chlorine concentration of RPF whose concentration is unknown, which will be described later, and the calibration curve is completed (step S203).

An example of the calibration curve created in this way is shown in FIG. In FIG. 3, for simplification of illustration, only three specimens of 0.5 mass%, 0.75 mass%, and 1.0 mass% are plotted, and the correlation coefficient (R ² value) is 1. . FIG. 3 is an example of a calibration curve for simplifying the description, and does not necessarily match an actual calibration curve.

  In the calibration curve shown in FIG. 3, the fluorescent X-ray intensity when the chlorine concentration is 0.5 mass% is 20 kcps, the fluorescent X-ray intensity when the chlorine concentration is 0.75 mass% is 30 kcps, and the chlorine concentration is 1. The fluorescent X-ray intensity at 0 mass% is 40 kcps. Therefore, the equation of the calibration curve obtained by the least square method for these plots (in FIG. 3, simply connecting the plots with a line) is y = 40x.

(3) Measuring object sample preparation step In this step, RPF (solid fuel) whose chlorine concentration is unknown is dried and pulverized, and the obtained granular pulverized material is pressure-molded by a pressurizing device and RPF sample plate (measuring object) Sample, fluorescent X-ray intensity measurement sample). This point will be described with reference to FIG.

  FIG. 4 is a measurement flow of the chlorine concentration of the RPF sample. In this embodiment, it is assumed that the concentration of chlorine contained in the RPF sample whose concentration is unknown is measured. Therefore, an RPF sample plate is produced for the RPF sample with an unknown concentration in the same manner as in the method for producing the RPF standard plate (steps S301 to S304). However, the production conditions and production method are preferably the same as the conditions and method in the above (1) standard sample production step, but are not necessarily exactly the same. Therefore, conditions and methods may be changed as appropriate within a range that does not significantly impair the effects of the present invention.

(4) Chlorine concentration measurement step In this step, the measurement conditions in the fluorescent X-ray intensity measurement in the (2) calibration curve creation step are compared with the measurement target sample prepared in the (3) measurement target sample preparation step. The X-ray fluorescence intensity obtained by measuring the X-ray fluorescence intensity under the same conditions as described above is associated with the X-ray fluorescence intensity created in the above (2) calibration curve creation step and the chlorine concentration in the solid fuel. Based on the obtained calibration curve (for example, the calibration curve shown in FIG. 3), the chlorine concentration in the measurement target sample is measured.

  Specifically, first, the measurement of the fluorescent X-ray intensity for the RPF sample plate is performed with the same apparatus and conditions as when the fluorescent X-ray intensity measurement for the RPF standard plate was performed (step S305 in FIG. 4). . However, the measurement conditions do not necessarily have to be exactly the same, and the conditions may be appropriately changed within a range that does not significantly impair the effects of the present invention. Then, based on the prepared calibration curve (see FIG. 3), the chlorine concentration corresponding to the measured intensity is measured (step S306).

  An example of the calculation method at this time will be described more specifically. As described above, the equation of the calibration curve shown in FIG. 3 is y = 40x (x is the chlorine concentration based on the JIS method, and y is the fluorescent X-ray intensity). Therefore, when x and y are interchanged to obtain an equation for calculating the chlorine concentration corresponding to the fluorescent X-ray intensity, an equation y = (1/40) x = 0.025x is obtained. In this equation, x is the fluorescent X-ray intensity, and y is the chlorine concentration.

  Therefore, “calculating the chlorine concentration using the calibration curve” in step S306 of the present embodiment means that the fluorescence X-ray intensity measured using the formula obtained by converting the calibration curve formula (y = 40x) ( x) is to calculate the chlorine concentration (y). Thereby, the chlorine concentration in RPF whose concentration is unknown can be measured using the measured fluorescent X-ray intensity and calibration curve.

  In this step, since the chlorine concentration in the RPF is specified (determined) using the calibration curve, the chlorine concentration in the RPF is not directly measured in a strict sense. However, in the present specification, specifying the chlorine concentration in the RPF using such a calibration curve is regarded as “measurement” in a broad sense, and is referred to as such for convenience.

  Next, the present embodiment will be described more specifically with reference to examples.

<Creation of calibration curve>
First, a calibration curve was prepared using 19 specimens of RPF with known chlorine concentrations measured by the JIS method.
First, each RPF was completely dried (absolutely dried) by drying at 105 ° C. for 1 hour using a constant temperature dryer (DV600 manufactured by Yamato Scientific Co., Ltd.).

  Next, each dried RPF was preliminarily pulverized using a pulverizing cutter, a pipe cutter (PRY-19 manufactured by MERRY) and a mixer (WDL-1 manufactured by Osaka Chemical Co.), and then a Willet mill on which a sieve having a pore diameter of 2 mm was set. Each RPF was pulverized using (Yoshida Seisakusho 1029 type) to obtain a granular pulverized product having a diameter of 2 mm or less. The RPF provided to the apparatus was about 100 g each.

  Finally, about 2 g of the pulverized product of each RPF was filled in a mold molding machine (φ30 mm, N1426-00, manufactured by Sansho Industries Co., Ltd.). Next, a pressure of 10,000 kg (10 t) was applied to the pulverized RPF by a manual hydraulic pressure molding machine (pressure device; SSP-10A manufactured by Shimadzu Corporation) to perform pressure molding. Then, the RPF plate was taken out from the mold, and it was confirmed that both surfaces were smooth, and 19 RPF standard plates were produced.

  About 19 RPF standard plates, the fluorescence X-ray intensity (kcps) was measured using the fluorescence X-ray analyzer (Twin-X by Oxford), and the graph was created. The created graph is shown in FIG. And about the plot of 19 samples, the approximate straight line was obtained using the least squares method, and the obtained approximate straight line was used as the calibration curve. The equation of this calibration curve (approximate straight line) was y = 44.001x (x is the known concentration, y is the fluorescent X-ray intensity), and the correlation coefficient was 0.9939.

<Concentration measurement for a relatively small number of samples (Example 1 and Example 2)>
The 19 RPF standard plates were used as RPF sample plates, and the X-ray fluorescence intensity was measured using the X-ray fluorescence analyzer. And the chlorine concentration was calculated | required based on the created calibration curve from the measured fluorescence X-ray intensity. The measured chlorine concentration (chlorine concentration based on fluorescent X-ray method) is plotted on the graph with the vertical axis (y-axis) and the corresponding known concentration (chlorine concentration based on JIS method) on the horizontal axis (x-axis). (Example 1).

  Further, a graph was plotted in the same manner as in Example 1 except that the used X-ray fluorescence analyzer was replaced with SEA1200VX manufactured by SII Nanotechnology (Example 2).

  The results of Example 1 and Example 2 are shown in FIG. In FIG. 6, the alternate long and short dash line is a straight line with a slope of 1, and the closer the shape of the graph is to this straight line, the more the chlorine concentration measured by the method for measuring the chlorine concentration in the solid fuel of this embodiment is based on the JIS method. It is close to the chlorine concentration, indicating a good system.

  The slope of the approximate straight line (thick solid line) in Example 1 was 1.0285, and the correlation coefficient was 0.8375. The slope of the approximate straight line (broken line) in Example 2 was 0.9045, and the correlation coefficient was 0.8906. As for the shape of the graph, in both Example 1 and Example 2, the inclination was close to the one-dot chain line straight line. Thus, regardless of the type of the fluorescent X-ray measurement apparatus, a result with high accuracy and little variation (the inclination of the approximate straight line is close to 1) was shown. This result is considered to be because the influence on the measurement due to the difference in the matrix could be reduced by configuring the standard plate used in the X-ray fluorescence analyzer with the same RPF as the sample to be measured.

  Further, the correlation coefficient was close to 1 in both Example 1 and Example 2, and although there was a slight variation, a good correlation was shown. This indicates that good results with good accuracy can be obtained regardless of the measurement conditions. In particular, various fluorescent X-ray analyzers are sold depending on differences in measurement mechanism and measurement accuracy. Therefore, from the results of Example 1 and Example 2, regardless of the measuring device, the chlorine concentration in solid fuel such as RPF can be measured with high accuracy, simply and quickly enough to comply with the JIS method. I found out that

<Conventional measurement not using the calibration curve of the present embodiment (Comparative Example 1 and Comparative Example 2)>
The following Comparative Example 1 and Comparative Example 2 were evaluated using 6 RPF samples with known chlorine concentrations measured by the JIS method.

  Example 1 and Example 2 except that 6 specimens of RPF were not dried and a Willet mill in which a sieve having a pore size of 5 mm was set at the time of pulverization (that is, the particle size of granular RPF was 5 mm or less). An RPF sample plate was produced in the same manner as described above.

  In addition, a standard curve recommended by each device manufacturer was used as a standard plate corresponding to the RPF sample plate of Example 1 and Example 2, and a calibration curve was created. The standard sample in Comparative Example 1 is a sodium chloride aqueous solution, and the standard sample in Comparative Example 2 is a polyethylene plate.

  The six RPF sample plates thus prepared were measured for fluorescent X-ray intensity in the same manner as in Example 1 and Example 2, and the chlorine concentration based on the fluorescent X-ray analysis method was determined using a calibration curve prepared from each of the standard samples. Was measured. The result is shown in FIG. 7 in the same manner as FIG.

  The slope of the approximate straight line (thick solid line) in Comparative Example 1 was 1.2909, and the correlation coefficient was 0.5591. The slope of the approximate straight line (broken line) in Comparative Example 2 was 0.3953, and the correlation coefficient was 0.8528. The shape of the graph is greatly different from the one-dot chain line of slope 1 in both Comparative Example 1 and Comparative Example 2, and the chlorine concentration measured based on the fluorescent X-ray method is based on JIS method. It was found that the measured chlorine concentration was very different. Therefore, it was found that the method of Comparative Example 1 and Comparative Example 2 can only obtain results with low accuracy.

  In addition, the correlation coefficient was particularly small in Comparative Example 1, indicating that the variation was large. This indicates that the variation is large depending on the measurement conditions, and the reliability of the chlorine concentration measured based on the fluorescent X-ray method is low.

<Change in accuracy due to increase / decrease in number of samples (Example 3)>
Implemented except that 100 samples of RPF with a known chlorine concentration measured by the JIS method were used, the force applied at the time of molding was 10,000 kg (10 t), and the fluorescent X-ray analyzer used was a wavelength-dispersed fluorescent X-ray PW2404 manufactured by Spectris Similar to Example 1, a graph similar to FIG. 6 was drawn.

  As a result, as shown in FIG. 8, the slope of the obtained approximate straight line was 1.0016, and the correlation coefficient was 0.9910. From this, it is considered that the larger the number of specimens, the higher the accuracy and the less variation.

<Change in fluorescence X-ray intensity due to the amount of water contained in the RPF sample>
RPF standard plates were prepared using RPF having a moisture content of 0% by mass (absolutely dry), RPF having a moisture content of 5% by mass, and RPF having a moisture content of 10% by mass. And about the produced three RPF standard plates, the fluorescent X ray intensity was measured using the fluorescent X ray analyzer used in Example 3. FIG. The results are shown in Table 1 below.

※ 表１中、括弧内の数字は、「０質量％」の結果からの減少率である。

* In Table 1, the number in parentheses is the rate of decrease from the result of “0% by mass”.

  As shown in Table 1, the intensity of fluorescent X-rays decreased as the amount of water increased. In particular, when the water content was 10% by mass, the strength decreased by up to about 30%. When the intensity of the fluorescent X-ray is lowered, the measurement accuracy is lowered. Therefore, it was found that the amount of water contained in the RPF sample is preferably as small as possible.

<Changes in fluorescent X-ray intensity due to differences in the degree of pulverization and molding method>
In order to examine how the degree of pulverization and the molding method affect the fluorescent X-ray intensity, the following evaluation was performed.

  RPF standard plates were prepared with three pulverization levels of 10 mm or more, 5 mm or less, and 2 mm or less. Note that the pulverization with a diameter of 10 mm or more is not pulverization using a Willet mill or the like, but is obtained by simply cutting the RPF into a round shape and cannot be said to be granular RPF. In addition, the molding is performed by human finger pressing, molding using a manual press machine (pressure device) (the magnitude of the applied force is 10,000 kg), and automatic press machine (pressurization) at each degree of crushing. Three types of molding using a device (the magnitude of the applied force is 20000 kg). Then, for the nine RPF standard plates, the fluorescent X-ray intensity was measured using the same fluorescent X-ray analyzer as in Example 3. The results are shown in Table 2.

※ 表２中、括弧内の数字は、「直径２ｍｍ以下」の結果からの減少率である。
また、評価項目において、「○」は強度十分、「△」は強度がやや弱い、「×」は強度が弱いことを示している。

* In Table 2, the number in parentheses is the rate of decrease from the result of “diameter 2 mm or less”.
In the evaluation items, “◯” indicates that the strength is sufficient, “Δ” indicates that the strength is slightly weak, and “×” indicates that the strength is weak.

  As shown in Table 2, in the “diameter of 10 mm or more” in which the RPF was simply cut into round pieces, the intensity of the tendency X-rays was weak in both the finger press molding and the pressure molding by the pressure device. Moreover, when it grind | pulverized until it became diameter 5mm or less and diameter 2mm or less, the intensity | strength of the fluorescent X-ray was weak in the shaping | molding by the magnitude | size of the magnitude | size of a finger press. Therefore, in these cases, there is a possibility that the chlorine concentration cannot be measured with good accuracy.

  On the other hand, when pulverized until it becomes a granule with a diameter of 5 mm or less and until it becomes a granule with a diameter of 2 mm or less, even when using either an automatic press or a manual press, a relatively good fluorescent X-ray intensity was gotten. Therefore, it was found that the chlorine concentration can be measured with good accuracy if pulverization is performed and pressure molding is performed by a pressure device such as an automatic press or a manual press. In particular, it was found that measurement with better accuracy can be performed by pulverization until the particle has a diameter of 2 mm or less.

  As described above, according to the present embodiment, if each measurer prepares a standard sample (RPF standard plate, etc.) and creates a calibration curve, thereafter, the method is the same as the standard sample preparation method. By preparing a measurement target sample (RPF sample plate or the like) and measuring the fluorescent X-ray intensity, the chlorine concentration in the measurement target sample can be measured easily, quickly and accurately. In particular, by performing fluorescent X-ray intensity analysis on the measurement target sample under the same measurement conditions as the fluorescent X-ray analysis conditions used at the time of creating the calibration curve, it is possible to suppress variation by the measurer.

Claims (7)

A method for measuring chlorine concentration in a solid fuel,
A measurement target sample preparation step of drying and pulverizing a solid fuel of unknown chlorine concentration, and pressurizing and molding the obtained granular pulverized product with a pressure device;
Based on the fluorescent X-ray intensity obtained by performing fluorescent X-ray intensity measurement on the prepared sample to be measured, and a calibration curve in which the fluorescent X-ray intensity and the chlorine concentration in the solid fuel are associated with each other. And a chlorine concentration measuring step for measuring the chlorine concentration in the sample to be measured. A standard sample preparation step of drying and pulverizing a solid fuel having a known chlorine concentration, and pressure-molding the obtained granular pulverized product with a pressurizing device;
A calibration curve creating step of creating a calibration curve by performing fluorescence X-ray intensity measurement under the same conditions as the measurement conditions in the fluorescence X-ray intensity measurement for the prepared standard sample,
The method for measuring a chlorine concentration in a solid fuel according to claim 1, wherein the chlorine concentration measuring step is performed using the calibration curve created in the calibration curve creating step.   The said solid fuel is a waste solidification fuel, The measuring method of the chlorine concentration in the solid fuel of Claim 1 or 2 characterized by the above-mentioned.   4. The method according to claim 1, wherein in at least one of the measurement target sample preparation step and the standard sample preparation step, the solid fuel is pulverized until the diameter becomes less than 10 mm. Of measuring chlorine concentration in solid fuel.   In at least one of the measurement sample preparation step and the standard sample preparation step, the dried and pulverized solid fuel is filled in a mold, and the whole solid fuel filled in the mold is filled The pressure of chlorine concentration in the solid fuel according to any one of claims 1 to 4, wherein pressure molding is performed by applying a force of 1000 kg or more using the pressurizer. Measuring method. A standard sample preparation step of drying and pulverizing a solid fuel having a known chlorine concentration, and pressure-molding the obtained granular pulverized product with a pressurizing device;
A calibration curve creating step of performing a fluorescence X-ray intensity measurement on the prepared standard sample and creating a calibration curve in which the fluorescence X-ray intensity and the chlorine concentration in the solid fuel are associated with each other. A characteristic calibration curve creation method.   Production of a fluorescent X-ray intensity measurement sample characterized by drying and pulverizing a solid fuel, and pressure-molding the obtained granular pulverized product with a pressure device to produce a fluorescent X-ray intensity measurement sample Method.

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