A method for measuring calorific value using XRF fluorescence spectrum

Abstract

The present invention belongs to the field of analytical technology. The present invention provides a method for measuring calorific value by using XRF fluorescence spectrum. The method establishes a fitting relationship between the calorific value of a standard sample and the total value of the spectral peak information value of a scattering peak of the XRF fluorescence spectrum or the spectral peak information value of the same type of characteristic peaks, and performs XRF fluorescence spectrum test on the sample to be tested, and the calorific value result can be calculated according to the fitting relationship. The method has high precision, good reproducibility, high accuracy, good repeatability, can realize direct measurement of the sample, and has short analysis time, simple and easy method, convenient and reliable.

Description

Technical Field

[0001] The invention belongs to the technical field of analysis, and relates to a quantitative analysis method for calorific value, and specifically to a method for measuring calorific value by using XRF fluorescence spectrum. Background Art

[0002] In modern industrial production, efficient use of energy plays a vital role in promoting sustainable economic development and environmental protection. As a key indicator for measuring the energy content of fuel, calorific value plays an irreplaceable role in energy management, thermal energy conversion and combustion equipment design. Specifically, calorific value is not only directly related to the accurate calculation of the consumption of solid fuels such as coal, the evaluation of thermal efficiency and the determination of the thermal balance state of combustion equipment, but also crucial for formulating plans for different material mixing ratios. In addition, calorific value is also one of the important bases for evaluating the quality of various materials. Therefore, accurate and rapid acquisition of calorific value information of solid materials has a far-reaching impact on optimizing energy structure, improving energy utilization efficiency and reducing environmental pollution.

[0003] At present, the material calorific value detection methods commonly used at home and abroad mainly include two categories: oxygen bomb calorimetry and elemental analysis.

[0004] Among them, oxygen bomb calorimetry is a classic direct measurement technique that determines the calorific value of a sample by placing it in a closed container for complete combustion and measuring the resulting heat change. This method has a clear principle and reliable results, and is widely used in the determination of the calorific value of traditional energy materials such as coal and petroleum products. However, the oxygen bomb calorimetry method has obvious limitations: for example, its operation process is cumbersome and requires multiple steps such as sample preparation, combustion reaction, and temperature monitoring, which results in a long test cycle, usually taking several hours or even longer to complete a complete measurement process; moreover, the test equipment is expensive and requires strict maintenance.

[0005] The elemental analysis method is to determine the mass fraction of the main elements such as carbon, hydrogen, and oxygen in the sample, and calculate its theoretical calorific value based on the relevant formula. The advantage of this method is that it can achieve non-destructive testing and can provide additional information about the chemical composition of the sample. However, the elemental analysis method also faces many challenges: first, the analysis accuracy is limited by the sensitivity of the instrument and the sample processing technology, and is easily interfered by impurities; second, the calculation model is complex and needs to consider the impact of multiple factors such as moisture content and ash content on the final result; third, it cannot directly reflect the complex physical and chemical changes in the actual combustion process, which may lead to a certain deviation between the theoretical value and the actual value.

[0006] In summary, although the existing oxygen bomb calorimetry and elemental analysis methods can meet the needs of solid material calorific value detection under certain conditions, their common problems such as complex operation and long test cycle seriously restrict their application in rapid response occasions. Therefore, how to develop a new calorific value measurement solution with simple operation, fast detection speed and high accuracy has important practical significance and broad application prospects. Summary of the invention

[0007] In view of the problems existing in the prior art, the purpose of the present invention is to provide a quantitative analysis method for calorific value. In view of the deficiencies in the prior art, the present invention provides a method for measuring calorific value using XRF fluorescence spectrum, wherein the method establishes a fitting relationship between the calorific value of a standard sample and the peak information value of a scattering peak of the XRF fluorescence spectrum or the total value of the peak information value of the same type of characteristic peaks, and performs an XRF fluorescence spectrum test on the sample to be tested, and the calorific value result can be calculated according to the fitting relationship. The method has high precision, good reproducibility, high accuracy, good repeatability, can realize direct measurement of samples, and has a short analysis time, a simple and easy method, and is convenient and reliable.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a method for measuring calorific value using XRF fluorescence spectroscopy, comprising the following steps:

[0010] Obtain the calorific value of the standard sample as the dependent variable;

[0011] Performing an XRF fluorescence spectrum test on the standard sample to obtain a spectrum peak information value of a scattering peak or a total value of spectrum peak information values ​​of the same type of characteristic peaks as an independent variable;

[0012] Fitting the independent variable and the dependent variable to obtain a fitting calculation formula;

[0013] Perform an XRF fluorescence spectrum test on the sample to be tested, obtain the spectral peak information value of the corresponding scattering peak or the total value of the spectral peak information value of the corresponding characteristic peak, substitute it into the fitting calculation formula for calculation, and obtain the calorific value result.

[0014] The method for measuring calorific value by XRF fluorescence spectrum (X Ray Fluorescence) of the present invention. The method uses an XRF fluorescence spectrometer to scan solid materials, and constructs the relationship between the relevant peak information values ​​of non-characteristic spectral lines (such as Compton scattering or Rayleigh scattering) or the same type of characteristic spectral lines (such as Kα series, Kβ series, Lα series or Lβ series, etc.) of the XRF fluorescence spectrum of the solid material. The peak information value refers to the peak intensity (peak count rate) or peak area, especially the net peak intensity or net peak area of ​​the corresponding spectral peak after deducting the background value, and the relevant value can usually be obtained on the test software.

[0015] Specifically, the calorific value of solid materials is directly proportional to the concentration of anions such as carbon, hydrogen, oxygen, nitrogen, and sulfur. The characteristic energy of light elements such as carbon, hydrogen, oxygen, nitrogen, and sulfur is relatively small, the X-ray fluorescence yield is relatively low, and the transmission energy is relatively weak. The sample is detected using an energy dispersive X-ray fluorescence spectrometer. The X-ray photons interact with the outer electrons of the atoms to cause strong scattering, which reduces the X-ray fluorescence energy counting rate. The calorific value is quantitatively analyzed based on the scattering peak intensity or the net peak intensity of a class of characteristic peaks. Therefore, the method can not only realize the non-destructive determination of the calorific value of solid materials, but also can be quickly detected. The method is used to determine the calorific value of solid material samples, and significantly shortens the detection cycle to 5 minutes. In summary, the present invention can quickly detect the calorific value in solid materials, has the advantages of high precision, convenient processing, saving chemical analysis reagents, etc., and is convenient and accurate to operate.

[0016] The following are preferred technical solutions of the present invention, but are not intended to be limitations of the technical solutions provided by the present invention. Through the following technical solutions, the technical objectives and beneficial effects of the present invention can be better achieved and realized.

[0017] As a preferred technical solution of the present invention, the spectrum peak information value includes the net peak intensity of the spectrum peak or the net peak area of ​​the spectrum peak.

[0018] As a preferred technical solution of the present invention, the scattering peak includes a Compton scattering peak or a Rayleigh scattering peak; the characteristic peak includes any one of a characteristic total peak, a Kα series spectral line peak, a Kβ series spectral line peak, an Lα series spectral line peak or an Lβ series spectral line peak; preferably, it is a Kα series Compton scattering peak.

[0019] It should be noted that the total value of the net peak intensity or net peak area of ​​the characteristic total peak in the present invention refers to the total value of the net peak intensity or net peak area of ​​all characteristic peaks of all elements, and the total value of the net peak intensity or net peak area of ​​the Kα series spectral line peak refers to the total value of the net peak intensity or net peak area of ​​the Kα spectral line peak of all elements. Taking the Compton scattering peak as an example, the peak information value of a scattering peak refers to the spectral peak information value of a peak position in the Compton scattering peak, such as the net peak intensity or net peak area of ​​the Kα series Compton scattering peak, or the net peak intensity or net peak area of ​​the Kβ series Compton scattering peak, or it can also be the total value of the spectral peak information of all peak positions.

[0020] As a preferred technical solution of the present invention, the fitting type for fitting the independent variable and the dependent variable includes polynomial fitting.

[0021] As a preferred technical solution of the present invention, the standard sample and the sample to be tested are dried in advance, and preferably the moisture content after drying is ≤30%.

[0022] As a preferred technical solution of the present invention, the method for obtaining the calorific value of the standard sample includes performing an oxygen bomb calorimetry test.

[0023] As a preferred technical solution of the present invention, after the standard sample and the sample to be tested are dried, before the XRF fluorescence spectrum test, the standard sample and the sample to be tested are ground and then pressed into sheets. The grinding particle size is 50-355 μm, such as 50 μm, 100 μm, 150 μm, 200 μm, 250 μm or 300 μm, but is not limited to the above numerical range, and values ​​not within the above range are also applicable.

[0024] As a preferred technical solution of the present invention, the parameters of the XRF fluorescence spectrum test include:

[0025] The tube voltage is 0~49kV, for example, 25kV, 30kV, 35kV, 40kV, 45kV, 49kV or 50kV, etc., preferably 45kV.

[0026] The tube current is 0~900μA, for example, 100μA, 200μA, 300μA, 400μA, 500μA, 600μA, 700μA, 800μA or 900μA, etc., preferably 300μA.

[0027] As a preferred technical solution of the present invention, the standard sample and the sample to be tested in the technical solution keep the same test conditions. It is not limited to the listed values, and the values ​​not listed in the above numerical range are also applicable.

[0028] As a preferred technical solution of the present invention, the method comprises:

[0029] (1) Provide standard samples and samples to be tested of solid materials, and pre-dry the standard samples and samples to be tested;

[0030] (2) Conduct oxygen bomb calorimetry test on some of the dried standard samples to obtain the calorific value of the standard samples as the dependent variable;

[0031] At the same time, another part of the dried standard sample is ground and pressed into a sheet, and an XRF fluorescence spectrum test is performed. The parameters of the XRF fluorescence spectrum test are set to include a tube voltage of 0-49 kV and a tube current of 0-900 μA to obtain a spectrum result; the scattering peak includes a Compton scattering peak or a Rayleigh scattering peak; the characteristic peak includes any one of a characteristic total peak, a Kα series spectral line peak, a Kβ series spectral line peak, an Lα series spectral line peak or an Lβ series spectral line peak; the net peak intensity or net peak area of ​​the obtained Compton scattering peak, or the net peak intensity or net peak area of ​​the Rayleigh scattering peak, or the total value of the net peak intensity or the total value of the net peak area of ​​the same type of characteristic peaks of all elements, or the total value of the net peak intensity or the total value of the net peak area of ​​the characteristic total peak is used as an independent variable;

[0032] (3) performing polynomial fitting on the independent variable and the dependent variable to obtain a fitting calculation formula;

[0033] (4) Grind the sample to be tested which has been dried to a constant weight and press it into a sheet, and test and calculate it according to the XRF fluorescence spectrum test method of step (2) to obtain the net peak intensity or net peak area of ​​the corresponding scattering peak of the sample to be tested, or the total value of the net peak intensity or the total value of the net peak area of ​​the corresponding characteristic peak, and substitute it into the fitting calculation formula for calculation to obtain the calorific value result.

[0034] In a second aspect, the present invention provides a use of the method for measuring calorific value using XRF fluorescence spectroscopy as described in the first aspect, wherein the use tests the calorific value of a solid, molten or liquid system, that is, the standard sample and the sample to be tested are selected from the solid, molten or liquid system.

[0035] Preferably, the solid comprises minerals and / or waste materials.

[0036] The present invention is applicable to other solids (such as powders), molten materials, non-water-containing liquids, or liquid phase systems, such as minerals or solid wastes, that have calorific value components or calorific value potential and can be tested by XRF fluorescence spectrum. The application is not limited to a certain field, for example, it can be used for the calorific value test of leached slag and coke mixture, and can also be used for the test of minerals or other industrial wastes.

[0037] Compared with the prior art solutions, the present invention has at least the following beneficial effects:

[0038] The method of the present invention utilizes the spectral peak information value of a scattering peak or the total value information of the spectral peak information values ​​of the same type of characteristic peaks determined by XRF fluorescence spectroscopy to establish a means for rapid detection of the calorific value of solid materials. The method has high precision, good reproducibility, high accuracy, good repeatability, can realize direct detection of samples, avoid the influence of the test environment on product peaks, reduce analysis time, and the method is simple, easy, convenient and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic diagram of the technical route of the method for measuring calorific value using XRF fluorescence spectroscopy in Example 1;

[0040] Figure 2 This is the result diagram of the calorific value standard curve fitted by polynomial in Example 1. DETAILED DESCRIPTION

[0041] The technical solution of the present invention is further illustrated below through specific implementation methods.

[0042] It should be clear to those skilled in the art that the embodiments are only intended to help understand the present invention and should not be considered as specific limitations of the present invention.

[0043] Example 1

[0044] This embodiment provides a method for measuring calorific value using XRF fluorescence spectroscopy, such as Figure 1 As shown, including:

[0045] (1) Prepare standard samples by collecting leaching residue coke mixtures from 6 different batches and drying them to constant weight;

[0046] (2) Conducting oxygen bomb calorimetry tests on some standard samples dried to constant weight to obtain the calorific value of the standard samples as the dependent variable;

[0047] At the same time, another part of the standard samples dried to constant weight were ground, passed through 80-mesh and 100-mesh standard sieves (particle size 100-200 μm), and then pressed into sheets for XRF fluorescence spectrum test. The parameters of the XRF fluorescence spectrum test were set to include tube voltage of 45 kV and tube current of 300 μA, and the spectrum results were obtained; Mo-Kα is the characteristic peak of the Mo element, and the Kα series Compton scattering peak is represented by Mo-Kα-C; the net peak area of ​​the obtained Kα series Compton scattering peak was used as the independent variable;

[0048] (3) Perform polynomial fitting on the independent variable and the dependent variable to obtain a fitting formula, such as Figure 2 As shown;

[0049] (4) Prepare leaching slag coke mixtures A and B with unknown calorific values, and a leaching slag coke mixture C with a known calorific value (low calorific value 4128 cal / g), and dry them to constant weight;

[0050] The sample to be tested which has been dried to a constant weight is ground, passed through 80-mesh and 100-mesh standard sieves (particle size 100-200 μm), and then pressed into tablets. The tablets are tested and calculated according to the XRF fluorescence spectrum test method in step (2) to obtain the net peak area of ​​the Kα Compton scattering peak of the sample to be tested, which is substituted into the fitting calculation formula for calculation to obtain the calorific value result.

[0051] [Heat value results]

[0052] After calculation, the low calorific value of the leached slag coke mixture A measured in Example 1 is 2813 cal / g, the low calorific value of the leached slag coke mixture B is 2399 cal / g, and the low calorific value of the leached slag coke mixture C is 3982 cal / g.

[0053] In order to verify the test results, oxygen bomb calorimetry was performed on leached slag coke mixture A and leached slag coke mixture B, and the calorific values ​​obtained were 2951 cal / g and 2400 cal / g, respectively.

[0054] From the above results, it can be seen that the method of determining calorific value using XRF fluorescence spectroscopy of the present invention is consistent with the test results of oxygen bomb calorimetry, and the test result of leached slag coke mixture C differs from its known calorific value by only 3.5% (<5%), and the test result is accurate.

[0055] [Precision]

[0056] Prepare a leached slag coke mixture D of unknown calorific value. The sample is dried, ground and divided into 5 equal parts, which are pressed into sheets respectively. The XRF fluorescence spectrum test method in step (2) is used for testing and calculation to obtain the net peak area of ​​the Kα Compton scattering peak Mo-Kα-C of the sample to be tested. The net peak area is substituted into the fitting calculation formula for calculation to obtain the calorific value result, as shown in Table 1.

[0057]

[0058] It can be seen from Table 1 that the RSD of the calorific values ​​of the five pressed tablets is 1.46%, which is less than 1.5%, indicating that the method of measuring calorific value by using XRF fluorescence spectroscopy of the present invention has good precision.

[0059] [Influence of spectral peak information type]

[0060] Example 2

[0061] The present embodiment provides a method for determining calorific value using XRF fluorescence spectroscopy. In the method, the spectral peak types targeted by the standard sample and the sample to be tested, the leached slag coke mixture C with known calorific value, are adjusted. That is, in step (2) and step (4), the net peak area of ​​the Kα series Rayleigh scattering peak in the obtained spectral result is calculated after deducting the background value, and a polynomial fitting is performed using the net peak area of ​​the Kα series Rayleigh scattering peak of the standard sample, and the net peak area of ​​the Kα series Rayleigh scattering peak of the sample to be tested, the leached slag coke mixture C, is substituted into the calculation.

[0062] Example 3

[0063] This embodiment provides a method for determining calorific value using XRF fluorescence spectroscopy. In the method, the spectral peak types targeted by the standard sample and the sample to be tested, the leached slag coke mixture C with known calorific value, are adjusted. That is, in step (2) and step (4), all characteristic peaks of all elements in the obtained spectral results are calculated to obtain the total value of the net peak area of ​​the characteristic total peaks. The total value of the net peak area of ​​the characteristic total peaks of the standard sample is used for polynomial fitting, and the total value of the net peak area of ​​the characteristic total peaks of the leached slag coke mixture C of the sample to be tested is substituted into the calculation.

[0064] Example 4

[0065] This embodiment provides a method for determining calorific value using XRF fluorescence spectroscopy. In the method, the spectral peak types targeted by the standard sample and the sample to be tested, the leached slag coke mixture C with known calorific value, are adjusted. That is, in step (2) and step (4), the Kα spectral line peaks of all elements in the obtained spectral results are calculated to obtain the total value of the net peak area of ​​the Kα series spectral line peaks. The total value of the net peak area of ​​the Kα series spectral line peaks of the standard sample is used for polynomial fitting, and the total value of the net peak area of ​​the Kα series spectral line peaks of the leached slag coke mixture C of the sample to be tested is substituted into the calculation.

[0066] Example 5

[0067] This embodiment provides a method for determining calorific value using XRF fluorescence spectroscopy. In the method, the spectral peak types targeted by the standard sample and the sample to be tested, the leached slag coke mixture C with known calorific value, are adjusted. That is, in step (2) and step (4), the Kβ spectral line peaks of all elements in the obtained spectral results are calculated to obtain the total value of the net peak area of ​​the Kβ series spectral line peaks. The total value of the net peak area of ​​the Kβ series spectral line peaks of the standard sample is used for polynomial fitting, and the total value of the net peak area of ​​the Kβ series spectral line peaks of the leached slag coke mixture C of the sample to be tested is substituted into the calculation.

[0068] Example 6

[0069] The present embodiment provides a method for determining calorific value using XRF fluorescence spectroscopy. In the method, the spectral peak types targeted by the standard sample and the sample to be tested, the leached slag coke mixture C with known calorific value, are adjusted. That is, in step (2) and step (4), the Lα series spectral line peaks in the obtained spectral results are calculated to obtain the total value of the net peak area of ​​the Lα series spectral line peaks. The total value of the net peak area of ​​the Lα series spectral line peaks of the standard sample is used for polynomial fitting, and the total value of the net peak area of ​​the Lα series spectral line peaks of the leached slag coke mixture C of the sample to be tested is substituted into the calculation.

[0070] Example 7

[0071] The present embodiment provides a method for determining calorific value using XRF fluorescence spectroscopy. In the method, the spectral peak types targeted by the standard sample and the sample to be tested, the leached slag coke mixture C with known calorific value, are adjusted. That is, in step (2) and step (4), the Lβ series spectral line peaks in the obtained spectral results are calculated to obtain the total value of the net peak area of ​​the Lβ series spectral line peaks. The total value of the net peak area of ​​the Lβ series spectral line peaks of the standard sample is used for polynomial fitting, and the total value of the net peak area of ​​the Lβ series spectral line peaks of the leached slag coke mixture C of the sample to be tested is substituted into the calculation.

[0072] The results of Examples 2-7 are recorded in Table 2.

[0073]

[0074] It can be seen from Table 2 that:

[0075] The total value of the net peak area of ​​the characteristic total peak, Kα series spectral line peak, Kβ series spectral line peak, Lα series spectral line peak or Lβ series spectral line peak, and the net peak area or net peak intensity of the Kα series Compton scattering peak have the same change trend with the calorific value, and the correlation coefficient can reach 0.97.

[0076] [Influence of particle size]

[0077] Examples 8 to 10 respectively provide a method for measuring calorific value using XRF fluorescence spectroscopy, in which the standard sample and the sample C to be tested with known calorific value are adjusted from passing through 80-mesh and 100-mesh standard sieves (particle size 100-200 μm) to passing through 50-mesh and 80-mesh standard sieves (particle size 200-355 μm), passing through 100-mesh and 200-mesh standard sieves (75-100 μm), and passing through 200-mesh and 250-mesh standard sieves (75-63 μm). Except for the above, the other conditions are exactly the same as those in Example 1. As a result, the fitting calculation formula obtained in step (3) and the calorific value result of the leached slag coke mixture C measured in step (4) change, and the results are recorded in Table 3.

[0078]

[0079] Embodiments 11 to 13 respectively provide a method for determining calorific value using XRF fluorescence spectroscopy, in which the standard sample and the sample C to be tested with known calorific value are adjusted from passing through 80-mesh and 100-mesh standard sieves (particle size 100-200 μm) to passing through 50-mesh and 80-mesh standard sieves (200-355 μm), passing through 100-mesh and 200-mesh standard sieves (75-100 μm) and passing through 200-mesh and 250-mesh standard sieves (75-63 μm); at the same time, the spectral peak types targeted by the standard sample and the sample leached slag coke mixture C to be tested with known calorific value are adjusted, that is, in step (2) and step (4), the Kα series spectral lines in the obtained spectral results are calculated to obtain the total value of the net peak area of ​​the Kα series spectral line peaks, the total value of the net peak area of ​​the Kα series spectral line peaks of the standard sample is used for polynomial fitting, and the total value of the net peak area of ​​the Kα series spectral line peaks of the sample leached slag coke mixture C to be tested is substituted into the calculation. The results of Examples 11-13 are recorded in Table 4.

[0080]

[0081] It can be seen from Table 3 and Table 4 that:

[0082] The correlation coefficient between the net peak area of ​​the Kα series Compton scattering peak and the calorific value does not change significantly with the particle size, and the correlation coefficient is greater than 0.97 when the particle size is 63~355μm. However, the correlation between the total value of the net peak area of ​​the Kα series spectral line peak and the calorific value is greatly affected by the particle size. When the particle size is 200~355μm, the correlation coefficient is less than 0.80, and the correlation is poor. Therefore, the Kα series Compton scattering peak is preferred.

[0083] [Influence of pipe pressure]

[0084] Examples 14 to 17 respectively provide a method for measuring calorific value using XRF fluorescence spectroscopy, in which the measuring tube pressure of the standard sample and the sample to be tested, the leached slag coke mixture C with a known calorific value, is adjusted from 45 kV to 25 kV, 30 kV, 40 kV and 49 kV respectively. Except for the above, the other conditions are exactly the same as those in Example 1. As a result, the fitting calculation formula obtained in step (3) and the calorific value result of the leached slag coke mixture C measured in step (4) change, and the results are recorded in Table 5.

[0085]

[0086] It can be seen from Table 5 that:

[0087] Under different tube pressure conditions, the correlation coefficient between the net peak area of ​​the sample X-ray fluorescence Kα Compton scattering and the calorific value will be affected to a certain extent, but all are above 0.96. Among them, when the tube pressure is 45kV, the error between the low calorific value predicted by the X-ray fluorescence method and the low calorific value measured by the oxygen bomb instrument is the smallest.

[0088] [Influence of pipe flow]

[0089] Examples 18 to 21 provide a method for measuring calorific value using XRF fluorescence spectroscopy, in which the measuring pipe flow of the standard sample and the sample to be tested, leached slag coke mixture C with known calorific value, is adjusted from 300 μA to 100 μA, 200 μA, 500 μA and 800 μA respectively. Except for the above, the other conditions are exactly the same as those in Example 1. As a result, the fitting calculation formula obtained in step (3) and the calorific value result of the leached slag coke mixture C measured in step (4) change, and the results are recorded in Table 6.

[0090]

[0091] It can be seen from Table 6 that:

[0092] Under different pipe flow conditions, the correlation coefficient between the net peak area of ​​the sample X-ray fluorescence Kα Compton scattering and the calorific value will be affected to a certain extent, but all are above 0.96. Among them, when the pipe flow is 300uA, the error between the low calorific value predicted by the X-ray fluorescence method and the low calorific value measured by the oxygen bomb instrument is the smallest.

[0093] [Influence of sample water content]

[0094] Examples 22 to 25 respectively provide a method for measuring calorific value using XRF fluorescence spectroscopy, in which the standard sample and the sample to be tested, the leached slag coke mixture C with a known calorific value, are dried to constant weight, and then 20 g, 19 g, 18 g, 16 g and 14 g are accurately weighed, and 0 g, 1 g, 2 g, 4 g and 6 g of ultrapure water are added respectively to obtain samples with a water content of 0 wt.%, 5 wt.%, 10 wt.%, 20 wt.% and 30 wt.%. Except for the above, the other conditions are exactly the same as those in Example 1. As a result, the fitting calculation formula obtained in step (3) and the calorific value result of the leached slag coke mixture C measured in step (4) change, and the results are recorded in Table 7.

[0095]

[0096] It can be seen from Table 7 that:

[0097] Under different moisture content conditions, the correlation coefficient between the net peak area of ​​the X-ray fluorescence Kα Compton scattering and the calorific value of the sample will be affected to a certain extent, but it is always above 0.94.

[0098] [Influence of sample type]

[0099] Implementation Case 26 provides a method for measuring calorific value using XRF fluorescence spectroscopy, in which the leached slag coke mixture standard sample and the sample to be tested are adjusted to electroplating sludge. Except for the above, other conditions are exactly the same as those in Example 1. As a result, the fitting calculation formula obtained in step (3) and the calorific value result of the electroplating sludge measured in step (4) change.

[0100] After calculation, the low calorific value of the electroplating sludge measured in Example 26 is 904 cal / g.

[0101] In summary, the method of the present invention utilizes the non-characteristic scattering spectrum peak information determined by XRF fluorescence spectroscopy to establish a means of rapid detection of the calorific value of solid materials. This method has high precision, good reproducibility, high accuracy, and good repeatability. It can realize direct detection of samples, avoid the influence of the test environment on product peaks, and reduce analysis time. The method is simple, easy, convenient and reliable.

[0102] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0103] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0104] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for measuring calorific value using XRF fluorescence spectroscopy, characterized in that: The following steps are involved: Obtain the calorific value of the standard sample as the dependent variable; Performing an XRF fluorescence spectrum test on the standard sample to obtain the net peak intensity or net peak area of ​​the Compton scattering peak, or the net peak intensity or net peak area of ​​the Rayleigh scattering peak as an independent variable; Performing polynomial fitting on the independent variable and the dependent variable to obtain a fitting calculation formula; Perform an XRF fluorescence spectrum test on the sample to be tested, obtain the spectrum peak information value of the corresponding scattering peak, substitute it into the fitting calculation formula for calculation, and obtain the calorific value result.

2. The method for measuring calorific value using XRF fluorescence spectroscopy according to claim 1, characterized in that: The standard sample and the sample to be tested are dried in advance.

3. The method for measuring calorific value using XRF fluorescence spectroscopy according to claim 1, characterized in that: Methods for obtaining the calorific value of a standard sample include conducting an oxygen bomb calorimetry test.

4. The method for measuring calorific value using XRF fluorescence spectroscopy according to claim 2, characterized in that: After the standard sample and the sample to be tested are dried in advance, before the XRF fluorescence spectrum test is performed, the standard sample and the sample to be tested are ground and then pressed into sheets.

5. The method for measuring calorific value using XRF fluorescence spectroscopy according to claim 1, characterized in that: The parameters of the XRF fluorescence spectrum test include: The tube voltage is 0~49kV; The tube current is 0~900μA.

6. The method for measuring calorific value using XRF fluorescence spectroscopy according to claim 1, characterized in that: The method comprises: (1) Provide standard samples and samples to be tested of solid materials, and pre-dry the standard samples and samples to be tested; (2) Conduct oxygen bomb calorimetry test on some of the dried standard samples to obtain the calorific value of the standard samples as the dependent variable; At the same time, another part of the dried standard sample is ground and pressed into a sheet, and an XRF fluorescence spectrum test is performed. The parameters of the XRF fluorescence spectrum test are set to include a tube voltage of 0 to 49 kV and a tube current of 0 to 900 μA to obtain a spectrum result; the scattering peak includes a Compton scattering peak or a Rayleigh scattering peak; the net peak intensity or net peak area of ​​the obtained Compton scattering peak, or the net peak intensity or net peak area of ​​the Rayleigh scattering peak is used as an independent variable; (3) performing polynomial fitting on the independent variable and the dependent variable to obtain a fitting calculation formula; (4) Grind the sample to be tested which has been dried to a constant weight and press it into a sheet, test and calculate it according to the XRF fluorescence spectrum test method of step (2), obtain the net peak intensity or net peak area of ​​the corresponding scattering peak of the sample to be tested, substitute it into the fitting calculation formula for calculation, and obtain the calorific value result.

7. The method for measuring calorific value using XRF fluorescence spectroscopy according to claim 1, characterized in that: The standard sample and the sample to be tested are selected from solid, molten or liquid phase systems.

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