Standard sample for detecting total iron content in siliceous glass raw material by X-ray fluorescence spectrometry and preparation method thereof

Abstract

The invention discloses a standard sample for detecting the total iron content in a siliceous glass raw material through X-ray fluorescence spectrometry and a preparation method of the standard sample, and relates to the technical field of chemical analysis, the preparation method comprises the following steps: (1) preparing high-purity quartz sand, and detecting the total iron content of the high-purity quartz sand; (2) mixing high-purity quartz sand and high-purity ferric oxide in proportion to prepare an intermediate standard sample; and (3) taking high-purity quartz sand and the intermediate standard sample in different proportions, and preparing a series of standard samples of which the total iron content is in gradient distribution. The standard sample prepared by the method has good uniformity and stability, and can be used as a standard sample of a low-iron-content siliceous glass raw material.

Description

Technical Field

[0001] The invention relates to the technical field of chemical analysis, and in particular to a standard sample for detecting the total iron content in silica glass raw material by X-ray fluorescence spectrometry and a preparation method thereof. Background Art

[0002] The total iron content in silica glass raw materials will directly affect the appearance color and transmittance of glass products, and is a key component monitored by silica glass raw material manufacturers and glass manufacturers. However, there is currently a lack of suitable silica low-iron content series standard samples for establishing working curves in China.

[0003] The X-ray fluorescence spectroscopy-powder tablet method has the characteristics of low cost, high speed, and easy operation, and is suitable for sample quality control. When the sample is irradiated with X-rays, the electrons in the inner shell (K, M or L shell) of each atom in the sample are excited and ejected from the orbit to generate holes, thereby causing the outer shell electrons to transition inward, and at the same time, the characteristic X-rays of the element are emitted. Each element has its own characteristic X-rays of a specific wavelength (or energy). The intensity of the element's characteristic X-rays is proportional to the number of atoms (i.e., content) of the element in the sample. Based on this, the present invention will provide a standard sample and a preparation method thereof for detecting the total iron content in silica glass raw materials by X-ray fluorescence spectroscopy. Summary of the invention

[0004] In order to solve the problem of shortage of low-iron content standard materials in the existing glass production industry, the present invention provides a method for preparing a standard sample for detecting the total iron content in silica glass raw materials by X-ray fluorescence spectroscopy, and the obtained standard sample has good uniformity and stability.

[0005] The technical problem to be solved by the present invention is achieved by adopting the following technical solutions:

[0006] One of the purposes of the present invention is to provide a method for preparing a standard sample for detecting the total iron content in silica glass raw material by X-ray fluorescence spectrometry, comprising the following steps:

[0007] (1) Preparing high-purity quartz sand and detecting its total iron content;

[0008] (2) Mixing high-purity quartz sand and high-purity ferric oxide in proportion to prepare an intermediate standard sample;

[0009] (3) Take different proportions of high-purity quartz sand and intermediate standard samples to prepare a series of standard samples with a gradient distribution of total iron content.

[0010] The second object of the present invention is to provide a standard sample prepared by the method for preparing a standard sample for detecting the total iron content in silica glass raw material by X-ray fluorescence spectrometry.

[0011] The third object of the present invention is to provide a method for detecting the total iron content in silica glass raw materials by using X-ray fluorescence spectroscopy, and to establish a standard working curve by using the standard sample.

[0012] The beneficial effects of the present invention are:

[0013] 1. The present invention uses high-purity quartz sand and high-purity ferric oxide as raw materials to prepare a standard sample with good uniformity and stability. The total iron content in the silica glass raw material can be detected by X-ray fluorescence spectrometry based on the standard sample. It is particularly suitable for silica glass raw materials with low iron content, and the minimum detection limit can reach 15ppm.

[0014] 2. The national certified standard materials of siliceous sandstone sold in China are GBW 03112a (total iron content is 0.076%), GBW 03113a (total iron content is 0.088%), GBW 03114 (total iron content is 0.48%), and the national certified standard materials of quartzite are GBW07835 (total iron content is 0.62%), GBW 07836 (total iron content is 0.61%), and GBW 07837 (total iron content is 0.16%). The total iron content of these certified standard materials is relatively high. The standard samples prepared by the present invention make up for the shortage of low-iron standard samples in the detection process of siliceous glass raw materials in the domestic glass industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The standard working curve was established using the standard samples prepared in Example 1. DETAILED DESCRIPTION

[0016] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below in conjunction with specific embodiments and diagrams.

[0017] The present invention provides a method for preparing a standard sample for detecting the total iron content in silica glass raw material by X-ray fluorescence spectrometry, comprising the following steps:

[0018] (1) Preparing high-purity quartz sand and detecting its total iron content;

[0019] (2) Mixing high-purity quartz sand and high-purity ferric oxide in proportion to prepare an intermediate standard sample;

[0020] (3) Take different proportions of high-purity quartz sand and intermediate standard samples to prepare a series of standard samples with a gradient distribution of total iron content.

[0021] Furthermore, the total iron content of the high-purity quartz sand is less than 0.0010%, and the particle size does not exceed 200 meshes.

[0022] Furthermore, the purity of the high-purity ferric oxide is not less than 99.99%, and the particle size is not more than 200 meshes.

[0023] Furthermore, the high-purity quartz sand is dried before use at 95-105° C. The purpose of drying is to remove excess water in the quartz sand to prevent it from agglomerating or causing errors in the sample ratio during the preparation of the standard sample.

[0024] Furthermore, the high-purity ferric oxide is calcined before use, and the calcination temperature is 400-450° C. The purpose of calcination is to remove the moisture that may be absorbed by the high-purity ferric oxide, and further improve the purity of the ferric oxide.

[0025] Furthermore, the mixing method is ball milling, and the ball milling is sealed in an agate ball mill to avoid pollution and grinding loss.

[0026] In the present invention, in order to reduce the weighing error when preparing a low-content standard sample in a series of standard samples, an intermediate standard sample is first prepared.

[0027] The invention provides a standard sample prepared by the method for preparing a standard sample for detecting the total iron content in a silica glass raw material by X-ray fluorescence spectrometry.

[0028] The present invention also provides a method for detecting the total iron content in silica glass raw materials by using X-ray fluorescence spectroscopy, and a standard working curve is established by using the standard sample.

[0029] Furthermore, the correlation coefficient of the standard working curve can reach 0.9993.

[0030] Furthermore, the minimum detection limit of the standard working curve can reach 15 ppm.

[0031] The technical solution of the present invention will be described in detail below through specific embodiments:

[0032] Ingredients Description:

[0033] High-purity quartz sand with a particle size of 200 mesh was fully passed and was dried at 105°C for 1 hour before use.

[0034] The purity of high-purity ferric oxide is 99.99%, and the particle size of 200 meshes fully passes through. It is calcined at 450℃ for 30 minutes before use.

[0035] Preparation Example 1

[0036] (1) High-purity quartz sand was prepared and its total iron content was detected to be 0.00014%.

[0037] (2) 9.9 g of high-purity quartz sand and 0.1 g of high-purity ferric oxide were sealed and ball-milled in an agate ball mill for 60 min to prepare an intermediate standard sample.

[0038] (3) According to Table 1, high-purity quartz sand and intermediate standard samples in different proportions were taken and sealed in an agate ball mill for 60 min to prepare a series of standard samples with a gradient distribution of total iron content.

[0039] Table 1

[0040] High purity quartz sand mass / g Intermediate standard sample mass / g Total iron content in standard sample / % 10.00000 0.00000 0.00014 9.97515 0.02531 0.0027 9.95015 0.05004 0.0052 9.92527 0.07523 0.0077 9.90017 0.09993 0.0101 9.87482 0.12506 0.0127 9.84979 0.15019 0.0152 9.82526 0.17549 0.0177 9.80002 0.20022 0.0202 9.70038 0.30007 0.0302 9.60025 0.39984 0.0402 9.50016 0.49997 0.0502 9.40020 0.60031 0.0602 9.30000 0.70003 0.0702 9.19996 0.79981 0.0802 9.10037 0.90011 0.0903 8.99982 1.00025 0.1003

[0041] The above series of standard samples were mixed with boric acid in a mass ratio of 10:1 and pressed into powder. A standard working curve was established on an X-ray fluorescence spectrometer. The linear relationship is shown in Figure 1 .

[0042] from Figure 1 It can be seen that within the working curve range of 0.00014-0.1003%, the linear fitting formula is: y=0.0126x-0.0068 (where the ordinate y is the total iron content and the abscissa x is the net signal intensity detected by the detector), and its linear correlation coefficient R 2 =0.9993, which meets the quantitative analysis requirements of X-ray fluorescence spectrometry.

[0043] Application Example 1

[0044] Based on the standard working curve obtained in Preparation Example 1, the total iron content of the national certified standard material GBW03112a and the unknown silica glass raw material sample was analyzed by X-ray fluorescence spectrometry-powder tablet method, and compared with the commonly used atomic absorption spectrometry. The results are shown in Table 2.

[0045] Table 2

[0046] Serial number XRF Analysis Atomic absorption spectroscopy Difference GBW 03112a 0.0710 0.076(standard value) 0.0050 GBW 03112a 0.0714 0.076(standard value) 0.0046 GBW 03112a 0.0709 0.076(standard value) 0.0051 GBW 03112a 0.0753 0.076(standard value) 0.0007 Unknown sample 1 0.0068 0.0060 0.0008 Unknown Sample 2 0.0108 0.0106 0.0002 Unknown Sample 3 0.0158 0.0156 0.0002 Unknown Sample 4 0.0227 0.0229 -0.0002 Unknown Sample 5 0.0288 0.0285 0.0003 Unknown Sample 6 0.0325 0.0330 -0.0005 Unknown Sample 7 0.0392 0.0389 0.0003 Unknown Sample 8 0.0423 0.0434 -0.0011 Unknown Sample 9 0.0520 0.0514 0.0006 Unknown sample 10 0.0552 0.0535 0.0017 Unknown Sample 11 0.0602 0.0655 -0.0053 Unknown Sample 12 0.0704 0.0734 -0.0030 Unknown Sample 13 0.0802 0.0856 -0.0054 Unknown Sample 14 0.0918 0.0933 -0.0015 Unknown Sample 15 0.1118 0.1103 0.0015

[0047] As can be seen from Table 2, the standard samples prepared by the method of the present invention combined with the X-ray fluorescence spectroscopy-powder pressing method can improve the accuracy of the detection of the total iron content in the silica glass raw material, and the consistency of the test results is good. When the total iron content is less than 0.050%, the reproducibility limit is 0.0040%; when the total iron content is 0.050-0.10%, the reproducibility limit is 0.0080. The above 19 groups of data all meet the required reproducibility limit requirements. In the comparison experiment of unknown samples 1-7, the absolute errors were all less than 0.0008%, which shows that the standard samples prepared by the method of the present invention have good accuracy.

[0048] A sample of quartz sand with a silicon dioxide content of 99.99% was selected (the total iron content was confirmed to be less than 0.0001% by inductively coupled plasma emission spectrometry, so the total iron content can be ignored), 10 parallel samples were prepared, and the total iron content was measured under the optimal experimental conditions of the X-ray fluorescence spectrometer. The standard deviation of the 10 sets of data was calculated to be 0.00017%, and the detection limit was calculated to be 0.00051% at 3 times the standard deviation, and the quantitative limit was calculated to be 0.0015% at 3 times the detection limit. The detection range of the total iron content is 0.0015-0.1000%. In different application scenarios, the mixing ratio of the intermediate standard sample and the high-purity quartz sand can be further adjusted to increase the upper limit of the content of the working curve, thereby increasing the upper limit of the detection range of the total iron content.

[0049] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for preparing a standard sample for detecting the total iron content in silica glass raw material by X-ray fluorescence spectrometry, characterized in that: The following steps are involved: (1) Preparing high-purity quartz sand and detecting its total iron content; (2) Mixing high-purity quartz sand and high-purity ferric oxide in proportion to prepare an intermediate standard sample; (3) Take different proportions of high-purity quartz sand and intermediate standard samples to prepare a series of standard samples with a gradient distribution of total iron content.

2. The method for preparing a standard sample for detecting the total iron content in silica glass raw material by X-ray fluorescence spectrometry according to claim 1, characterized in that: The total iron content of the high-purity quartz sand is less than 0.0010% and the particle size does not exceed 200 meshes.

3. The method for preparing a standard sample for detecting the total iron content in silica glass raw material by X-ray fluorescence spectrometry according to claim 1, characterized in that: The purity of the high-purity ferric oxide is not less than 99.99%, and the particle size is not more than 200 meshes.

4. The method for preparing a standard sample for detecting the total iron content in silica glass raw material by X-ray fluorescence spectrometry according to claim 1, characterized in that: The high-purity quartz sand is dried before use at a drying temperature of 95-105°C.

5. The method for preparing a standard sample for detecting the total iron content in silica glass raw material by X-ray fluorescence spectrometry according to claim 1, characterized in that: The high-purity ferric oxide is calcined before use, and the calcination temperature is 400-450°C.

6. The method for preparing a standard sample for detecting the total iron content in silica glass raw material by X-ray fluorescence spectrometry according to claim 1, characterized in that: The mixing method is ball milling.

7. A standard sample prepared by the method for preparing a standard sample for detecting the total iron content in silica glass raw material by X-ray fluorescence spectrometry according to any one of claims 1 to 6.

8. A method for detecting the total iron content in silica glass raw material by X-ray fluorescence spectroscopy, characterized in that: The standard working curve is established using the standard sample described in claim 7.

9. The method for detecting the total iron content in silica glass raw material by using X-ray fluorescence spectrometry according to claim 8, characterized in that: The correlation coefficient of the standard working curve can reach 0.9993.

10. The method for detecting the total iron content in silica glass raw material by using X-ray fluorescence spectrometry according to claim 8, characterized in that: The minimum detection limit of the standard working curve can reach 15 ppm.

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