A chemical analysis method for detecting oxides in carbon-containing silicon carbide refractory material by non-chemical reagent oxidation method

Abstract

The application discloses a chemical analysis method for detecting oxides in carbon-containing silicon carbide refractory materials by a non-chemical reagent oxidation method. First, raw materials are crushed, dried and cooled to obtain a treated sample; the silicon carbide content in the treated sample is detected; the treated sample is subjected to a calcination oxidation reaction, and is cooled after the reaction; the weight loss after calcination is calculated; the sample with a tested silicon carbide content of zero is weighed, mixed flux is added, and the sample is fused into a glass sheet; the glass sheet is analyzed and detected to obtain the actual content of the target oxide; finally, data correction is performed to obtain the content of each oxide in the raw materials. The method effectively solves the problems of the use of hazardous chemicals in traditional wet analysis and the environmental and safety problems caused by waste gas and waste liquid treatment, and solves the problem that the refractory materials containing silicon carbide cannot be detected in GB / T21114-2019 "Refractory Materials X-ray Fluorescence Spectrometric Chemical Analysis Fused Glass Sheet Method", so that the detection method is more green and environmentally friendly.

Description

Technical Field

[0001] This invention belongs to the field of refractory material testing and analysis technology, specifically relating to a chemical analysis method for detecting oxides in silicon carbide-containing refractory materials using a non-chemical reagent oxidation method. Background Technology

[0002] Refractory materials, commonly used kiln linings in industrial kilns, are indispensable structural and functional materials. Their chemical composition significantly impacts their refractoriness, softening temperature under load, thermal shock resistance, and slag erosion resistance by influencing their mineral composition, phase structure, and microstructure. The design, configuration, construction, and application of refractory materials, along with related processes and equipment conditions, collectively affect the lifespan, production capacity, and energy consumption of industrial kilns. Therefore, chemical composition testing of refractory materials is a crucial link in quality control and assurance, performance prediction and evaluation, R&D and innovation support, cost control, and fault analysis and resolution, and is vital to the development of the refractory materials industry.

[0003] Currently, the wet analytical methods used, such as GB / T6900-2025 "Chemical Analysis Methods for Aluminosilicate Refractory Materials", generally involve easily manufactured hazardous chemicals such as hydrochloric acid and concentrated sulfuric acid, easily explosive hazardous chemicals such as nitric acid, hydrogen peroxide, and potassium nitrate, toxic and harmful hazardous chemicals such as hydrofluoric acid and fluorides, and flammable hazardous chemicals such as anhydrous ethanol. The use of these chemical reagents has a significant impact on the health and safety of operators, and the generated waste gases and liquids also cause certain environmental damage. Furthermore, each detection method can only analyze one chemical element, resulting in long detection cycles and low detection efficiency. Therefore, researchers developed GB / T21114-2019 "X-ray Fluorescence Spectrochemical Analysis of Refractory Materials - Fused Glass Plate Method". This detection method uses a mixed flux of Li₂B₄O₇ and LiBO₂ to assist in the detection of relevant oxides in refractory materials. While this overcomes the shortcomings of wet analysis methods, such as long detection cycles and the use of numerous hazardous chemicals, it currently cannot detect "refractory materials containing silicon carbide" using GB / T21114-2019, "X-ray Fluorescence Spectrochemical Analysis of Refractory Materials - Fused Glass Plate Method". Since the silicon carbide content in refractory materials significantly affects product performance and its use, there is an urgent need to develop a new detection method that overcomes both the problems of wet analysis methods and the inability of GB / T21114-2019 to detect "refractory materials containing silicon carbide". Summary of the Invention

[0004] The technical problem to be solved by this invention is that, in view of the problems of long detection cycle, large use of hazardous chemicals, and inability of GB / T21114-2019 "X-ray fluorescence spectrochemical analysis of refractory materials - fused glass slide method" to detect "silicon carbide-containing refractory materials", this invention provides a chemical analysis method for detecting oxides in silicon carbide-containing refractory materials by non-chemical reagent oxidation method.

[0005] To solve the above problems, the present invention adopts the following technical solution:

[0006] This invention provides a chemical analysis method for detecting oxides in silicon carbide-containing refractory materials using a non-chemical reagent oxidation method, the method comprising the following steps:

[0007] 1) The raw materials containing silicon carbide refractory materials are crushed, dried and cooled in sequence to obtain the processed sample;

[0008] 2) The content of silicon carbide ω(SiC) in the treated sample was detected using a high-frequency infrared carbon-sulfur analyzer.

[0009] 3) Weigh the sample treated in step 1) (place it in a container and spread it out in the container) and perform an ignition oxidation reaction. Cool the sample after the reaction. Weigh the cooled sample and calculate the loss on ignition ω(LOI). 1500℃ (The reduction in ablation can be either positive or negative).

[0010] 4) Grind the sample cooled in step 3), and test the silicon carbide content in the sample after the calcination oxidation reaction using a high-frequency infrared carbon-sulfur analyzer (if the silicon carbide content in the sample is zero after the oxidation reaction, then the silicon carbide in the sample is completely oxidized).

[0011] 5) Weigh the sample after the calcination and oxidation reaction in step 4) where the silicon carbide content is zero, add mixed flux and melt it into a uniform and transparent glass sheet.

[0012] 6) The obtained glass slide was analyzed using an X-ray fluorescence spectrometer to determine the measured content ω(R) of each oxide. X O Y ) 实测 This includes the measured SiO2 content ω(SiO2). 实测 ;

[0013] 7) Data correction:

[0014] Calculation of the content of each oxide except SiO2:

[0015] ω(A X O Y ) 原样品 =ω(R X OY ) 实测 ×(1-ω(LOI)1500℃ / 100);

[0016] Calculation of SiO2 content:

[0017] ω(SiO2) 原样品 = ω(SiO2) 实测 (1-ω(LOI)) 1500℃ / 100)- ω(SiC)×a;

[0018] ω(R X O Y ) 实测 Step 6) Detect the measured content of each oxide; ω(SiO2) 实测 ω(SiC): The measured content of SiO2 obtained in step 6) (including silicon dioxide generated by the oxidation of silicon carbide); ω(SiC): The content of silicon carbide in the sample after treatment in step 2).

[0019] According to the above-mentioned chemical analysis method for detecting oxides in silicon carbide-containing refractory materials using non-chemical reagent oxidation, in step 1), the raw materials are ground and pulverized using a tungsten carbide mortar and pestle.

[0020] According to the above-mentioned chemical analysis method for detecting oxides in silicon carbide-containing refractory materials using non-chemical reagent oxidation, the particle size of the pulverized sample is below 200 mesh.

[0021] According to the above-mentioned chemical analysis method for detecting oxides in silicon carbide refractory materials by non-chemical reagent oxidation, the drying temperature in step 1) is controlled at 110±5℃ and the drying time is 2h; the cooling to room temperature is then performed.

[0022] According to the above-mentioned chemical analysis method for detecting oxides in silicon carbide-containing refractory materials by non-chemical reagent oxidation, the sample treated in step 3) is placed in a corundum boat container for calcination oxidation reaction; the equipment used for the calcination oxidation reaction is a high-temperature experimental furnace.

[0023] According to the above-mentioned chemical analysis method for detecting oxides in silicon carbide-containing refractory materials by non-chemical reagent oxidation, in step 3), the reaction temperature is controlled at 1500±25℃ and the reaction time is 4h.

[0024] According to the above-mentioned chemical analysis method for detecting oxides in silicon carbide-containing refractory materials by non-chemical reagent oxidation, the mixed flux mentioned in step 5) is a mixture of lithium tetraborate (Li2B4O7) and lithium metaborate (LiBO2) in a mass ratio of 67:33.

[0025] According to the above-mentioned chemical analysis method for detecting oxides in silicon carbide-containing refractory materials by non-chemical reagent oxidation, the mass ratio of the fully oxidized sample to the mixed flux in step 5) is 1:10.

[0026] According to the above-mentioned chemical analysis method for detecting oxides in silicon carbide-containing refractory materials using non-chemical reagent oxidation, the equipment used for casting in step 5) is a sample melting machine.

[0027] According to the above-mentioned chemical analysis method for detecting oxides in silicon carbide-containing refractory materials by non-chemical reagent oxidation, 'a' in step 7) is the conversion coefficient of silicon carbide to silicon dioxide, which is 1.4983.

[0028] The calculation process for the 1.4983 conversion factor is as follows:

[0029] The relative atomic mass of silicon (Si) is approximately 28.09.

[0030] Carbon (C) ≈ 12.01 → Molar mass of SiC ≈ 40.10 g / mol;

[0031] Oxygen (O) ≈ 16.00 → Molar mass of SiO2 ≈ 60.08 g / mol;

[0032] Therefore, the conversion factor is: SiC→SiO2: 60.08 / 40.10≈1.4983 (that is, 1g of SiC generates about 1.4983g of SiO2).

[0033] The positive and beneficial effects of this invention are:

[0034] 1. The analytical method of this invention, replacing traditional methods, can detect the content of various oxide components (including silicon carbide) in silicon carbide-containing refractory materials. The detection process uses only a flux prepared from lithium tetraborate (Li₂B₄O₇) and lithium metaborate (LiBO₂). Furthermore, the technical solution of this invention involves pre-treating the silicon carbide-containing refractory material and then subjecting it to an oxidation reaction to convert the silicon carbide into silicon dioxide. Combined with subsequent data correction, this enables the detection of the content of various oxides in silicon carbide-containing refractory materials. Therefore, this method can reduce the use of hazardous chemicals and easily explosive chemicals (such as potassium carbonate, barium carbonate, potassium nitrate, and barium peroxide) in traditional wet analysis, reducing the risk of hazardous chemical control, thereby achieving the goals of green environmental protection, energy conservation, and emission reduction. It also solves the problem that the existing GB / T21114-2019 standard, "X-ray Fluorescence Spectrochemical Analysis of Refractory Materials - Fused Glass Plate Method," cannot detect silicon carbide-containing refractory materials.

[0035] 2. The method of this invention for detecting the oxide content in silicon carbide-containing refractory materials covers common oxides: silicon dioxide, aluminum oxide, ferric oxide, titanium oxide, calcium oxide, magnesium oxide, potassium oxide, sodium oxide, zirconium oxide, and chromium oxide, demonstrating a broad detection range. Traditional methods for detecting silicon carbide-containing refractory materials often utilize oxidizing reagents such as potassium nitrate and sodium carbonate to oxidize the silicon carbide in the sample, thus rendering potassium oxide and sodium oxide undetectable. Furthermore, the detection of zirconium oxide and chromium oxide requires reference to different standard methods, leaving no effective standard method for silicon dioxide detection. Therefore, the method of this invention, employing a non-chemical reagent method to oxidize silicon carbide, solves these problems, enabling rapid and effective detection of potassium oxide, sodium oxide, zirconium oxide, chromium oxide, and silicon dioxide.

[0036] Taking a refractory material sample with a silicon carbide content of 6.50% as an example, the method of the present invention was used for testing, and the test data are detailed in Table 1.

[0037] Table 1. Content of various oxides in refractory samples containing 6.50% silicon carbide, determined using the method of this invention.

[0038]

[0039] 3. The method of this invention significantly improves the detection efficiency for silicon carbide-containing refractory materials. Traditional wet methods, such as GB / T6900-2025 "Chemical Analysis Methods for Aluminosilicate Refractory Materials," analyze only one chemical element at a time. Different concentrations of the same chemical element require different methods and reagents, and the analytical steps are complex. For example, in determining SiO2 content, ω(SiO2) ≤ 5% uses the molybdenum blue spectrophotometry method, while 5% ≤ ω(SiO2) ≤ 95% uses the condensed gravimetric molybdenum blue spectrophotometry method. The condensed gravimetric molybdenum blue spectrophotometry method alone requires 12 reagents, with a detection cycle of up to 3 days, and the total detection cycle for all samples exceeding 10 days. Using the method of this invention, the detection cycle can be shortened to 3-4 days.

[0040] In summary, the method of this invention can detect various oxides such as K2O, Na2O, ZrO2, and Cr2O3 in silicon carbide-containing refractory materials, and improves detection accuracy and efficiency. It effectively solves the environmental and safety problems associated with the use of hazardous chemicals and the treatment of their waste gas and waste liquid. It also addresses the limitation of GB / T21114-2019 "Refractory Materials X-ray Fluorescence Spectrochemical Analysis - Fused Glass Plate Method" in detecting "refractory materials containing silicon carbide," making the detection method more environmentally friendly. Therefore, this invention has significant economic and social benefits. Attached Figure Description

[0041] Figure 1In Example 1 of this invention, the measured content ω(R) of each oxide obtained by detecting glass slide 1-1# in an X-ray fluorescence spectrometer was... X O Y ) 实测 picture;

[0042] Figure 2 In Example 1 of this invention, the measured content ω(R) of each oxide obtained by detecting glass slides 1-2# in an X-ray fluorescence spectrometer was... X O Y ) 实测 picture;

[0043] Figure 3 In Example 2 of this invention, the measured content ω(R) of each oxide obtained by detecting the glass slide using an X-ray fluorescence spectrometer X O Y ) 实测 picture. Detailed Implementation

[0044] The present invention will be further illustrated below with reference to the embodiments, but this does not limit the scope of protection of the technical solution of the present invention.

[0045] Example 1:

[0046] The present invention provides a chemical analysis method for detecting oxides in silicon carbide-containing refractory materials using a non-chemical reagent oxidation method. The detailed steps are as follows:

[0047] 1) The silicon carbide refractory material sample 1 was ground to below 200 mesh using a tungsten carbide mortar and dried at 110±5℃ for 2h, and then cooled to room temperature to obtain the treated sample 1;

[0048] 2) The silicon carbide content ω(SiC) in sample 1 after treatment was detected by a high-frequency infrared carbon-sulfur analyzer and was 6.33%;

[0049] 3) Weigh two 3g portions of sample 1 after step 1) into a corundum boat, namely 1-1 and 1-2, which are parallel experimental samples (spread the two parallel experimental samples 1-1 and 1-2 evenly in the boat). Then place them in a high-temperature experimental furnace for ignition oxidation reaction, controlling the reaction temperature at 1500±25℃ and the time at 4h. Cool after the reaction. After cooling, take them out and weigh them, and calculate the loss on ignition ω(LOI) at 1500℃: 1-1: -3.06%, 1-2: -3.10%.

[0050] 4) After grinding step 3), the silicon carbide content in samples 1-1 and 1-2 after oxidation treatment was detected by a high-frequency infrared carbon-sulfur analyzer. The results showed that the oxidation was complete.

[0051] 5) Weigh 0.6000±0.0002g of the fully oxidized and ground sample 1-1, then add 6.0000±0.0004g of a mixed flux prepared by mixing Li2B4O7 and LiBO2 in a mass ratio of 67:33 (analytical grade), place it in a platinum crucible and mix well, then melt and cast it into a transparent glass sheet (1-1#) in a melting machine.

[0052] Weigh 0.6000±0.0002g of the fully oxidized and ground sample 1-2, then add 6.0000±0.0004g of a mixed flux prepared by mixing Li2B4O7 and LiBO2 in a mass ratio of 67:33 (analytical grade), place it in a platinum crucible and mix well, then melt and cast it into a transparent glass sheet (1-2#) in a melting machine.

[0053] 6) The obtained glass slides (1-1#, 1-2#) were tested using an X-ray fluorescence spectrometer to determine the measured content ω(R) of each oxide: silicon dioxide, aluminum oxide, ferric oxide, titanium oxide, calcium oxide, magnesium oxide, potassium oxide, sodium oxide, zirconium oxide, and chromium oxide. X O Y ) 实测 This includes the measured SiO2 content ω(SiO2). 实测 For details of the obtained atlas, please refer to [link / reference]. Figure 1 and Figure 2 The measured content data of each oxide obtained from the test are detailed in Table 2;

[0054]

[0055] 7) Data correction:

[0056] Calculation of the content of each oxide except SiO2:

[0057] ω(A X O Y ) 原样品 =ω(R X O Y ) 实测 ×(1-ω(LOI)1500℃ / 100);

[0058] Calculation of SiO2 content:

[0059] ω(SiO2) 原样品 = ω(SiO2) 实测 ×(1-ω(LOI) 1500℃ / 100)- ω(SiC)×1.4983;

[0060] ω(R X O Y ) 实测Step 6) Detect the measured content of each oxide; ω(SiO2) 实测 ω(SiC): The measured content of SiO2 obtained in step 6) (including silicon dioxide generated by the oxidation of silicon carbide); ω(SiC): The content of silicon carbide in the sample after treatment in step 2); 1.4983 is the conversion coefficient of silicon carbide to silicon dioxide.

[0061] The corrected results are the contents of each chemical component in the original sample 1. The contents of each oxide in the original sample after correction are detailed in Table 3.

[0062]

[0063] 8) For the original sample 1, the errors of the parallel experimental samples 1-1 and 1-2 are detailed in Table 4.

[0064]

[0065] The allowable error is specified in GB / T6900-2025 "Chemical Analysis Methods for Aluminosilicate Refractory Materials".

[0066] Example 2:

[0067] The present invention provides a chemical analysis method for detecting oxides in silicon carbide-containing refractory materials using a non-chemical reagent oxidation method. The detailed steps are as follows:

[0068] 1) Weigh 1.0000g of YSBC28683-2021 silicon carbide 354# standard sample and 9.0000g of YSS068-2013 vanadate standard sample using a 0.0000g electronic balance, mix thoroughly to obtain a 1:10 mixed standard sample. The theoretical content of each element is detailed in Table 5.

[0069]

[0070] 2) Dry the 1:10 mixed standard sample at 110±5℃ for 2 hours, then cool to room temperature;

[0071] 3) Weigh 3g of the 1:10 mixed standard sample treated in step 2) into a corundum boat (spread the 1:10 mixed standard sample evenly in the boat), and then place it in a high-temperature experimental furnace for ignition oxidation reaction, controlling the reaction temperature at 1500±25℃ and the time at 4h; cool after the reaction; after cooling, take it out and weigh it, and calculate the loss on ignition ω(LOI)1500℃ as -4.79%;

[0072] 4) The 1:10 mixed standard sample after the oxidation treatment in grinding step 3) was tested with a high-frequency infrared carbon-sulfur analyzer. The silicon carbide content in the 1:10 mixed standard sample after the oxidation reaction was zero, indicating that the oxidation was complete.

[0073] 5) Weigh 0.6000±0.0002g of the 1:10 mixed standard sample after complete oxidation and grinding, then add 6.0000±0.0004g of the mixed flux prepared by mixing Li2B4O7 and LiBO2 in a mass ratio of 67:33 (analytical grade), place it in a platinum crucible and mix well, then melt and cast it into a transparent glass sheet in a melting machine;

[0074] 6) The glass slide obtained in step 5) was subjected to X-ray fluorescence spectrometry to determine the measured content ω(R) of each oxide: silicon dioxide, aluminum oxide, ferric oxide, titanium dioxide, calcium oxide, magnesium oxide, potassium oxide, and sodium oxide. X O Y ) 实测 This includes the measured SiO2 content ω(SiO2). 实测 For details of the obtained atlas, please refer to [link / reference]. Figure 3 The measured content data of each oxide obtained from the test are detailed in Table 6.

[0075]

[0076] 7) Data correction:

[0077] Calculation of the content of each oxide except SiO2:

[0078] ω(A X O Y ) 原样品 = ω(R X O Y ) 实测 ×(1-ω(LOI)1500℃ / 100);

[0079] Calculation of SiO2 content:

[0080] ω(SiO2) 原样品 = ω(SiO2) 实测 ×(1-ω(LOI) 1500℃ / 100)- ω(SiC)×1.4983;

[0081] ω(R X O Y ) 实测 Step 6) Detect the measured content of each oxide; ω(SiO2) 实测 : The measured content of SiO2 obtained in step 6) (including silicon dioxide generated by the oxidation of silicon carbide); ω(SiC): The theoretical content of silicon carbide in the mixed standard sample in step 1); The 1.4983 is the conversion coefficient of silicon carbide to silicon dioxide.

[0082] The corrected results are the contents of each chemical component in the original sample 1:10 mixed standard sample. The contents of each oxide after correction are detailed in Table 7.

[0083]

[0084] 8) The errors between the content of each chemical component and the theoretical value in the 1:10 mixed standard sample are detailed in Table 8.

[0085]

[0086] The allowable error is specified in GB / T6900-2025 "Chemical Analysis Methods for Aluminosilicate Refractory Materials".

[0087] The above embodiments show that the chemical analysis method of the present invention for detecting oxides in silicon carbide-containing refractory materials using non-chemical reagent oxidation method has obtained the total content of each chemical component (including silicon carbide) in the silicon carbide-containing refractory materials within the range of 100±0.50%. The results of parallel experimental samples show that the method of the present invention has high precision, and the detection value of the self-prepared standard sample is consistent with the theoretical value, proving that the method of the present invention has high accuracy.

Claims

1. A chemical analysis method for detecting oxides in silicon carbide-containing refractory materials using a non-chemical reagent oxidation method, characterized in that, The method includes the following steps: 1) The raw materials containing silicon carbide refractory materials are crushed, dried, and cooled in sequence to obtain the processed sample; 2) Detect the silicon carbide content ω(SiC) in the treated sample; 3) Weigh the sample treated in step 1) and perform an ignition oxidation reaction, then cool it; weigh the cooled sample and calculate the loss on ignition ω(LOI). 1500℃ ; 4) Grind the sample cooled in step 3), and then test the silicon carbide content in the sample after the calcination oxidation reaction. 5) Weigh the sample after the calcination and oxidation reaction in step 4) where the silicon carbide content is zero, add mixed flux and melt it into a uniform and transparent glass sheet. 6) The obtained glass slide was analyzed and tested to determine the measured content ω(R) of each oxide. x O Y ) 实测 This includes the measured SiO2 content ω(SiO2). 实测 ; 7) Data correction: Calculation of the content of each oxide except SiO2: ω(A x The Y ) 原样品 =ω(R x The Y ) 实测 ×(1-ω(LOI)1500℃ / 100); Calculation of SiO2 content: ω(SiO2) 原样品 = ω(SiO2) 实测 (1-h(LOI) 1500℃ / 100)- ω(SiC)×a; ω(R x O Y ) 实测 Step 6) Detect the measured content of each oxide; ω(SiO2) 实测 ω(SiC): The measured content of SiO2 obtained in step 6); ω(SiC): The content of silicon carbide in the sample after treatment in step 2).

2. The chemical analysis method for detecting oxides in silicon carbide-containing refractory materials using a non-chemical reagent oxidation method according to claim 1, characterized in that: In step 1), the raw materials are ground and pulverized using a tungsten carbide mortar and pestle.

3. The chemical analysis method for detecting oxides in silicon carbide-containing refractory materials using a non-chemical reagent oxidation method according to claim 2, characterized in that: The particle size of the pulverized sample is below 200 mesh.

4. The chemical analysis method for detecting oxides in silicon carbide-containing refractory materials using a non-chemical reagent oxidation method according to claim 1, characterized in that: In step 1), the drying temperature is controlled at 110±5℃ and the drying time is 2h; then, the temperature is cooled to room temperature.

5. The chemical analysis method for detecting oxides in silicon carbide-containing refractory materials using a non-chemical reagent oxidation method according to claim 1, characterized in that: The sample treated in step 3) is placed in a corundum boat for calcination oxidation reaction; the equipment used for the calcination oxidation reaction is a high-temperature experimental furnace.

6. The chemical analysis method for detecting oxides in silicon carbide-containing refractory materials using the non-chemical reagent oxidation method according to claim 5, characterized in that: During the calcination oxidation reaction described in step 3), the reaction temperature is controlled at 1500±25℃ and the reaction time is 4h.

7. The chemical analysis method for detecting oxides in silicon carbide-containing refractory materials using a non-chemical reagent oxidation method according to claim 1, characterized in that: The mixed flux mentioned in step 5) is a mixture of lithium tetraborate (Li2B4O7) and lithium metaborate (LiBO2) in a mass ratio of 67:

33.

8. The chemical analysis method for detecting oxides in silicon carbide-containing refractory materials using a non-chemical reagent oxidation method according to claim 1, characterized in that: The mass ratio of the fully oxidized sample to the mixed flux in step 5) is 1:

10.

9. The chemical analysis method for detecting oxides in silicon carbide-containing refractory materials using a non-chemical reagent oxidation method according to claim 1, characterized in that: The equipment used for melting and casting in step 5) is a sample melting machine.

10. The chemical analysis method for detecting oxides in silicon carbide-containing refractory materials using a non-chemical reagent oxidation method according to claim 1, characterized in that: In step 7), 'a' represents the conversion factor of silicon carbide to silicon dioxide, which is 1.4983.

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