Titration detection method for content of boron oxide in powder

Abstract

The invention relates to a titration detection method for the content of boron oxide in powder, which comprises the following steps: (1) carrying out first mixing and heating on powder to be detected and a mixed solution of an organic solvent and deionized water, and carrying out solid-liquid separation to obtain a solution to be detected; and (2) carrying out second mixing on the solution to be detected in the step (1) and polyol, adding an indicator, carrying out titration by adopting a sodium hydroxide standard solution, recording the volume of the sodium hydroxide standard solution used for titration as V, and calculating the content of boron oxide in the powder to be detected. According to the method, B2O3 in a sample is completely converted into H3BO3, the content of B2O3 is indirectly detected by detecting H3BO3, a traditional acid-base neutralization titration method is adopted, no complex electrochemical instrument is involved, a titration end point is convenient to identify, the method is efficient, simple, convenient, safe and good in repeatability, the technical effect of accurately detecting the content of boron oxide in powder is achieved, and the method is suitable for being applied to industrial continuous production.

Description

Technical Field

[0001] This invention relates to the field of chemical detection technology, and in particular to a titration method for detecting boron oxide content in powder. Background Technology

[0002] During the preparation and sintering process of hexagonal boron nitride (h-BN), B2O3 is generated. Since B2O3 has a low melting point (450℃) and is hygroscopic at room temperature, the presence of B2O3 in hexagonal boron nitride ceramics will seriously affect the mechanical properties of the fixture at both room temperature and high temperature, leading to fixture damage. Therefore, it is necessary to provide a method for detecting the B2O3 content in h-BN raw material powder and sintered body to accurately monitor the B2O3 content in h-BN raw material powder and sintered body.

[0003] The prior art CN118209510A discloses a method for detecting the boron oxide content in electronic glass for display, comprising the following steps: Step 1: Preparing the electronic glass for display into a solution state; Step 2: Selecting a suitable ultraviolet spectrophotometer and setting the spectral scanning range; Step 3: Establishing a standard curve: Under the same measurement conditions, measuring a series of standard solutions and plotting a standard curve of absorbance versus concentration; Step 4: Determining the boron oxide content to be measured in the display: Based on the measured absorption spectrum curve of the sample, the absorbance value at a specific wavelength can be determined, and the boron oxide content in the sample can be calculated by comparing the absorbance of the sample with the standard curve.

[0004] Existing technology TWI814233B discloses a boric acid test strip and a boric acid detection method. First, a boric acid test strip (fabricated by assembling a gold electrode, a carbon electrode, and an AgCl reference electrode on a substrate) is prepared. The sample to be tested is mixed with a conductive reagent and dropped onto the test strip. A voltage within a set range is input, and a linear sweep voltammetry (LSV) method is used to obtain the corresponding output electrical signal. This electrical signal is then compared with a pre-established standard curve to obtain the specific boric acid value.

[0005] The detection methods mentioned in the existing technology require first testing a standard curve, then processing the sample to be tested, and finally fitting and calculating the electrical signal of the sample with the standard curve to obtain specific values. The process involves electrode preparation and electrochemical instrument operation, and the underlying principles are quite complex.

[0006] In summary, developing a new and simple titration method for detecting boron oxide content in powders has become an urgent problem to be solved. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention provides a titration method for detecting boron oxide content in powder. The method involves first mixing the powder to be tested with a mixed solution of an organic solvent and deionized water, heating the mixture, and then separating the solid and liquid phases to obtain the test solution. The test solution is then second-mixed with a polyol, and an indicator is added before titration with sodium hydroxide solution to determine the boron oxide content in the powder. This method completely converts B2O3 in the sample to H3BO3, indirectly detecting the B2O3 content through the detection of H3BO3, thus accurately detecting the boron oxide content in the powder. The method is efficient, simple, safe, and has good repeatability.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a method for titrating and detecting the boron oxide content in powder, the method comprising the following steps:

[0010] (1) The powder to be tested is mixed with a mixture of organic solvent and deionized water, heated, and then separated into solid and liquid components to obtain the solution to be tested;

[0011] (2) Mix the test solution described in step (1) with the polyol for the second time, add an indicator, titrate with sodium hydroxide standard solution, record the volume of sodium hydroxide standard solution used for titration as V, and calculate the boron oxide content in the powder to be tested.

[0012] The present invention provides a titration method for detecting boron oxide content in powders. This method involves a first mixing of the powder to be tested with a mixture of an organic solvent and deionized water, followed by heating and solid-liquid separation to obtain the test solution. The test solution is then mixed a second time with a polyol, and an indicator is added before titration with sodium hydroxide solution to determine the boron oxide content in the powder. This invention utilizes the organic solvent to improve the wetting and penetration ability of the mixed solution on the powder to be tested, thereby ensuring that deionized water can fully contact and dissolve the B2O3, converting it into H3BO3. Heating accelerates the reaction of boron oxide with water to form boric acid, ensuring that no B2O3 remains and that all is converted into H3BO3. The content of B2O3 is indirectly detected by detecting H3BO3. The detection results are accurate, efficient, simple, safe, and have good repeatability.

[0013] As a preferred technical solution of the present invention, the powder to be tested in step (1) includes any one or at least two of the following: hexagonal boron nitride, boron carbide, titanium diboride, zirconium boride, or powder after fine crushing and sieving of ceramic tool products. Typical but non-limiting combinations include: a combination of hexagonal boron nitride and boron carbide, a combination of hexagonal boron nitride and titanium diboride, a combination of hexagonal boron nitride and zirconium boride, a combination of hexagonal boron nitride and powder after fine crushing and sieving of ceramic tool products, a combination of boron carbide and titanium diboride, a combination of boron carbide and zirconium boride, a combination of boron carbide and powder after fine crushing and sieving of ceramic tool products, a combination of titanium diboride and zirconium boride, a combination of titanium diboride and powder after fine crushing and sieving of ceramic tool products, a combination of zirconium boride and powder after fine crushing and sieving of ceramic tool products, etc.

[0014] Preferably, the particle size of the powder to be tested is 1-100μm, for example, it can be 1μm, 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm or 100μm, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0015] As a preferred technical solution of the present invention, the organic solvent in step (1) includes any one of methanol, ethanol, acetone, benzene, diethyl ether, NMP, N-methylpyrrolidone or N,N-dimethylformamide.

[0016] As a preferred technical solution of the present invention, the liquid-solid ratio of the mixed solution of organic solvent and deionized water to the powder to be tested in step (1) is (150-250) mL:(1-10) g, for example, it can be 150 mL:1 g, 150 mL:5 g, 150 mL:10 g, 200 mL:1 g, 200 mL:5 g, 200 mL:10 g, 250 mL:1 g, 250 mL:5 g or 250 mL:10 g, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0017] Preferably, the volume ratio of the organic solvent to deionized water in step (1) is (2-4):1, for example, it can be 2:1, 2.5:1, 3:1, 3.5:1 or 4:1, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0018] In this invention, when the volume ratio of organic solvent to water is too high, i.e., when too much organic solvent is added, the relative content of water is too low. Boron oxide needs to react chemically with water to be dissolved. Organic solvents themselves usually cannot dissolve boron oxide. If the solution is mostly organic solvent, there is not enough water available for the reaction, and boron oxide cannot be completely converted into boric acid. When the volume ratio of organic solvent to water is too low, i.e., when too little organic solvent is added, the hydrophobicity of hexagonal boron nitride cannot be overcome. Pure water will form a large contact angle on the h-BN surface, which cannot effectively spread and penetrate into the interior of the powder aggregate, and boron oxide cannot be completely converted into boric acid.

[0019] Preferably, the heating temperature in step (1) is 60-100℃, for example, it can be 60℃, 70℃, 80℃, 90℃ or 100℃, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0020] This invention, by further limiting the heating temperature, can ensure that there is no boron oxide residue and that it is completely converted into boric acid. When the heating temperature is too low, the reaction rate is slow and boron oxide cannot be completely converted into boric acid. Only the surface boron oxide may react, while the internal boron oxide is encapsulated and cannot come into contact with organic solvents and water, affecting the overall reaction efficiency. When the heating temperature is too high, it will cause boric acid to dehydrate, generating metaboric acid (HBO2) or returning to the original boron oxide state.

[0021] In this invention, after heating is completed, the mixture is allowed to cool to room temperature by air cooling or water cooling.

[0022] Preferably, the heating time in step (1) is 0.1-2h, for example, it can be 0.1h, 0.5h, 1h, 1.5h or 2h, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0023] As a preferred technical solution of the present invention, the polyol in step (2) includes mannitol.

[0024] This invention adds a polyol, which transforms the analyte (boric acid) from an extremely weak acid that cannot be accurately titrated into a moderately strong acid that can be accurately titrated through a chemical reaction. This improves the characteristics of borate ions, reduces calculation errors, and ensures the accuracy of B2O3 content.

[0025] Preferably, the liquid-to-solid ratio of the test solution to mannitol in step (2) is 100mL:(0.5-3)g, for example, it can be 100mL:0.5g, 100mL:1g, 100mL:1.5g, 100mL:2g, 100mL:2.5g or 100mL:3g, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0026] As a preferred technical solution of the present invention, the indicator in step (2) includes phenolphthalein indicator.

[0027] As a preferred technical solution of the present invention, the concentration of the sodium hydroxide standard solution in step (2) is 0.01-0.1 mol / L, for example, it can be 0.01 mol / L, 0.02 mol / L, 0.03 mol / L, 0.04 mol / L, 0.05 mol / L, 0.06 mol / L, 0.07 mol / L, 0.08 mol / L, 0.09 mol / L or 0.1 mol / L, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0028] Preferably, the endpoint of the titration in step (2) is when the sodium hydroxide standard solution is titrated until the test solution turns pink and the color remains stable.

[0029] Preferably, the titration endpoint in step (2) can also be determined by real-time monitoring of the pH change of the solution through the electrodes of the electrochemical workstation. When the pH reaches 8-8.5, it is the titration endpoint. For example, it can be 8, 8.1, 8.2, 8.3, 8.4 or 8.5, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0030] As a preferred technical solution of the present invention, the method further includes a blank experiment. The test process of the blank experiment is as follows: repeat steps (1)-(2), and when repeating step (1), no powder to be tested is added, and the volume of the sodium hydroxide standard solution used for titration is recorded as V0.

[0031] Preferably, the boron oxide content in the powder to be tested is calculated using the following formula:

[0032]

[0033] Where C is the concentration of the sodium hydroxide standard solution (mol / L), V is the volume of sodium hydroxide solution consumed in the titration of the test solution (mL), V0 is the volume of sodium hydroxide solution consumed in the blank experiment (mL), M is the relative molecular mass of boron oxide, and m is the mass of the powder to be tested (g).

[0034] As a preferred technical solution of the present invention, the method specifically includes the following steps:

[0035] (1) The test powder with a particle size of 1-100 μm is mixed with a mixture of organic solvent and deionized water in a volume ratio of (2-4):1 at a liquid-solid ratio of (150-250) mL:(1-10) g. The mixture is heated at 60-200℃ for 0.1-2 h and then separated into solid and liquid components to obtain the test solution. The test powder includes any one or a combination of at least two of the following: hexagonal boron nitride, boron carbide, titanium diboride, zirconium boride, or sieved powder of ceramic tool products. The organic solvent includes any one of methanol, ethanol, acetone, benzene, diethyl ether, NMP, N-methylpyrrolidone, or N,N-dimethylformamide.

[0036] (2) The test solution described in step (1) is mixed with polyol at a liquid-solid ratio of 100 mL: (0.5-3) g. An indicator is added, and titration is performed using a sodium hydroxide standard solution with a concentration of 0.01-0.1 mol / L. The titration endpoint is when the sodium hydroxide standard solution is titrated until the test solution turns pink and the color remains stable. The volume of the sodium hydroxide standard solution used in the titration is recorded as V. The boron oxide content in the test powder is calculated. The polyol includes mannitol, and the indicator includes phenolphthalein indicator. The titration endpoint can also be monitored in real time by the electrodes of the electrochemical workstation to detect the change in pH of the solution. When the pH is 8-8.5, the titration endpoint is reached.

[0037] (3) Blank test: Repeat steps (1)-(2), and when repeating step (1), do not add the powder to be tested, record the volume of the sodium hydroxide standard solution used for titration, and record it as V0. Calculate the boron oxide content in the powder to be tested according to formula 1.

[0038] Compared with the prior art, the present invention has at least the following beneficial effects:

[0039] The boron nitride content titration detection method in powder provided by this invention involves heating the powder to be tested with a mixed solution of organic solvent and deionized water to convert all the boron oxide in the powder into boric acid, and then titrating it with a sodium hydroxide standard solution. The boron oxide content is indirectly detected by detecting the boric acid. This method uses a traditional acid-base neutralization titration method, does not involve complex electrochemical instruments, the titration endpoint is easy to identify, and it is efficient, simple, safe, and has good repeatability, making it suitable for continuous industrial production. Detailed Implementation

[0040] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0041] Samples 1-3 used in the following examples and comparative examples were all from Yingkou Liaobin Fine Chemical Co., Ltd. (BN-B).

[0042] Example 1

[0043] This embodiment provides a method for titrating and detecting the boron oxide content in powder, the method comprising the following steps:

[0044] (1) Weigh 6g of hexagonal boron nitride sample 1, mix it with a mixture of 150mL of methanol and 50mL of deionized water, heat at 80℃ for 0.5h, and obtain the test solution after solid-liquid separation;

[0045] (2) Take 100 mL of the test solution described in step (1), add 1.5 g of mannitol for the second mixing, add 10 drops of phenolphthalein indicator, and titrate with a sodium hydroxide standard solution with a concentration of 0.06072 mol / L. When the test solution turns pink and the color remains stable, record the volume V of sodium hydroxide solution consumed.

[0046] (3) Blank test: Repeat steps (1)-(2), and when repeating step (1), do not add the powder to be tested, and record the volume V0 of sodium hydroxide solution consumed; finally, calculate the boron oxide content according to formula 1.

[0047] Example 2

[0048] This embodiment provides a method for titrating and detecting the boron oxide content in powder, the method comprising the following steps:

[0049] (1) Weigh 4g of hexagonal boron nitride sample 2, mix it with a mixture of 100mL of ethanol and 50mL of deionized water, heat it at 60℃ for 2h, and obtain the test solution after solid-liquid separation.

[0050] (2) Take 100 mL of the test solution described in step (1), add 0.5 g of mannitol for the second mixing, add 8 drops of phenolphthalein indicator, and titrate with a sodium hydroxide standard solution with a concentration of 0.01012 mol / L. When the test solution turns pink and the color remains stable, record the volume V of sodium hydroxide solution consumed.

[0051] (3) Blank test: Repeat steps (1)-(2), and when repeating step (1), do not add the powder to be tested, record the volume V0 of sodium hydroxide solution consumed, and finally calculate the boron oxide content according to formula 1.

[0052] Example 3

[0053] This embodiment provides a method for titrating and detecting the boron oxide content in powder, the method comprising the following steps:

[0054] (1) Weigh 8g of hexagonal boron nitride sample 3, mix it with a mixture of 200mL of acetone and 50mL of deionized water, heat it at 100℃ for 1h, and obtain the test solution after solid-liquid separation.

[0055] (2) Take 100 mL of the test solution described in step (1), add 3 g of mannitol for a second mixing, add 12 drops of phenolphthalein indicator, and titrate with a sodium hydroxide standard solution with a concentration of 0.06072 mol / L. When the test solution turns pink and the color remains stable, record the volume V of sodium hydroxide solution consumed.

[0056] (3) Blank test: Repeat steps (1)-(2), and when repeating step (1), do not add the powder to be tested, record the volume V0 of sodium hydroxide solution consumed, and finally calculate the boron oxide content according to formula 1.

[0057] Example 4

[0058] This embodiment provides a method for titrating and detecting the boron oxide content in powder, the method comprising the following steps:

[0059] (1) Weigh 1g of boron carbide with an average particle size of 100μm, mix it with a mixture of 100mL of ethanol and 50mL of deionized water, heat it at 80℃ for 1h, and then separate the solid and liquid to obtain the test solution.

[0060] (2) Take 100 mL of the test solution described in step (1), add 1.5 g of mannitol for the second mixing, add 10 drops of phenolphthalein indicator, and titrate with a sodium hydroxide standard solution with a concentration of 0.0135 mol / L. When the test solution turns pink and the color remains stable, record the volume V of sodium hydroxide solution consumed.

[0061] (3) Blank test: Repeat steps (1)-(2), and when repeating step (1), do not add the powder to be tested, record the volume V0 of sodium hydroxide solution consumed, and finally calculate the boron oxide content according to formula 1.

[0062] Example 5

[0063] This embodiment provides a method for titrating and detecting the boron oxide content in powder, the method comprising the following steps:

[0064] (1) Weigh 10g of finely crushed and sieved powder of ceramic tool products with an average particle size of 80μm, mix it with a mixture of 150mL methanol and 50mL deionized water, heat at 80℃ for 2h, and obtain the test solution after solid-liquid separation.

[0065] (2) Take 100 mL of the test solution described in step (1), add 3 g of mannitol for a second mixing, add 10 drops of phenolphthalein indicator, and titrate with a sodium hydroxide standard solution with a concentration of 0.0986 mol / L. When the test solution turns pink and the color remains stable, record the volume V of sodium hydroxide solution consumed.

[0066] (3) Blank test: Repeat steps (1)-(2), and when repeating step (1), do not add the powder to be tested, record the volume V0 of sodium hydroxide solution consumed, and finally calculate the boron oxide content according to formula 1.

[0067] Example 6

[0068] This embodiment provides a titration method for detecting boron oxide content in powder. The difference between this embodiment and Embodiment 1 is that, except for the heating temperature of step (1) being 40°C, the rest is the same as in Embodiment 1.

[0069] Example 7

[0070] This embodiment provides a titration method for detecting boron oxide content in powder. The difference between this embodiment and Embodiment 1 is that, except for the heating temperature of step (1) being 120°C, the rest is the same as in Embodiment 1.

[0071] Example 8

[0072] This embodiment provides a titration method for detecting boron oxide content in powder. The difference from Embodiment 1 is that in step (1), the volume ratio of organic solvent to deionized water is 1:1, that is, the powder to be tested is first mixed with a mixed solution of 100 mL of methanol and 100 mL of deionized water.

[0073] Example 9

[0074] This embodiment provides a titration method for detecting boron oxide content in powder. The difference from Embodiment 1 is that in step (1), the volume ratio of organic solvent to deionized water is 5:1, that is, the powder to be tested is first mixed with a mixed solution of 166.67 mL of methanol and 33.33 mL of deionized water.

[0075] Comparative Example 1

[0076] This comparative example provides a titration method for detecting boron oxide content in powder, which differs from Example 1 in that the addition of organic solvent in step (1) is omitted.

[0077] Comparative Example 2

[0078] This comparative example provides a titration method for detecting boron oxide content in powder, which differs from Example 1 in that the addition of deionized water in step (1) is omitted.

[0079] Comparative Example 3

[0080] This comparative example provides a titration method for detecting boron oxide content in powder, which differs from Example 1 in that the heating step in step (1) is omitted.

[0081] Comparative Example 4

[0082] This comparative example provides a titration method for detecting boron oxide content in powder, which differs from Example 1 in that the addition of polyol in step (2) is omitted.

[0083] Test method: The accuracy of the titration detection method provided in Examples 1-9 and Comparative Examples 1-4 was tested. Each group of samples was tested three times to obtain the boron oxide content in the powder. The calculation results are shown in Table 1.

[0084] Table 1

[0085]

[0086] The test results show that:

[0087] (1) As can be seen from Examples 1 to 5, the present invention can achieve the technical effect of accurately detecting the boron oxide content by mixing the powder to be tested with a mixed solution of organic solvent and deionized water, heating it, adding polyol for a second mixing, and titrating it with sodium hydroxide standard solution. The boron oxide content in the powder to be tested can be completely converted into boric acid. The detection results have good repeatability and are close to the manufacturer's standard value.

[0088] (2) As can be seen from the combined examples 1 and 6 and 7, the content of B2O3 deviates significantly from the standard content. This shows that by further limiting the heating temperature, the present invention can ensure that there is no boron oxide residue and that it is completely converted into boric acid. When the heating temperature is too low, the reaction rate is slow and boron oxide cannot be completely converted into boric acid. Only the surface boron oxide may react, while the internal boron oxide is encapsulated and cannot come into contact with organic solvents and water, affecting the overall reaction efficiency. When the heating temperature is too high, it will cause boric acid to dehydrate and generate metaboric acid (HBO2) or return to the original state of boron oxide. Therefore, both excessively high and excessively low heating temperatures will affect the detection of boron oxide content.

[0089] (3) It can be seen from the combined examples 1 and 8 and 9 that the B2O3 content deviates significantly from the standard content. When the volume ratio of organic solvent to water is too high, that is, when too much organic solvent is added, the relative content of water is too low. Boron oxide needs to react chemically with water to be dissolved. Organic solvents themselves usually cannot dissolve boron oxide. If most of the solution is organic solvent, there is not enough water available for the reaction, and boron oxide cannot be completely converted into boric acid. When the volume ratio of organic solvent to water is too low, that is, when too little organic solvent is added, the hydrophobicity of hexagonal boron nitride cannot be overcome. Pure water will form a large contact angle on the h-BN surface, which cannot effectively spread and penetrate into the interior of the powder aggregate, and boron oxide cannot be completely converted into boric acid.

[0090] (4) It can be seen from the combined examples 1 and 2 that when the addition of organic solvent or deionized water in step (1) is omitted, the boron oxide in the powder cannot be completely converted into boric acid, which affects the accuracy of determining the boron oxide content in the powder by titration.

[0091] (5) It can be seen from the combined examples of Example 1 and Comparative Example 3 that when the heating step in step (1) is omitted, the reaction rate of the powder to be tested with the mixed solution of organic solvent and deionized water is slow. It is possible that only the boron oxide on the surface reacts, while the boron oxide inside is encapsulated and cannot be completely converted into boric acid.

[0092] (6) As can be seen from the combined examples 1 and 4, when the addition of polyol in step (2) is omitted, the color change of the solution during titration is slow, trailing, and unstable, making it impossible to accurately determine the endpoint of the reaction, resulting in inaccurate titration results. The present invention adds polyol, which transforms the analyte (boric acid) from an extremely weak acid that cannot be accurately titrated into a medium-strong acid that can be accurately titrated through a chemical reaction, thereby improving the characteristics of borate ions, reducing calculation errors, and ensuring the accuracy of B2O3 content.

[0093] In summary, this invention achieves the technical effect of accurately detecting the boron oxide content in powder by first mixing the powder to be tested with a mixed solution of organic solvent and deionized water, heating, and then separating the solid and liquid components to obtain the test solution. The process involves mixing the test solution with a polyol, adding an indicator, and titrating with sodium hydroxide solution to determine the boron oxide content in the powder. This process completely converts B2O3 in the sample to H3BO3, and indirectly detects the B2O3 content through the detection of H3BO3.

[0094] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A titration method for detecting boron oxide content in powder, characterized in that, The method includes the following steps: (1) The powder to be tested is mixed with a mixture of organic solvent and deionized water, heated, and then separated into solid and liquid components to obtain the solution to be tested; (2) Mix the test solution described in step (1) with the polyol for the second time, add an indicator, titrate with sodium hydroxide standard solution, record the volume of sodium hydroxide standard solution used for titration as V, and calculate the boron oxide content in the powder to be tested.

2. The method according to claim 1, characterized in that, The powder to be tested in step (1) includes any one or a combination of at least two of the following: hexagonal boron nitride, boron carbide, titanium diboride, zirconium boride, or finely crushed and sieved powder of ceramic tool products; Preferably, the particle size of the powder to be tested is 1-100 μm.

3. The method according to claim 1 or 2, characterized in that, The organic solvent in step (1) includes any one of methanol, ethanol, acetone, benzene, diethyl ether, NMP, N-methylpyrrolidone or N,N-dimethylformamide.

4. The method according to any one of claims 1-3, characterized in that, In step (1), the liquid-to-solid ratio of the mixed solution of organic solvent and deionized water to the powder to be tested is (150-250) mL:(1-10) g; Preferably, the volume ratio of the organic solvent to deionized water in step (1) is (2-4):

1.

5. The method according to any one of claims 1-4, characterized in that, The heating temperature in step (1) is 60-100℃; Preferably, the heating time in step (1) is 0.1-2 hours.

6. The method according to any one of claims 1-5, characterized in that, The polyol mentioned in step (2) includes mannitol; Preferably, the liquid-to-solid ratio of the test solution to mannitol in step (2) is 100 mL: (0.5-3) g.

7. The method according to any one of claims 1-6, characterized in that, The indicator in step (2) includes phenolphthalein indicator.

8. The method according to any one of claims 1-7, characterized in that, The concentration of the sodium hydroxide standard solution in step (2) is 0.01-0.1 mol / L; Preferably, the endpoint of the titration in step (2) is when the sodium hydroxide standard solution is titrated until the test solution turns pink and the color remains stable; Preferably, the titration endpoint in step (2) can also be determined by real-time monitoring of the pH change of the solution using the electrodes of an electrochemical workstation, with the pH reaching 8-8.

5.

9. The method according to any one of claims 1-8, characterized in that, The method also includes a blank experiment. The test process of the blank experiment is as follows: repeat steps (1)-(2), and when repeating step (1), do not add the powder to be tested, record the volume of the sodium hydroxide standard solution used for titration, and record it as V0. Preferably, the boron oxide content in the powder to be tested is calculated using the following formula: Where C is the concentration of the sodium hydroxide standard solution (mol / L), V is the volume of sodium hydroxide solution consumed in the titration of the test solution (mL), V0 is the volume of sodium hydroxide solution consumed in the blank experiment (mL), M is the relative molecular mass of boron oxide, and m is the mass of the powder to be tested (g).

10. The method according to any one of claims 1-9, characterized in that, The method specifically includes the following steps: (1) The test powder with a particle size of 1-100 μm is mixed with a mixture of organic solvent and deionized water in a volume ratio of (2-4):1 at a liquid-solid ratio of (150-250) mL:(1-10) g. The mixture is heated at 60-200℃ for 0.1-2 h and then separated into solid and liquid components to obtain the test solution. The test powder includes any one or a combination of at least two of the following: hexagonal boron nitride, boron carbide, titanium diboride, zirconium boride, or sieved powder of ceramic tool products. The organic solvent includes any one of methanol, ethanol, acetone, benzene, diethyl ether, NMP, N-methylpyrrolidone, or N,N-dimethylformamide. (2) The test solution described in step (1) is mixed with polyol at a liquid-solid ratio of 100 mL: (0.5-3) g. An indicator is added, and titration is performed using a sodium hydroxide standard solution with a concentration of 0.01-0.1 mol / L. The titration endpoint is when the sodium hydroxide standard solution is titrated until the test solution turns pink and the color remains stable. The volume of the sodium hydroxide standard solution used in the titration is recorded as V. The boron oxide content in the test powder is calculated. The polyol includes mannitol, and the indicator includes phenolphthalein indicator. The titration endpoint can also be monitored in real time by the electrodes of the electrochemical workstation to detect the change in pH of the solution. When the pH is 8-8.5, the titration endpoint is reached. (3) Blank test: Repeat steps (1)-(2), and when repeating step (1), do not add the powder to be tested, record the volume of the sodium hydroxide standard solution used for titration, and record it as V0. Calculate the boron oxide content in the powder to be tested according to formula 1.

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