Method for enriching and identifying insoluble carbon in tungsten carbide and application thereof

Abstract

The present application belongs to the technical field of material analysis and detection, and particularly relates to a method for enriching and identifying insoluble carbon in tungsten carbide and application thereof. The insoluble carbon in tungsten carbide can be effectively enriched, which is convenient for detection and can accurately determine the type (graphite particles or free carbon) of the insoluble carbon in tungsten carbide. Through analysis of the type and proportion of the insoluble carbon, scientific feedback can be provided for adjustment of the carbonization process of tungsten carbide, which is conducive to improving the quality of tungsten carbide and facilitating large-scale industrial application.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of material analysis and detection, and particularly relates to a method for enriching and identifying insoluble carbon in tungsten carbide powder and application thereof. BACKGROUND

[0002] Hard alloy is an alloy material made of hard compound of refractory metal and binder metal through powder metallurgy process. The hard alloy has a series of excellent performances such as high hardness, good wear resistance, strength and toughness, heat resistance and corrosion resistance, and is widely used as a tool material, such as turning tool, milling tool, planing tool, drill bit and boring tool, for cutting cast iron, non-ferrous metal, plastic, chemical fiber, graphite, glass, stone and ordinary steel, and can also be used to cut heat-resistant steel, stainless steel, high manganese steel and tool steel.

[0003] The performance of the hard alloy is affected by the carbon content in the alloy, and the carbon in the alloy mainly comes from raw material tungsten carbide, forming agent, filler, graphite boat and heat preservation material. The tungsten carbide is prepared by tungsten powder and carbon black through high-temperature carbonization. The carbon black is amorphous carbon, quasi-graphitized microcrystalline, and will appear graphitization reaction to form graphite particles when the temperature is higher than 2000 DEG C. The higher the temperature, the more obvious the reaction.

[0004] At present, in the production process of tungsten carbide powder, the uniformly mixed tungsten powder and carbon black are loaded into a graphite boat in a carbon tube furnace or a molybdenum wire furnace for carbonization. During the carbonization process, a small amount of carbon is infiltrated into the furnace charge from the graphite boat, or the poor quality part of the boat material falls off into the tungsten carbide powder, so that the content of free carbon in the powder is too high. If the free carbon in the tungsten carbide is too high due to too much carbon black, atmosphere and boat infiltration, etc. during production, the problem can be solved through subsequent treatment. If the carbon black is graphitized due to high temperature to form graphite particles, or the poor quality part of the boat material falls off into the tungsten carbide powder, so that the content of free carbon in the tungsten carbide is too high, the influence will be irreversible, thereby seriously affecting the performance of the subsequent alloy.

[0005] The free carbon in tungsten carbide powder is generally determined by high-frequency combustion infrared absorption method at present, and the normal free carbon content in tungsten carbide is generally not more than 0.06%. When the free carbon content in tungsten carbide exceeds 0.06%, the high-frequency combustion infrared method can only determine the content of insoluble carbon, and cannot determine whether the insoluble carbon is caused by excessive carbon black or graphite particles; there is no relatively scientific and rigorous basis for judging the quality of graphite boat material, and the previous judgment is based on the observation of the surface damage degree and the material sticking degree; when the electron microscope is used for detection, only the surface layer of the sample can be observed, and the remaining part cannot be effectively detected, and it is not intuitive to judge whether there is a lot of graphite in the tungsten carbide powder. It can be seen that the existing method can only determine the content of insoluble carbon, and cannot distinguish whether the insoluble carbon is free carbon or graphite particles, and cannot realize the scientific feedback of the adjustment of the carbonization process of tungsten carbide. In view of this problem, it is urgent to develop a method for enriching and identifying insoluble carbon in tungsten carbide and its application, which can provide favorable guidance for production and effectively improve the product quality. SUMMARY

[0006] In order to solve the problems in the prior art, the main purpose of the present application is to provide a method for enriching and identifying insoluble carbon in tungsten carbide and its application, which can effectively enrich the insoluble carbon in tungsten carbide, facilitate detection, and accurately judge the type of insoluble carbon in tungsten carbide.

[0007] In order to solve the above technical problems, according to one aspect of the present application, the present application provides the following technical scheme:

[0008] A method for enriching and identifying insoluble carbon in tungsten carbide, comprising the following steps:

[0009] S1. A certain amount of tungsten carbide is added to a reactor, and a certain amount of hydrogen peroxide solution is added to the reactor, and after heating and boiling, a solution A is obtained;

[0010] S2. Potassium dichromate is dissolved in pure water, and then concentrated sulfuric acid is slowly added and stirred uniformly to obtain solution B, and a sand core crucible is immersed in solution B; after immersion, the sand core crucible is taken out and placed on a Buchner funnel;

[0011] S3. Start the suction filtration, and pour the solution A into the sand core crucible in small amounts and multiple times to obtain filter residue;

[0012] S4. The sand core crucible and the filter residue are placed in an oven for drying;

[0013] S5. The filter residue is taken out, weighed, and then sampled for scanning electron microscope detection and identification of insoluble carbon.

[0014] As a preferred scheme of the method for enriching and identifying insoluble carbon in tungsten carbide, in the step S1, the solid-liquid ratio of tungsten carbide to hydrogen peroxide solution is 1g:(25-30)mL.

[0015] As a preferred scheme of the method for enriching and identifying insoluble carbon in tungsten carbide according to the application, in the step S1, the concentration of the hydrogen peroxide solution is 27-28wt%.

[0016] As a preferred scheme of the method for enriching and identifying insoluble carbon in tungsten carbide according to the application, in the step S1, the heating boiling time is 40-80min.

[0017] As a preferred scheme of the method for enriching and identifying insoluble carbon in tungsten carbide according to the application, in the step S2, the solid-liquid ratio of potassium dichromate to pure water is 1g:(1.5-2.5)mL.

[0018] As a preferred scheme of the method for enriching and identifying insoluble carbon in tungsten carbide according to the application, in the step S2, the concentration of the concentrated sulfuric acid is 98wt%.

[0019] As a preferred scheme of the method for enriching and identifying insoluble carbon in tungsten carbide according to the application, in the step S2, the volume ratio of pure water to concentrated sulfuric acid is 1:8-10.

[0020] As a preferred scheme of the method for enriching and identifying insoluble carbon in tungsten carbide according to the application, in the step S2, the soaking time is 20-25h.

[0021] As a preferred scheme of the method for enriching and identifying insoluble carbon in tungsten carbide according to the application, in the step S2, after the soaking is completed, the sand core crucible is taken out and placed on a Buchner funnel, and suction filtration is started, and the sand core crucible is washed with boiling water.

[0022] As a preferred scheme of the method for enriching and identifying insoluble carbon in tungsten carbide according to the application, in the step S3, the solution A is poured into the sand core crucible in 10-15 times to obtain filter residue.

[0023] As a preferred scheme of the method for enriching and identifying insoluble carbon in tungsten carbide according to the application, in the step S4, the drying temperature is 100-105℃.

[0024] To solve the above technical problems, according to another aspect of the application, the application provides the following technical scheme:

[0025] The application of the method for enriching and identifying insoluble carbon in tungsten carbide according to the above-mentioned application, comprising:

[0026] B1. According to the scanning electron microscope results, the proportion of graphite particles in insoluble carbon and the proportion of free carbon in insoluble carbon are calculated, and converted into the proportion of graphite particles in tungsten carbide and the proportion of free carbon in tungsten carbide.

[0027] B2. Adjust the tungsten carbide carbonization process according to the proportion of graphite particles in tungsten carbide and the proportion of free carbon in tungsten carbide:

[0028] When the proportion of graphite particles in tungsten carbide is > 0.02%, it will cause the free carbon in tungsten carbide to increase significantly, thereby affecting the quality of tungsten carbide, and the graphite boat needs to be replaced in time;

[0029] When the proportion of graphite particles in tungsten carbide is ≤ 0.02%, it has little effect on the content of free carbon in tungsten carbide, and the existing graphite boat can continue to be used, and whether the carbonization process parameters need to be adjusted is determined according to the proportion of free carbon in tungsten carbide:

[0030] When the proportion of free carbon in tungsten carbide is > 0.06%, the carbonization process parameters are adjusted;

[0031] When the proportion of free carbon in tungsten carbide is ≤ 0.06%, the existing carbonization process parameters can continue to be used.

[0032] The beneficial effects of the present application are as follows:

[0033] The present application provides a method for enriching and identifying insoluble carbon in tungsten carbide and its application, which can effectively enrich the insoluble carbon in tungsten carbide, facilitate detection, and accurately determine the type of insoluble carbon (graphite particles or free carbon) in tungsten carbide; through analysis of the type and proportion of insoluble carbon, scientific feedback is provided for the adjustment of the tungsten carbide carbonization process, which is beneficial to improve the quality of tungsten carbide and facilitate large-scale industrialization and application. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the drawings shown.

[0035] Figure 1 SEM image of raw tungsten carbide of the present application;

[0036] Figure 2 SEM image of enriched insoluble carbon of the present application;

[0037] Figure 3 SEM image of filter residue of the present application.

[0038] The implementation of the present application, functional characteristics and advantages will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person skilled in the art without creative work fall within the protection scope of the present application.

[0040] The main purpose of the present application is to provide a method for enriching and identifying insoluble carbon in tungsten carbide and its application, which solves the problem that the existing method can only determine the content of insoluble carbon, but cannot distinguish whether the insoluble carbon is free carbon or graphite particles, and cannot realize scientific feedback for adjusting the carbonization process of tungsten carbide.

[0041] According to one aspect of the present application, the present application provides the following technical solutions:

[0042] A method for enriching and identifying insoluble carbon in tungsten carbide, comprising the following steps:

[0043] S1. A certain amount of tungsten carbide (SEM image as shown in Figure 1 ) is taken into a reactor, and a certain amount of hydrogen peroxide solution is added into the reactor. After heating and boiling, solution A is obtained;

[0044] S2. Potassium dichromate is dissolved in pure water, and then concentrated sulfuric acid is slowly added and stirred uniformly to obtain solution B. The sand core crucible is immersed in solution B; after immersion, the sand core crucible is taken out and placed on a Buchner funnel;

[0045] S3. The suction filtration is started, and solution A is poured into the sand core crucible in small amounts and multiple times to obtain filter residue;

[0046] S4. The sand core crucible and the filter residue are placed in an oven for drying;

[0047] S5. The filter residue is taken out, weighed, and then sampled for scanning electron microscopy to detect and identify the insoluble carbon. The SEM image of the enriched insoluble carbon is shown in Figure 2 , and the SEM image of the filter residue is shown in Figure 3 .

[0048] Preferably, in step S1, the reactor can be, for example but not limited to, a beaker, a stirrer, etc. The solid-liquid ratio of tungsten carbide to hydrogen peroxide solution is 1g:(25-30)mL. Specifically, the solid-liquid ratio of tungsten carbide to hydrogen peroxide solution can be, for example but not limited to, any one of 1g:25mL, 1g:25.5mL, 1g:26mL, 1g:26.5mL, 1g:27mL, 1g:27.5mL, 1g:28mL, 1g:28.5mL, 1g:29mL, 1g:29.5mL, 1g:30mL or a range between any two thereof;

[0049] Preferably, in the step S1, the concentration of the hydrogen peroxide solution is 27-28wt%. Specifically, the concentration of the hydrogen peroxide solution can be, for example but not limited to, any one of 27wt%, 27.1wt%, 27.2wt%, 27.3wt%, 27.4wt%, 27.5wt%, 27.6wt%, 27.7wt%, 27.8wt%, 27.9wt%, 28wt% or a range between any two of them.

[0050] Preferably, in the step S1, the heating boiling time is 40-80min. Specifically, the heating boiling time can be, for example but not limited to, any one of 40min, 45min, 50min, 55min, 60min, 65min, 70min, 75min, 80min or a range between any two of them.

[0051] Preferably, in the step S2, the solid-liquid ratio of potassium dichromate to pure water is 1g:(1.5-2.5)mL. Specifically, the solid-liquid ratio of potassium dichromate to pure water can be, for example but not limited to, any one of 1g:1.5mL, 1g:1.6mL, 1g:1.7mL, 1g:1.8mL, 1g:1.9mL, 1g:2.0mL, 1g:2.1mL, 1g:2.2mL, 1g:2.3mL, 1g:2.4mL, 1g:2.5mL or a range between any two of them.

[0052] Preferably, in the step S2, the concentration of the concentrated sulfuric acid is 98wt%.

[0053] Preferably, in the step S2, the volume ratio of pure water to concentrated sulfuric acid is 1:8-10. Specifically, the volume ratio of pure water to concentrated sulfuric acid can be, for example but not limited to, any one of 1:8, 1:8.2, 1:8.5, 1:8.8, 1:9, 1:9.3, 1:9.5, 1:9.7, 1:10 or a range between any two of them.

[0054] Preferably, in the step S2, the soaking time is 20-25h. Specifically, the soaking time can be, for example but not limited to, any one of 20h, 21h, 22h, 23h, 24h, 25h or a range between any two of them.

[0055] Preferably, in the step S2, after the soaking is completed, the sand core crucible is taken out and placed on a Buchner funnel, and the suction filtration is started, and the sand core crucible is washed thoroughly with boiling water.

[0056] Preferably, in the step S3, the small amount of multiple times is not specifically limited, as long as it does not overflow during suction filtration, for example, the solution A is poured into the sand core crucible in 10-15 times to obtain the filter residue.

[0057] Preferably, in the step S4, the drying temperature is 100-105℃. Specifically, the drying temperature can be, for example, but not limited to, any one of 100℃, 101℃, 102℃, 103℃, 104℃, 105℃ or a range between any two of them;

[0058] According to another aspect of the present application, the present application provides the following technical solutions:

[0059] The application of a method for enriching and identifying insoluble carbon in tungsten carbide, comprising:

[0060] B1. According to the scanning electron microscope results, the proportion of graphite particles to insoluble carbon and the proportion of free carbon to insoluble carbon are calculated, and converted into the proportion of graphite particles to tungsten carbide and the proportion of free carbon to tungsten carbide;

[0061] B2. According to the proportion of graphite particles to tungsten carbide and the proportion of free carbon to tungsten carbide, the carbonization process of tungsten carbide is adjusted:

[0062] When the proportion of graphite particles to tungsten carbide is >0.02%, it will cause a significant increase in free carbon in tungsten carbide, thereby affecting the quality of tungsten carbide, and the graphite boat needs to be replaced in time;

[0063] When the proportion of graphite particles to tungsten carbide is ≤0.02%, the content of free carbon in tungsten carbide is not significantly affected, and the graphite boat does not need to be replaced, and the existing graphite boat can continue to be used, and whether the carbonization process parameters need to be adjusted is determined according to the proportion of free carbon to tungsten carbide:

[0064] When the proportion of free carbon to tungsten carbide is >0.06%, the carbonization process parameters, such as carbonization temperature and carbon content, are adjusted;

[0065] When the proportion of free carbon to tungsten carbide is ≤0.06%, the existing carbonization process parameters can be continued to be used.

[0066] The technical solutions of the present application are further described below in combination with specific embodiments.

[0067] Embodiment 1

[0068] A method for enriching and identifying insoluble carbon in tungsten carbide, comprising the following steps:

[0069] S1. Take 3.0g of tungsten carbide and add it to a beaker, then add 90mL of hydrogen peroxide solution with a concentration of 27.5wt% to the beaker, heat the reactor to boiling on an electric furnace for 60min to obtain solution A;

[0070] S2. Take 20 g of potassium dichromate and dissolve it in 40 mL of pure water, then slowly add 360 mL of concentrated sulfuric acid with a concentration of 98 wt%, and stir until uniform to obtain solution B. Put the sand core crucible into solution B and soak for 24 h. After soaking, take out the sand core crucible and place it on a Buchner funnel. Start the suction filtration, and rinse thoroughly with boiling water;

[0071] S3. Start the suction filtration, and pour solution A into the sand core crucible in 10 times to obtain filter residue;

[0072] S4. Put the sand core crucible and filter residue into an oven and dry at 100℃;

[0073] S5. Take out the filter residue, weigh it, prepare a sample, and use a scanning electron microscope to detect and identify insoluble carbon.

[0074] The application of the method for enriching and identifying insoluble carbon in tungsten carbide includes:

[0075] B1. According to the results of the scanning electron microscope, the proportion of graphite particles in insoluble carbon and the proportion of free carbon in insoluble carbon are calculated. After conversion, the proportion of graphite particles in tungsten carbide is 0.04%, and the proportion of free carbon in tungsten carbide is 0.08%.

[0076] B2. According to the proportion of graphite particles in tungsten carbide and the proportion of free carbon in tungsten carbide, adjust the carbonization process of tungsten carbide:

[0077] The proportion of graphite particles in tungsten carbide is greater than 0.02%, which leads to a significant increase in free carbon in tungsten carbide, thereby affecting the quality of tungsten carbide. Therefore, replace the graphite boat. After replacing the graphite boat, the free carbon in the produced tungsten carbide is 0.04%, and the free carbon is significantly reduced.

[0078] Example 2

[0079] A method for enriching and identifying insoluble carbon in tungsten carbide includes the following steps:

[0080] S1. Take 3.0 g of tungsten carbide and add it to a beaker. Then add 90 mL of hydrogen peroxide solution with a concentration of 27.5 wt% to the beaker. Heat the reactor on an electric furnace and boil for 60 min to obtain solution A;

[0081] S2. Take 20 g of potassium dichromate and dissolve it in 40 mL of pure water. Then slowly add 360 mL of concentrated sulfuric acid with a concentration of 98 wt% and stir until uniform to obtain solution B. Put the sand core crucible into solution B and soak for 24 h. After soaking, take out the sand core crucible and place it on a Buchner funnel. Start the suction filtration, and rinse thoroughly with boiling water;

[0082] S3. Start the suction filtration, and pour solution A into the sand core crucible in 15 times to obtain filter residue;

[0083] S4. Put the sand core crucible and filter residue together into the oven and dry at 100℃;

[0084] S5. Take out the filter residue, weigh it, and after sample preparation, use scanning electron microscopy to detect and identify insoluble carbon.

[0085] The application of the method for enriching and identifying insoluble carbon in tungsten carbide includes:

[0086] B1. According to the scanning electron microscopy results, calculate the proportion of graphite particles in insoluble carbon and the proportion of free carbon in insoluble carbon. After conversion, the proportion of graphite particles in tungsten carbide is 0.01%, and the proportion of free carbon in tungsten carbide is 0.08%.

[0087] B2. Adjust the tungsten carbide carbonization process according to the proportion of graphite particles in tungsten carbide and the proportion of free carbon in tungsten carbide:

[0088] The proportion of graphite particles in tungsten carbide is ≤0.02%, which has little effect on the content of free carbon in tungsten carbide. The existing graphite boat can continue to be used, and whether the carbonization process parameters need to be adjusted is determined according to the proportion of free carbon in tungsten carbide:

[0089] The proportion of free carbon in tungsten carbide is >0.06%, indicating that the high content of free carbon is caused by inappropriate carbonization process. After timely increasing the carbonization temperature and adjusting the carbonization process, the content of free carbon in the prepared tungsten carbide is 0.03%, and the content of free carbon is significantly reduced.

[0090] Example 3

[0091] A method for enriching and identifying insoluble carbon in tungsten carbide includes the following steps:

[0092] S1. Take 3.0g of tungsten carbide and add it to a beaker. Then add 90mL of hydrogen peroxide solution with a concentration of 27.5wt% to the beaker. Heat the reactor on an electric stove to boiling for 60min to obtain solution A;

[0093] S2. Dissolve 20g of potassium dichromate in 40mL of pure water, then slowly add 360mL of concentrated sulfuric acid with a concentration of 98wt% and stir evenly to obtain solution B. Put the sand core crucible into solution B and soak for 24h. After soaking, take out the sand core crucible and place it on a Buchner funnel. Turn on the suction filtration and rinse thoroughly with boiling water.

[0094] S3. Turn on the suction filtration and pour solution A into the sand core crucible in 15 times to obtain filter residue;

[0095] S4. Put the sand core crucible and filter residue together into the oven and dry at 100℃;

[0096] S5. Take out the filter residue, weigh it, and after sample preparation, use scanning electron microscopy to detect and identify insoluble carbon.

[0097] The application of the method for enriching and identifying insoluble carbon in tungsten carbide comprises the following steps:

[0098] B1. According to the scanning electron microscope results, the proportion of graphite particles in insoluble carbon and the proportion of free carbon in insoluble carbon are calculated, and after conversion, the proportion of graphite particles in tungsten carbide is 0.03%, and the proportion of free carbon in tungsten carbide is 0.06%;

[0099] B2. According to the proportion of graphite particles in tungsten carbide and the proportion of free carbon in tungsten carbide, the carbonization process of tungsten carbide is adjusted:

[0100] The proportion of graphite particles in tungsten carbide is greater than 0.02%, which leads to a significant increase in free carbon in tungsten carbide, thereby affecting the quality of tungsten carbide, so the graphite boat is replaced, and after replacing the graphite boat, the free carbon in the produced tungsten carbide is 0.03%, and the free carbon is significantly reduced.

[0101] The present application can effectively enrich the insoluble carbon in tungsten carbide, facilitate detection, and accurately determine the type of insoluble carbon (graphite particles or free carbon) in tungsten carbide; through analysis of the type and proportion of insoluble carbon, scientific feedback is provided for the adjustment of the carbonization process of tungsten carbide, which is conducive to improving the quality of tungsten carbide and facilitating large-scale industrialization and application.

[0102] The above is only a preferred embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structural transformation made under the inventive concept of the present application, or direct / indirect application in other related technical fields is included in the patent protection scope of the present application.

Claims

1. Use of a method for the enrichment and identification of insoluble carbon in tungsten carbide, characterized in that, Comprise: B1. According to the scanning electron microscope results, the proportion of graphite particles in insoluble carbon, the proportion of free carbon in insoluble carbon, and the proportion of graphite particles in tungsten carbide, the proportion of free carbon in tungsten carbide are calculated; B2. According to the proportion of graphite particles in tungsten carbide, the proportion of free carbon in tungsten carbide, the tungsten carbide carbonization process is adjusted: When the proportion of graphite particles in tungsten carbide is > 0.02%, replace the graphite boat; When the proportion of graphite particles in tungsten carbide is ≤0.02%, continue to use the existing graphite boat, and determine whether the carbonization process parameters need to be adjusted according to the proportion of free carbon in tungsten carbide: When the proportion of free carbon in tungsten carbide is > 0.06%, adjust the carbonization process parameters; When the proportion of free carbon in tungsten carbide is ≤0.06%, continue to use the existing carbonization process parameters; The enrichment and identification method of insoluble carbon in tungsten carbide comprises the following steps: S1. A certain amount of tungsten carbide is added to the reactor, and a certain amount of hydrogen peroxide solution is added to the reactor, and after heating and boiling, solution A is obtained; S2. Potassium dichromate is dissolved in pure water, and then concentrated sulfuric acid is slowly added and stirred uniformly to obtain solution B, and the sand core crucible is immersed in solution B; After soaking, the sand core crucible is taken out and placed on a Buchner funnel; S3. Open the suction filtration, pour the solution A into the sand core crucible in small amounts and multiple times, and filter to obtain the filter residue; S4. The sand core crucible and the filter residue are placed in an oven for drying; S5. The filter residue is taken out, weighed, and then sampled for scanning electron microscope detection and identification of insoluble carbon.

2. The use of the method for enriching and identifying insoluble carbon in tungsten carbide according to claim 1, characterized in that, In step S1, the solid-liquid ratio of tungsten carbide to hydrogen peroxide solution is 1g:(25~30)mL.

3. The use of the method for enriching and identifying insoluble carbon in tungsten carbide according to claim 1, characterized in that, In step S1, the concentration of hydrogen peroxide solution is 27~28wt%.

4. The use of the method for enriching and identifying insoluble carbon in tungsten carbide according to claim 1, characterized in that, In step S1, the heating and boiling time is 40~80min.

5. The use of the method for enriching and identifying insoluble carbon in tungsten carbide according to claim 1, characterized in that, In step S2, the solid-liquid ratio of potassium dichromate to pure water is 1g:(1.5~2.5)mL.

6. The use of the method for enriching and identifying insoluble carbon in tungsten carbide according to claim 1, characterized in that, In step S2, the concentration of concentrated sulfuric acid is 98wt%.

7. The use of the method for enriching and identifying insoluble carbon in tungsten carbide according to claim 1, characterized in that, In step S2, the volume ratio of pure water to concentrated sulfuric acid is 1:8~10.

8. The use of the method for enriching and identifying insoluble carbon in tungsten carbide according to claim 1, characterized in that, In step S2, the soaking time is 20~25h.

9. The use of the method for enriching and identifying insoluble carbon in tungsten carbide according to claim 1, characterized in that, In step S4, the drying temperature is 100~105℃.

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