A method for recovering abrasive grains and base solvent in a silicon carbide wafer multi-wire saw slurry

Abstract

The application discloses a method for recovering abrasive grains and base solvents in silicon carbide wafer multi-wire cutting mortar, which comprises the following steps: S1, cleaning a solid part A to remove residual oily substances and metal contaminants, and obtaining a solid part B; S2, adding a dispersant solution to the solid part B for ultrasonic dispersion treatment; S3, naturally settling the treated solid part B to remove suspended liquid, and obtaining primary diamond micro powder; and S4, treating the primary diamond micro powder with SC-1 (NH4OH (28%): H2O2 (30%): DIW=1:1:5) and ultrasonic waves to remove residual organic substances and extremely fine powder particles. The silicon carbide agglomerates are dis-agglomerated by the dispersant, the powder dispersibility is improved, and the silicon carbide powder can be completely separated out. The fine particles and organic substances adhered to the surface of the diamond are better treated clean by using the SC-1 solution and ultrasonic waves. The recovered diamond micro powder has a more round diamond crystal type, and is not easy to scratch during subsequent repeated use.

Description

Technical Field

[0001] This invention relates to the field of abrasive and grinding tool technology, and in particular to a method for recovering abrasive particles and basic solvents from silicon carbide wafer multi-wire cutting slurry. Background Technology

[0002] Silicon carbide, as a third-generation semiconductor material, boasts significant advantages in the history of functional semiconductor development, including higher saturation drift velocity and higher critical breakdown voltage. Third-generation semiconductor materials can meet the new demands of modern society for high temperature, high power, high voltage, high frequency, and radiation resistance. Furthermore, they offer economic and environmental benefits such as small size, low pollution, and low operating losses. Therefore, third-generation semiconductor materials are gradually becoming the focus of development. Currently, the mainstream third-generation semiconductor materials are silicon carbide and silicon nitride. The former is mostly used in high-voltage applications such as smart grids and rail transportation; the latter has greater applications in high-frequency fields (such as 5G).

[0003] With the continuous development of the global silicon carbide industry, China's domestic layout in this field is also relatively complete, and the industry as a whole is showing a thriving development trend. Since 2020, the usage of consumables such as cutting fluids and polishing fluids in silicon carbide wafer and silicon carbide wafer applications has gradually increased. Although there are many water-soluble cutting fluids on the market, oil-based cutting fluids are still the main type used in silicon carbide wafer cutting. With the increase in the use of slurry for multi-wire cutting of silicon carbide wafers, the diamond abrasive content in diamond cutting fluids is high, leading to an increase in the price of diamond abrasives; the amount of oil-based cutting waste liquid is increasing, resulting in serious environmental pollution. Therefore, the recycling and utilization of oil-based cutting fluids is of great significance.

[0004] Current research on mortar recycling mainly focuses on the recovery and reuse of abrasives from water-soluble mortars, with limited research on the recovery and reuse of abrasives from oil-based mortars. However, oil-based mortars are the mainstream product in the silicon carbide wafer processing industry, making the recovery of abrasives and the recycling of basic solvents from oil-based mortars an urgent issue. The main components of oil-based mortar waste liquid are oily substances (including base oil and oily additives), diamond powder, silicon carbide fragments, and wire debris (mainly Fe) lost during the cutting process. The most difficult aspects to handle in the post-processing of mortar waste liquid after cutting include: ① removal of residual oily substances from the solid components; ② complete separation of silicon carbide fine powder from diamond powder; and ③ recovery and reuse of basic solvents. Summary of the Invention

[0005] To address the shortcomings in the aforementioned background technology, this invention proposes a method for recovering abrasive particles and basic solvents from silicon carbide wafer multi-wire cutting slurry, solving the problem of difficulty in recovering abrasive particles from oily slurry used for silicon carbide wafer cutting in the prior art.

[0006] The technical solution of this invention is implemented as follows:

[0007] A method for recovering abrasive particles and basic solvents from silicon carbide wafer multi-wire cutting slurry includes obtaining a solid component A from the slurry waste liquid through solid-liquid separation, comprising the following steps:

[0008] S1. Clean the solid part A to remove residual oily substances and metal contaminants, and obtain the solid part B;

[0009] S2. Add solid part B to the dispersant solution and perform ultrasonic dispersion treatment to disperse the silicon carbide fine particle agglomerates in the solution;

[0010] S3. Allow the solid portion B after step S2 to settle naturally to remove the suspension and obtain primary diamond powder;

[0011] S4. The primary diamond micro powder is treated with SC-1 (NH4OH (28%):H2O2 (30%):DIW=1:1:5) and ultrasonically to remove residual organic matter and extremely fine powder particles.

[0012] Further, the primary diamond micro powder processed in step S4 is washed with pure water until neutral, and then freeze-dried at low temperature to obtain diamond micro powder.

[0013] Further, step S1 includes the following steps:

[0014] S11. Add solid part A to cleaning solution for cleaning to remove residual oily substances and obtain solid part A1;

[0015] S12. Wash solid part A1 with pure water to obtain solid part A2;

[0016] S13. The solid portion A2 is acid-washed to remove metallic contaminants, resulting in a mixture;

[0017] S14. Wash the mixture with pure water until it is colorless and separate the solid and liquid components to obtain solid part B.

[0018] Furthermore, the cleaning solution includes one or more of isopropanol, N-methylpyrrolidone, and dishwashing liquid.

[0019] Further, step S13 includes adding solid part A2 to an 8-16% hydrochloric acid solution, heating it on a 100°C heating plate, and when the solution temperature reaches 70-80°C, adding 30% hydrogen peroxide to the solution to remove metal contaminants.

[0020] Furthermore, the amount of hydrogen peroxide used is 0.3-1% of the hydrochloric acid solution.

[0021] Furthermore, the volume of the hydrochloric acid solution is 1.3-3 times the volume of the solid portion A2.

[0022] Furthermore, the volume of the SC-1 (NH4OH (28%):H2O2 (30%):DIW=1:1:5) solution is 1.2-3 times the volume of the primary diamond micron powder.

[0023] Furthermore, the dispersant is ammonium polyacrylate.

[0024] Furthermore, the upper solution C obtained after solid-liquid separation of the mortar waste liquid is filtered through a filtration device. The filter element of the filtration device is treated with pore sizes of 3um, 1um, 0.5um, and 100nm respectively to obtain the base oil solvent.

[0025] The beneficial effects of this invention are:

[0026] 1. The present invention uses a dispersant to deagglomerate silicon carbide agglomerates, thereby improving the powder dispersibility and enabling the silicon carbide powder to be completely separated, thus avoiding the silicon carbide agglomerates from settling together with diamond abrasive grains and becoming difficult to separate.

[0027] 2. By washing with pure water, some fine powder particles are removed by utilizing the difference in settling velocity;

[0028] 3. This invention uses diluted hydrochloric acid for pickling, which saves acid consumption and reduces pollution compared to the traditional process of using concentrated acid to remove metals. At the same time, the addition of hydrogen peroxide to catalyze the reaction results in higher processing efficiency and is more environmentally friendly.

[0029] 4. Using SC-1 solution and ultrasonic treatment can better remove fine particles and organic matter adhering to the diamond surface;

[0030] 5. The diamond micro powder recovered by this invention, after being cut by multi-wire cutting, has a more rounded diamond crystal shape, making it less prone to scratches during subsequent reuse;

[0031] 6. The diamond abrasive of this invention has a recycling rate of 70-90%; the base oil solvent can be recycled with a recycling rate of 60-80%, reducing the pollution caused by oily solvents to the environment. Attached Figure Description

[0032] To more clearly illustrate the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a comparison chart of the particle size detection results of the recycled material and the raw material in Example 1 of the present invention;

[0034] Figure 2 This is a comparison chart of the image analysis results of recycled material particles and raw material particles in Example 1 of the present invention;

[0035] Figure 3 This is a comparison chart of the particle size detection results of the recycled material and the raw material in Example 2 of the present invention;

[0036] Figure 4 This is a comparison chart of the image analysis results of the recycled material particles and the raw material particles in Example 2 of the present invention;

[0037] Figure 5 This is a comparison chart of the particle size detection results of the recycled material and the raw material in Example 3 of the present invention;

[0038] Figure 6 This is a comparison chart of the image analysis results of the recycled material particles and the raw material particles in Example 3 of the present invention. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Example 1

[0041] A type of silicon carbide wafer multi-wire cutting slurry waste liquid, whose main components are base oil, solvent oil, suspending agent, surfactant, corrosion inhibitor, extreme pressure agent, etc.

[0042] The steps for treating mortar waste liquid are as follows:

[0043] 1. Weigh the mortar waste liquid to be treated by weight m, and separate the solid and liquid by centrifugation or natural sedimentation. In order to speed up the processing efficiency, a high-speed centrifuge of model DL-8M from a certain manufacturer can be used to centrifuge at 3800r / min for 10min. The upper oily mixed solvent m1 and the bottom solid part m2 are kept for later use.

[0044] 2. The obtained solid portion m2 is processed as follows:

[0045] 1) Add N-methylpyrrolidone to the solid part m2 obtained in step 1 and wash it to remove residual oily substances. Then add isopropanol to the bottom solid part and treat it once.

[0046] 2) The solution treated with isopropanol was subjected to solid-liquid separation using a DL-8M high-speed centrifuge from a certain manufacturer at 3000 r / min for 10 min. The resulting solid fraction A1 was then used for further processing.

[0047] 3) Wash the obtained solid part A1 with pure water three times, and then let it settle naturally to separate into solid and liquid. Keep the obtained solid part A2 for later use.

[0048] 4) Add a 16% hydrochloric acid solution to the solid part A2 above. The amount of hydrochloric acid solution added is 1.3 times the volume of solid part A2. Place it on a 100°C heating plate and heat it. When the solution temperature reaches 80°C, add 0.3% of the hydrochloric acid solution to the solution and add 30% hydrogen peroxide to accelerate the reaction and remove the metal contamination introduced by the steel wire loss during the cutting process. At this time, the solution color changes from colorless and transparent to light yellow, and then to dark yellow and transparent solution.

[0049] 5) After solid-liquid separation of the above-mentioned treatment solution, the solid part is washed with pure water. After three cycles of pure water treatment, the upper pure water solution will become colorless.

[0050] 6) Repeat steps 4) and 5) above. When the upper hydrochloric acid solution turns colorless and no longer turns yellow when step 4) is repeated, it is determined that the Fe metal has been completely removed. After solid-liquid separation, the solid part B is obtained.

[0051] 7) Add 0.5% of the weight of Dow CA-2500 dispersant solution to the solid part B obtained in the above steps, and place it under a high-power ultrasonic cell disruptor for ultrasonic dispersion treatment for 3 minutes. The purpose is to deagglomerate the agglomerated silicon carbide fine particle agglomerates and make them uniformly dispersed in the solution.

[0052] 8) By utilizing natural sedimentation classification, silicon carbide powder and extremely fine crushed diamond powder suspended in the solution are removed when the abrasive particles settle to the bottom of the container.

[0053] 9) Repeat steps 7) and 8) multiple times until the upper solution is colorless and transparent and no fine silicon carbide powder particles are visible floating. At this time, the bottom solid turns yellowish-white, which is the primary diamond micro powder.

[0054] 10) The above primary diamond micro powder was treated with SC-1 (NH4OH (28%):H2O2 (30%):DIW=1:1:5) + ultrasound to remove residual organic matter and extremely fine powder particles from the micro powder; the amount of SC-1 (NH4OH (28%):H2O2 (30%):DIW=1:1:5) solution used was 1.2 times the volume of the solid in the container, i.e., the volume of the primary diamond micro powder, for quantitative determination;

[0055] 11) The diamond micro powder obtained by solid-liquid separation in step 10) above is washed with pure water until neutral, freeze-dried at low temperature, and weighed in m3.

[0056] 12) Submit diamond micron powder for testing, including ICP-AES, particle size analysis, roundness and particle morphology.

[0057] The upper oily mixed solution m1 obtained in step 1 is processed through the following steps:

[0058] 1) The upper oily mixed solution m1 is filtered through a filtration device with filter element pore sizes of 3um, 1um, 0.5um and 100nm respectively.

[0059] 2) Weigh m4 of the base oil solvent after it has been processed through 4 layers of filter elements, and then perform basic tests.

[0060] 4. Calculate the yield:

[0061] Diamond recovery rate = (m³ / m²) * 100%

[0062] Basic solvent recovery rate = (m4 / m1) * 100%.

[0063] The basic solvent recovery rate was 65%, and the test results are as follows:

[0064] The diamond abrasive recovery rate was 72%, and the test results are as follows:

[0065] The ICP-AES test results are as follows:

[0066]

[0067] The ICP-AES test results of the abrasive after the above steps show:

[0068] ① After solid-liquid separation of the mortar, the abrasive contains a large amount of Fe elements, which means it contains steel wire scrap mixed in during the cutting process; ② The ICP-AES test results of the treated abrasive meet the pre-shipment testing standards, with a total amount ≤100ppm.

[0069] The results of comparative testing of diamond abrasive and recycled materials are summarized below:

[0070] name MV SD D50 Circularity raw material 5.11 1.317 4.88 0.61 Recycled materials 5.0 1.443 4.67 0.65

[0071] like Figure 1 The image shows a comparison between the particle size analysis results of the recycled material and the raw material. Figure 2The images shown are the results of the analysis of recycled abrasive particles and raw material particles. The comparison revealed that, compared to the raw material test results, the recycled abrasive particle size was slightly smaller, while the particle roundness was increased, indicating that the abrasive particle roundness was better after multi-wire cutting.

[0072] Example 2

[0073] The second type of silicon carbide wafer multi-wire cutting slurry waste liquid mainly consists of base oil, solvent oil, suspending agent, surfactant, corrosion inhibitor, extreme pressure agent, etc.

[0074] The steps for treating mortar waste liquid are as follows:

[0075] 1. Weigh the mortar waste liquid to be treated by weight m, and centrifuge it for 10 minutes at 3000 r / min using a high-speed centrifuge of a certain manufacturer's DL-8M model. Keep the upper oily mixed solvent m1 and the bottom solid part m2 for later use.

[0076] 2. The obtained solid portion m2 is processed as follows:

[0077] 1) Add isopropanol to the solid part m2 obtained in step 1 and wash it once to remove residual oily substances. Then add isopropanol to the bottom solid part and treat it once more.

[0078] 2) The solution treated with isopropanol was subjected to solid-liquid separation using a DL-8M high-speed centrifuge from a certain manufacturer at 3000 r / min for 10 min. The resulting solid fraction A1 was kept for later use.

[0079] 3) Wash the obtained solid part A1 with pure water three times, and then let it settle naturally to separate into solid and liquid. Keep the obtained solid part A2 for later use.

[0080] 4) Add 8% hydrochloric acid solution to solid part A2, the amount of hydrochloric acid solution added is twice the volume of solid part A2, place it on a 100℃ heating plate and heat it. When the solution temperature reaches 70℃, add 0.6% of the hydrochloric acid solution to 30% hydrogen peroxide to accelerate the reaction and remove the metal contamination introduced by the steel wire loss during the cutting process; at this time, the solution color changes from colorless and transparent to light yellow, and then to dark yellow transparent solution;

[0081] 5) After solid-liquid separation of the above-mentioned treatment solution, the solid part is washed with pure water. After two rounds of pure water treatment, the upper pure water solution will become colorless.

[0082] 6) Repeat steps 4) and 5) above. When the upper hydrochloric acid solution turns colorless and no longer turns yellow when step 4) is repeated, it is determined that the Fe metal has been completely removed. After solid-liquid separation, the solid part B is obtained.

[0083] 7) Add 1% by weight of Dow CA-2500 dispersant solution to solid part B obtained in the above steps, and place it under a high-power ultrasonic cell disruptor for ultrasonic dispersion treatment for 3 minutes. The purpose is to deagglomerate the agglomerated silicon carbide fine particle agglomerates and make them uniformly dispersed in the solution.

[0084] 8) Using a high-speed centrifuge of model DL-8M from a certain manufacturer, the centrifugation process was carried out at a speed of 1000 r / min for 10 min. After centrifugation, the abrasive particles settled at the bottom of the container, removing the silicon carbide powder and extremely fine crushed diamond powder suspended in the solution.

[0085] 9) Repeat steps 7) and 8) multiple times until the upper solution is colorless and transparent and no fine silicon carbide powder particles are visible floating. At this time, the bottom solid turns yellowish-white, which is the primary diamond micro powder.

[0086] 10) The above primary diamond micro powder was treated with SC-1 (NH4OH (28%):H2O2 (30%):DIW=1:1:5) + ultrasound to remove residual organic matter and extremely fine powder particles from the micro powder; the amount of SC-1 (NH4OH (28%):H2O2 (30%):DIW=1:1:5) solution used was twice the volume of the solid in the container, i.e., the volume of the primary diamond micro powder, for quantitative determination; NH4OH (28%), H2O2 (30%), and DIW were ammonia, hydrogen peroxide, and ultrapure water, respectively.

[0087] 11) The diamond micro powder obtained by solid-liquid separation in step 10) above is washed with pure water until neutral, freeze-dried at low temperature, and weighed in m3.

[0088] 12) Submit diamond micron powder for testing, including ICP-AES, particle size analysis, roundness and particle morphology.

[0089] 3. The resulting upper oily mixed solution is processed through the following steps:

[0090] 1) The upper layer solution is filtered through a filtration device with filter elements of 3µm, 1µm, 0.5µm, and 100nm pore sizes.

[0091] 2) Weigh m4 of the base oil solvent after it has been processed through 4 layers of filter elements, and then perform basic tests.

[0092] 4. Calculate the yield.

[0093] Diamond recovery rate = (m³ / m²) * 100%

[0094] Basic solvent recovery rate = (m4 / m1) * 100%.

[0095] 5. The test results are as follows:

[0096] The basic solvent recovery rate was 78%, and the test results are as follows:

[0097]

[0098] The diamond abrasive recovery rate was 90%, and the test results are as follows:

[0099] The ICP-AES test results are as follows:

[0100]

[0101] The ICP-AES test results of the abrasive after the above steps show:

[0102] ① After solid-liquid separation of the mortar, the abrasive contains a large amount of Fe elements, which means it contains steel wire scrap mixed in during the cutting process; ② The ICP-AES test results of the treated abrasive meet the pre-shipment testing standards, with a total amount ≤100ppm.

[0103] The results of comparative testing of diamond abrasive and recycled materials are summarized below:

[0104] name MV SD D50 Circularity raw material 5.34 1.257 5.13 0.62 Recycled materials 5.12 1.290 4.89 0.65

[0105] like Figure 3 The image shows a comparison between the particle size analysis results of the recycled material and the raw material. Figure 4 The images shown are the results of the analysis of recycled abrasive particles and raw material particles. The comparison revealed that, compared to the raw material test results, the recycled abrasive particle size was slightly smaller, while the particle roundness was increased, indicating that the abrasive particle roundness was better after multi-wire cutting.

[0106] Example 3

[0107] A type of silicon carbide wafer multi-wire cutting slurry waste liquid, whose main components are base oil, solvent oil, suspending agent, surfactant, corrosion inhibitor, extreme pressure agent, etc.

[0108] The steps for treating mortar waste liquid are as follows:

[0109] 1. Weigh the mortar waste liquid to be treated by weight m, and centrifuge it for 10 minutes at 3500 r / min using a high-speed centrifuge of a certain manufacturer's DL-8M model. Keep the upper oily mixed solvent m1 and the bottom solid part m2 for later use.

[0110] 2. The obtained solid portion m2 is processed as follows:

[0111] 1) Add isopropanol to the solid part m2 and wash it once to remove residual oily substances. Then add dish soap to the bottom solid part and treat it twice.

[0112] 2) The solution treated with the above detergent was subjected to solid-liquid separation using a DL-8M high-speed centrifuge from a certain manufacturer at 3000 r / min for 10 min. The resulting solid fraction A1 was reserved for later use.

[0113] 3) Wash the obtained solid part A1 with pure water three times, and then let it settle naturally to separate into solid and liquid. Keep the obtained solid part A2 for later use.

[0114] 4) Add a 12% hydrochloric acid solution to the solid part A2 above. The amount of hydrochloric acid solution added should be three times the volume of solid part A2. Place the solution on a 100°C heating plate and heat it. When the solution temperature reaches 75°C, add 1% of the hydrochloric acid solution and 30% hydrogen peroxide to the solution to accelerate the reaction and remove the metal contamination introduced by the steel wire loss during the cutting process. At this time, the solution color changes from colorless and transparent to light yellow, and then to a deep yellow and transparent solution.

[0115] 5) After solid-liquid separation of the above-mentioned treatment solution, the solid part is washed with pure water. After two rounds of pure water treatment, the upper pure water solution will turn colorless.

[0116] 6) Repeat steps 4) and 5) above until the upper hydrochloric acid and hydrogen peroxide solution are colorless and no longer turn yellow when step 4) is repeated. Then it is determined that the metal Fe has been completely removed and the solid part B is obtained after solid-liquid separation.

[0117] 7) Add 0.5% by weight of Dow CA-2500 dispersant solution to solid part B obtained in the above steps, and place it under a high-power ultrasonic cell disruptor for ultrasonic dispersion treatment for 3 minutes. The purpose is to deagglomerate the agglomerated silicon carbide fine particle agglomerates and make them uniformly dispersed in the solution.

[0118] 8) Using a high-speed centrifuge of model DL-8M from a certain manufacturer, the centrifugation process was carried out at a speed of 2000 r / min for 10 min. After centrifugation, the abrasive particles settled at the bottom of the container, removing the silicon carbide powder and extremely fine crushed diamond powder suspended in the solution.

[0119] 9) Repeat steps 7) and 8) multiple times until the upper solution is colorless and transparent and no fine silicon carbide powder particles are visible floating. At this time, the solid at the bottom turns yellowish-white, which is the primary diamond micro powder.

[0120] 10) The above primary diamond micro powder was treated with SC-1 (NH4OH (28%):H2O2 (30%):DIW=1:1:5) + ultrasound to remove residual organic matter and extremely fine powder particles from the micro powder; the amount of SC-1 (NH4OH (28%):H2O2 (30%):DIW=1:1:5) solution used was 1.5 times the volume of the solid in the container, i.e., the volume of the primary diamond micro powder, for quantitative determination;

[0121] 11) The diamond micro powder obtained by solid-liquid separation in step 10) above is washed with pure water until neutral, freeze-dried at low temperature, and weighed in m3.

[0122] 12) Submit diamond micron powder for testing, including ICP-AES, particle size analysis, roundness and particle morphology.

[0123] 3. The upper oily mixed solution m1 obtained in step 1 is processed through the following steps:

[0124] 1) The upper oily mixed solution m1 is filtered through a filtration device with filter element pore sizes of 3um, 1um, 0.5um and 100nm respectively.

[0125] 2) Weigh m4 of the base oil solvent after it has been processed through 4 layers of filter elements, and then perform basic tests.

[0126] 4. Calculate the yield.

[0127] Diamond recovery rate = (m³ / m²) * 100%

[0128] Basic solvent recovery rate = (m4 / m1) * 100%.

[0129] 5. The test results are as follows:

[0130] The basic solvent recovery rate was 70%, and the test results are as follows:

[0131]

[0132] The diamond abrasive recovery rate was 80%, and the test results are as follows:

[0133] The ICP-AES test results are as follows:

[0134]

[0135] The ICP-AES test results of the abrasive after the above steps show:

[0136] ① After solid-liquid separation of the mortar, the abrasive contains a large amount of Fe elements, which means it contains steel wire scrap mixed in during the cutting process; ② The ICP-AES test results of the treated abrasive meet the pre-shipment testing standards, with a total amount ≤100ppm.

[0137] The results of comparative testing of diamond abrasive and recycled materials are summarized below:

[0138] name MV SD D50 Circularity raw material 5.24 1.305 5.01 0.64 Recycled materials 5.06 1.282 4.83 0.69

[0139] like Figure 5 The image shows a comparison between the particle size analysis results of the recycled material and the raw material. Figure 6 The images shown are the results of the analysis of recycled abrasive particles and raw material particles. The comparison revealed that, compared to the raw material test results, the recycled abrasive particle size was slightly smaller, while the particle roundness was increased, indicating that the abrasive particle roundness was better after multi-wire cutting.

[0140] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for recovering abrasive grains and base solvent in a silicon carbide wafer multi-wire saw slurry, comprising: passing the slurry waste liquid through a solid-liquid separation to obtain a solid part A, characterized in that, Includes the following steps: S1. Clean the solid part A to remove residual oily substances and metal contaminants, and obtain the solid part B; S2. Add solid part B to the dispersant solution and perform ultrasonic dispersion treatment to disperse the silicon carbide fine particle agglomerates in the solution; S3. Allow the solid portion B after step S2 to settle naturally to remove the suspension and obtain primary diamond powder; S4. The primary diamond micro powder is treated with SC-1 (NH4OH (28%):H2O2 (30%):DIW=1:1:5) and ultrasonically to remove residual organic matter and extremely fine powder particles; Step S1 includes the following steps: S11. Add solid part A to cleaning solution for cleaning to remove residual oily substances and obtain solid part A1; S12. Wash solid part A1 with pure water to obtain solid part A2; S13. The solid portion A2 is acid-washed to remove metallic contaminants, resulting in a mixture; S14. Wash the mixture with pure water until it is colorless and then separate the solid and liquid components to obtain solid part B; Step S13 includes adding solid part A2 to an 8-16% hydrochloric acid solution, heating it on a 100°C heating plate, and adding 30% hydrogen peroxide to the solution when the solution temperature reaches 70-80°C to remove metal contaminants.

2. The method of reclaiming abrasive particles from a base solvent in a silicon carbide wafer multi-wire saw slurry according to claim 1, wherein: It also includes the following steps: S5. After washing the primary diamond micro powder processed in step S4 with pure water until neutral, freeze-dry it at low temperature to obtain diamond micro powder.

3. The method for recovering abrasive particles and basic solvents from silicon carbide wafer multi-wire cutting slurry according to claim 1 or 2, characterized in that: The cleaning solution includes one or more of isopropanol, N-methylpyrrolidone, and dishwashing liquid.

4. The method for recovering abrasive particles and basic solvents from silicon carbide wafer multi-wire cutting slurry according to claim 1 or 2, characterized in that: The amount of hydrogen peroxide used is 0.3-1% of the hydrochloric acid solution.

5. The method for recovering abrasive particles and basic solvents in silicon carbide wafer multi-wire cutting slurry according to claim 4, characterized in that: The volume of the hydrochloric acid solution is 1.3 to 3 times the volume of the solid portion A2.

6. The method for recovering abrasive particles and basic solvents from silicon carbide wafer multi-wire cutting slurry according to claim 1, 2, or 5, characterized in that: The volume of the SC-1 (NH4OH (28%):H2O2 (30%):DIW=1:1:5) solution is 1.3-3 times the volume of the primary diamond micron powder.

7. The method for recovering abrasive particles and basic solvents from silicon carbide wafer multi-wire cutting slurry according to claim 1, 2, or 5, characterized in that: The dispersant is ammonium polyacrylate.

8. The method for recovering abrasive particles and basic solvent in silicon carbide wafer multi-wire cutting slurry according to claim 1, 2, or 5, characterized in that: The upper solution C obtained after solid-liquid separation of the mortar waste liquid is filtered through a filtration device. The filter element of the filtration device is treated with pore sizes of 3um, 1um, 0.5um and 100nm respectively to obtain the base oil solvent.

Images