Method for recycling waste slurry of silicon carbide wafer free abrasive multi-wire sawing

Abstract

A method for recycling waste slurry of silicon carbide wafer free abrasive multi-wire sawing, comprising the following steps: (1) uniformly mixing the waste slurry and an organic solvent to obtain a mixture slurry; (2) separating the slurry into a liquid mixture and a filter cake, separating the liquid mixture into mineral oil and the organic solvent by using the difference in volatility of components, recycling the organic solvent, mixing the filter cake after washing and drying with an acid solution to obtain a solid-liquid mixture; (3) separating the solid in the solid-liquid mixture to obtain a filter cake, washing and drying the filter cake and then performing oxidation treatment to obtain a mixed powder; (4) grading the mixed powder to obtain diamond micro powder and silicon carbide micro powder; the present application reduces the viscosity of the waste slurry by using the organic solvent, so that the solid particles are easily separated; the boiling point difference between the organic solvent and the mineral oil in the waste slurry is large, and the two are easily separated; the particle size and density of the diamond particles and the silicon carbide particles are obviously different, and they are easily separated in the aqueous solution; and the present application has the characteristics of high recovery rate.

Description

Technical Field

[0001] This invention belongs to the field of resource utilization technology of mineral oil-containing waste, and specifically relates to a method for resource utilization of waste slurry from multi-wire cutting of silicon carbide wafers containing free abrasive. Background Technology

[0002] The fields of communication technology, high-speed rail transit, new energy vehicles, uninterruptible power supplies, solar energy, smart grids, new energy grid integration, fast charging, and wireless charging have presented new challenges to the performance of power devices. Traditional silicon devices, limited by the properties of silicon material, have reached their theoretical limits, and their performance is far from meeting the demands. Driven by Moore's Law, finding a replacement for silicon devices has become imperative. Therefore, semiconductor manufacturers are turning their attention to silicon carbide (SiC), a third-generation semiconductor material.

[0003] As a wide-bandgap semiconductor material with advantages such as high critical breakdown field strength, high electron saturation drift velocity, and high thermal conductivity, silicon carbide (SiC) is an excellent material for fabricating high-temperature, high-power, high-voltage, high-frequency, and radiation-resistant miniaturized power semiconductor devices. Furthermore, due to its highly matched lattice constant and coefficient of thermal expansion with the epitaxial material gallium nitride (GaN), SiC is an ideal substrate material for GaN-based devices. SiC has become an indispensable substrate material in the field of semiconductor lighting technology.

[0004] Semiconductor devices fabricated using silicon carbide as a substrate can better meet the application requirements under conditions such as high temperature, high pressure, and high power. Silicon carbide wafer fabrication technology is a crucial foundation for device manufacturing, and the quality and precision of its surface processing directly affect the quality of the epitaxial thin film and the performance of the device. However, due to the characteristics of silicon carbide crystals—high hardness, high brittleness, good wear resistance, and stable chemical properties—silicon carbide wafer fabrication is extremely difficult.

[0005] The precision machining processes for silicon carbide wafers mainly include the following: directional cutting, grinding (rough grinding and fine grinding), polishing (mechanical polishing) and ultra-precision polishing (chemical mechanical polishing).

[0006] Currently, there are three technologies for cutting and processing silicon carbide wafers: free abrasive multi-wire cutting, diamond wire multi-wire cutting, and laser cutting.

[0007] Free abrasive multi-wire cutting technology is the most mature and is currently the mainstream technology for silicon carbide wafer cutting in China. The abrasive used in the free abrasive cutting process for silicon carbide wafers is 10-15μm diamond powder, and the dispersion medium is usually mineral oil, with mineral oil and diamond powder mixed in a 9:1 ratio to form the cutting slurry. A steel wire carries the diamond powder, rolling it at high speed on a silicon carbide rod. The higher hardness of the diamond powder sculpts the silicon carbide rod, achieving the purpose of cutting the silicon carbide rod into wafers. During the cutting process, silicon carbide debris and steel wire debris (mainly composed of iron) continuously mix into the cutting fluid, causing its viscosity to increase and rendering it unusable, thus becoming waste slurry. The main components of waste slurry are mineral oil, fine diamond powder, steel wire debris, and silicon carbide powder. Because it contains mineral oil, it is harmful to the environment and has been identified as hazardous waste by environmental protection departments. Therefore, the resource utilization of waste slurry is of great significance for improving environmental quality and increasing resource utilization efficiency.

[0008] Diamond wire cutting technology is a second-generation cutting technology, attracting much attention due to its high cutting speed and high yield. However, this technology suffers from high material costs and difficulties in splicing silicon carbide rods. Currently, it is only considered as an option for cutting technology iteration and has not yet been widely adopted in China.

[0009] Laser cutting technology is the third-generation technology for cutting silicon carbide wafers. Due to its high cutting speed, high material utilization rate, and high-quality silicon carbide wafers, it is considered the ultimate technology for silicon carbide wafer cutting. However, its high technical content, large equipment investment, and the difficulty of cutting large-size silicon carbide wafers have prevented its industrial application in China. Summary of the Invention

[0010] To overcome the shortcomings of free abrasive multi-wire cutting technology, this invention aims to provide a method for the resource utilization of waste slurry from free abrasive multi-wire cutting of silicon carbide wafers. This method recycles the waste slurry generated during the cutting process of silicon carbide wafers with free abrasive, solving the problems of environmental pollution and waste of diamond powder caused by direct discharge of waste slurry.

[0011] The objective of this invention can be achieved through the following technical solutions:

[0012] A method for resource recovery of waste slurry from multi-wire cutting of silicon carbide wafers using free abrasive materials includes the following steps:

[0013] (1) Add organic solvent A to the waste mortar that is being stirred to obtain a mixture slurry;

[0014] (2) Separate the slurry mixture into a liquid mixture and a filter cake;

[0015] (3) Separate the liquid mixture into mineral oil and organic solvent A;

[0016] (4) Wash the filter cake repeatedly with organic solvent A several times. Mix the washing liquid with the liquid mixture in step (2), wash it once with organic solvent B, and then centrifuge to separate it. Dry the separated filter cake and then put the dried solid mixture into an acid solution under stirring to carry out the digestion reaction.

[0017] (5) After the digestion reaction is completed, the solid in the mixture is separated, and the obtained filter cake is dispersed in pure water to obtain a solid-liquid mixture. Then the solid in the solid-liquid mixture is separated again to obtain a filter cake. After the filter cake is dried, a solid mixture is obtained.

[0018] (6) Oxidize the solid mixture;

[0019] (7) The solid mixture after oxidation treatment is hydraulically classified to obtain a suspension of diamond micro powder and silicon carbide micro powder. The silicon carbide suspension is centrifuged to obtain silicon carbide micro powder.

[0020] In step (1), the waste slurry is a slurry produced by the continuous mixing of silicon carbide debris and steel wire debris into the cutting fluid during the cutting process of silicon carbide wafer free abrasive. Its components include mineral oil, diamond powder, silicon carbide powder and / or steel wire debris.

[0021] In step (1), organic solvent A is gasoline, naphtha, solvent oil or oxygen-containing organic compound, and the oxygen-containing organic compound is one or more of low-boiling alcohols, ethers, ketones and esters in any proportion.

[0022] In step (1), the mass ratio of waste mortar to organic solvent A is 1:(0.1-20).

[0023] In step (1), after organic solvent A and waste mortar are mixed, the temperature of the mixed slurry is controlled at 10℃~80℃, preferably 20℃~50℃.

[0024] In step (3), the separation of mineral oil and organic solvent is achieved by distillation or rectification, and the separation is carried out under normal or reduced pressure conditions.

[0025] In step (4), organic solvent B is one or more low-boiling alcohols, ethers, ketones, and esters in any proportion.

[0026] In step (4), the drying is carried out in air or in a vacuum at a temperature of 80°C to 180°C.

[0027] In step (4), the acid solution is one or more of hydrochloric acid, sulfuric acid, phosphoric acid, and hydrofluoric acid in any proportion, and the mass ratio of the solid mixture to the acid is 1:(0.5-10).

[0028] In step (4), the digestion reaction temperature is maintained at 10℃~80℃ and the reaction time does not exceed 24h.

[0029] In step (5), drying is carried out in air or in a vacuum at a temperature of 80°C to 120°C.

[0030] In step (6), during the oxidation treatment, a water-soluble compound is used as a catalyst; the catalyst is one or more of alkali metal compounds, nitric acid, sulfuric acid, and ammonium hydroxide in any proportion; the oxidant is one or more of normal oxides, peroxides, superoxides, and ozonides in any proportion, and the oxidation temperature does not exceed 800°C.

[0031] The solid mixture in step (7) is subjected to hydraulic classification, and the classification fluid medium is water or an aqueous solution.

[0032] The beneficial effects of this invention are:

[0033] 1. In step (1) of the present invention, the solid-liquid separation of the slurry is promoted by introducing an organic solvent, thereby improving the separation efficiency.

[0034] 2. This invention utilizes the difference between the boiling points of mineral oil and organic solvents to achieve the recovery of mineral oil and the recycling of organic solvents, thereby reducing environmental pollution.

[0035] 3. Step (6) of the present invention removes organic residues from the solid mixture through oxidation.

[0036] 4. In step (7) of the present invention, hydraulic classification is used to achieve effective separation of diamond micro powder and silicon carbide micro powder.

[0037] In summary, this invention provides a method for the resource utilization of waste abrasive generated during the cutting of silicon carbide wafers using free abrasive, solving the problems of environmental pollution and waste of diamond powder caused by direct discharge of waste abrasive slurry. The mineral oil recovered by this invention can be used as a base solvent or fuel oil; the recovered diamond powder has sharp edges, a smooth surface, and no cracking issues, and can be used to prepare fresh cutting slurry; the mineral oil recovery rate of this invention is ≥95%, the diamond powder recovery rate is ≥90%, and the silicon carbide powder recovery rate is ≥90%. Attached Figure Description

[0038] Figure 1 This is a flowchart illustrating the process for the resource utilization of waste slurry from multi-wire cutting of silicon carbide wafers according to the present invention.

[0039] Figure 2 The mineral oil and recycled organic solvents are recovered using the method described in Example 1 of this invention.

[0040] Figure 3This is a comparison image of the microstructure of diamond powder recovered using the method described in Example 2 of this invention with that of the original powder.

[0041] Figure 4 The microstructure of silicon carbide micropowder recovered by the method described in Example 2 of this invention is shown at different magnifications.

[0042] Figure 5 The appearance of the diamond micron powder recovered using the method described in Example 5 of this invention. Detailed Implementation

[0043] The method described in this invention will now be clearly and completely described in conjunction with the accompanying drawings and embodiments.

[0044] Example 1

[0045] This embodiment includes the following steps:

[0046] (1)Reference Figure 1 Place 10g of waste mortar into a 100mL polytetrafluoroethylene beaker, place the polytetrafluoroethylene beaker in a constant temperature water bath, maintain the water bath temperature at 30℃, keep the waste mortar in a stirring state, and after the mortar temperature stabilizes, add 30g of 89# gasoline dropwise, and keep stirring for 2 hours after the addition is complete.

[0047] (2) The mixture slurry is separated by centrifugation to obtain a liquid mixture and a filter cake;

[0048] (3) Separate the liquid mixture into mineral oil and 89# gasoline, refer to Figure 2 Specifically, all the liquids obtained from centrifugation were mixed and distilled under a pressure of 500 Pa to obtain 8.8 g of mineral oil.

[0049] (4) The filter cake was uniformly dispersed in 10g of 89# gasoline and washed to obtain a solid-liquid mixture. Then, the mixture was centrifuged to obtain a filter cake. The above dispersion-centrifugation operation was repeated eight times. The obtained filter cake was uniformly dispersed in 10g of methyl tert-butyl ether and then centrifuged to obtain filter cake A. A was dried in air for 15h at a drying temperature of 140℃. The dried solid mixture was added to 40mL of 20% sulfuric acid to form a solid-liquid mixture. The temperature of the solid-liquid mixture was maintained at 50℃ and stirred overnight.

[0050] (5) Centrifuge the above solid-liquid mixture to obtain a filter cake. Disperse the filter cake evenly in 40 mL of pure water to obtain a solid-liquid mixture. Then centrifuge the mixture to obtain a filter cake. Repeat the above dispersion-centrifugation operation until the liquid obtained by centrifugation is neutral. Finally, dry the filter cake B obtained by solid-liquid separation in air for 12 h at a drying temperature of 100 °C.

[0051] (6) The solid mixture obtained by drying above was ultrasonically dispersed into 10 mL of SPM cleaning solution (H2SO4:H2O2:H2O=5:1:1) for oxidation reaction;

[0052] (7) After reacting for 12 hours, water was heated for hydraulic classification to obtain diamond micro powder and silicon carbide suspension. The silicon carbide suspension was centrifuged to obtain silicon carbide micro powder.

[0053] Example 2

[0054] This embodiment includes the following steps:

[0055] (1) Place 15g of waste mortar into a 50mL polytetrafluoroethylene beaker, place the polytetrafluoroethylene beaker in a constant temperature water bath, maintain the water bath temperature at 30℃, keep the waste mortar in a stirring state, and add 40g of solvent naphtha after the mortar temperature stabilizes. After adding the naphtha, keep stirring for 3 hours.

[0056] (2) The mixture slurry is separated by centrifugation to obtain a liquid mixture and a filter cake;

[0057] (3) Separate the liquid mixture into mineral oil and naphtha. Specifically, all the liquids obtained by centrifugation above are mixed and distilled at a pressure of 200 Pa to obtain 13g of mineral oil.

[0058] (4) The filter cake was uniformly dispersed in 10g of solvent naphtha and washed to obtain a solid-liquid mixture. Then, the mixture was centrifuged to obtain the filter cake. The above dispersion-centrifugation operation was repeated six times. Finally, the obtained filter cake was uniformly dispersed in 15g of ethanol and centrifuged to obtain filter cake C. C was dried in air for 15h at a drying temperature of 140℃. The dried solid mixture was added to 50mL of 20% sulfuric acid to form a solid-liquid mixture. The temperature of the solid-liquid mixture was maintained at 50℃ and stirred overnight.

[0059] (5) Centrifuge the above solid-liquid mixture to obtain a filter cake. Disperse the filter cake evenly in 40 mL of pure water to obtain a solid-liquid mixture. Then centrifuge to obtain a filter cake. Repeat the above dispersion-centrifugation operation until the liquid obtained by centrifugation is neutral. Finally, dry the filter cake B obtained by solid-liquid separation in air for 12 h at a drying temperature of 120 °C.

[0060] (6) The solid mixture obtained by drying above and 0.5g sodium bicarbonate + potassium nitrate were mixed and heat-treated in an oxygen atmosphere at 360℃ for 6h.

[0061] (7) The reaction product is added to water for hydraulic classification to obtain diamond micro powder and silicon carbide suspension. The silicon carbide suspension is centrifuged to obtain silicon carbide micro powder.

[0062] like Figure 3 The image shown is a comparison of the microstructure of the diamond powder recovered using the method described in this embodiment, illustrating that the microstructure of the recovered powder and the original powder are consistent.

[0063] like Figure 4 The figure shows the microstructure of silicon carbide micro powder recovered by the method described in this embodiment at different magnifications, illustrating that silicon carbide micro powder was obtained by the method of the present invention.

[0064] Example 3

[0065] This embodiment includes the following steps:

[0066] (1) Put 10g of waste mortar into a 100mL polytetrafluoroethylene beaker, place the polytetrafluoroethylene beaker in a constant temperature water bath, and maintain the water bath temperature at 30℃; keep the waste mortar in a stirring state, and after the mortar temperature stabilizes, add 40g of 120# solvent oil, and keep stirring for 2 hours after adding the oil.

[0067] (2) The mixture slurry is separated by centrifugation to obtain a liquid mixture and a filter cake;

[0068] (3) Separate the liquid mixture into mineral oil and 120# solvent oil. Specifically, mix all the liquids obtained by centrifugation and perform simple distillation at a pressure of 100 Pa to obtain 8.9 g of mineral oil.

[0069] (4) Disperse the filter cake evenly into 10g of 120# solvent oil to obtain a solid-liquid mixture, and then centrifuge to obtain the filter cake. Repeat the above dispersion-centrifugation operation eight times. Finally, disperse the filter cake evenly into 15g of ethanol. Then centrifuge to obtain filter cake E. Dry E in air for 15h at a drying temperature of 160℃. Add the dried solid mixture to 50mL of 30% hydrochloric acid + sulfuric acid mixture to form a solid-liquid mixture. Maintain the temperature of the solid-liquid mixture at 40℃ and stir overnight.

[0070] (5) Centrifuge the above solid-liquid mixture to obtain a filter cake. Disperse the filter cake evenly in 50 mL of pure water to obtain a solid-liquid mixture. Then centrifuge the mixture to obtain a filter cake. Repeat the above dispersion-centrifugation operation until the liquid obtained by centrifugation is neutral. Finally, dry the filter cake F obtained by solid-liquid separation in air for 12 h at a drying temperature of 120 °C.

[0071] (6) The solid mixture obtained by drying above was ultrasonically dispersed into 10 mL of APM cleaning solution (NH4OH:H2O2:H2O=1:1:5) for oxidation reaction;

[0072] (7) After reacting for 12 hours, water was heated for hydraulic classification to obtain diamond fine powder and silicon carbide suspension. The silicon carbide suspension was centrifuged to obtain silicon carbide micro powder.

[0073] Example 4

[0074] This embodiment includes the following steps:

[0075] (1) Put 10g of waste mortar into a 100mL polytetrafluoroethylene beaker, place the polytetrafluoroethylene beaker in a constant temperature water bath, and maintain the water bath temperature at 30℃; keep the waste mortar in a stirring state, and after the mortar temperature stabilizes, add 30g of cyclohexanone to the mixture, and keep stirring for 1h after the addition is complete.

[0076] (2) The mixture slurry is separated by centrifugation to obtain a liquid mixture and a filter cake;

[0077] (3) Separate the liquid mixture into mineral oil and cyclohexanone. Specifically, mix all the liquids obtained by centrifugation and distill them under a pressure of 100 Pa to obtain 8.6 g of mineral oil.

[0078] (4) Disperse the filter cake evenly into 10g of cyclohexanone to obtain a solid-liquid mixture, and then centrifuge to obtain the filter cake. Repeat the above dispersion-centrifugation operation eight times. Finally, disperse the obtained filter cake evenly into 15g of diethyl ether, and then centrifuge to obtain filter cake G. Dry G in air for 15h at a drying temperature of 160℃. Add the dried solid mixture to 40mL of 25% phosphoric acid + sulfuric acid mixed acid to form a solid-liquid mixture. Maintain the temperature of the solid-liquid mixture at 60℃ and stir overnight.

[0079] (5) Centrifuge the above solid-liquid mixture to obtain a filter cake. Disperse the filter cake evenly in 40 mL of pure water to obtain a solid-liquid mixture. Then centrifuge the mixture to obtain a filter cake. Repeat the above dispersion-centrifugation operation until the liquid obtained by centrifugation is neutral. Finally, dry the filter cake H obtained by solid-liquid separation in air for 12 h at a drying temperature of 120 °C.

[0080] (6) The solid mixture obtained by drying above is added to 10 mL of concentrated sulfuric acid with a mass fraction of 96% to form a suspension. After heating the suspension to boiling, 2 mL of concentrated nitric acid with a mass fraction of 67% is added dropwise to the suspension to carry out an oxidation reaction.

[0081] (7) After reacting for 6 hours, water was added for hydraulic classification to obtain diamond micro powder and silicon carbide suspension; the silicon carbide suspension was centrifuged to obtain silicon carbide micro powder.

[0082] Example 5

[0083] This embodiment includes the following steps:

[0084] (1) Place 10g of waste mortar into a 50mL polytetrafluoroethylene beaker, place the polytetrafluoroethylene beaker in a constant temperature water bath, and maintain the water bath temperature at 30℃; keep the waste mortar in a stirring state, and add 35g of solvent naphtha after the mortar temperature stabilizes. After adding the naphtha, keep stirring for 1 hour.

[0085] (2) The mixture slurry is separated by centrifugation to obtain a liquid mixture and a filter cake;

[0086] (3) Separate the liquid mixture into mineral oil and naphtha. Specifically, mix all the liquids obtained by centrifugation and distill them under a pressure of 100 Pa to obtain 8.7 g of mineral oil.

[0087] (4) The filter cake was evenly dispersed in 15g of solvent naphtha to obtain a solid-liquid mixture. Then, the mixture was centrifuged to obtain the filter cake. The above dispersion-centrifugation operation was repeated six times. Finally, the obtained filter cake was evenly dispersed in 15g of ethanol and centrifuged to obtain filter cake K. K was dried in air for 15h at a drying temperature of 140℃. The solid mixture obtained by the above drying was added to 40mL of sulfuric acid with a mass fraction of 20% to form a solid-liquid mixture. The temperature of the solid-liquid mixture was maintained at 50℃ and stirred overnight.

[0088] (5) Centrifuge the above solid-liquid mixture to obtain a filter cake. Disperse the filter cake evenly in 40 mL of pure water to obtain a solid-liquid mixture. Then centrifuge to obtain a filter cake. Repeat the above dispersion-centrifugation operation until the liquid obtained by centrifugation is neutral. Finally, dry the filter cake L obtained by solid-liquid separation in air for 12 h at a drying temperature of 120 °C.

[0089] (6) The solid mixture obtained by drying above was added to 10 mL of 72% perchloric acid, 0.1 g of potassium chromate was added, and the solution was heated to carry out the oxidation reaction;

[0090] (7) After reacting for 6 hours, water was added for hydraulic classification to obtain diamond micro powder and silicon carbide suspension. The silicon carbide suspension was centrifuged to obtain silicon carbide micro powder.

[0091] like Figure 5 As shown in the figure, the appearance of the diamond micron powder recovered by the method is consistent with that of the original powder.

[0092] This invention uses organic solvents to reduce the viscosity of waste mortar, making it easy to separate solid particles. The boiling point of the organic solvent differs significantly from that of the mineral oil in the waste mortar, facilitating their separation. Furthermore, the mixed powder exhibits significant differences in particle size and density between diamond and silicon carbide particles, allowing for easy separation in water or aqueous solutions. This invention features high recovery rates of diamond micron powder, silicon carbide micron powder, and mineral oil.

Claims

1. A method for resource utilization of waste slurry from multi-wire cutting of silicon carbide wafers using free abrasive, characterized in that, Includes the following steps: (1) Add organic solvent A to the waste mortar that is being stirred to obtain a mixed slurry; (2) Separate the slurry mixture into a liquid mixture and a filter cake; (3) Separate the liquid mixture into mineral oil and organic solvent A; (4) Wash the filter cake repeatedly with organic solvent A several times, mix the washing liquid with the liquid mixture in step (2), wash it once with organic solvent B, then centrifuge to separate it, dry the separated filter cake, and then put the dried solid mixture into an acid solution under stirring to carry out the digestion reaction. (5) After the digestion reaction is completed, the solid in the mixture is separated, and the obtained filter cake is dispersed in pure water to obtain a solid-liquid mixture. Then the solid in the solid-liquid mixture is separated again to obtain a filter cake. After the filter cake is dried, a solid mixture is obtained. (6) Oxidize the solid mixture; (7) The solid mixture after oxidation treatment is subjected to hydraulic classification to obtain a suspension of diamond micro powder and silicon carbide micro powder. The silicon carbide suspension is centrifuged to obtain silicon carbide micro powder. In step (1), the waste slurry is a slurry produced by the continuous mixing of silicon carbide debris and steel wire debris into the cutting fluid during the cutting process of silicon carbide wafer free abrasive. Its components include mineral oil, diamond powder, silicon carbide powder and / or steel wire debris. In step (4), organic solvent B is one or more low-boiling alcohols, ethers, ketones, and esters in any proportion. In step (4), the drying is carried out in air or in a vacuum at a temperature of 80°C. o C~180 o C; In step (4), the acid solution is one or more of hydrochloric acid, sulfuric acid, phosphoric acid, and hydrofluoric acid in any proportion, and the mass ratio of the solid mixture to the acid is 1:(0.5-10). In step (4), the digestion reaction temperature is maintained at 10°C. o C~80 o C, the reaction time should not exceed 24 hours; In step (6), during the oxidation treatment, a water-soluble compound is used as a catalyst; the catalyst is one or more of alkali metal compounds, nitric acid, sulfuric acid, and ammonium hydroxide in any proportion; the oxidant is one or more of normal oxides, peroxides, superoxides, and ozonides in any proportion, and the oxidation temperature does not exceed 800°C. o C.

2. The method for resource utilization of waste slurry from multi-wire cutting of silicon carbide wafers using free abrasive as described in claim 1, characterized in that, In step (1), organic solvent A is gasoline, naphtha, solvent oil or oxygen-containing organic compound, and the oxygen-containing organic compound is one or more of low-boiling-point alcohols, ethers, ketones and esters in any proportion.

3. The method for resource utilization of waste slurry from multi-wire cutting of silicon carbide wafers using free abrasive as described in claim 1, characterized in that, In step (1), the mass ratio of waste mortar to organic solvent A is 1:(0.1-20). In step (1), after organic solvent A and waste mortar are mixed, the temperature of the mixed slurry is controlled at 10°C. o C~80 o C.

4. The method for resource utilization of waste slurry from multi-wire cutting of silicon carbide wafers using free abrasive as described in claim 3, characterized in that, After organic solvent A and waste mortar are mixed, the temperature of the mixed slurry is controlled at 20°C. o C~50 o C.

5. The method for resource utilization of waste slurry from multi-wire cutting of silicon carbide wafers using free abrasive as described in claim 1, characterized in that, In step (3), the separation of mineral oil and organic solvent is achieved by distillation or rectification, and the separation is carried out under normal or reduced pressure conditions.

6. The method for resource utilization of waste slurry from multi-wire cutting of silicon carbide wafers using free abrasive as described in claim 1, characterized in that, In step (5), drying is carried out in air or in a vacuum at a temperature of 80°C. o C~ 120 o C.

7. The method for resource utilization of waste slurry from multi-wire cutting of silicon carbide wafers using free abrasive as described in claim 1, characterized in that, The solid mixture in step (7) is subjected to hydraulic classification, and the classification fluid medium is water or an aqueous solution.

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