Method for preparing silicon dioxide from rice hull ash and polishing solution prepared from silicon dioxide

Abstract

The invention provides a method for preparing silicon dioxide by using rice hull ash as a silicon source and a polishing solution prepared by using the silicon dioxide. The purity of silicon dioxide is improved through the acid pickling process, the structure of water glass and the sphericity degree and dispersity of silicon dioxide are controlled by adding a segmented copolymer in the liquefaction process, the method for preparing the polishing solution grinding material with the rice hull ash as the silicon source is found, and the prepared silicon dioxide is very suitable for being applied to the polishing solution grinding material and is suitable for being used as the polishing solution grinding material. The crystallization is difficult. The prepared polishing solution is simple in component, low in cost and good in polishing effect. The polishing solution has great application value in the field of mechanical polishing.

Description

Technical Field

[0001] This invention belongs to the field of biomass utilization technology, and relates to a method for preparing silicon dioxide from rice husk ash, and a polishing liquid prepared using the silicon dioxide. Background Technology

[0002] China's annual rice production averages over 200 million tons, and rice husks are a major byproduct of rice processing, accounting for approximately 20% of the rice's weight. The conventional method for disposing of rice husks is to directly landfill the ash from their combustion, which not only wastes resources significantly but also causes a certain degree of environmental pollution.

[0003] With in-depth research into bio-based resources, it has been discovered that rice husk ash contains approximately 80% to 95% silica. This discovery has spurred the development and application of rice husk ash, such as using it as a silicon source to prepare functional building materials, sodium silicate, and silica. Compared to traditional silicon sources, rice husk ash offers a cost advantage. However, existing technologies for preparing silica from rice husk ash suffer from problems such as high impurity levels, yellowing of the finished product, and poor dispersibility. This limits the application of current products to low-end fields like tire fillers, failing to meet the demands of high-value-added applications such as polishing fluids, electronic-grade silicon materials, and pharmaceutical carriers. Therefore, developing a high-purity silica preparation process based on rice husk ash has become a key technological bottleneck in overcoming the upgrading of the silicon materials industry. Summary of the Invention

[0004] This invention provides a method for preparing silica using rice husk ash as a silicon source, and a polishing slurry prepared using this silica. The prepared silica is highly suitable for use as an abrasive in polishing slurries, exhibiting suitable hardness and resistance to crystallization. The prepared polishing slurry has a simple composition, low cost, and excellent polishing effect.

[0005] The method for preparing silicon dioxide using rice husk ash as a silicon source disclosed in this invention is characterized by comprising the following steps: (1) Soak the rice husk ash in hydrochloric acid solution, and then stir and acid wash it to improve the purity of the rice husk ash; (2) After filtering the acid-washed rice husk ash, rinse it repeatedly in pure water until it is neutral; (3) Disperse sodium hydroxide and block copolymer in water to form an alkaline solution; (4) Place the washed rice husk ash in a reaction vessel and add the above-mentioned alkaline solution to react and generate a mixed solution; (5) Remove the mixed solution, filter out solid impurities, and then put the solution back into the reaction vessel and heat it to react with the acid; (6) After aging the reactants for a period of time, ball milling and dilution can be used to obtain abrasive silica.

[0006] In some implementations, the hydrochloric acid solution in step (1) is a 10% hydrochloric acid solution, the soaking time is 2 to 5 hours, and the stirring time is 2 to 5 hours; the number of times the pure water is washed in step (2) is 3 to 5, and the pH after washing is 6.0 to 8.0.

[0007] In some embodiments, the block copolymer in step (3) is synthesized by the following method: heating the isocyanate to 50-90°C, then adding an organotin catalyst and a hydrophilic chain extender solution and reacting for 1-3 hours; then adding the mixture to polyethylene glycol at 60-100°C and reacting for 1-3 hours to obtain the block copolymer; wherein the isocyanate is one or any combination of dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, toluene diisocyanate, phenyl dimethylene diisocyanate, and methylcyclohexyl diisocyanate; and the hydrophilic chain extender is dimethylolpropionic acid, dimethylolbutyric acid, sodium 1,2-dihydroxy-3-propanesulfonate, sodium 1,4-dihydroxybutane-2-sulfonate, diethylenetriamine, N One or any combination of methyl diethanolamine; the solvent of the hydrophilic chain extender is toluene, xylene, trimethylbenzene, cyclohexanone, etc. N -Methylpyrrolidone, ethyl acetate, propyl acetate, butyl acetate, ethyl propionate, ethyl butyrate, propyl butyrate, butyl butyrate, acetone, N, N- The polyethylene glycol is one or any combination of dimethylformamide, etc.; the average molecular weight of the polyethylene glycol is 600~3500 g / mol; the organotin catalyst is one or any combination of dibutyltin dilaurate, stannous octoate, di(dodecyl sulfide)dibutyltin, and dibutyltin diacetate.

[0008] In some embodiments, the mass ratio of the isocyanate, organotin catalyst, hydrophilic chain extender, and polyethylene glycol is 1:0.0005~0.01:0.5~1.5:0.5~1.0.

[0009] In some implementations, the mass ratio of the block copolymer, sodium hydroxide, and water in step (3) is 1:5~9:70~100, and the dispersion method is stirring at 90~100℃ for 3~5 hours.

[0010] In some implementations, the reaction temperature in step (4) is 70~90℃; the acid in step (5) is dilute hydrochloric acid or dilute sulfuric acid; the reaction time is 2~4 hours, and the final pH value is 3.5~4.5.

[0011] The silica prepared using the method disclosed in this invention, which uses rice husk ash as a silicon source, can be used to prepare a polishing solution, which is an aqueous solution comprising the following components: 15 wt% silica prepared by the method of this invention, 5 wt% sodium hydroxide, 1 wt% EDTA, and 0.5 wt% sorbitol. The polishing solution can be prepared using the following steps: (1) Soak the rice husk ash in hydrochloric acid solution, and then stir and acid wash it to improve the purity of the rice husk ash; (2) After filtering the acid-washed rice husk ash, rinse it repeatedly in pure water until it is neutral; (3) Disperse sodium hydroxide and block copolymer in water to form an alkaline solution; (4) Place the washed rice husk ash in a reaction vessel and add the above-mentioned alkaline solution to react and generate a mixed solution; (5) Remove the mixed solution, filter out solid impurities, and then put the solution back into the reaction vessel and heat it to react with the acid; (6) After aging the reactants for a period of time, ball mill and dilute them until the silica solid content is 15%. Add sodium hydroxide, EDTA and sorbitol to obtain the polishing solution.

[0012] This invention has the following beneficial effects: compared with existing polishing slurries and silica abrasives, (1) The silicon dioxide prepared by this invention utilizes rice husk ash bio-based silicon source, which enables resource recycling and is more green and environmentally friendly.

[0013] (2) Soaking rice husk ash in hydrochloric acid and then stirring thoroughly removes impurities such as carbonates and metal oxides from the rice husk ash, effectively improving the purity of silicon dioxide in the rice husk ash.

[0014] (3) In the prior art, water glass is usually prepared by rice husk ash at high temperature of 160~200℃ and high pressure of 0.4~1MPa. The present invention uses rice husk ash to prepare water glass at lower pressure and temperature, which reduces energy consumption and saves costs.

[0015] (4) The addition of block copolymers during the liquefaction process effectively improves the dispersibility of polysilicic acid in water glass.

[0016] (5) Block copolymers, as structure directing agents, enable the synthesized silica to have better sphericity and monodispersity.

[0017] In summary, this invention improves the purity of silica through acid washing and controls the structure of water glass, as well as the sphericity and dispersibility of silica by adding block copolymers during liquefaction. It has found a method for preparing polishing slurry abrasives using rice husk ash as a silicon source. The polishing slurry prepared with this silica has a simple composition, low cost, simple and easy preparation method, and good polishing effect, and has great application value in the field of mechanical polishing. Attached Figure Description

[0018] Figure 1 The image below shows a silica microscope image from Example 1.

[0019] Figure 2 The image below is a microscopic view of silica, as shown in Comparative Example 1.

[0020] Figure 3 The image below is a microscopic view of silica, which is shown in Comparative Example 2.

[0021] Figure 4 The image below shows a microscope image of the sapphire surface after polishing in Example 1.

[0022] Figure 5 The image below shows a microscope view of the sapphire surface after polishing in Example 4.

[0023] Figure 6 The image below shows the surface of the polished sapphire as shown in Comparative Example 1, under a microscope.

[0024] Figure 7 The image below shows the surface of the polished sapphire as shown in Comparative Example 2, under a microscope.

[0025] Figure 8 The image below shows a microscope image of the stainless steel surface after polishing in Example 1.

[0026] Figure 9 The image below shows a microscope view of the stainless steel surface after polishing in Example 4.

[0027] Figure 10 The image below shows a microscope image of the polished stainless steel surface in Comparative Example 1.

[0028] Figure 11 The image below shows a microscope image of the polished stainless steel surface in Comparative Example 2. Detailed Implementation

[0029] The following describes the embodiments of the present invention in detail. It should be noted that the following embodiments are only used to illustrate the present invention and not to limit the present invention.

[0030] Example 1 (1) Soak 500g of rice husk ash in 5000mL of 10% hydrochloric acid solution for 4 hours, and then stir for 2 hours to increase the silica content in the rice husk ash. Let the mixed solution of hydrochloric acid and rice husk ash stand for 1 hour, pour off the supernatant, and filter the precipitated rice husk ash to further remove residual hydrochloric acid.

[0031] (2) Wash the acid-washed rice husk ash in pure water 5 times until the pH reaches 7.3.

[0032] (3) Place the washed rice husk ash in a reaction vessel and add 1800mL of pure water, 160g of sodium hydroxide and 24g of block copolymer. Heat to 99 degrees and stir for 5 hours.

[0033] (4) After the reaction is complete, take out the mixed solution, filter to remove solid residue, leaving 1600mL of solution. Put the solution back into the reaction vessel and heat it to 78℃. Start adding 0.5mol / L sulfuric acid at a rate of 10mL / min. Continue stirring the reaction until the pH reaches 4.18 and then age for 10 minutes.

[0034] (5) Centrifuge and filter the material in the reactor, and wash it with water until the conductivity is 428 μs / cm.

[0035] (6) After taking out the solid material, use a planetary ball mill at 1000 rpm for 10 minutes to obtain abrasive silica; dilute with water to a silica solid content of 15%, and add 5% sodium hydroxide, 1% EDTA and 0.5% sorbitol by weight to obtain polishing liquid.

[0036] The block copolymer was prepared by heating 100g of dicyclohexylmethane diisocyanate to 50°C, then adding 0.05g of dibutyltin dilaurate and 50g of dimethylolpropionic acid in toluene solution and reacting for 1 hour; then adding the mixture to 50g of polyethylene glycol 600 at 60°C and reacting for 1 hour to obtain the block copolymer.

[0037] Example 2 (1) Soak 500g of rice husk ash in 5000mL of 10% hydrochloric acid solution for 2 hours, and then stir for another 2 hours to increase the silica content in the rice husk ash. Let the mixed solution of hydrochloric acid and rice husk ash stand for 1 hour, pour off the supernatant, and filter the precipitated rice husk ash to further remove residual hydrochloric acid.

[0038] (2) Wash the acid-washed rice husk ash in pure water three times until the pH reaches 6.0.

[0039] (3) Place the washed rice husk ash in a reaction vessel and add 1800 mL of pure water, 160 g of sodium hydroxide solid and 24 g of block copolymer. Heat to 90 degrees and stir for 5 hours.

[0040] (4) After the reaction is complete, take out the mixed solution, filter to remove the solid residue, put the solution back into the reaction vessel, heat to 70°C and start adding 1 mol / L hydrochloric acid at a rate of 10 mL / min, and continue stirring the reaction until the pH reaches 4.5 and then age for 10 minutes.

[0041] (5) Centrifuge and filter the material in the reactor, and wash it with water until the conductivity is 433 μs / cm.

[0042] (6) After taking out the solid material, use a planetary ball mill at 1500 rpm for 10 minutes to obtain abrasive silica; dilute with water to a silica solid content of 15%, and add 5% sodium hydroxide, 1% EDTA and 0.5% sorbitol by weight to obtain polishing liquid.

[0043] The block copolymer was prepared in the same manner as in Example 1; Example 3 (1) Soak 500g of rice husk ash in 5000mL of 10% hydrochloric acid solution for 4 hours, and then stir for another hour to increase the silica content in the rice husk ash. Let the mixed solution of hydrochloric acid and rice husk ash stand for 1 hour, pour off the supernatant, and filter the precipitated rice husk ash to further remove residual hydrochloric acid.

[0044] (2) Wash the acid-washed rice husk ash in pure water 5 times until the pH reaches 8.0.

[0045] (3) Place the washed rice husk ash in a reaction vessel and add 2000 mL of pure water, 100 g of sodium hydroxide solid and 20 g of block copolymer. Heat to 99 degrees and stir for 5 hours.

[0046] (4) After the reaction is complete, take out the mixed solution, filter to remove the solid residue, put the solution back into the reaction vessel, heat to 90°C and start adding 0.5 mol / L sulfuric acid at a rate of 10 mL / min, and continue stirring the reaction until the pH reaches 3.5 and then age for 10 minutes.

[0047] (5) Centrifuge and filter the material in the reactor, and wash it with water until the conductivity is 471 μs / cm.

[0048] (6) After removing the solid material, use a planetary ball mill at 1000 rpm for 10 minutes to obtain abrasive silica; dilute with water to a silica solid content of 15%, and add 5% sodium hydroxide, 1% EDTA and 0.5% sorbitol by weight to obtain polishing liquid. The block copolymer is prepared as follows: 100g of hexamethylene diisocyanate is heated to 90℃, then 0.1g of stannous octoate and ethyl acetate solution containing 100g of dimethylolpropionic acid are added and reacted for 3 hours; then the mixture is added to 100g of polyethylene glycol 2000 at 100℃ and reacted for 2 hours to obtain the block copolymer; Example 4 (1) Soak 500g of rice husk ash in 5000mL of 10% hydrochloric acid solution for 4 hours, and then stir for another hour to increase the silica content in the rice husk ash. Let the mixed solution of hydrochloric acid and rice husk ash stand for 1 hour, pour off the supernatant, and filter the precipitated rice husk ash to further remove residual hydrochloric acid.

[0049] (2) Wash the acid-washed rice husk ash in pure water 5 times until the pH reaches 7.2.

[0050] (3) Place the washed rice husk ash in a reaction vessel and add 1400 mL of pure water, 180 g of sodium hydroxide solid and 20 g of block copolymer. Heat to 99 degrees and stir for 5 hours.

[0051] (4) After the reaction is complete, take out the mixed solution, filter to remove the solid residue and the remaining solution, put the solution back into the reaction vessel and heat it to 78°C to start adding 0.5 mol / L sulfuric acid at a rate of 10 mL / min. Continue stirring the reaction until the pH reaches 4.04 and then age for 10 minutes.

[0052] (5) Centrifuge and filter the material in the reactor, and wash it with water until the conductivity is 395 μs / cm.

[0053] (6) After removing the solid material, use a planetary ball mill at 1000 rpm for 10 minutes to obtain abrasive silica; dilute with water to a silica solid content of 15%, and add 5% sodium hydroxide, 1% EDTA and 0.5% sorbitol by weight to obtain polishing liquid. The block copolymer is prepared as follows: 100g of dicyclohexylmethane diisocyanate is heated to 70℃, then 0.08g of di(dodecyl sulfide)dibutyltin and a xylene solution containing 150g of dimethylolpropionic acid are added and reacted for 2 hours; then the mixture is added to 80g of polyethylene glycol 600 at 70℃ and reacted for 2 hours to obtain the block copolymer; Example 5 (1) Soak 500g of rice husk ash in 5000mL of 10% hydrochloric acid solution for 4 hours, and then stir for another hour to increase the silica content in the rice husk ash. Let the mixed solution of hydrochloric acid and rice husk ash stand for 1 hour, pour off the supernatant, and filter the precipitated rice husk ash to further remove residual hydrochloric acid.

[0054] (2) Wash the acid-washed rice husk ash in pure water 5 times until the pH reaches 7.6.

[0055] (3) Place the washed rice husk ash in a reaction vessel and add 1800 mL of pure water, 160 g of sodium hydroxide solid and 20 g of block copolymer. Heat to 99 degrees and stir for 5 hours.

[0056] (4) After the reaction is complete, take out the mixed solution, filter to remove the solid residue and the remaining solution, put the solution back into the reaction vessel and heat it to 78°C to start adding 0.5 mol / L sulfuric acid at a rate of 10 mL / min. Continue stirring the reaction until the endpoint pH reaches 4.14 and age for 10 minutes.

[0057] (5) Centrifuge and filter the material in the reactor, and wash it with water until the conductivity is 368 μs / cm.

[0058] (6) After taking out the solid material, use a planetary ball mill at 1000 rpm for 10 minutes to obtain abrasive silica; dilute with water to a silica solid content of 15%, and add 5% sodium hydroxide, 1% EDTA and 0.5% sorbitol by weight to obtain polishing liquid.

[0059] The block copolymer was prepared by heating 100g of dicyclohexylmethane diisocyanate to 70°C, then adding 0.08g of di(dodecyl sulfide)dibutyltin and a toluene solution containing 100g of sodium 1,2-dihydroxy-3-propanesulfonate and reacting for 2 hours; then adding the mixture to 80g of polyethylene glycol 600 at 60°C and reacting for 2 hours to obtain the block copolymer. Example 6 (1) Soak 500g of rice husk ash in 5000mL of 10% hydrochloric acid solution for 4 hours, and then stir for another hour to increase the silica content in the rice husk ash. Let the mixed solution of hydrochloric acid and rice husk ash stand for 1 hour, pour off the supernatant, and filter the precipitated rice husk ash to further remove residual hydrochloric acid.

[0060] (2) Wash the acid-washed rice husk ash in pure water 5 times until the pH reaches 7.3.

[0061] (3) Place the washed rice husk ash in a reaction vessel and add 1800 mL of pure water, 160 g of sodium hydroxide solid and 20 g of block copolymer. Heat to 99 degrees and stir for 5 hours.

[0062] (4) After the reaction is complete, take out the mixed solution, filter to remove the solid residue and the remaining solution, put the solution back into the reaction vessel and heat it to 78°C to start adding 0.5 mol / L sulfuric acid at a rate of 10 mL / min. Continue stirring the reaction until the pH reaches 4.12 and then age for 10 minutes.

[0063] (5) Centrifuge and filter the material in the reactor, and wash with water. The conductivity is 394 μs / cm.

[0064] (6) After taking out the solid material, use a planetary ball mill at 1000 rpm for 10 minutes to obtain abrasive silica; dilute with water to a silica solid content of 15%, and add 5% sodium hydroxide, 1% EDTA and 0.5% sorbitol by weight to obtain polishing liquid.

[0065] The block copolymer was prepared by heating 100g of dicyclohexylmethane diisocyanate to 70°C, then adding 0.08g of di(dodecyl sulfide)dibutyltin and an ethyl acetate solution containing 100g of sodium 1,2-dihydroxy-3-propanesulfonate and reacting for 2 hours; then adding the mixture to 80g of polyethylene glycol 600 at 60°C and reacting for 2 hours to obtain the block copolymer.

[0066] Comparative Example 1 Except for step (3), which does not involve the addition of block copolymers, all other steps are the same as in Example 1. Comparative Example 2 Except for step (3) in which poly-2-acrylamide-2-methylpropanesulfonic acid is used instead of the block copolymer, all other steps are the same as in Example 1; Experimental Example 1: Detection of silica particle size, shape, and dispersibility Microscopic observation was performed on the silica prepared in Examples 1-6 and Comparative Examples 1-2 to examine its shape and whether it was easily suspended in the polishing solution. The results showed that the silica prepared in Examples 1-6 had uniform particle size and high sphericity, was easily suspended in the polishing solution, and was less prone to aggregation and sedimentation, which was superior to the comparative examples. Specific details are shown in Table 1. Figure 1 , Figure 2 , Figure 3 As shown.

[0067] Table 1. Particle size, shape, and dispersibility of silica

[0068] Test Example 2: Polishing Fluid Inspection The polishing solutions prepared in Examples 1-6 and Comparative Examples 1-2 were tested for effectiveness. The polishing test conditions were as follows: single-sided polishing equipment (Shenggao Grinding), room temperature, rotation speed 60 prm, pressure 10 kg, polishing time 30 min, polishing solution flow rate 24 mL / min (with continuous stirring during the dropwise addition), and sapphire and stainless steel were polished. The polishing test results of the polishing solutions in Examples 1-6 and Comparative Examples 1-2 showed that the polishing speed and / or roughness of the examples were better than those of the comparative examples. Furthermore, the examples all showed good surface finishes without defects such as orange peel, pitting, pinholes, or lines. The comparative examples, however, had surface defects, as detailed in Table 2 below. Figures 4-11 As shown.

[0069] Table 2. Polishing Test Results

Claims

1. A method for preparing silicon dioxide from rice husk ash, characterized by, Comprising the following steps: (1) Put the rice husk ash into hydrochloric acid solution for soaking, and then stir and acid wash to improve the purity of the rice husk ash; (2) After filtering the acid-washed rice husk ash, repeatedly wash it in pure water until it is neutral; (3) Disperse sodium hydroxide and block copolymer in water to form an alkali solution; (4) Put the washed rice husk ash into a reaction kettle and add the alkali solution to generate a mixed solution; (5) Take out the mixed solution, filter the solid impurities, and then re-add the solution to the reaction kettle for heating and reaction with acid; (6) After aging for a period of time, ball milling and dilution, abrasive silica is obtained.

2. The method for preparing silicon dioxide from rice husk ash as described in claim 1, characterized in that, In step (1), the hydrochloric acid solution is 10% concentration, the soaking time is 2-5 hours, and the stirring time is 2-5 hours; in step (2), the pure water washing times are 3-5 times, and the pH after washing is 6.0-8.

0.

3. The method of producing silicon dioxide from rice husk ash according to claim 1 or 2, characterized by, In step (3), the block copolymer is synthesized by the following method: heat isocyanate to 50-90℃, then add organic tin catalyst and hydrophilic chain extender solution and react for 1-3 hours; then add the mixed system to 60-100℃ polyethylene glycol and react for 1-3 hours to obtain the block copolymer.

4. The method for preparing silicon dioxide from rice husk ash as described in claim 3, characterized in that, The isocyanate is one or any combination of dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, toluene diisocyanate, xylylene diisocyanate, and methylcyclohexyl diisocyanate; the organic tin catalyst is one or any combination of dibutyltin dilaurate, stannous octoate, bis(dodecylthio) dibutyl tin, and dibutyltin diacetate.

5. The method for preparing silicon dioxide from rice husk ash as described in claim 3, characterized in that, The hydrophilic chain extender is one or any combination of dimethylol propionic acid, dimethylol butyric acid, 1,2-dihydroxy-3-propanesulfonic acid sodium, 1,4-dihydroxybutane-2-sulfonic acid sodium, diethylenetriamine, N one or any combination of methyl diethanol amine; the solvent of the hydrophilic chain extender is one or any combination of toluene, xylene, trimethylbenzene, cyclohexanone, N-methyl pyrrolidone, ethyl acetate, propyl acetate, butyl acetate, ethyl propionate, ethyl butyrate, propyl butyrate, butyl butyrate, acetone, N,N- dimethylformamide, etc.; the average molecular weight of the polyethylene glycol is 600-3500 g / moL.

6. The method for preparing silicon dioxide from rice husk ash as described in claim 3, characterized in that, The mass ratio of isocyanate, organic tin catalyst, hydrophilic chain extender, and polyethylene glycol is 1:0.0005-0.01:0.5-1.5:0.5-1.

0.

7. The method of claim 1, wherein the polishing liquid abrasive silica is prepared using rice husk ash, characterized by, In step (3), the mass ratio of block copolymer, sodium hydroxide, and water is 1:5-9:70-100, and the dispersion method is stirring at 90-100℃ for 3-5 hours.

8. The method for preparing silicon dioxide from rice husk ash as described in claim 1, characterized in that, In step (4), the reaction temperature is 70-90℃; in step (5), the acid is dilute hydrochloric acid or dilute sulfuric acid; the reaction time is 2-4 hours, and the final pH value is 3.5-4.

5.

9. A polishing liquid characterized by comprising: An aqueous solution comprising: 15 wt% of the silica prepared by the method of any one of claims 1 to 8, 5 wt% of sodium hydroxide, 1 wt% of EDTA, and 0.5 wt% of sorbitol.

10. The method of claim 9, wherein the polishing solution is prepared by adding the abrasive grains to the base solution. Comprising the following steps: (1) Put the rice husk ash into hydrochloric acid solution for soaking, and then stir and acid wash to improve the purity of the rice husk ash; (2) After filtering the acid-washed rice husk ash, repeatedly wash it in pure water until it is neutral; (3) Disperse sodium hydroxide and block copolymer in water to form an alkali solution; (4) Put the washed rice husk ash into a reaction kettle and add the alkali solution to generate a mixed solution; (5) Take out the mixed solution, filter the solid impurities, and then re-add the solution to the reaction kettle for heating and reaction with acid; (6) After aging for a period of time, ball milling and dilution to a silica solid content of 15%, add sodium hydroxide, EDTA, and sorbitol to obtain a polishing liquid.

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