Efficient composite Portland cement clinker grinding aid and application thereof

Abstract

The invention relates to the technical field of cement grinding aids, and particularly discloses an efficient composite Portland cement clinker grinding aid and application thereof. The grinding aid comprises a liquid A and a liquid B which are separated from each other. Wherein the solution A comprises a mixed solution of ethylene glycol and water and iron dihydrogen phosphate. Wherein the volume ratio of the ethylene glycol to the water is (3-3.7): 1, and the iron dihydrogen phosphate in the mixed solution is in a saturated state. The solution B comprises a sodium borohydride and / or potassium borohydride solution, a polycarboxylate superplasticizer and modified magnesium oxide powder. Wherein the mass fraction of the sodium borohydride and / or potassium borohydride solution is 3-5%, the mass fraction of the polycarboxylate superplasticizer in the solution B is 12-17%, and the content of the modified magnesium oxide powder is 4.5-7 g / L. The grinding aid disclosed by the invention can effectively eliminate the electrostatic effect of cement particles, reduce re-agglomeration among the particles and improve the dispersity of cement clinker particles, so that the grinding efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of cement grinding aids, and in particular to a high-efficiency composite silicate cement clinker grinding aid and application thereof. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] Grinding of cement clinker is an important process in cement production. This is because cement clinker becomes a block after high-temperature calcination and cooling, and needs to be ground to become powder. The ground cement clinker particles have a larger specific surface area, and thus have a higher hydration reaction activity, which helps to improve the density and mechanical strength of the prepared concrete structure.

[0004] Cement grinding is usually done with a grinding machine, and grinding aids are added to improve grinding efficiency. This is because grinding aids can reduce the adhesion between cement particles and improve fluidity, which helps to shorten grinding time and reduce power consumption. However, during the grinding process, cement particles are charged by constant friction and tend to reagglomerate, resulting in reduced cement grinding efficiency, reduced production capacity, and increased power consumption, which is not conducive to energy conservation and consumption reduction for enterprises. Summary of the invention

[0005] The present invention provides a high-efficiency composite silicate cement clinker grinding aid and its application, the grinding aid can effectively eliminate the electrostatic effect of cement particles, reduce the re-agglomeration between particles, improve the dispersion of cement clinker particles, and thus improve the grinding efficiency. Specifically, the technical solution of the present invention is as follows.

[0006] First, the present invention discloses a high-efficiency composite silicate cement clinker grinding aid, which comprises separate liquid A and liquid B. Wherein: the liquid A comprises a mixed liquid of ethylene glycol and water, and ferric dihydrogen phosphate. The volume ratio of ethylene glycol to water is 3-3.7:1, and the ferric dihydrogen phosphate in the mixed liquid is in a saturated state. The liquid B comprises a sodium borohydride and / or potassium borohydride solution, a polycarboxylic acid water reducer and modified magnesium oxide powder. The mass fraction of the sodium borohydride and / or potassium borohydride solution is 3-5%, the mass fraction of the polycarboxylic acid water reducer in the liquid B is 12-17%, and the content of the modified magnesium oxide powder is 4.5-7 g / L.

[0007] Furthermore, the mass ratio of liquid A to liquid B is 1:0.4-0.52.

[0008] Furthermore, the modified magnesium oxide powder is prepared by the following method: dispersing magnesium oxide powder in ethanol, then adding a silane coupling agent, stirring evenly and then evaporating to dryness, calcining the obtained solid product, and cooling to room temperature to obtain the modified magnesium oxide powder.

[0009] Furthermore, the ratio of the magnesium oxide powder to ethanol is 1 g: 10-30 ml. Optionally, the fineness of the magnesium oxide powder is 100-200 mesh.

[0010] Further, the mass fraction of the silane coupling agent in the ethanol is 1-2%. Optionally, the mass fraction of the ethanol is not less than 80%.

[0011] Furthermore, the silane coupling agent includes at least one of KH550, KH560, KH570, KH792 and the like.

[0012] Furthermore, the temperature of the evaporation to dryness treatment is 90-110° C., and the evaporation to dryness is performed at this temperature until the weight of the solid product no longer changes.

[0013] Furthermore, the calcination treatment is carried out at a temperature of 400-500°C and a time of 30-40 minutes. In this process, the silane coupling agent grafted on the surface of the magnesium oxide particles decomposes at high temperature to form nano-silicon dioxide, which not only helps to increase the steric hindrance of the magnesium oxide particles, thereby reducing agglomeration and improving the dispersion effect, but also the nano-silicon dioxide can participate in the hydration reaction of cement and form a hydrated calcium silicate gelling component with the hydration product calcium hydroxide, which helps to increase the mechanical strength of cement-based materials.

[0014] Secondly, the present invention discloses the application of the high-efficiency composite silicate cement clinker grinding aid in cement grinding, and the application method is: first spraying the A liquid into the cement clinker after primary grinding and mixing it evenly, then stirring the B liquid and spraying it into the cement clinker, and grinding after mixing evenly.

[0015] Furthermore, the addition amount of the grinding aid is 0.10-0.25% of the mass of cement clinker.

[0016] Compared with the prior art, the technical solution of the present invention has at least the following beneficial effects: The cement clinker grinding aid of the present invention adopts a liquid A formed by a mixed solution of ethylene glycol and water and ferrous dihydrogen phosphate, and a liquid B formed by a sodium borohydride and / or potassium borohydride solution, a polycarboxylic acid water reducer, and a modified magnesium oxide powder. When the grinding aid is used to grind cement clinker, the ethylene glycol can effectively reduce the friction between cement clinker particles and improve the fluidity of the particles. The magnesium oxide helps to increase the grinding effect on cement particles, thereby improving grinding efficiency and reducing energy consumption. After the ferrous dihydrogen phosphate and sodium borohydride and / or potassium borohydride infiltrated into the cement clinker react, the iron ions are reduced to elemental iron particles and buried in the clinker particles. During the grinding process, the elemental iron particles absorb friction heat and expand in volume, which helps to create microcracks in the clinker particles, accelerates the rupture of the clinker particles, and thus improves the grinding efficiency. At the same time, the elemental iron particles in the clinker particles also help to eliminate the charge generated by the clinker particles during the grinding process, reduce the bonding and agglomeration of the clinker particles due to electrostatic adsorption, improve the dispersion of the clinker particles, and improve the grinding efficiency. At the same time, after the cement particles are broken under the grinding action, a large number of calcium ion active sites formed after the Ca-O bond is broken will be formed on the surface, and these active sites prompt the cement particles to produce a trend of re-combining and restoring Ca-O, thereby reducing the grinding effect. The polycarboxylate water reducer can form a stable complex with the calcium ions at the active sites using its rich carboxyl, hydroxyl and sulfonic acid groups, thereby reducing the calcium ion active sites, reducing the phenomenon of cement particles re-aggregating, and improving the grinding efficiency. In addition, the ferric dihydrogen phosphate and sodium borohydride and / or potassium borohydride react to form sodium dihydrogen phosphate and potassium dihydrogen phosphate. When cement-based materials are prepared using cement clinker containing the substance and the magnesium oxide particles, the sodium dihydrogen phosphate, potassium dihydrogen phosphate and magnesium oxide can be hydrated to form high-strength hydration products struvite, and the mechanical strength of this product is much higher than the strength of the hydration products of silicate cement clinker, thereby helping to increase the mechanical strength of cement-based materials prepared by silicate cement clinker. At the same time, the reaction of the elemental iron particles with the hydroxide ions released by cement hydration during the hydration process to form iron glue also helps to increase the density of the cement-based material and further enhance the mechanical strength. The water reducer attached to the cement particles also helps to improve the fluidity of the prepared cement-based material and improve the working performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0018] Figure 1 This is a sample diagram of modified magnesium oxide powder prepared in the following Example 1.

[0019] Figure 2 This is a sample picture of the grinding aid liquid A prepared in the following Example 1. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods in the following examples without specifying specific conditions are usually carried out under conventional conditions or under conditions recommended by the manufacturer.

[0021] Unless otherwise defined, all professional and scientific terms used in the present invention have the same meanings as those familiar to those skilled in the art. The reagents or raw materials used in the present invention can be purchased through conventional channels. Unless otherwise specified, the reagents or raw materials used in the present invention are used in a conventional manner in the art or in accordance with the product instructions.

[0022] In addition, any method and material similar or equivalent to the described content can be applied to the method of the present invention. The preferred implementation methods and materials described in the present invention are only for demonstration purposes. The technical solution of the present invention is now further described in conjunction with specific implementation methods.

[0023] Example 1 A preparation method of a high-efficiency composite silicate cement clinker grinding aid comprises the following steps: (1) Add 200-mesh magnesium oxide powder to 90% ethanol at a ratio of 1 g:15 ml and stir evenly, then add silane coupling agent (KH550) and stir evenly to obtain a mixture with a silane coupling agent mass fraction of 1.0%. Heat the mixture to 90°C and evaporate to dryness until the weight of the obtained solid product does not change. Then heat the solid product to 400°C and calcine for 40 minutes, and cool to room temperature to obtain modified magnesium oxide powder (such as Figure 1 as shown), for standby use.

[0024] (2) Mix ethylene glycol and water in a volume ratio of 3.5:1 and stir evenly. Then, add ferric dihydrogen phosphate under stirring until saturated to obtain liquid A (such as Figure 2 as shown), for standby use.

[0025] (3) A polycarboxylate water reducer was added to a sodium borohydride aqueous solution with a mass fraction of 5% to obtain a mixed solution with a water reducer mass fraction of 14%, and then the modified magnesium oxide powder prepared in this example was added and stirred evenly to obtain a liquid B with a modified magnesium oxide powder content of 6 g / L.

[0026] (4) The liquid A and the liquid B are used in a mass ratio of 1:0.45 to form a silicate cement clinker grinding aid. The liquid A and the liquid B are stored separately before use.

[0027] When in use, the amount of the grinding aid added is 0.15% of the mass of the cement clinker. First, under stirring conditions, the A liquid is sprayed onto the 42.5 ordinary Portland cement clinker that is initially ground to a particle size distribution between 0.5 and 2 mm and stirred evenly. Then, the B liquid is stirred and sprayed onto the cement clinker in a stirred state. After stirring evenly, the cement clinker is ground in a ball mill for 30 minutes. After completion, it is cooled to room temperature to obtain cement clinker powder.

[0028] Performance test: (1) The cement clinker powder obtained in this embodiment is mixed according to a water-cement ratio of 0.41 and poured into a mold. After hardening and demolding, it is placed in a curing box for curing for 28 days, and then the compressive strength of the specimen is tested according to the "Test Method for Cement Mortar Strength (ISO Method)" (GBT 17671-2021). (2) The fluidity of the cement slurry formed by the cement clinker powder of this embodiment is tested according to the "Cement Mortar Fluidity Determination Method" (GBT2419-2005). (3) The specific surface area of ​​the cement clinker powder of this embodiment is tested according to GB / T26748-2011 "Cement Grinding Aids". The larger the value, the better the grinding aid effect of the grinding aid. The results are shown in the following table: .

[0029] Example 2 A preparation method of a high-efficiency composite silicate cement clinker grinding aid comprises the following steps: (1) Add 200-mesh magnesium oxide powder to 80% ethanol at a ratio of 1 g:10 ml and stir evenly, then add silane coupling agent (KH560) and stir evenly to obtain a mixture with a silane coupling agent mass fraction of 1.5%. Heat the mixture to 110°C and evaporate to dryness until the weight of the obtained solid product no longer changes. Then heat the solid product to 450°C and calcine for 30 minutes, cool to room temperature to obtain modified magnesium oxide powder, and set aside.

[0030] (2) Mix ethylene glycol and water in a volume ratio of 3.7:1 and stir evenly. Then, add ferric dihydrogen phosphate under stirring until saturated to obtain liquid A for later use.

[0031] (3) A polycarboxylic acid water reducer was added to a sodium borohydride aqueous solution with a mass fraction of 3% to obtain a mixed solution with a water reducer mass fraction of 12%, and then the modified magnesium oxide powder prepared in this example was added and stirred evenly to obtain a liquid B with a modified magnesium oxide powder content of 7 g / L.

[0032] (4) The liquid A and the liquid B are used in a mass ratio of 1:0.52 to form a silicate cement clinker grinding aid. The liquid A and the liquid B are stored separately before use.

[0033] When in use, the amount of the grinding aid added is 0.1% of the mass of the cement clinker. First, under stirring conditions, the A liquid is sprayed onto the 42.5 ordinary Portland cement clinker that is initially ground to a particle size distribution between 0.5 and 2 mm and stirred evenly. Then, the B liquid is stirred and sprayed onto the cement clinker in a stirred state. After stirring evenly, the cement clinker is ground in a ball mill for 30 minutes. After completion, it is cooled to room temperature to obtain cement clinker powder.

[0034] Performance test: The performance indicators of the cement clinker powder prepared in this embodiment were tested by the same method as in the above embodiment 1, and the results are shown in the following table: .

[0035] Example 3 A preparation method of a high-efficiency composite silicate cement clinker grinding aid comprises the following steps: (1) Add 100-mesh magnesium oxide powder to 95% ethanol at a ratio of 1 g:30 ml and stir evenly, then add silane coupling agent (KH570) and stir evenly to obtain a mixture with a 2% silane coupling agent mass fraction. Heat the mixture to 105°C and evaporate to dryness until the weight of the obtained solid product no longer changes. Then heat the solid product to 500°C and calcine for 40 minutes, cool to room temperature to obtain modified magnesium oxide powder, and set aside.

[0036] (2) Mix ethylene glycol and water in a volume ratio of 3:1 and stir evenly. Then, add ferric dihydrogen phosphate under stirring until saturated to obtain liquid A for later use.

[0037] (3) A polycarboxylate water reducer was added to a 4% by mass potassium borohydride aqueous solution to obtain a mixed solution with a water reducer mass fraction of 17%, and then the modified magnesium oxide powder prepared in this example was added and stirred evenly to obtain a liquid B with a modified magnesium oxide powder content of 4.5 g / L.

[0038] (4) The liquid A and the liquid B are used in a mass ratio of 1:0.4 to form a silicate cement clinker grinding aid. The liquid A and the liquid B are stored separately before use.

[0039] When in use, the amount of the grinding aid added is 0.25% of the mass of the cement clinker. First, under stirring conditions, the A liquid is sprayed onto the 42.5 ordinary Portland cement clinker that is initially ground to a particle size distribution between 0.5 and 2 mm and stirred evenly. Then, the B liquid is stirred and sprayed onto the cement clinker in a stirred state. After stirring evenly, the cement clinker is ground in a ball mill for 30 minutes. After completion, it is cooled to room temperature to obtain cement clinker powder.

[0040] Performance test: The performance indicators of the cement clinker powder prepared in this embodiment were tested by the same method as in the above embodiment 1, and the results are shown in the following table: .

[0041] Example 4 A preparation method of a high-efficiency composite silicate cement clinker grinding aid comprises the following steps: (1) Add 200-mesh magnesium oxide powder to 90% ethanol at a ratio of 1 g:15 ml and stir evenly, then add silane coupling agent (KH550) and stir evenly to obtain a mixture with a 1% silane coupling agent mass fraction. Heat the mixture to 90°C and evaporate to dryness until the weight of the obtained solid product no longer changes. Then heat the solid product to 400°C and calcine for 40 minutes, cool to room temperature to obtain modified magnesium oxide powder, and set aside.

[0042] (2) Mix ethylene glycol and water in a volume ratio of 3.5:1 and stir evenly to obtain Liquid A for later use.

[0043] (3) A polycarboxylate water reducer was added to a sodium borohydride aqueous solution with a mass fraction of 5% to obtain a mixed solution with a water reducer mass fraction of 14%, and then the modified magnesium oxide powder prepared in this example was added and stirred evenly to obtain a liquid B with a modified magnesium oxide powder content of 6 g / L.

[0044] (4) The liquid A and the liquid B are used in a mass ratio of 1:0.45 to form a silicate cement clinker grinding aid. The liquid A and the liquid B are stored separately before use.

[0045] When in use, the amount of the grinding aid added is 0.15% of the mass of the cement clinker. First, under stirring conditions, the A liquid is sprayed onto the 42.5 ordinary Portland cement clinker that is initially ground to a particle size distribution between 0.5 and 2 mm and stirred evenly. Then, the B liquid is stirred and sprayed onto the cement clinker in a stirred state. After stirring evenly, the cement clinker is ground in a ball mill for 30 minutes. After completion, it is cooled to room temperature to obtain cement clinker powder.

[0046] Performance test: The performance indicators of the cement clinker powder prepared in this embodiment were tested by the same method as in the above embodiment 1, and the results are shown in the following table: .

[0047] Example 5 A preparation method of a high-efficiency composite silicate cement clinker grinding aid comprises the following steps: (1) Add 200-mesh magnesium oxide powder to 80% ethanol at a ratio of 1 g:10 ml and stir evenly, then add silane coupling agent (KH560) and stir evenly to obtain a mixture with a silane coupling agent mass fraction of 1.5%. Heat the mixture to 110°C and evaporate to dryness until the weight of the obtained solid product no longer changes. Then heat the solid product to 450°C and calcine for 30 minutes, cool to room temperature to obtain modified magnesium oxide powder, and set aside.

[0048] (2) Mix ethylene glycol and water in a volume ratio of 3.7:1 and stir evenly. Then, add ferric dihydrogen phosphate under stirring until saturated to obtain liquid A for later use.

[0049] (3) Add polycarboxylate water reducer to clean water to obtain a mixed solution with a water reducer mass fraction of 12%, then add the modified magnesium oxide powder prepared in this example and stir evenly to obtain liquid B with a modified magnesium oxide powder content of 7 g / L.

[0050] (4) The liquid A and the liquid B are used in a mass ratio of 1:0.52 to form a silicate cement clinker grinding aid. The liquid A and the liquid B are stored separately before use.

[0051] When in use, the amount of the grinding aid added is 0.1% of the mass of the cement clinker. First, under stirring conditions, the A liquid is sprayed onto the 42.5 ordinary Portland cement clinker that is initially ground to a particle size distribution between 0.5 and 2 mm and stirred evenly. Then, the B liquid is stirred and sprayed onto the cement clinker in a stirred state. After stirring evenly, the cement clinker is ground in a ball mill for 30 minutes. After completion, it is cooled to room temperature to obtain cement clinker powder.

[0052] Performance test: The performance indicators of the cement clinker powder prepared in this embodiment were tested by the same method as in the above embodiment 1, and the results are shown in the following table: .

[0053] Example 6 A preparation method of a high-efficiency composite silicate cement clinker grinding aid comprises the following steps: (1) Mix ethylene glycol and water in a volume ratio of 3.5:1 and stir evenly. Then, add ferric dihydrogen phosphate under stirring until saturated to obtain liquid A for later use.

[0054] (2) Add polycarboxylic acid water reducer to a 5% by mass sodium borohydride aqueous solution to obtain a mixed solution with a water reducer mass fraction of 14%, and then add magnesium oxide powder with a fineness of 200 mesh and stir evenly to obtain liquid B with a modified magnesium oxide powder content of 6 g / L.

[0055] (3) The liquid A and the liquid B are used in a mass ratio of 1:0.45 to form a silicate cement clinker grinding aid. The liquid A and the liquid B are stored separately before use.

[0056] When in use, the amount of the grinding aid added is 0.15% of the mass of the cement clinker. First, under stirring conditions, the A liquid is sprayed onto the 42.5 ordinary Portland cement clinker that is initially ground to a particle size distribution between 0.5 and 2 mm and stirred evenly. Then, the B liquid is stirred and sprayed onto the cement clinker in a stirred state. After stirring evenly, the cement clinker is ground in a ball mill for 30 minutes. After completion, it is cooled to room temperature to obtain cement clinker powder.

[0057] Performance test: The performance indicators of the cement clinker powder prepared in this embodiment were tested by the same method as in the above embodiment 1, and the results are shown in the following table: .

[0058] Example 7 A preparation method of a high-efficiency composite silicate cement clinker grinding aid comprises the following steps: (1) Add 100-mesh magnesium oxide powder to 95% ethanol at a ratio of 1 g:30 ml and stir evenly, then add silane coupling agent (KH570) and stir evenly to obtain a mixture with a 2% silane coupling agent mass fraction. Heat the mixture to 105°C and evaporate to dryness until the weight of the obtained solid product no longer changes. Then heat the solid product to 500°C and calcine for 40 minutes, cool to room temperature to obtain modified magnesium oxide powder, and set aside.

[0059] (2) Mix ethylene glycol and water in a volume ratio of 3:1 and stir evenly. Then, add ferric dihydrogen phosphate under stirring until saturated to obtain liquid A for later use.

[0060] (3) The modified magnesium oxide powder prepared in this example was added to a 4% by mass potassium borohydride aqueous solution and stirred evenly to obtain a solution B having a modified magnesium oxide powder content of 4.5 g / L.

[0061] (4) The liquid A and the liquid B are used in a mass ratio of 1:0.4 to form a silicate cement clinker grinding aid. The liquid A and the liquid B are stored separately before use.

[0062] When in use, the amount of the grinding aid added is 0.25% of the mass of the cement clinker. First, under stirring conditions, the A liquid is sprayed onto the 42.5 ordinary Portland cement clinker that is initially ground to a particle size distribution between 0.5 and 2 mm and stirred evenly. Then, the B liquid is stirred and sprayed onto the cement clinker in a stirred state. After stirring evenly, the cement clinker is ground in a ball mill for 30 minutes. After completion, it is cooled to room temperature to obtain cement clinker powder.

[0063] Performance test: The performance indicators of the cement clinker powder prepared in this embodiment were tested by the same method as in the above embodiment 1, and the results are shown in the following table: .

[0064] Example 8 A preparation method of a high-efficiency composite silicate cement clinker grinding aid comprises the following steps: (1) Mix ethylene glycol and water in a volume ratio of 3.7:1 and stir evenly. Then, add ferric dihydrogen phosphate under stirring until saturated to obtain liquid A for later use.

[0065] (2) Add polycarboxylic acid water reducer to a 3% by mass sodium borohydride aqueous solution to obtain a liquid B with a water reducer mass fraction of 25% for later use.

[0066] (3) The liquid A and the liquid B are used in a mass ratio of 1:0.52 to form a silicate cement clinker grinding aid. The liquid A and the liquid B are stored separately before use.

[0067] When in use, the amount of the grinding aid added is 0.1% of the mass of the cement clinker. First, under stirring conditions, the A liquid is sprayed onto the 42.5 ordinary Portland cement clinker that is initially ground to a particle size distribution between 0.5 and 2 mm and stirred evenly. Then, the B liquid is stirred and sprayed onto the cement clinker in a stirred state. After stirring evenly, the cement clinker is ground in a ball mill for 30 minutes. After completion, it is cooled to room temperature to obtain cement clinker powder.

[0068] Performance test: The performance indicators of the cement clinker powder prepared in this embodiment were tested by the same method as in the above embodiment 1, and the results are shown in the following table: .

[0069] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high-efficiency composite silicate cement clinker grinding aid, characterized in that: The grinding aid comprises separate liquid A and liquid B; wherein the liquid A comprises a mixture of ethylene glycol and water and ferric dihydrogen phosphate; wherein the volume ratio of the ethylene glycol to water is 3-3.7:1, and the ferric dihydrogen phosphate in the mixture is in a saturated state; the liquid B comprises a sodium borohydride and / or potassium borohydride solution, a polycarboxylate water reducer and modified magnesium oxide powder; wherein the mass fraction of the sodium borohydride and / or potassium borohydride solution is 3-5%, the mass fraction of the polycarboxylate water reducer in the liquid B is 12-17%, and the content of the modified magnesium oxide powder is 4.5-7 g / L.

2. The high-efficiency composite silicate cement clinker grinding aid according to claim 1, characterized in that: The mass ratio of liquid A to liquid B is 1:0.4-0.

52.

3. The high-efficiency composite silicate cement clinker grinding aid according to claim 1, characterized in that: The modified magnesium oxide powder is prepared by the following method: dispersing magnesium oxide powder in ethanol, then adding a silane coupling agent, stirring evenly and then evaporating to dryness, calcining the obtained solid product, and cooling to room temperature to obtain the modified magnesium oxide powder.

4. The high-efficiency composite silicate cement clinker grinding aid according to claim 3, characterized in that: The ratio of the magnesium oxide powder to ethanol is 1 g: 10-30 ml; optionally, the fineness of the magnesium oxide powder is 100-200 mesh.

5. The high-efficiency composite silicate cement clinker grinding aid according to claim 3, characterized in that: The mass fraction of the silane coupling agent in the ethanol is 1-2%; optionally, the mass fraction of the ethanol is not less than 80%.

6. The high-efficiency composite silicate cement clinker grinding aid according to claim 3, characterized in that: The silane coupling agent includes at least one of KH550, KH560, KH570 and KH792.

7. The high-efficiency composite silicate cement clinker grinding aid according to any one of claims 3 to 6, characterized in that: The evaporation temperature is 90-110° C., and the evaporation temperature is set at 90-110° C. until the weight of the solid product does not change.

8. The high-efficiency composite silicate cement clinker grinding aid according to any one of claims 3 to 6, characterized in that: The calcination treatment is carried out at a temperature of 400-500° C. and for a time of 30-40 minutes.

9. The use of the high-efficiency composite silicate cement clinker grinding aid according to any one of claims 1 to 8 in cement grinding, characterized in that: The application method is: first spray the A liquid into the cement clinker after primary grinding to mix evenly, then spray the B liquid, mix evenly and then grind.

10. The use according to claim 9, characterized in that: The addition amount of the grinding aid is 0.10-0.25% of the mass of cement clinker.

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