A grinding aid for low activity blends and a method of making the same

Abstract

The application discloses a grinding aid for low-activity admixture and a preparation method thereof, the grinding aid is prepared from component A, component B and component C according to a mass ratio of 35:15-20:45-50; the component A is a polymer blend containing phosphate ester; the component B comprises 24-32% of acrylamide-acrylic acid copolymer, 3-6% of zero-valent iron powder, 6-10% of maleimide, 18-20% of long carbon chain alkyl amine, 6-12% of small-molecule quaternary ammonium salt and 28-35% of dendritic macroporous mesoporous silica in percentage by mass; and the component C is a Hanbaitu hair material; when used, the component A, the component B and the component C are separately weighed according to the mass ratio, and are put into a mill before grinding material enters the mill; the application can improve the grinding aid effect of the admixture, and solves the problems of activity, water requirement and powder fluidity of the low-activity admixture.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, and more specifically, to a grinding aid for low-activity admixtures and its preparation method. Background Technology

[0002] Cement is the most important material in construction and infrastructure, with an annual output exceeding 4 billion tons. Various industrial wastes, such as fly ash, abrasive blast furnace slag, and silica fume, can be used as supplementary cementitious materials, participating in hydration and acting as fillers, thus replacing cement clinker. However, the main components of these industrial wastes are inert; their suitability as cementitious materials in concrete depends primarily on whether they possess pozzolanic activity after grinding.

[0003] Grinding aids, as chemical additives, can rapidly eliminate or reduce the aggregation and adhesion between particles and between particles and grinding media, thereby improving grinding efficiency and increasing post-grinding activity. They can also significantly reduce energy consumption, improve flowability, and increase powder utilization, thus possessing significant economic and social value. Currently, the most common grinding aids are mainly organic compounds containing polar groups such as -OH, -NH2, -COOR, and -SO3, such as propylene glycol, ethylene glycol, polyethylene glycol, and glycerol-containing polyhydroxy grinding aids.

[0004] CN108947312A discloses an early-strength functional grinding aid, comprising water, diethanolamine monoisopropanolamine, sodium tripolyphosphate, molasses, and propylene glycol. This early-strength functional grinding aid is used in combination with cement during application, with a mass ratio of early-strength functional grinding aid to cement of 1:1000. The formulation of this early-strength functional grinding aid is simple and reasonable, with good grinding aid effect, effectively improving grinding efficiency, reducing grinding energy consumption, and improving the early strength of cement. However, the study only investigated its grinding aid effect on cement.

[0005] CN114573266A discloses a grinding aid for activating steel slag and a method for preparing activated steel slag using the grinding aid. The aim is to overcome the shortcomings of existing technologies where traditional grinding aids, when used to grind steel slag, often lead to poor compatibility between cement and admixtures, thus reducing the effectiveness of cement application. The aid comprises: a polycarboxylate solution, sodium sulfate, sodium nitrate, polyethylene glycol, and a defoamer. The grinding aid for activating steel slag of this invention uses polycarboxylate as the main component, which can improve the cementitious activity of steel slag without affecting the compatibility between cement and admixtures when the activated steel slag is mixed with cement.

[0006] CN115057636A discloses a slag grinding aid, its preparation method, and cement using the slag grinding aid. The slag grinding aid comprises ethanol, polyol, modified glucomannan, and water. The preparation method involves mixing tris(hydroxymethyl)aminomethane, ethanol, and water to obtain a mixture; subsequently, the modified glucomannan is mixed evenly with the obtained mixture to form the slag grinding aid. The slag grinding aid of this application can be used for grinding slag, and it has the advantage of improving the strength of the resulting cement.

[0007] CN104529227A discloses a grinding aid for grinding slag and manganese slag and its preparation method. This invention uses paste-like waste acid slag produced from the transesterification of natural vegetable or animal oils or waste cooking oil to produce fatty acid methyl esters as raw material. After neutralization with quicklime and removal of methanol, appropriate amounts of cement, slag, and fly ash are added to obtain the grinding aid, achieving the clean and resource-based utilization of waste acid slag. This grinding aid is easy to use and has a good grinding effect on slag and manganese slag systems. It not only solves the problem of disposing of waste acid slag generated in plasticizer production and prepares a high-efficiency grinding aid, but also improves the grinding efficiency of slag, manganese slag, and other materials and reduces production costs.

[0008] The aforementioned steel slag, mineral slag, and manganese slag are all used as active admixtures. Current research on grinding aids focuses on industrial waste admixtures with high chemical reactivity, while research on grinding aids for low-activity and inert admixtures is rarely addressed. Our technical personnel, during the verification of grinding aid performance, found that: traditional cement grinding aids have a significant grinding aid effect on admixtures with high calcium and silicon content, but almost no grinding aid effect on admixtures with low activity and low calcium and silicon content, such as boiler slag, gasification slag, and water slag; amine-based grinding aids can negatively impact the water demand of admixtures, especially exhibiting compatibility issues with water-reducing agents; the grinding aid effect of grinding aids presents many contradictions when evaluated from both powder performance and concrete perspectives—that is, the grinding aid effect is fine when evaluated solely from the powder perspective, but many problems arise when applied to concrete. Summary of the Invention

[0009] The technical problem to be solved by this invention is to provide a grinding aid for low-activity admixtures and its preparation method, focusing on low-activity water slag, boiler slag and gasification slag. This invention improves the grinding effect of admixtures while solving the problems of activity, water demand and powder flowability of low-activity admixtures.

[0010] To achieve the above objectives, the grinding aid for low-activity admixtures of the present invention is formulated from components A, B, and C in a mass ratio of 35:15-20:45-50; component A is a polymer blend containing phosphate esters; component B, by mass percentage, comprises 24-32% acrylamide-acrylic acid copolymer, 3-6% zero-valent iron powder, 6-10% maleimide, 18-20% long-chain alkylamine, 6-12% small molecule quaternary ammonium salt, and 28-35% dendritic macroporous mesoporous silica; and component C is raw white marble.

[0011] Preferably, component A comprises the following components in parts by weight: 18-24 parts of hydroxyethyl dibutyl phosphate, 12-16 parts of hydroxyethyl dimethoxy polyethylene glycol phosphate, 15-20 parts of calcium acrylate, 0.1-1 parts of sodium 2-acrylamido-2-methylpropanesulfonate, 0.1-1 parts of sodium persulfate, and 38-54.8 parts of water; more preferably, the acrylamide-acrylic acid copolymer has an average molecular weight of 200-600 g / mol.

[0012] Preferably, the long-chain alkylamine is one or more of dodecylamine, tetradecylamine, hexadecylamine, octadecylamine, eicosamine, and docosylamine.

[0013] Preferably, the small molecule quaternary ammonium salt is one or more of butyltrimethylammonium bisulfate, dodecyltrimethylammonium sulfate, hexadecyltrimethylammonium sulfate, octadecyltrimethylammonium sulfate, hexadecyltrimethylammonium nitrate, dodecyltrimethylammonium acetate, octadecyltrimethylammonium acetate, and dodecyldimethylbenzylammonium bromide.

[0014] Preferably, the dendritic macroporous silica has an average particle size of 300 nm and an average pore size of 13 nm.

[0015] Preferably, the white marble rough has a particle size ≤ 4.75 mm.

[0016] This invention also provides a low-activity admixture grinding aid and its preparation method, comprising:

[0017] S1 Preparation of Component A

[0018] (1) Dissolve sodium persulfate in water to prepare a 10% solution A;

[0019] (2) Mix hydroxyethyl dibutyl phosphate, hydroxyethyl dimethoxy polyethylene glycol phosphate and calcium acrylate to obtain solution B;

[0020] (3) At room temperature, sodium 2-acrylamido-2-methylpropanesulfonate and the remaining water were added to the reactor and stirred for 20 min. The temperature was then raised to 40-50℃. After the temperature was constant, solutions A and B were added dropwise at the same time for 10 h. After the addition was completed, the temperature was kept constant for 3 h. Then, excess water was removed under negative pressure using a vacuum pump to make the solid content of the system ≥90%, thus obtaining a polymer blend containing phosphate esters. The polymer blend containing phosphate esters was packaged separately as component A.

[0021] S2 Preparation of component B

[0022] Component B is obtained by adding 24-32% acrylamide-acrylic acid copolymer, 3-6% zero-valent iron powder, 6-10% maleimide, 18-20% long-chain alkylamine, 6-12% small molecule quaternary ammonium salt and 28-35% dendritic macroporous silica (by mass percentage) into a powder material mixer, mixing evenly and then packaging separately.

[0023] S3 preparation component C

[0024] The raw white marble was packaged separately as component C;

[0025] S4 is used to prepare grinding aids for low-activity admixtures.

[0026] Components A, B, and C are combined in a mass ratio of 35:15-20:45-50 to obtain a grinding aid for low-activity admixtures. When using, the grinding aid for low-activity admixtures is added before the abrasive enters the mill.

[0027] The working principle of this invention is as follows:

[0028] Phosphate ester structures possess unique advantages in neutralizing and shielding the surface charge of low-activity admixture particles. They can adsorb onto the fresh surfaces formed by the breaking of chemical bonds during the grinding process of low-activity admixtures, thereby preventing particle re-aggregation and improving grinding efficiency. Furthermore, phosphate-containing polymer blends synthesized from phosphate esters and calcium acrylate can be directionally adsorbed onto the surface of low-activity admixture particles, giving the particle surfaces the same charge and creating electrostatic repulsion, promoting particle dispersion. In concrete applications, this can synergistically increase the fluidity of the low-activity admixture slurry when combined with polycarboxylate superplasticizers. Additionally, calcium ions in the system can promote the hydration of low-activity admixtures while also stimulating their pozzolanic activity.

[0029] Acrylamide-acrylic acid copolymers can react with Ca 2+ The formation of complexes promotes the Ca in the system 2+The dissolution of maleimide participates in hydration. The nitrogen atoms, long-chain alkylamines, and small-molecule quaternary ammonium salts in maleimide can target and interact with the newly fractured surfaces of low-activity admixture particles, eliminating electrostatic effects, preventing crack re-closure, reducing external stress for crack propagation, and thus improving grinding efficiency and the dispersion of low-activity admixture particles. Simultaneously, based on the characteristics of molecular polarity, a thicker adsorption layer can be formed on the surface of low-activity admixture particles, keeping the particles at greater distances, thereby improving powder flowability and reducing intergranular adhesion. Zero-valent iron powder has high reduction potential and reactivity, and can reduce high-valence heavy metals in low-activity admixtures to low-toxicity, low-valence metals.

[0030] The white marble tailings are mainly composed of CaCO3, MgCO3, and SiO2, with small amounts of Al2O3 and Fe2O3. The addition of dendritic macroporous silica and white marble tailings compensates for some of the calcium and silicon content deficiencies. Furthermore, during the grinding process, the collision between the grinding balls and the dendritic macroporous silica exacerbates the further cracking of the micro-cracks in the low-activity admixture. The significant steric hindrance (dendritic structure) stably shields the active sites of the low-activity admixture, improving the dispersion performance between particles. In addition, when the low-activity admixture is ground to a higher fineness, its particle surface becomes loose and porous, thus increasing its water retention capacity and leading to increased water demand. The interaction between the dendritic macroporous silica and the particles releases the water contained in the flocculated structure of the low-activity admixture, thereby effectively increasing the fluidity and water-reducing properties of the concrete paste.

[0031] The beneficial effects of this invention are as follows:

[0032] 1. The grinding aid prepared by this invention for low-activity admixtures promotes the development of green and low-carbon cementitious materials and improves the comprehensive utilization rate of bulk solid waste.

[0033] 2. The grinding aid prepared by this invention for low-activity admixtures exhibits excellent enhancing effects in both grinding aid and compressive strength when applied to admixtures with poor grindability and low activity.

[0034] 3. The grinding aid prepared by the present invention for low-activity admixtures not only solves the problems of activity, water demand, and powder flowability of low-activity admixtures, but also solves the compatibility problem between the grinding aid and the additives. Detailed Implementation

[0035] The technical solution of the present invention will be further described in detail below with reference to specific embodiments, but the present invention is not limited to the following technical solutions.

[0036] Example 1

[0037] 1. Dissolve 10g of sodium persulfate in 90g of water to prepare a 10% (w / w) solution A. Mix 180g of hydroxyethyl dibutyl phosphate, 160g of hydroxyethyl dimethoxy polyethylene glycol phosphate, and 160g of calcium acrylate to obtain solution B. At room temperature, add 5g of sodium 2-acrylamido-2-methylpropanesulfonate and 395g of water to a reaction vessel, stir for 20 minutes, and then heat to 50℃. After the temperature stabilizes, simultaneously add solutions A and B dropwise over 10 hours. After the addition is complete, maintain the temperature for another 3 hours. Then, use a vacuum pump under negative pressure to remove excess water, ensuring the solid content of the system is ≥90%, thus obtaining a phosphate-containing polymer blend, i.e., component A.

[0038] 2. Weigh out 32g of acrylamide-acrylic acid copolymer (429 g / mol), 3g of zero-valent iron powder, 6g of maleimide, 19g of dodecylamine, 12g of butyltrimethylammonium bisulfate, and 28g of dendritic macroporous silica in sequence and add them to a powder material mixer. Stir until homogeneous to obtain component B.

[0039] 3. Pack the raw white marble material separately as component C.

[0040] 4. Weigh components A, B, and C separately according to a mass ratio of 35:15:50 and add them before the abrasive enters the mill.

[0041] Example 2

[0042] 1. Dissolve 5g of sodium persulfate in 45g of water to prepare a 10% solution A. Mix 240g of hydroxyethyl dibutyl phosphate, 120g of hydroxyethyl dimethoxy polyethylene glycol phosphate, and 200g of calcium acrylate to obtain solution B. At room temperature, add 1g of sodium 2-acrylamido-2-methylpropanesulfonate and 389g of water to a reaction vessel, stir for 20 minutes, and then heat to 40℃. After the temperature stabilizes, simultaneously add solutions A and B dropwise over 10 hours. After the addition is complete, maintain the temperature for another 3 hours. Then, use a vacuum pump under negative pressure to remove excess water, ensuring the solid content of the system is ≥90%, thus obtaining a phosphate-containing polymer blend, i.e., component A.

[0043] 2. Weigh out 28g of acrylamide-acrylic acid copolymer (500 g / mol), 4.5g of zero-valent iron powder, 10g of maleimide, 20g of octadecylamine, 5g of dodecyltrimethylammonium sulfate, 4.5g of dodecyldimethylbenzylammonium bromide, and 28g of dendritic macroporous mesoporous silica in sequence and add them to a powder material mixer. Stir evenly to obtain component B.

[0044] 3. Pack the raw white marble material separately as component C.

[0045] 4. Weigh components A, B, and C separately according to a mass ratio of 35:18:47 and add them before the abrasive enters the mill.

[0046] Example 3

[0047] 1. Dissolve 1g of sodium persulfate in 9g of water to prepare a 10% (w / w) solution A. Mix 220g of hydroxyethyl dibutyl phosphate, 140g of hydroxyethyl dimethoxy polyethylene glycol phosphate, and 150g of calcium acrylate to obtain solution B. At room temperature, add 10g of sodium 2-acrylamido-2-methylpropanesulfonate and 470g of water to a reaction vessel, stir for 20 minutes, and then heat to 48℃. After the temperature stabilizes, simultaneously add solutions A and B dropwise over 10 hours. After the addition is complete, maintain the temperature for another 3 hours. Then, use a vacuum pump under negative pressure to remove excess water, ensuring the solid content of the system is ≥90%, thus obtaining a phosphate-containing polymer blend, i.e., component A.

[0048] 2. Weigh out 24g of acrylamide-acrylic acid copolymer (280 g / mol), 6g of zero-valent iron powder, 9g of maleimide, 20g of docosylamine, 6g of octadecyltrimethylammonium acetate, and 35g of dendritic macroporous silica in sequence and add them to a powder material mixer. Stir until homogeneous to obtain component B.

[0049] 3. Pack the raw white marble material separately as component C.

[0050] 4. Weigh components A, B, and C separately according to a mass ratio of 35:20:45 and add them before the abrasive enters the mill.

[0051] Example 4

[0052] 1. Dissolve 6g of sodium persulfate in 54g of water to prepare a 10% (w / w) solution A. Mix 200g of hydroxyethyl dibutyl phosphate, 120g of hydroxyethyl dimethoxy polyethylene glycol phosphate, and 180g of calcium acrylate to obtain solution B. At room temperature, add 10g of sodium 2-acrylamido-2-methylpropanesulfonate and 430g of water to a reaction vessel, stir for 20 minutes, and then heat to 48℃. After the temperature stabilizes, simultaneously add solutions A and B dropwise over 10 hours. After the addition is complete, maintain the temperature for another 3 hours. Then, use a vacuum pump under negative pressure to remove excess water, ensuring the solid content of the system is ≥90%, thus obtaining a phosphate-containing polymer blend, i.e., component A.

[0053] 2. Weigh out 28g of acrylamide-acrylic acid copolymer (360 g / mol), 6g of zero-valent iron powder, 8g of maleimide, 10g of octadecylamine, 8g of eicosamine, 8g of dodecyltrimethylammonium acetate, and 32g of dendritic macroporous silica in sequence and add them to a powder material mixer. Stir until homogeneous to obtain component B.

[0054] 3. Pack the raw white marble material separately as component C.

[0055] 4. Weigh components A, B, and C separately according to a mass ratio of 35:20:45 and add them before the abrasive enters the mill.

[0056] Comparative Example 1

[0057] 10g of sodium persulfate was dissolved in 90g of water to prepare a 10% (w / w) solution A. 180g of hydroxyethyl dibutyl phosphate, 160g of hydroxyethyl dimethoxy polyethylene glycol phosphate, and 160g of calcium acrylate were mixed to obtain solution B. At room temperature, 5g of sodium 2-acrylamido-2-methylpropanesulfonate and 395g of water were added to a reaction vessel and stirred for 20 minutes, then heated to 50℃. After the temperature stabilized, solutions A and B were simultaneously added dropwise over 10 hours. After the addition was complete, the temperature was maintained for another 3 hours. Excess water was then removed under negative pressure using a vacuum pump, ensuring the solid content of the system was ≥90%, thus obtaining a grinding aid for low-activity admixtures.

[0058] Comparative Example 2

[0059] Weigh out 32g of acrylamide-acrylic acid copolymer (429 g / mol), 3g of zero-valent iron powder, 6g of maleimide, 19g of dodecylamine, 12g of butyltrimethylammonium bisulfate, and 28g of dendritic macroporous mesoporous silica in sequence and add them to a powder material mixer. Stir evenly to obtain a grinding aid for low-activity admixtures.

[0060] Comparative Example 3

[0061] By packaging raw white marble separately, a grinding aid for use in low-activity admixtures can be obtained.

[0062] Comparative Example 4

[0063] Sodium tripolyphosphate was used as a grinding aid.

[0064] Comparative Example 5

[0065] Glycerol, triethanolamine and triisopropanolamine were mixed in a mass ratio of 1:1:1 to obtain a grinding aid.

[0066] According to GB / T 1345-2005 "Test Method for Fineness of Cement - Sieve Analysis Method" and GB / T 8074-2008 "Determination Method for Specific Surface Area of ​​Cement - Blaine Method", the sieve residue and specific surface area were tested, and the grinding aids of Examples 1-4 and Comparative Examples 1-5 were analyzed to improve the grinding effect on water slag, boiler slag and gasification slag.

[0067] Table 1. Effects of grinding aids on the specific surface area and sieve residue of water slag, boiler slag, and gasification slag.

[0068]

[0069] As can be seen from the data in Table 1:

[0070] (1) Compared with the blank sample (without any grinding aid), the residue on the 45μm sieve of water slag, boiler slag and gasification slag decreased significantly and the specific surface area increased significantly after using the grinding aids of Examples 1-4, and the grinding effect was significantly improved.

[0071] (2) The grinding aid performance (sieve residue, specific surface area) of Examples 1-4 is better than that of Comparative Example 4 (sodium tripolyphosphate) and Comparative Example 5 (alcohols and alkanolamines) with the same dosage.

[0072] (3) The performance of using component A, component B or component C alone (corresponding to Comparative Examples 1-3) is not as good as the mixed sample of component A, component B and component C (Examples 1-4).

[0073] (4) Judging from the amount of residue on the sieve, the grinding effect of several types of grinding aids on water slag is weaker than that on boiler slag and gasification slag, possibly because the water slag has a high content of carbon residue and glass.

[0074] Strength activity index test was conducted according to GB / T 1596-2017 "Fly ash used in cement and concrete".

[0075] Table 2. Effects of grinding aids on the strength and activity of water slag, boiler slag, and gasification slag.

[0076]

[0077] As can be seen from the data in Table 2:

[0078] (1) Compared with the blank sample (without any grinding aid), the strength activity index of water slag, boiler slag and gasification slag was significantly improved after using the grinding aids of Examples 1-4, and all met the requirements of fly ash strength activity index (≥70%).

[0079] (2) The activity of the grinding aids after Examples 1-4 is better than that of Comparative Example 4 (sodium tripolyphosphate) and Comparative Example 5 (alcohols and amines) with the same dosage.

[0080] (3) The performance of using component A, component B or component C alone (corresponding to Comparative Examples 1-3) is not as good as the mixture of components A, component B and component C (Examples 1-4).

[0081] Water requirement ratio test was conducted according to GB / T 1596-2017 "Fly ash for use in cement and concrete".

[0082] Table 3. Effects of grinding aids on the water requirement ratio of water slag, boiler slag, and gasification slag.

[0083]

[0084] As can be seen from the data in Table 3:

[0085] (1) Compared with the blank sample (without any grinding aid), the water demand ratio of water slag, boiler slag and gasification slag was reduced to a certain extent after using the grinding aids of Examples 1-4, and all met the requirements of the water demand ratio of secondary fly ash (≤105%).

[0086] (2) Comparative Example 4 (sodium tripolyphosphate) helped to reduce the water requirement ratio of the admixture, but Comparative Example 5 (alcohols and alkanolamines) did not help to reduce the water requirement ratio of the admixture, and even had a negative effect;

[0087] (3) Both component A and component B (corresponding to Comparative Example 1 and Comparative Example 2) have a certain effect on reducing the water requirement ratio of the admixture.

[0088] Concrete performance tests were conducted according to GB / T 50080-2016 "Standard for Test Methods of Performance of Ordinary Concrete Mixtures" and GB / T 8076-2008 "Concrete Admixtures". The admixture used in this experiment was a composite admixture made by co-milling 60% boiler slag, 30% gasification slag, 10% water slag, and a grinding aid. The cement dosage was 300 kg / m³. 3 Water-cement ratio 0.53, composite admixture dosage 60 kg / m³ 3 .

[0089] Table 4. Effects of grinding aids on the performance of concrete with boiler slag, gasification slag, and water slag as admixtures.

[0090]

[0091] As can be seen from the data in Table 4, compared with the blank sample (without any grinding aid), the concrete state of water slag, boiler slag, and gasification slag was significantly improved after using the grinding aids in Examples 1-4. This may be because the grinding aids used for low-activity admixtures promote the mutual dispersion of admixture particles. In concrete applications, they can form a synergistic effect with polycarboxylate superplasticizers, while releasing the moisture contained in the flocculated structure of low-activity admixtures, thereby effectively increasing the fluidity and water-reducing properties of concrete paste.

Claims

1. A grinding aid for low-activity admixtures, characterized in that, It is formulated from components A, B, and C in a mass ratio of 35:15-20:45-50; component A is a polymer blend containing phosphate esters; component B comprises, by mass percentage, 24-32% acrylamide-acrylic acid copolymer, 3-6% zero-valent iron powder, 6-10% maleimide, 18-20% long-chain alkylamine, 6-12% small molecule quaternary ammonium salt, and 28-35% dendritic macroporous mesoporous silica; component C is raw white marble. The phosphate-containing polymer blend comprises the following components in parts by weight: 18-24 parts of hydroxyethyl dibutyl phosphate, 12-16 parts of hydroxyethyl dimethoxy polyethylene glycol phosphate, 15-20 parts of calcium acrylate, 0.1-1 parts of sodium 2-acrylamido-2-methylpropanesulfonate, 0.1-1 parts of sodium persulfate, and 38-54.8 parts of water.

2. The grinding aid for low-activity admixtures according to claim 1, characterized in that, The acrylamide-acrylic acid copolymer has an average molecular weight of 200~600 g / mol.

3. The grinding aid for low-activity admixtures according to claim 1, characterized in that, The long-chain alkylamine is one or more of the following: dodecylamine, tetradecylamine, hexadecylamine, octadecylamine, eicosamine, and docosylamine.

4. The grinding aid for low-activity admixtures according to claim 1, characterized in that, The small molecule quaternary ammonium salt is one or more of butyltrimethylammonium bisulfate, dodecyltrimethylammonium sulfate, hexadecyltrimethylammonium sulfate, octadecyltrimethylammonium sulfate, hexadecyltrimethylammonium nitrate, dodecyltrimethylammonium acetate, octadecyltrimethylammonium acetate, and dodecyldimethylbenzylammonium bromide.

5. The grinding aid for low-activity admixtures according to claim 1, characterized in that, The dendritic macroporous mesoporous silica has an average particle size of 300 nm and an average pore size of 13 nm.

6. The grinding aid for low-activity admixtures according to claim 1, characterized in that, The particle size of the white marble rough is ≤4.75mm.

7. A method for preparing a low-activity admixture grinding aid according to any one of claims 1-6, comprising: S1 Preparation of Component A (1) Dissolve sodium persulfate in water to prepare a 10% solution A; (2) Mix hydroxyethyl dibutyl phosphate, hydroxyethyl dimethoxy polyethylene glycol phosphate and calcium acrylate to obtain solution B; (3) At room temperature, sodium 2-acrylamido-2-methylpropanesulfonate and the remaining water are added to the reaction vessel and stirred for 20 min. The temperature is then raised to 40-50℃. After the temperature is constant, solution A and solution B are added dropwise at the same time for 10 h. After the addition is completed, the temperature is kept constant for 3 h. Then, excess water is extracted under negative pressure using a vacuum pump so that the solid content of the system is ≥90%, and a polymer blend containing phosphate ester is obtained. The polymer blend containing phosphate ester is packaged separately as component A. S2 Preparation of component B Component B is obtained by adding 24-32% acrylamide-acrylic acid copolymer, 3-6% zero-valent iron powder, 6-10% maleimide, 18-20% long-chain alkylamine, 6-12% small molecule quaternary ammonium salt and 28-35% dendritic macroporous silica (by mass percentage) into a powder material mixer, mixing evenly and then packaging separately. S3 preparation component C The raw white marble was packaged separately as component C; S4 is used to prepare grinding aids for low-activity admixtures. Components A, B, and C are combined in a mass ratio of 35:15-20:45-50 to obtain a grinding aid for low-activity admixtures.

8. A method of using a grinding aid for low-activity admixtures according to any one of claims 1-6, characterized in that, When using, the grinding aid for low-activity admixtures is added before the abrasive enters the mill.

Images