A special grinding aid for functional calcium carbonate and preparation method thereof

Abstract

The invention discloses a special grinding aid for functional calcium carbonate and a preparation method thereof, and belongs to the field of grinding aids. The special grinding aid comprises the following raw materials: sodium oleate 23.5-24.5wt%, alcohol amine 7-8wt%, palmitic acid 0.2-0.5wt%, methanol 2-3wt%, ethanol 2.5-3.5wt%, and water as the remainder; the alcohol amine is one or a mixture of two or more of triethanolamine, triisopropanolamine, and diethanol monoisopropanolamine. The special grinding aid for calcium carbonate prepared by the present invention can improve the grinding output and grinding efficiency of calcium carbonate, reduce grinding energy consumption, and the calcium carbonate particles obtained by grinding have good dispersibility, high stability, and good physical properties.

Description

Technical Field

[0001] The invention belongs to the field of grinding aids, and in particular relates to a special grinding aid for functional calcium carbonate and a preparation method thereof. Background Art

[0002] Calcium carbonate is a common inorganic compound in the form of white powder. It has the advantages of abundant resources, low price, non-toxicity, high whiteness, etc. It plays an important role in the fields of plastics, rubber, papermaking, concrete, coatings, inks, medicine, etc. As a filler, calcium carbonate can be used to improve the processing performance, mechanical properties and appearance quality of products, and can also reduce the processing cost of products. According to different production processes, calcium carbonate can be divided into two types: dry process and wet process. Among them, calcium carbonate produced by dry process is limited by grinding and grading technology, and it is difficult to achieve ultrafine. In contrast, wet process is the production method commonly used for ultrafine calcium carbonate. Wet grinding can not only prepare calcium carbonate products with high purity, fine and uniform particle size and stable quality, but also reduce the surface polarity and specific surface energy of calcium carbonate through surface modification, reduce particle agglomeration, and improve the affinity of calcium carbonate particles with other additives. However, wet grinding of calcium carbonate currently also has the problems of low grinding efficiency and easy wall hanging of slurry.

[0003] Grinding aids usually include but are not limited to triethanolamine, alcohols, polyacrylic acid or other organic substances. In the production of calcium carbonate, grinding aids can improve grinding efficiency, reduce energy consumption, and improve powder performance. The following existing patents also provide some auxiliary agent formulas used in the grinding process of calcium carbonate. For example, Chinese patent CN102220032A discloses a grinding method for ultrafine heavy calcium carbonate, wherein the grinding aid includes polyethylene glycol, polydimethylsiloxane, potassium carbonate / sodium carbonate. The auxiliary agent can reduce the agglomeration produced during the grinding of heavy calcium carbonate and improve the grinding efficiency. Chinese patent CN103012637A discloses a heavy calcium carbonate wet grinding dispersant and a preparation method thereof. The wet grinding dispersant (grinding aid) includes acrylic acid, sodium bisulfite, ammonium persulfate, sodium carbonate, polyethylene glycol, sodium hydroxide and water. The auxiliary agent can enhance the electrostatic repulsion and steric hindrance of the auxiliary agent on calcium carbonate to ensure smooth grinding. Chinese patent CN107674243A discloses a calcium carbonate grinding aid modifier for plastic rubber and its processing technology, wherein the grinding aid modifier includes 7-10 parts of saturated fatty acid, 10-20 parts of heptasilsesquioxane, 10-15 parts of polyethylene glycol oleate, and 70-100 parts of water. The grinding aid helps to grind the particles and activate the powder, which can not only disperse calcium carbonate well, but also improve the mechanical properties of the product. However, the performance of the above-mentioned additives in improving grinding efficiency is still not ideal, and the residual additive components may also have adverse effects on downstream products and affect certain properties of downstream products. Summary of the invention

[0004] In view of the shortcomings of the above-mentioned prior art, the present invention provides a special grinding aid for functional calcium carbonate, which effectively improves the grinding output and grinding efficiency of calcium carbonate and reduces the grinding energy consumption by optimizing the combination of various raw materials and their concentration ratios and adjusting the optimal addition amount of the grinding aid. At the same time, the calcium carbonate particles obtained by grinding have good dispersibility and high stability. The present invention also provides a preparation method of the above-mentioned grinding aid.

[0005] The technical solution adopted by the present invention is:

[0006] A special grinding aid for functional calcium carbonate, comprising the following raw materials:

[0007] Sodium oleate, ethanolamine, palmitic acid, methanol, ethanol, water.

[0008] Preferably, a special grinding aid for functional calcium carbonate comprises the following raw materials:

[0009] Sodium oleate 20-30wt%, alkanolamine 5-10wt%, palmitic acid 0.1-1wt%, methanol 1-5wt%, ethanol 1-5wt%, and water as the balance.

[0010] Preferably, a special grinding aid for functional calcium carbonate comprises the following raw materials:

[0011] Sodium oleate 23.5-24.5wt%, olamine 7-8wt%, palmitic acid 0.2-0.5wt%, methanol 2-3wt%, ethanol 2.5-3.5wt%, and water as the balance.

[0012] Preferably, the alcohol amine is one of triethanolamine, triisopropanolamine, diethanol monoisopropanolamine, or a mixture of two or more thereof.

[0013] In the current ultrafine powder preparation process in the industry, the crushing of raw materials consumes a lot of energy. 80% of the energy is used for the crushing and grinding of raw materials. The use of appropriate grinding aids can increase grinding output and reduce energy consumption. However, there are many types of grinding aids, and the grinding aid effects vary greatly. The addition ratio of grinding aids also has a great influence on the grinding effect of calcium carbonate. The present invention optimizes the combination of raw materials and their concentration ratios, adjusts the optimal addition amount of grinding aids, produces heavy calcium carbonate of the same particle size in the same ring roller mill, and conducts physical property tests to obtain the optimal raw material combination and ratio of grinding aids. It has good wettability to raw materials, reduces surface oil absorption, improves the grindability and fluidity of raw materials, effectively improves the grinding output and grinding efficiency of calcium carbonate, and the calcium carbonate particles have good dispersibility and higher stability.

[0014] Preferably, the raw materials of the special grinding aid also include a synergist.

[0015] Preferably, a special grinding aid for functional calcium carbonate comprises the following raw materials:

[0016] Sodium oleate 23.5-24.5wt%, olamine 7-8wt%, palmitic acid 0.2-0.5wt%, methanol 2-3wt%, ethanol 2.5-3.5wt%, synergist 2-3.5wt%, and water as the balance.

[0017] Preferably, the preparation method of the synergist is as follows:

[0018] Acrylic acid, pentaerythritol triacrylate and 3-acetyl-N-vinyl pyrrolidone are uniformly mixed to obtain a monomer mixture; the monomer mixture, an initiator sodium persulfate aqueous solution and a reducing agent sodium pyrosulfite aqueous solution are added dropwise to the heated water, and after the addition is completed, the temperature is raised to react, the reaction is cooled, and the pH and solid content are adjusted to obtain a synergistic component A;

[0019] Nano-silicon dioxide is added to ethanol and ultrasonicated, then tetraethoxysilane is added to react at a high temperature, and then N-(3-trimethoxysilylethyl)ethylenediamine is added to water to continue reacting, and the reaction is continued, and the pH and solid content are adjusted to obtain a synergistic component B; the synergistic component A and the synergistic component B are evenly mixed to obtain the synergistic auxiliary agent.

[0020] The synergistic aid used in the present invention comprises a synergistic component A and a synergistic component B, wherein the synergistic component A is synthesized into a multifunctional organic polymer by reacting functional monomers such as pentaerythritol triacrylate and 3-acetyl-N-vinyl pyrrolidone with acrylic monomers, and can form a spatial network structure around calcium carbonate particles during the grinding process, thereby enhancing the spatial steric hindrance and electrostatic repulsion between particles, achieving excellent dispersion effect and viscosity reduction effect, and thus playing a grinding aid role; the multipolar functional groups of pentaerythritol triacrylate, and the pyrrolidone and acetyl groups of 3-acetyl-N-vinyl pyrrolidone have strong adsorption properties, can promote the formation of an adsorption film on the surface of calcium carbonate particles, and improve the dispersibility of the particles; the unsaturated olefin group is used for polymerization reaction, and the cyclic structure contained therein helps to improve stability, avoid agglomeration and adhesion of calcium carbonate particles, and narrow the particle size distribution, thereby achieving a grinding aid effect.

[0021] Wherein the synergistic component B is mainly composed of nano silicon dioxide, and its surface contains a large number of polar functional groups and has a high hardness. During grinding, nano silicon dioxide interacts with the surface of calcium carbonate particles and adsorbs thereon, enhancing the roughness and friction of the particle surface, thereby promoting the effective grinding, improving grinding efficiency, and reducing energy consumption. Further, the present invention modifies nano silicon dioxide by adding tetraethoxysilane and N-(3-trimethoxysilylethyl)ethylenediamine, which helps to form a contact bridge between inorganic substances, improve the dispersion effect of inorganic substances, improve the compatibility of inorganic substances and organic substances in raw materials, and also avoid the agglomeration of particles caused by the mutual adsorption of nano silicon dioxide. The synergistic component A and the synergistic component B in the synergistic aid of the present invention work synergistically, significantly improving the grinding aid effect, and improving the comprehensive performance of the product. Under the same production conditions, the above-mentioned calcium carbonate special grinding aid of the present invention can achieve increased output and reduced energy consumption, and the product has low viscosity and excellent processing performance.

[0022] Preferably, the preparation method of the synergist is as follows:

[0023] 100-150 parts by weight of acrylic acid, 10-15 parts by weight of pentaerythritol triacrylate and 5-10 parts by weight of 3-acetyl-N-vinyl pyrrolidone are uniformly mixed to obtain a monomer mixture; 30-60 parts by weight of water are heated to 85-90° C., and then 70-80 parts by weight of the monomer mixture, 5-10 parts by weight of an initiator sodium persulfate aqueous solution and 15-20 parts by weight of a reducing agent sodium pyrosulfite aqueous solution are dropwise added, the dropwise addition is controlled to end for 100-150 minutes, and then the temperature is raised to 90-95° C. for constant temperature reaction for 50-100 minutes, and then cooled to room temperature, and the pH is adjusted to neutral and the solid content is adjusted to 40-50wt% to obtain a synergistic component A;

[0024] 1-3 parts by weight of nano silicon dioxide is added to 80-120 parts by weight of ethanol and ultrasonicated for 20-50 minutes, then 1-1.5 parts by weight of tetraethoxysilane is added, the temperature is raised to 55-60° C. and the reaction is carried out at a constant temperature for 10-20 minutes, then 0.2-0.5 parts by weight of N-(3-trimethoxysilylethyl)ethylenediamine and 20-30 parts by weight of water are added and the reaction is continued for 100-150 minutes, the reaction is cooled to room temperature, the pH is adjusted to neutral, and the solid content is adjusted to 40-50wt% to obtain a synergistic component B; the synergistic component A and the synergistic component B are uniformly mixed in a weight ratio of 1:0.5-2 to obtain the synergistic auxiliary agent.

[0025] Preferably, the concentration of the sodium persulfate aqueous solution is 10-15wt%.

[0026] Preferably, the concentration of the sodium metabisulfite aqueous solution is 10-15wt%.

[0027] Preferably, the ultrasonic conditions are: ultrasonic power 100-300W, ultrasonic frequency 20-40kHz.

[0028] The present invention also discloses a method for preparing the special grinding aid for functional calcium carbonate, which specifically comprises the following steps:

[0029] The raw materials are weighed according to the raw material formula, and the alcoholamine, methanol, ethanol, synergist and water are evenly mixed, and then sodium oleate and palmitic acid are added and stirred until uniform, so as to obtain the special grinding aid for functional calcium carbonate.

[0030] Beneficial effects of the present invention:

[0031] The calcium carbonate grinding aid prepared by the invention can improve the grinding output and grinding efficiency of calcium carbonate and reduce the grinding energy consumption. The optimal addition amount of the grinding aid in the grinding of calcium carbonate production is in the range of 0.3-1.0%, and the calcium carbonate particles obtained by grinding have good dispersibility, high stability and good physical properties. DETAILED DESCRIPTION

[0032] The above-mentioned invention contents of the present invention are further described in detail below in conjunction with specific implementation methods. The embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the contents of the present invention and implement them accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit and essence of the present invention should be included in the protection scope of the present invention.

[0033] Example 1

[0034] A special grinding aid for functional calcium carbonate, comprising the following raw materials:

[0035] Sodium oleate 23.5wt%, triethanolamine 8wt%, palmitic acid 0.5wt%, methanol 3wt%, ethanol 2.5wt%, and water as the balance.

[0036] A method for preparing a special grinding aid for functional calcium carbonate, comprising the following steps:

[0037] The raw materials are weighed according to the raw material formula, triethanolamine, methanol, ethanol and water are evenly mixed, and then sodium oleate and palmitic acid are added and stirred until uniform, so as to obtain the special grinding aid for functional calcium carbonate.

[0038] Example 2

[0039] A special grinding aid for functional calcium carbonate, comprising the following raw materials:

[0040] Sodium oleate 24.5wt%, triethanolamine 7wt%, palmitic acid 0.2wt%, methanol 2wt%, ethanol 3.5wt%, and water as the balance.

[0041] A method for preparing a special grinding aid for functional calcium carbonate, comprising the following steps:

[0042] The raw materials are weighed according to the raw material formula, triethanolamine, methanol, ethanol and water are evenly mixed, and then sodium oleate and palmitic acid are added and stirred until uniform, so as to obtain the special grinding aid for functional calcium carbonate.

[0043] Example 3

[0044] A special grinding aid for functional calcium carbonate, comprising the following raw materials:

[0045] Sodium oleate 24wt%, triethanolamine 7.5wt%, palmitic acid 0.3wt%, methanol 2.5wt%, ethanol 3wt%, and water as the balance.

[0046] A method for preparing a special grinding aid for functional calcium carbonate, comprising the following steps:

[0047] The raw materials are weighed according to the raw material formula, triethanolamine, methanol, ethanol and water are evenly mixed, and then sodium oleate and palmitic acid are added and stirred until uniform, so as to obtain the special grinding aid for functional calcium carbonate.

[0048] Test Example 1

[0049] Prepare the raw materials, open the ring roller mill to produce the same specification of 8μm heavy calcium carbonate, take samples to test the particle size, whiteness, sieve residue and other parameters. According to the addition of grinding aids of 0.3%, 0.7%, and 1.0%, produce the corresponding samples (D1001, D1002, and D1003), and immediately test their whiteness, particle size (Malvern), moisture, and sieve residue to see if they are qualified.

[0050] Table 1 Physical parameters of ground samples

[0051]

[0052] Example 4

[0053] A special grinding aid for functional calcium carbonate, comprising the following raw materials:

[0054] Sodium oleate 24wt%, triethanolamine 7.5wt%, palmitic acid 0.3wt%, methanol 2.5wt%, ethanol 3wt%, synergist 2.7wt%, and water as the balance.

[0055] The preparation method of the synergistic aid is as follows:

[0056] 130 parts by weight of acrylic acid, 12 parts by weight of pentaerythritol triacrylate (CAS No. 3524-68-3) and 8 parts by weight of 3-acetyl-N-vinyl pyrrolidone (CAS No. 727418-59-9) were uniformly mixed to obtain a monomer mixture; 50 parts by weight of water were heated to 86° C., and then 75 parts by weight of the monomer mixture, 7 parts by weight of a 12wt% sodium persulfate aqueous solution and 18 parts by weight of a 14wt% sodium pyrosulfite aqueous solution were dropwise added, and the dropwise addition was controlled to end for 120 minutes, and then the temperature was raised to 92° C. for constant temperature reaction for 80 minutes, and then cooled to room temperature, and the pH was adjusted to neutral and the solid content was adjusted to 45wt% to obtain a synergistic component A;

[0057] 2.5 parts by weight of nano-silicon dioxide (particle size of 30 nm) are added to 100 parts by weight of ethanol and ultrasonicated for 30 minutes, with an ultrasonic power of 200 W and an ultrasonic frequency of 35 kHz, and then 1.2 parts by weight of tetraethoxysilane (CAS No. 78-10-4) are added, the temperature is raised to 58° C. and the reaction is carried out at a constant temperature for 15 minutes, and then 0.3 parts by weight of N-(3-trimethoxysilylethyl)ethylenediamine (CAS No. 7719-00-8) and 25 parts by weight of water are added and the reaction is continued for 135 minutes, and the mixture is cooled to room temperature, the pH is adjusted to neutral, and the solid content is adjusted to 45wt% to obtain a synergistic component B; the synergistic component A and the synergistic component B are evenly mixed in a weight ratio of 1:1 to obtain the synergistic auxiliary agent.

[0058] A method for preparing a special grinding aid for functional calcium carbonate, comprising the following steps:

[0059] The raw materials are weighed according to the raw material formula, triethanolamine, methanol, ethanol, synergist and water are evenly mixed, and then sodium oleate and palmitic acid are added and stirred until uniform, so as to obtain the special grinding aid for functional calcium carbonate.

[0060] Example 5

[0061] A special grinding aid for functional calcium carbonate, comprising the following raw materials:

[0062] Sodium oleate 24wt%, triethanolamine 7.5wt%, palmitic acid 0.3wt%, methanol 2.5wt%, ethanol 3wt%, synergist 2.7wt%, and water as the balance.

[0063] The preparation method of the synergistic aid is as follows:

[0064] 130 parts by weight of acrylic acid, 12 parts by weight of pentaerythritol triacrylate (CAS No. 3524-68-3) and 8 parts by weight of 3-acetyl-N-vinyl pyrrolidone (CAS No. 727418-59-9) are uniformly mixed to obtain a monomer mixture; 50 parts by weight of water are heated to 86° C., and then 75 parts by weight of the monomer mixture, 7 parts by weight of a 12wt% sodium persulfate aqueous solution and 18 parts by weight of a 14wt% sodium pyrosulfite aqueous solution are dropwise added, the dropwise addition is controlled to end for 120 minutes, the temperature is then raised to 92° C. for constant temperature reaction for 80 minutes, the mixture is cooled to room temperature, the pH is adjusted to neutral, and the solid content is adjusted to 45wt%, to obtain the synergist.

[0065] A method for preparing a special grinding aid for functional calcium carbonate, comprising the following steps:

[0066] The raw materials are weighed according to the raw material formula, triethanolamine, methanol, ethanol, synergist and water are evenly mixed, and then sodium oleate and palmitic acid are added and stirred until uniform, so as to obtain the special grinding aid for functional calcium carbonate.

[0067] Example 6

[0068] A special grinding aid for functional calcium carbonate, comprising the following raw materials:

[0069] Sodium oleate 24wt%, triethanolamine 7.5wt%, palmitic acid 0.3wt%, methanol 2.5wt%, ethanol 3wt%, synergist 2.7wt%, and water as the balance.

[0070] The preparation method of the synergistic aid is as follows:

[0071] 2.5 parts by weight of nano-silicon dioxide (particle size of 30 nm) are added to 100 parts by weight of ethanol and ultrasonicated for 30 minutes, with an ultrasonic power of 200 W and an ultrasonic frequency of 35 kHz, and then 1.2 parts by weight of tetraethoxysilane (CAS No. 78-10-4) are added, the temperature is raised to 58° C. and the reaction is carried out at a constant temperature for 15 minutes, and then 0.3 parts by weight of N-(3-trimethoxysilylethyl)ethylenediamine (CAS No. 7719-00-8) and 25 parts by weight of water are added and the reaction is continued for 135 minutes, and the reaction is cooled to room temperature, and the pH is adjusted to neutral and the solid content is adjusted to 45wt% to obtain the synergistic aid.

[0072] A method for preparing a special grinding aid for functional calcium carbonate, comprising the following steps:

[0073] The raw materials are weighed according to the raw material formula, triethanolamine, methanol, ethanol, synergist and water are evenly mixed, and then sodium oleate and palmitic acid are added and stirred until uniform, so as to obtain the special grinding aid for functional calcium carbonate.

[0074] Test Example 2

[0075] The heavy calcium carbonate powder (D 50 8μm, calcium carbonate particles <2μm initial weight content of 5%) for ultrafine grinding, add 0.3% of the dry weight of the grinding powder obtained in the above examples of special grinding aids for grinding experiments. After grinding for 60 minutes, the yield of the experimental group samples (calcium carbonate particles <2μm) was measured, and the yield increase rate was calculated. Among them, the control group samples without grinding aids were used as the control group samples, and the yield increase rate = (the yield of the experimental group samples-the yield of the control group samples) / the yield of the control group samples × 100%. The solid content of the experimental group samples was adjusted to 75%, and the kinematic viscosity at 25°C and the static viscosity after 1 day were measured.

[0076] Table 2 Performance test results of special grinding aids

[0077]

[0078] It can be seen that under the same production conditions, the special grinding aid for functional calcium carbonate prepared by the present invention can achieve increased production and reduced energy consumption, the product has lower viscosity and excellent processing performance during application. Compared with Examples 3, 5, and 6, the special grinding aid of Example 4 of the present invention further adds a synergistic aid made of synergistic component A and synergistic component B, which has the best effect. The synergistic component A is synthesized by reacting functional monomers such as pentaerythritol triacrylate and 3-acetyl-N-vinyl pyrrolidone with acrylic monomers to synthesize a multifunctional organic polymer, which can form a spatial network structure around the calcium carbonate particles during the grinding process, thereby enhancing the steric hindrance and electrostatic repulsion between the particles, and achieving excellent dispersion and viscosity reduction effects, thereby playing a grinding aid role; the multipolar functional groups of pentaerythritol triacrylate, and the pyrrolidone and acetyl groups of 3-acetyl-N-vinyl pyrrolidone have strong adsorption properties, which can promote the formation of an adsorption film on the surface of the calcium carbonate particles and improve the dispersibility of the particles. The unsaturated olefin group is used for polymerization reaction, and the cyclic structure contained therein helps to improve stability, avoid agglomeration and adhesion of calcium carbonate particles, and narrow the particle size distribution, thereby achieving a grinding aid effect. Wherein the synergistic component B is based on nano silicon dioxide, and its surface contains a large amount of polar functional groups, and the hardness is relatively high. During grinding, the nano silicon dioxide interacts with the surface of calcium carbonate particles and adsorbs thereon, enhancing the roughness and friction of the particle surface, thereby promoting the effective conduct of grinding, improving grinding efficiency, and reducing energy consumption. Further, the present invention modifies the nano silicon dioxide by adding tetraethoxysilane and N-(3-trimethoxysilylethyl)ethylenediamine, which helps to form a contact bridge between inorganic substances, improves the dispersion effect of inorganic substances, improves the compatibility of inorganic substances and organic substances in raw materials, and can also avoid the mutual adsorption of nano silicon dioxide and cause the agglomeration of particles. The synergistic component A and the synergistic component B in the synergistic aid of the present invention work synergistically, significantly improving the grinding aid effect, and improving the comprehensive performance of the product.

[0079] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A special grinding aid for functional calcium carbonate, characterized in that: Including the following ingredients: Sodium oleate 23.5-24.5wt%, alcohol amine 7-8wt%, palmitic acid 0.2-0.5wt%, methanol 2-3wt%, ethanol 2.5-3.5wt%, synergist 2-3.5wt%, water as the balance; The preparation method of the synergistic aid is as follows: 100-150 parts by weight of acrylic acid, 10-15 parts by weight of pentaerythritol triacrylate and 5-10 parts by weight of 3-acetyl-N-vinyl pyrrolidone are uniformly mixed to obtain a monomer mixture; 30-60 parts by weight of water are heated to 85-90° C., and then 70-80 parts by weight of the monomer mixture, 5-10 parts by weight of an initiator sodium persulfate aqueous solution and 15-20 parts by weight of a reducing agent sodium pyrosulfite aqueous solution are dropwise added, the dropwise addition is controlled to end for 100-150 minutes, and then the temperature is raised to 90-95° C. for constant temperature reaction for 50-100 minutes, and then cooled to room temperature, and the pH is adjusted to neutral and the solid content is adjusted to 40-50wt% to obtain a synergistic component A; 1-3 parts by weight of nano silicon dioxide is added to 80-120 parts by weight of ethanol and ultrasonicated for 20-50 minutes, then 1-1.5 parts by weight of tetraethoxysilane is added, the temperature is raised to 55-60° C. and the reaction is carried out at a constant temperature for 10-20 minutes, then 0.2-0.5 parts by weight of N-(3-trimethoxysilylethyl)ethylenediamine and 20-30 parts by weight of water are added and the reaction is continued for 100-150 minutes, the reaction is cooled to room temperature, the pH is adjusted to neutral, and the solid content is adjusted to 40-50wt% to obtain a synergistic component B; the synergistic component A and the synergistic component B are uniformly mixed in a weight ratio of 1:0.5-2 to obtain the synergistic auxiliary agent.

2. The special grinding aid for functional calcium carbonate according to claim 1, characterized in that: The alcohol amine is one of triethanolamine, triisopropanolamine, diethanol monoisopropanolamine or a mixture of two or more thereof.

3. The method for preparing a special grinding aid for functional calcium carbonate as claimed in any one of claims 1 to 2, characterized in that: The method comprises the following steps: weighing raw materials according to the raw material formula, uniformly mixing alcohol amine, methanol, ethanol, a synergist and water, and then adding sodium oleate and palmitic acid and stirring until uniform, so as to obtain the special grinding aid for functional calcium carbonate.

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