An enhanced cement grinding aid and its preparation method

Abstract

This invention discloses an enhanced cement grinding aid and its preparation method, belonging to the technical field of cement admixtures. It is made from the following raw materials in parts by weight: 20-30 parts of an alcohol amine complex, 10-20 parts of ethylene glycol, 1-3 parts of a surfactant, 0.3-0.5 parts of a defoamer, 3-5 parts of a macromolecular synergist, 1-3 parts of a polycarboxylate superplasticizer, 0.5-1.5 parts of molasses, and 20-30 parts of water; the alcohol amine complex includes triethanolamine and modified alcohol amines; the macromolecular synergist is a sodium alginate-β-cyclodextrin macromolecular complex. This cement grinding aid can significantly improve cement grinding efficiency, increasing hourly output by more than 24.5%; the 3-day strength of cement increases by more than 5.9 MPa, and the 28-day strength increases by more than 10.7 MPa, showing good market application prospects.

Description

Technical Field

[0001] This invention belongs to the field of cement admixture technology, specifically relating to an enhanced cement grinding aid and its preparation method. Background Technology

[0002] In the cement industry, the grinding process is highly energy-intensive. Approximately 3 tons of various materials need to be ground to produce one ton of cement, and the electricity consumption of the grinding process accounts for about 60% to 70% of the total electricity consumption in cement production. To reduce energy consumption and improve grinding efficiency, adding a small amount of grinding aid is one effective method. Cement grinding aids are admixtures added during cement grinding to improve grinding efficiency without impairing cement properties. The use of cement grinding aids can significantly improve the dispersion of cement during grinding, not only increasing output and reducing electricity consumption, but also improving cement performance and reducing clinker content, resulting in significant economic benefits.

[0003] Existing cement grinding aids are mainly composed of traditional organic compounds such as alkanolamines and alcohols, as well as inorganic salts. Alkanolamines are relatively expensive and their dosage is sensitive; excessive alkanolamines can adversely affect cement grinding, such as causing excessively fast cement flow rates, resulting in short residence time in the mill, insufficient grinding, and coarse cement, thus affecting cement yield and strength. Alcohols mainly improve cement grinding efficiency and have little impact on strength development. Inorganic salts increase the alkali content in cement, affecting concrete durability. Furthermore, some existing grinding aids have poor stability and unreasonable mix design, preventing them from meeting actual engineering needs, such as insufficient improvement in cement strength.

[0004] Therefore, there is an urgent need to research and design an enhanced cement grinding aid that has good product stability, significant grinding effect, and can significantly improve cement strength. Summary of the Invention

[0005] The purpose of this invention is to provide an enhanced cement grinding aid. This grinding aid requires a small dosage, has wide applicability, significantly increases the hourly output of cement mills, improves production efficiency, and can increase the 3-day strength of cement by more than 5.9 MPa and the 28-day strength by more than 10.7 MPa.

[0006] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows:

[0007] An enhanced cement grinding aid is made from the following raw materials in parts by weight: 20-30 parts of an alcohol amine complex, 10-20 parts of ethylene glycol, 1-3 parts of a surfactant, 0.3-0.5 parts of a defoamer, 3-5 parts of a macromolecular synergist, 1-3 parts of a polycarboxylate superplasticizer, 0.5-1.5 parts of molasses, and 20-30 parts of water; wherein the alcohol amine complex includes triethanolamine and modified alcohol amines; and the macromolecular synergist is a sodium alginate-β-cyclodextrin macromolecular complex.

[0008] Preferably, the mass ratio of triethanolamine to modified alcoholamine in the alcoholamine complex is 1:3.

[0009] Preferably, the modified alkanolamine is prepared by the following method: adding diethanol monoisopropanolamine to a reaction vessel, adding an appropriate amount of 0.1M KOH solution under magnetic stirring, then adding sunflower seed oil, heating to 130°C, maintaining the reaction for 4-6 hours, and cooling to 45°C after the reaction is completed to obtain the modified alkanolamine.

[0010] Preferably, the molar ratio of diethanol monoisopropanolamine to sunflower seed oil is 3:1.

[0011] Preferably, the amount of KOH solution used is 1% of the mass of sunflower seed oil.

[0012] Preferably, the macromolecular synergist is prepared by the following method: sodium alginate, phytic acid, and β-cyclodextrin are added to deionized water, stirred evenly, and then an appropriate amount of KH2PO4 is added. The mixture is heated to 100°C and stirred for 1 h. The above mixed solution is then placed in a constant temperature oven and reacted at 150°C for 10 h. After the reaction, the obtained product is placed in 200 mL of 0.1 mol / L NaOH solution and stirred at room temperature for 2 h. After filtration, the above operation is repeated once. Finally, the product is washed with deionized water until the pH of the filtrate is neutral. The product is then placed in a vacuum drying oven and dried at 55°C for 12 h to obtain the sodium alginate-β-cyclodextrin macromolecular complex.

[0013] Preferably, the ratio of sodium alginate, phytic acid, β-cyclodextrin, deionized water and KH2PO4 is 1g:4g:8g:100ml:0.6g.

[0014] Preferably, the surfactant is carboxymethyl cellulose or sodium lignosulfonate.

[0015] Preferably, the defoamer is fatty alcohol polyoxyethylene ether sulfate or sodium stearate.

[0016] The present invention also provides a method for preparing the above-mentioned enhanced cement grinding aid, which includes the following steps:

[0017] A: Prepare modified alkanolamines, and then compound them with triethanolamine in a certain proportion to obtain alkanolamine complexes;

[0018] B: Preparation of macromolecular synergists;

[0019] C: First, place water in a stirring device, add the alcohol amine complex, stir and heat to 45°C, then add the macromolecular synergist and continue stirring for 20-30 minutes;

[0020] D: Raise the system temperature to 50~55℃, then add ethylene glycol, surfactant, defoamer, polycarboxylate superplasticizer and molasses in sequence, continue to stir evenly, and then cool to room temperature to obtain the final product, reinforced cement grinding aid.

[0021] All raw materials used in this invention were purchased commercially.

[0022] The grinding aid of this invention is designed to be added at a dosage of 0.03-0.06%.

[0023] The macromolecular synergist added in this invention is a macromolecular complex composed of sodium alginate, phytic acid, and β-cyclodextrin. The carboxyl groups on the surface of sodium alginate undergo esterification with the hydroxyl groups on the surface of β-cyclodextrin. The phosphate in phytic acid undergoes dehydration condensation with the hydroxyl groups on the surfaces of β-cyclodextrin and sodium alginate to form the macromolecular complex. This complex contains multiple functional groups, including carboxyl, hydroxyl, and phosphate groups, which have good adsorption properties on the surface of cement particles. These functional groups adsorb onto the surface of cement particles, forming a lubricating layer that reduces friction and cohesion between particles. This facilitates the dispersion of cement particles in the mill. The dispersed cement particles are more easily impacted and ground by the grinding media within the mill, thereby improving grinding efficiency. Furthermore, the macromolecular synergist of this invention also contains phosphate groups, which can react with the calcium in cement... 2+ The reaction forms calcium phosphate particles, which can fill the tiny pores in cement. The macromolecular particles within these pores continuously deposit and coat the surfaces of hydration products and unhydrated cement particles. This macromolecular complex and the cement hydration products form an interwoven spatial network structure, thereby increasing the density and strength of the cement. Simultaneously, the reinforcing agent contains multiple groups, such as hydroxyl groups, which can chelate metal ions on the surface of the cementitious material, making its surface more soluble, accelerating early hydration, and improving the early strength of cement mortar.

[0024] This invention uses an alkanolamine complex, prepared by blending triethanolamine and modified alkanolamine in a specific ratio, as the main grinding aid. The modified alkanolamine replaces a portion of the triethanolamine, reducing the adverse effects on the hydration process of cement grinding agents caused by excessive triethanolamine use. The modified alkanolamine is obtained by amidation reaction of sunflower seed oil with diethanolmonoisopropanolamine under suitable conditions, yielding an alkanolamide product with active groups such as amide and hydroxyl groups. Since amide molecules significantly promote the hydration reaction of cement, they can prevent cracking and leakage caused by excessively rapid cement drying, and also reduce the formation of pores in the cement, further improving its density and strength.

[0025] The beneficial effects of this invention are:

[0026] 1) This invention uses a combination of modified alkanolamine and triethylamine, which reduces the amount of triethanolamine added, avoids the adverse effects of excessive alkanolamine on cement, and also enhances the grinding aid effect.

[0027] 2) The sodium alginate, phytic acid and β-cyclodextrin used in the macromolecular synergist prepared in this invention are all natural high molecular compounds with biodegradability and non-toxicity. This makes the application of the synergist in cement grinding aids more environmentally friendly and safe, and makes the prepared cement grinding aids suitable for different types of cement and mills, with wide applicability.

[0028] 3) The alcohol amine complex prepared by this invention has a significant synergistic effect with the macromolecular synergist. The combination of the two improves the cement grinding efficiency, promotes both early and late hydration of cement, and improves the 3-day and 28-day strength of cement, which has good market application prospects. Attached Figure Description

[0029] Figure 1 This invention illustrates the effect of different dosages of grinding aid on the 3-day and 28-day compressive strength of cement.

[0030] Figure 2 The images shown are scanning electron microscope (SEM) images of cement mortar prepared by different treatment groups of the present invention, where a is the blank control group cement mortar, b is the comparative example 1 cement mortar, c is the comparative example 2 cement mortar, and d is the example 3 cement mortar. Detailed Implementation

[0031] The technical solution of the present invention will be further described below with reference to specific embodiments, but it is not limited thereto.

[0032] Example 1

[0033] An enhanced cement grinding aid is made from the following raw materials in parts by weight: 20 kg of an alcohol amine complex, 10 kg of ethylene glycol, 1 kg of carboxymethyl cellulose, 0.3 kg of sodium fatty alcohol polyoxyethylene ether sulfate, 3 kg of a macromolecular synergist, 1 kg of polycarboxylate superplasticizer, 0.5 kg of molasses, and 20 kg of water; wherein the alcohol amine complex is composed of triethanolamine and modified alcohol amine in a mass ratio of 1:3; and the macromolecular synergist is a sodium alginate-β-cyclodextrin macromolecular complex.

[0034] The preparation method of the above-mentioned enhanced cement grinding aid includes the following steps:

[0035] A: Preparation of modified alkanolamine: Diethanol monoisopropanolamine was added to a reaction vessel, and 1% (by weight) of sunflower seed oil in 0.1M KOH solution was added under magnetic stirring. Then, sunflower seed oil was added to the mixture, and the mixture was heated to 130℃ and maintained for 4-6 hours. After the reaction was completed, the temperature was lowered to 45℃ to obtain the modified alkanolamine. The molar ratio of diethanol monoisopropanolamine to sunflower seed oil was 3:1. The obtained modified alkanolamine was combined with triethanolamine in a mass ratio of 3:1 to form an alkanolamine complex.

[0036] B: Preparation of macromolecular synergist: 1g sodium alginate, 4g phytic acid, and 8g β-cyclodextrin were added to 100ml of deionized water and stirred evenly. Then, 0.6g KH2PO4 was added and heated to 100℃ and stirred for 1 h. The above mixed solution was then placed in a constant temperature oven and reacted at 150℃ for 10 hours. After the reaction, the obtained product was placed in 200 mL of 0.1 mol / L NaOH solution and stirred at room temperature for 2 h. After filtration, the above operation was repeated once. Finally, the product was washed with deionized water until the pH of the filtrate was neutral. The product was placed in a vacuum drying oven and dried at 55℃ for 12 h to obtain the sodium alginate-β-cyclodextrin macromolecular complex.

[0037] C: Place the water in the formula in a stirring device, first add the alcohol amine complex, stir and heat to 45°C, then add the macromolecular synergist, and continue stirring for 20-30 minutes;

[0038] D: Raise the system temperature to 50~55℃, then add ethylene glycol, surfactant, defoamer, polycarboxylate superplasticizer and molasses in sequence, continue to stir evenly, and then cool to room temperature to obtain the final product, reinforced cement grinding aid.

[0039] Example 2

[0040] An enhanced cement grinding aid is made from the following raw materials in parts by weight: 30 kg of an alcohol amine complex, 20 kg of ethylene glycol, 3 kg of sodium lignosulfonate, 0.5 kg of sodium stearate, 5 kg of a macromolecular synergist, 3 kg of polycarboxylate superplasticizer, 1.5 kg of molasses, and 30 kg of water; wherein the alcohol amine complex is composed of triethanolamine and modified alcohol amine in a mass ratio of 1:3; and the macromolecular synergist is a sodium alginate-β-cyclodextrin macromolecular complex.

[0041] The preparation method of the above-mentioned enhanced cement grinding aid includes the following steps:

[0042] A: Preparation of modified alkanolamine: Diethanol monoisopropanolamine was added to a reaction vessel, and 1% (by weight) of sunflower seed oil in 0.1M KOH solution was added under magnetic stirring. Then, sunflower seed oil was added to the mixture, and the mixture was heated to 130℃ and maintained for 4-6 hours. After the reaction was completed, the temperature was lowered to 45℃ to obtain the modified alkanolamine. The molar ratio of diethanol monoisopropanolamine to sunflower seed oil was 3:1. The obtained modified alkanolamine was combined with triethanolamine in a mass ratio of 3:1 to form an alkanolamine complex.

[0043] B: Preparation of macromolecular synergist: 1g sodium alginate, 4g phytic acid, and 8g β-cyclodextrin were added to 100ml of deionized water and stirred evenly. Then, 0.6g KH2PO4 was added and heated to 100℃ and stirred for 1 h. The above mixed solution was then placed in a constant temperature oven and reacted at 150℃ for 10 hours. After the reaction, the obtained product was placed in 200 mL of 0.1 mol / L NaOH solution and stirred at room temperature for 2 h. After filtration, the above operation was repeated once. Finally, the product was washed with deionized water until the pH of the filtrate was neutral. The product was placed in a vacuum drying oven and dried at 55℃ for 12 h to obtain the sodium alginate-β-cyclodextrin macromolecular complex.

[0044] C: Place the water in the formula in a stirring device, first add the alcohol amine complex, stir and heat to 45°C, then add the macromolecular synergist, and continue stirring for 20-30 minutes;

[0045] D: Raise the system temperature to 50~55℃, then add ethylene glycol, surfactant, defoamer, polycarboxylate superplasticizer and molasses in sequence, continue to stir evenly, and then cool to room temperature to obtain the final product, reinforced cement grinding aid.

[0046] Example 3

[0047] An enhanced cement grinding aid is made from the following raw materials in parts by weight: 25 kg of an alkanolamine complex, 15 kg of ethylene glycol, 2 kg of sodium lignosulfonate, 0.4 kg of sodium fatty alcohol polyoxyethylene ether sulfate, 4 kg of a macromolecular synergist, 2 kg of polycarboxylate superplasticizer, 1 kg of molasses, and 25 kg of water; wherein the alkanolamine complex is composed of triethanolamine and modified alkanolamine in a mass ratio of 1:3; and the macromolecular synergist is a sodium alginate-β-cyclodextrin macromolecular complex.

[0048] The preparation method of the above-mentioned enhanced cement grinding aid includes the following steps:

[0049] A: Preparation of modified alkanolamine: Diethanol monoisopropanolamine was added to a reaction vessel, and 1% (by weight) of sunflower seed oil in 0.1M KOH solution was added under magnetic stirring. Then, sunflower seed oil was added to the mixture, and the mixture was heated to 130℃ and maintained for 4-6 hours. After the reaction was completed, the temperature was lowered to 45℃ to obtain the modified alkanolamine. The molar ratio of diethanol monoisopropanolamine to sunflower seed oil was 3:1. The obtained modified alkanolamine was combined with triethanolamine in a mass ratio of 3:1 to form an alkanolamine complex.

[0050] B: Preparation of macromolecular synergist: 1g sodium alginate, 4g phytic acid, and 8g β-cyclodextrin were added to 100ml of deionized water and stirred evenly. Then, 0.6g KH2PO4 was added and heated to 100℃ and stirred for 1 h. The above mixed solution was then placed in a constant temperature oven and reacted at 150℃ for 10 hours. After the reaction, the obtained product was placed in 200 mL of 0.1 mol / L NaOH solution and stirred at room temperature for 2 h. After filtration, the above operation was repeated once. Finally, the product was washed with deionized water until the pH of the filtrate was neutral. The product was placed in a vacuum drying oven and dried at 55℃ for 12 h to obtain the sodium alginate-β-cyclodextrin macromolecular complex.

[0051] C: Place the water in the formula in a stirring device, first add the alcohol amine complex, stir and heat to 45°C, then add the macromolecular synergist, and continue stirring for 20-30 minutes;

[0052] D: Raise the system temperature to 50~55℃, then add ethylene glycol, surfactant, defoamer, polycarboxylate superplasticizer and molasses in sequence, continue to stir evenly, and then cool to room temperature to obtain the final product, reinforced cement grinding aid.

[0053] Comparative Example 1

[0054] An enhanced cement grinding aid is made from the following raw materials in parts by weight: 25 kg of an alcohol amine complex, 15 kg of ethylene glycol, 2 kg of sodium lignosulfonate, 0.4 kg of sodium fatty alcohol polyoxyethylene ether sulfate, 2 kg of polycarboxylate superplasticizer, 1 kg of molasses, and 25 kg of water; wherein the alcohol amine complex is composed of triethanolamine and modified alcohol amine in a mass ratio of 1:3; and the macromolecular synergist is a sodium alginate-β-cyclodextrin macromolecular complex.

[0055] The preparation method of the above-mentioned enhanced cement grinding aid includes the following steps:

[0056] A: Preparation of modified alkanolamine: Diethanol monoisopropanolamine was added to a reaction vessel, and 1% (by weight) of sunflower seed oil in 0.1M KOH solution was added under magnetic stirring. Then, sunflower seed oil was added to the mixture, and the mixture was heated to 130℃ and maintained for 4-6 hours. After the reaction was completed, the temperature was lowered to 45℃ to obtain the modified alkanolamine. The molar ratio of diethanol monoisopropanolamine to sunflower seed oil was 3:1. The obtained modified alkanolamine was combined with triethanolamine in a mass ratio of 3:1 to form an alkanolamine complex.

[0057] B: Place the water in the formula into a stirring device, first add the alcohol amine complex, stir and heat to 45°C, and continue stirring for 20-30 minutes;

[0058] C: Raise the system temperature to 50~55℃, then add ethylene glycol, surfactant, defoamer, polycarboxylate superplasticizer and molasses in sequence, continue to stir evenly, and then cool to room temperature to obtain the final product, reinforced cement grinding aid.

[0059] This comparative example is basically the same as Example 3, except that it does not contain the content related to macromolecular synergists and preparation methods.

[0060] Comparative Example 2

[0061] An enhanced cement grinding aid is made from the following raw materials in parts by weight: 25 kg of an alcohol amine complex, 15 kg of ethylene glycol, 2 kg of sodium lignosulfonate, 0.4 kg of sodium fatty alcohol polyoxyethylene ether sulfate, 4 kg of a macromolecular synergist, 2 kg of polycarboxylate superplasticizer, 1 kg of molasses, and 25 kg of water; wherein the alcohol amine complex is composed of triethanolamine and diethanol monoisopropanolamine in a mass ratio of 1:3; and the macromolecular synergist is a sodium alginate-β-cyclodextrin macromolecular complex.

[0062] The preparation method of the above-mentioned enhanced cement grinding aid includes the following steps:

[0063] A: Diethanol monoisopropanolamine and triethanolamine are combined in a mass ratio of 3:1 to form an alcohol amine complex;

[0064] B: Preparation of macromolecular synergist: 1g sodium alginate, 4g phytic acid, and 8g β-cyclodextrin were added to 100ml of deionized water and stirred evenly. Then, 0.6g KH2PO4 was added and heated to 100℃ and stirred for 1 h. The above mixed solution was then placed in a constant temperature oven and reacted at 150℃ for 10 hours. After the reaction, the obtained product was placed in 200 mL of 0.1 mol / L NaOH solution and stirred at room temperature for 2 h. After filtration, the above operation was repeated once. Finally, the product was washed with deionized water until the pH of the filtrate was neutral. The product was placed in a vacuum drying oven and dried at 55℃ for 12 h to obtain the sodium alginate-β-cyclodextrin macromolecular complex.

[0065] C: Place the water in the formula in a stirring device, first add the alcohol amine complex, stir and heat to 45°C, then add the macromolecular synergist, and continue stirring for 20-30 minutes;

[0066] D: Raise the system temperature to 50~55℃, then add ethylene glycol, surfactant, defoamer, polycarboxylate superplasticizer and molasses in sequence, continue to stir evenly, and then cool to room temperature to obtain the final product, reinforced cement grinding aid.

[0067] This comparative example is basically the same as Example 3, except that it does not contain modified alkanolamines. The alkanolamine complex is composed of triethanolamine and diethanol monoisopropanolamine in a mass ratio of 1:3.

[0068] Grinding aid effect verification test

[0069] The materials to be ground were ground together with the cement grinding aids of Examples 1-3 and Comparative Examples 1-2 in a Φ5370mm vertical mill for 30 minutes to obtain cement. Various physical properties of the ground cement were then tested. The grinding aid dosage was 0.05% of the total weight of the materials to be ground. A blank comparative example (without any grinding aid) and a commercially available grinding aid (commercially available triethanolamine) were set up as controls. The material composition was 84% ​​clinker, 5% limestone, 6% phosphorus slag, and 5% dihydrate gypsum.

[0070] Test method:

[0071] The particle size distribution of cement was determined using a BT-9300 laser particle size analyzer; the results are shown in Table 1.

[0072] The specific surface area was tested using the Blaine method; the cement residue on a 45μm sieve was tested according to GB / T 1345-2005 "Cement Fineness Test Method - Sieve Analysis Method".

[0073] The cement obtained by grinding with the above-mentioned cement grinding aid was mixed with water at a water-cement ratio of 0.4. The resulting cement mixture was poured into molds and cured for 3 days and 28 days, respectively. The compressive strength was then tested according to the methods specified in GB / T17671-1999 "Test Method for Strength of Cement Mortar". The surface morphology of the cement mortar was observed using a scanning electron microscope. The results are shown in Table 2 and... Figure 2 .

[0074] Table 1. Test results of cement particle size distribution in different treatment groups

[0075]

[0076] As can be seen from the results in Table 1, compared with the blank control, the cement grinding aid prepared in this invention has a particle size distribution of <30μm that is significantly larger than that of Comparative Examples 1 and 2, the blank control, and the commercially available comparison. This is mainly because the macromolecular synergist used in this invention contains multiple functional groups such as carboxyl, hydroxyl, and phosphate groups, which have a good adsorption effect on the surface of cement particles. The functional groups adsorb on the surface of cement particles to form a lubricating layer, reducing the friction and cohesion between particles, resulting in good dispersion of cement particles in the mill. The dispersed cement particles are more easily impacted and ground by the grinding media in the mill, thus making the grinding finer. The smaller cement particles have higher activity and can fully react with water to generate more hydration products, thereby improving the strength and durability of concrete.

[0077] Table 2 Test Results

[0078]

[0079] As can be seen from the results in Table 2 above, the grinding efficiency of the cement grinding aids prepared in Examples 1-3 of this invention was significantly improved after use, with an hourly output increase of 24.5% compared to the blank control. Compared to the blank control group, the addition of the grinding aids prepared in this invention to cement clinker significantly increased the specific surface area of ​​cement particles and reduced the sieve residue by 45 μm, indicating that the components of this invention work synergistically to achieve a good grinding aid effect. Meanwhile, compared to the blank control, the 3-day strength of cement increased by more than 5.9 MPa, and the 28-day strength increased by more than 10.7 MPa. Furthermore, from... Figure 2 It can also be seen that the macromolecular synergist of the present invention reacts with Ca in cement. 2+ The reaction forms calcium phosphate particles, which fill the tiny pores in the cement. The macromolecular particles in the tiny pores continuously deposit and coat the hydration products and the surface of the unhydrated cement particles. The macromolecular particles and the cement hydration products form an interwoven spatial network structure, thereby further improving the density and strength of the cement.

[0080] This invention also investigated the effect of different dosages of grinding aid on the 3-day and 28-day compressive strength of cement. Taking the grinding aid of Example 2 as an example, the effect of dosages between 0-0.1% on cement strength was studied. Specific results are as follows... Figure 1 As shown. From Figure 1 It can be seen that the 3-day compressive strength and 28-day compressive strength increase with the increase of admixture dosage. However, when the admixture dosage exceeds 0.06%, both the 3-day and 28-day compressive strengths begin to decline. This indicates that the optimal addition amount of the grinding aid of the present invention is 0.03-0.06 wt%. Further increases in admixture dosage will not continuously improve the distribution of cement particles. Excessive admixture dosage will actually weaken its grinding aid effect. Too many grinding aid molecules dispersed in the cement paste will also hinder the hydration of cement, thereby reducing the strength of cement.

[0081] It should be noted that the above embodiments are merely some preferred embodiments of the present invention, and not all embodiments. Obviously, based on the above embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

Claims

1. An enhanced cement grinding aid characterized by, It is made of the following raw materials by weight: alcohol amine compound 20-30 parts, ethylene glycol 10-20 parts, surfactant 1-3 parts, defoaming agent 0.3-0.5 parts, macromolecular synergist 3-5 parts, polycarboxylic acid water reducer 1-3 parts, molasses 0.5-1.5 parts, water 20-30 parts; the alcohol amine compound includes triethanolamine and modified alcohol amine; the macromolecular synergist is sodium alginate-beta-cyclodextrin macromolecular complex; The modified alcohol amine is prepared by the following method: diethanol mono-isopropanolamine is added to a reaction container, an appropriate amount of 0.1M KOH solution is added under magnetic stirring, then sunflower seed oil is added, heated to 130℃, and kept for 4-6 hours, and then cooled to 45℃ to obtain the modified alcohol amine; The macromolecular synergist is prepared by the following method: sodium alginate, phytic acid and beta-cyclodextrin are added to deionized water respectively, stirred uniformly, then an appropriate amount of KH2PO4 is added, heated to 100℃ and stirred for 1h, then put into a thermostat and reacted at 150℃ for 10 hours, after the reaction is completed, the obtained product is put into 200mL 0.1mol / L NaOH solution, stirred at room temperature for 2h, filtered, and then the above operation is repeated once, finally the product is washed with deionized water until the pH value of the filtrate is neutral, and the product is placed in a vacuum drying oven at 55℃ for 12h to obtain the sodium alginate-beta-cyclodextrin macromolecular complex.

2. The enhanced cement grinding aid of claim 1, wherein, The mass ratio of triethanolamine and modified alcohol amine in the alcohol amine compound is 1:

3.

3. The enhanced cement grinding aid of claim 1, wherein, The molar ratio of diethanol mono-isopropanolamine to sunflower seed oil is 3:

1.

4. The enhanced cement grinding aid of claim 1, wherein, The amount of KOH solution is 1% of the mass of sunflower seed oil.

5. The enhanced cement grinding aid of claim 1, wherein, The amount ratio of sodium alginate, phytic acid, beta-cyclodextrin, deionized water and KH2PO4 is 1g:4g:8g:100ml:0.6g.

6. The enhanced cement grinding aid of claim 1, wherein, The surfactant is carboxymethyl cellulose or sodium lignosulfonate.

7. The enhanced cement grinding aid of claim 1, wherein, The defoaming agent is sodium stearate.

8. A process for the preparation of the enhanced cement grinding aid of any one of claims 1 to 7, characterized in that, The following steps are included: A: preparing modified alcohol amine, then compounding with triethanolamine in proportion to obtain alcohol amine compound; B: preparing macromolecular synergist; C: first put water into a stirring device, add alcohol amine compound, stir and heat to 45℃, then add macromolecular synergist, continue to stir for 20-30min; D: raise the system temperature to 50-55℃, then add ethylene glycol, surfactant, defoaming agent, polycarboxylic acid water reducer and molasses in sequence, continue to stir uniformly, then cool to room temperature to obtain enhanced cement grinding aid.

Images