Cement hydration accelerant as well as preparation method and application thereof

Abstract

The invention relates to the technical field of cement reinforcing agents, in particular to a cement hydration accelerant as well as a preparation method and application thereof. The cement hydration accelerant is prepared from the following components in parts by mass: 20 to 55 parts of composite nucleating agent, 10 to 20 parts of inorganic salt, 15 to 30 parts of alcohol amine and water, wherein the composite nucleating agent comprises calcium silicate, carbon nitride and a polycarboxylate superplasticizer in a mass ratio of (0.5-5): (0.01-1): 1. According to the cement hydration accelerant, the early strength is effectively improved, hydration of cement is effectively promoted, the later strength is improved, the cement of the type can meet different types of application scenes, and the working efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of cement strengthening agents, and in particular to a cement hydration accelerator and a preparation method and application thereof. Background Art

[0002] Cement is an indispensable basic material in modern building materials, and its performance directly affects the quality, life and safety of buildings. The performance of cement is often affected by the degree of hydration, the type and microstructure of hydration products, and the porosity. Traditional cement materials often have problems such as insufficient early strength and slow strength growth after a long period of time during the hydration reaction. In addition, cement also faces challenges such as poor resistance to chemical corrosion and insufficient durability during use.

[0003] In order to overcome these problems, various cement enhancers have been widely studied and applied in recent years. These enhancers improve the performance of cement by providing additional crystal nuclei, changing the structure of hydration products, and improving the dispersibility of cement paste. However, traditional cement additives still have certain limitations in improving early strength and long-term durability.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The object of the present invention is to provide a cement hydration accelerator and a preparation method and application thereof. The cement hydration accelerator can improve the strength of cement at various ages, especially the early strength and late strength, and accelerate the degree of cement hydration.

[0006] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted: One aspect of the present invention relates to a cement hydration accelerator, which comprises the following components in parts by mass: 20-55 parts of composite nucleating agent, 10-20 parts of inorganic salt, 15-30 parts of alcoholamine and water; The composite nucleus agent comprises calcium silicate, carbon nitride and polycarboxylic acid water reducer in a mass ratio of 0.5-5:0.01-1:1.

[0007] The cement hydration accelerator not only effectively improves the early strength, but also effectively promotes the hydration of cement and improves the later strength, so that this type of cement can meet different types of application scenarios and improve work efficiency.

[0008] Another aspect of the present invention also relates to a method for preparing the cement accelerator, comprising the following steps: Mix all ingredients well.

[0009] The preparation method of the cement hydration accelerator is simple and easy to operate without relying on complicated processes and equipment. The prepared cement hydration accelerator can improve the strength of cement at all ages and promote cement hydration.

[0010] Another aspect of the present invention also relates to a cement, comprising the cement hydration accelerator or the cement accelerator prepared by the preparation method of the cement hydration accelerator.

[0011] Compared with the prior art, the present invention has the following beneficial effects: (1) The cement hydration accelerator provided by the present invention is added with a composite nucleating agent, an inorganic salt and an alcohol amine. The components can work synergistically to improve the strength of cement at various ages, especially the early strength and late strength, and accelerate the degree of cement hydration.

[0012] (2) The cement hydration accelerator provided by the present invention comprises a composite nucleating agent containing calcium silicate, carbon nitride and a polycarboxylic acid water reducer. The particle size of the calcium silicate is controlled within a certain range. The small-sized calcium silicate can promote the dispersion of the carbon nitride nanosheets, increase the exposure of the carbon nitride nanosheets, and promote the combination of the calcium silicate and the carbon nitride. The carbon nitride and the small-sized calcium silicate provide nucleation sites for the cement hydration products at the same time, which is conducive to achieving an improvement in the early strength. At the same time, the later strength is also improved to a certain extent, thereby promoting the degree of hydration. The polycarboxylic acid water reducer is a high molecular weight polymer with a macromolecular comb-shaped structure. It provides a steric hindrance for the carbon nitride. During the nucleation process of the calcium silicate nucleating agent, it promotes the dispersion of the carbon nitride, prevents the agglomeration of the carbon nitride, and improves the dispersion of the two-dimensional nano carbon nitride.

[0013] (3) The method for preparing the cement hydration accelerator provided by the present invention is simple and easy to operate without relying on complicated processes and equipment. The prepared cement hydration accelerator can improve the strength of cement at all ages and promote cement hydration. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 The thermogravimetric curves of comparative example 1 and example 1 after curing for 3 days. DETAILED DESCRIPTION

[0016] The technical scheme of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments, but it will be understood by those skilled in the art that the following described embodiments are part of embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. If specific conditions are not specified in the embodiments, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not specified in the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0017] One aspect of the present invention relates to a cement hydration accelerator, which comprises the following components in parts by mass: 20-55 parts of composite nucleating agent, 10-20 parts of inorganic salt, 15-30 parts of alcoholamine and water; The composite nucleus agent includes calcium silicate, carbon nitride and polycarboxylic acid water reducer in a mass ratio of 0.5-5:0.01-1:1 (for example, but not limited to 0.5:1:1, 1:0.8:1, 2:0.5:1, 3:0.3:1, 4:0.1:1 or 5:0.01:1). The raw materials in the composite nucleus agent are combined according to the mass ratio, which is conducive to better dispersion of carbon nitride.

[0018] In some specific embodiments, the composite nucleating agent may be, for example, but not limited to, any one of 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, or 55 parts by mass, or a range between any two of them.

[0019] In some specific embodiments, the inorganic salt may be, for example, but not limited to, any one of 10 parts, 12 parts, 14 parts, 16 parts, 18 parts, or 20 parts by mass, or a range of values ​​between any two of them.

[0020] In some specific embodiments, the alcohol amine may be, for example, but not limited to, any one of 15 parts, 18 parts, 20 parts, 23 parts, 25 parts, 28 parts or 30 parts by mass, or a range between any two of them.

[0021] Traditional grinding aids or synergists cannot meet the requirements of early strength and late strength at the same time. The cement hydration accelerator provided by the present invention not only effectively improves the early strength, but also effectively promotes the hydration of cement and improves the late strength, so that this type of cement can meet different types of application scenarios and improve work efficiency.

[0022] The cement hydration accelerator is added with a composite crystal nucleating agent, an inorganic salt and an alcohol amine, and each component can act synergistically to improve the strength of cement at various ages, especially the early strength and the late strength, and accelerate the cement hydration degree.

[0023] In the composite calcium silicate nanocrystal nucleating agent, calcium silicate serves as the main nucleating agent, and carbon nitride serves as a two-dimensional material that exposes more active sites, providing more nucleating sites for the cement hydration product, hydrated calcium silicate gel, effectively reducing its nucleation barrier, accelerating the degree of cement hydration, and improving the early strength of cement.

[0024] As a two-dimensional material, nano carbon nitride can provide new sites for the synthesis of calcium silicate in composite nucleation agents, and jointly regulate the growth of calcium silicate nucleation agents with polycarboxylic acid water reducers to control the size of calcium silicate nucleation agents; carbon nitride nanosheet materials are cheap and easy to obtain, which is conducive to industrial applications.

[0025] The composite nucleating agent introduced nano carbon nitride material and synthesized a new type of composite nano crystal nucleating agent. The calcium silicate and carbon nitride in the nucleating agent jointly regulated the hydration products of the early gel material, thereby achieving an increase in early strength and promoting the degree of cement hydration.

[0026] The polycarboxylate water reducer is a macromolecular comb-shaped polymer, which provides steric hindrance for carbon nitride, promotes the dispersion of carbon nitride, prevents the agglomeration of carbon nitride, and improves the dispersion of two-dimensional nano carbon nitride during the nucleation process of the calcium silicate nucleating agent. The present invention does not specifically limit the specific type of the polycarboxylate water reducer, and conventional polycarboxylate water reducers in the art can be used to implement the technical solution of the present invention.

[0027] The addition of inorganic salts and alcoholamines, together with the composite nucleating agent, further improves the early and later strengths of cement.

[0028] Furthermore, the cement hydration accelerator comprises the following components in parts by mass: 25-50 parts of composite nucleating agent, 12-18 parts of inorganic salt, 20-25 parts of alcoholamine and water; The composite nucleating agent comprises calcium silicate, carbon nitride and polycarboxylic acid water reducer in a mass ratio of 0.5-3:0.02-0.8:1. Within the dosage range, the components of the cement hydration accelerator have a significant effect of improving the early strength and late strength of cement.

[0029] Further, the particle size of the calcium silicate is 100-300nm, including but not limited to any point value of 100nm, 130nm, 150nm, 180nm, 200nm, 230nm, 250nm, 280nm or 300nm or the range value between any two. The nanocrystalline nucleating agent is a composite nucleating agent of small-sized calcium silicate and carbon nitride of 100-300 nm, and the small-sized calcium silicate can promote the dispersion of carbon nitride nanosheets, improve the exposure of carbon nitride nanosheets, and promote the combination of calcium silicate and carbon nitride. Carbon nitride and small-sized calcium silicate provide nucleation sites for cement hydration products at the same time, which is conducive to achieving the improvement of early strength, and the later strength is also improved to a certain extent.

[0030] Furthermore, the inorganic salts include but are not limited to: CaCl 2 At least one of HCOONa, NaCl or NaSCN. Adding the above inorganic salts is beneficial to promoting the hydration degree of cement.

[0031] Furthermore, the alcoholamine includes but is not limited to at least one of triethanolamine, diethanol monoisopropanolamine, triisopropanolamine or monoethanol diisopropanolamine. Adding the above alcoholamines is beneficial to improving the early strength and late strength of cement.

[0032] Another aspect of the present invention also relates to a method for preparing the cement accelerator, comprising the following steps: Mix all ingredients well.

[0033] The preparation method of the cement hydration accelerator is simple and easy to operate without relying on complicated processes and equipment. The prepared cement hydration accelerator can improve the strength of cement at all ages and promote cement hydration.

[0034] Furthermore, the preparation method of the composite crystal nucleating agent comprises the following steps: Calcium salt and silicate are added to the mixed solution containing the carbon nitride and the polycarboxylate water-reducing agent at the same time for stirring reaction. The composite nucleating agent prepared by the method has a small particle size of calcium silicate, uniform dispersion of carbon nitride, good combination effect of calcium silicate and carbon nitride, provides nucleation sites for cement hydration products, and is beneficial to improving the early strength and late strength of cement.

[0035] Further, the stirring speed of the stirring reaction is 100~800rpm, including but not limited to any one of 100rpm, 150rpm, 200rpm, 250rpm, 300rpm, 350rpm, 400rpm, 450rpm, 500rpm, 550rpm, 600rpm, 650rpm, 700rpm, 750rpm or 800rpm or the range between any two of them.

[0036] Furthermore, the stirring reaction time is 18 to 120 hours, including but not limited to any one of 18 hours, 30 hours, 40 hours, 50 hours, 60 hours, 70 hours, 80 hours, 90 hours, 100 hours, 110 hours or 120 hours or a range between any two of them.

[0037] Controlling the time and speed of the stirring reaction within a certain range is conducive to the full mixing and dispersion of the components.

[0038] Further, the pH of the stirring reaction is 10.8-13.0, including but not limited to any point value of 10.8, 11, 11.5, 12, 12.5 or 13 or any range value between two of them. The stirring reaction is carried out under the pH condition, which is conducive to the formation of nano calcium silicate and controls the particle size of calcium silicate within a reasonable range.

[0039] Furthermore, the pH of the stirred reaction was regulated using 30% NaOH and 1M HCl.

[0040] Furthermore, the molar ratio of calcium in the calcium salt to silicon in the silicate is 0.2 to 1:1, including but not limited to 0.2:1, 0.4:1, 0.6:1, 0.8:1 or 1:1. Feeding according to this ratio can fully react to generate calcium silicate, avoiding the occurrence of side reactions and waste of raw materials.

[0041] Further, the calcium salt is added in the form of a calcium salt solution at a rate of 1-20 mL / min, including but not limited to any one of 1 mL / min, 3 mL / min, 5 mL / min, 8 mL / min, 10 mL / min, 13 mL / min, 15 mL / min, 18 mL / min or 20 mL / min or a range between any two of them.

[0042] Furthermore, the silicate is added in the form of a silicate solution at a rate of 1 to 20 mL / min, including but not limited to any point value of 1 mL / min, 3 mL / min, 5 mL / min, 8 mL / min, 10 mL / min, 13 mL / min, 15 mL / min, 18 mL / min or 20 mL / min or a range value between any two of them.

[0043] By limiting the feeding speed within a certain range, the particle size of the generated calcium silicate can be controlled within a reasonable range, and the particle size of the calcium silicate will not be too large or too small, which is not conducive to improving the strength of cement.

[0044] Furthermore, the concentration of the calcium salt solution is 0.2-5M, including but not limited to any one of 0.2M, 0.5M, 1M, 2M, 3M or 5M or a range between any two of them.

[0045] Furthermore, the concentration of the silicate solution is 0.5-5M, including but not limited to any point value of 0.5M, 1M, 2M, 3M or 5M or a range value between any two of them.

[0046] Furthermore, the calcium salt includes but is not limited to at least one of calcium nitrate, calcium formate or calcium chloride.

[0047] Furthermore, the silicate includes but is not limited to: sodium silicate and / or potassium silicate.

[0048] Furthermore, the method for preparing carbon nitride comprises the following steps: The precursor is calcined, cooled and ground to obtain carbon nitride nanomaterials.

[0049] Furthermore, the precursor includes but is not limited to: at least one of urea, cyanamide, dicyandiamide or melamine.

[0050] Furthermore, the calcination temperature is 450-550°C, including but not limited to any one of 450°C, 460°C, 470°C, 480°C, 490°C, 500°C, 510°C, 520°C, 530°C, 540°C or 550°C or a range between any two of them.

[0051] Furthermore, the calcination time is 3 to 6 hours, including but not limited to any one of 3 hours, 4 hours, 5 hours or 6 hours or a range between any two of them.

[0052] Another aspect of the present invention also relates to a cement, comprising the cement hydration accelerator or the cement accelerator prepared by the preparation method of the cement hydration accelerator.

[0053] The embodiments of the present invention will be described in detail below in conjunction with the examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present invention and should not be considered as limiting the scope of the present invention. If no specific conditions are specified in the examples, the conditions are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be obtained commercially.

[0054] The particle size of the calcium silicate used in the following examples is between 100 and 300 nm.

[0055] Example 1 The cement hydration accelerator provided in this embodiment includes the following components by weight: 45 parts of composite nucleating agent, CaCl 2 10 parts, NaCl 5 parts, triethanolamine 20 parts and water 20 parts; Wherein, the composite nucleus agent comprises: calcium silicate, carbon nitride and polycarboxylic acid water reducer in a mass ratio of 0.7:0.7:1.

[0056] The preparation method of the cement hydration accelerator provided in this embodiment comprises the following steps: 1. Mix 7g of carbon nitride material with 10g of polycarboxylate water reducer, adjust the volume to 60mL, and disperse by ultrasonic to obtain a mixed solution; 2. Pump 20 mL of 3M sodium silicate solution and 20 mL of 3M calcium nitrate solution into the above mixed solution at a speed of 2 mL / min respectively; 3. Adjust the pH to 12.5 with NaOH, stir at 300 rpm, and react for 20 hours to obtain a composite nucleation agent solution; 4. Combine the composite nucleating agent and CaCl 2 The cement accelerator is prepared by mixing 2,4-dihydro-1 ...

[0057] Example 2 The cement hydration accelerator provided in this embodiment includes the following components by weight: 50 parts of composite nucleating agent, 8 parts of NaSCN, 8 parts of NaCl, 15 parts of diethanol monoisopropanolamine, 5 parts of triethanolamine and 14 parts of water; The composite nucleus agent comprises calcium silicate, carbon nitride and polycarboxylic acid water reducer in a mass ratio of 1.8:0.33:1.

[0058] The preparation method of the cement hydration accelerator provided in this embodiment comprises the following steps: 1. Mix 2.6 g of carbon nitride material with 8 g of polycarboxylate water reducer, adjust the volume to 50 mL, and disperse by ultrasonic to obtain a mixed solution; 2. Pump 25 mL of 5 M sodium silicate solution and 25 mL of 5 M calcium nitrate solution into the above mixed solution at a speed of 6 mL / min respectively; 3. Adjust the pH to 12.0 with NaOH, stir at 350 rpm, and react for 48 hours to obtain a composite nucleation agent solution; 4. Prepare a cement accelerator by mixing a composite nucleating agent, NaSCN, NaCl, diethanol monoisopropanolamine, triethanolamine and water.

[0059] Example 3 The cement hydration accelerator provided in this embodiment includes the following components by weight: 48 parts of composite nucleating agent, 15 parts of HCOONa, 12 parts of diethanol monoisopropanolamine, 10 parts of monoethanol diisopropanolamine and 15 parts of water; Wherein, the composite nucleus agent comprises: calcium silicate, carbon nitride and polycarboxylic acid water reducer in a mass ratio of 2.8:1:1.

[0060] The preparation method of the cement hydration accelerator provided in this embodiment comprises the following steps: 1. Mix 5g of carbon nitride material and 5g of polycarboxylate water reducer, adjust the volume to 40mL, and disperse by ultrasonic to obtain a mixed solution; 2. Pump 30 mL of 4 M sodium silicate solution and 30 mL of 4 M calcium nitrate solution into the above mixed solution at a rate of 5 mL / min respectively; 3. Adjust the pH to 11.0 with NaOH, stir at 150 rpm, and react for 72 hours to obtain a composite nucleation agent solution; 4. The composite nucleus agent, HCOONa, diethanol monoisopropanolamine, monoethanol diisopropanolamine and water are prepared to obtain a cement accelerator.

[0061] Example 4 The cement hydration accelerator provided in this embodiment includes the following components by weight: Composite nucleating agent 55 parts, HCOONa 12 parts, CaCl 2 5 parts, triisopropanolamine 10 parts, triethanolamine 10 parts and water 8 parts; Wherein, the composite nucleus agent comprises: calcium silicate, carbon nitride and polycarboxylic acid water reducer in a mass ratio of 0.5:0.31:1.

[0062] The preparation method of the cement hydration accelerator provided in this embodiment comprises the following steps: 1. Mix 5g of carbon nitride material with 16g of polycarboxylate water reducer, adjust the volume to 50mL, and disperse by ultrasonic to obtain a mixed solution; 2. Pump 25 mL of 2.7 M sodium silicate solution and 25 mL of 2.7 M calcium nitrate solution into the above mixed solution at a rate of 3 mL / min respectively; 3. Adjust the pH to 11.5 with NaOH, stir at 250 rpm, and react for 24 hours to obtain a composite nucleation agent solution; 4. Combine the composite crystal nucleating agent, HCOONa, and CaCl 2 The cement accelerator is prepared by mixing triisopropanolamine, triethanolamine and water.

[0063] Example 5 The cement hydration accelerator provided in this embodiment includes the following components by weight: 20 parts of composite nucleating agent, CaCl 210 parts, NaCl 10 parts, triethanolamine 30 parts and water 30 parts; Wherein, the composite crystal nucleus agent comprises: calcium silicate, carbon nitride and polycarboxylic acid water reducer in a mass ratio of 1:0.5:1.

[0064] The preparation method of the cement hydration accelerator provided in this embodiment is the same as that in Example 1.

[0065] Example 6 The cement hydration accelerator provided in this embodiment includes the following components by weight: 30 parts of composite crystal nucleating agent, CaCl 2 5 parts, NaCl 5 parts, triethanolamine 15 parts and water 45 parts; Wherein, the composite nucleus agent comprises: calcium silicate, carbon nitride and polycarboxylic acid water reducer in a mass ratio of 5:1:1.

[0066] The preparation method of the cement hydration accelerator provided in this embodiment is the same as that in Example 1.

[0067] Example 7 The contents of the various components of the cement hydration accelerator provided in this embodiment are the same as those in Example 1.

[0068] The preparation method of the cement hydration accelerator provided in this embodiment comprises the following steps: 1. Same as Example 1; 2. Pump 20 mL of 3M sodium silicate solution and 20 mL of 3M calcium nitrate solution into the above mixed solution at a speed of 15 mL / min respectively; 3. Adjust the pH to 10.8 with NaOH, stir at 100 rpm, and react for 100 h to obtain a composite nucleating agent solution; 4. Combine the composite nucleating agent and CaCl 2 , NaCl, triethanolamine and water to prepare cement accelerator.

[0069] Example 8 The contents of the various components of the cement hydration accelerator provided in this embodiment are the same as those in Example 1.

[0070] The preparation method of the cement hydration accelerator provided in this embodiment comprises the following steps: 1. Same as Example 1; 2. Pump 20 mL of 3M sodium silicate solution and 20 mL of 3M calcium nitrate solution into the above mixed solution at a speed of 20 mL / min respectively; 3. Adjust the pH to 13.0 with NaOH, stir at 800 rpm, and react for 120 hours to obtain a composite nucleation agent solution; 4. Combine the composite nucleating agent and CaCl 2, NaCl, triethanolamine and water to prepare cement accelerator.

[0071] Comparative Example 1 Use 100 parts of water to test the mortar strength of P·I 42.5 cement.

[0072] Comparative Example 2 The preparation method of the cement hydration accelerator provided in this comparative example comprises the following steps: 18 g of polycarboxylate water reducer was mixed, the volume was fixed to 50 mL, and ultrasonic dispersion was performed to obtain a mixed solution; Pump 20 mL of 4 M sodium silicate solution and 20 mL of 3 M calcium nitrate solution into the above mixed solution at a rate of 3 mL / min respectively; The pH was adjusted to 11.5 with NaOH, the stirring speed was 250 rpm, and the reaction was continued for 24 hours to obtain a crystal nucleating agent solution; 45 parts of the carbon nitride-free crystal nucleating agent, 12 parts of HCOONa, 5 parts of CaCl 2 , 10 parts of triisopropanolamine, 10 parts of triethanolamine and 18 parts of water to prepare a cement accelerator.

[0073] Comparative Example 3 The cement hydration accelerator provided in this comparative example is composed of 12 parts of HCOONa, 5 parts of CaCl 2 , 10 parts of triisopropanolamine, 10 parts of triethanolamine and 63 parts of water to prepare a cement accelerator.

[0074] Comparative Example 4 The difference between this comparative example and Example 1 is that no triethanolamine is added and triethanolamine is replaced by water.

[0075] Comparative Example 5 The only difference between this comparative example and Example 1 is that the pH of the stirring reaction is 9.

[0076] Comparative Example 6 The difference between this comparative example and Example 1 is that the addition rate of the sodium silicate solution and the calcium nitrate solution is 25 mL / min.

[0077] Experimental example After curing for 3 days, the comparative example 1 and the example 1 were hydrated with anhydrous ethanol, dried at 45°C, and then subjected to thermogravimetric analysis. Figure 1The thermogravimetric curves of comparative example 1 and embodiment 1 after curing for 3 days are shown in the figure. It can be seen from the figure that the weight loss of embodiment 1 is greater after 3 days, which is the removal of chemically bound water, corresponding to the deepening of the degree of hydration. According to the empirical formula, the degree of hydration of embodiment 1 is 48.6% after 3 days, and the degree of hydration of comparative example 1 is 46.2%. The degree of hydration of embodiment 1 is 2.4% higher than that of comparative example 1. It can be seen from this that the cement hydration accelerator prepared by the present invention can effectively promote the hydration of cement and improve the strength of cement.

[0078] The cement hydration accelerators prepared in the embodiments and comparative examples were subjected to mortar strength tests. The addition amount of the cement hydration accelerator was 0.2% of the cement mass and was applied to P·I 42.5 type cement.

[0079] Table 1 Cement strength at different ages

[0080] In addition, it can be seen from Table 1 that, compared with the comparative example, the strength at each age of each sample in the embodiment is higher than that of the comparative example.

[0081] In summary, the cement hydration accelerator provided by the present invention has good effects in promoting cement hydration, improving early strength, late strength, etc., and provides a demonstration for cement applications that adapt to different environments and different requirements.

[0082] Although the present invention has been illustrated and described with specific embodiments, it should be appreciated that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Those skilled in the art should understand that the technical solutions described in the above embodiments may be modified, or some or all of the technical features thereof may be replaced by equivalents without departing from the spirit and scope of the present invention. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention. Therefore, this means that all such replacements and modifications within the scope of the present invention are included in the appended claims.

Claims

1. A cement hydration accelerator, characterized in that: According to the mass percentage, it includes the following components: 20-55 parts of composite nucleating agent, 10-20 parts of inorganic salt, 15-30 parts of alcoholamine and water; The composite nucleus agent comprises calcium silicate, carbon nitride and polycarboxylic acid water reducer in a mass ratio of 0.5-5:0.01-1:

1.

2. The cement hydration accelerator according to claim 1, characterized in that According to the mass percentage, it includes the following components: 25-50 parts of composite nucleating agent, 12-18 parts of inorganic salt, 20-25 parts of alcoholamine and water; The composite nucleus agent comprises calcium silicate, carbon nitride and polycarboxylic acid water reducer in a mass ratio of 0.5-3:0.02-0.8:

1.

3. The cement hydration accelerator according to claim 1 or 2, characterized in that: The particle size of the calcium silicate is 100-300 nm.

4. The cement hydration accelerator according to claim 1 or 2, characterized in that: The inorganic salt comprises at least one of CaCl2, HCOONa, NaCl or NaSCN; And / or, the alcohol amine includes at least one of triethanolamine, diethanol monoisopropanolamine, triisopropanolamine or monoethanol diisopropanolamine.

5. The method for preparing a cement hydration accelerator according to any one of claims 1 to 4, wherein: The following steps are involved: Mix all ingredients well.

6. The method for preparing a cement hydration accelerator according to claim 5, characterized in that: The preparation method of the composite crystal nucleating agent comprises the following steps: Calcium salt and silicate are added simultaneously to the mixed solution containing the carbon nitride and the polycarboxylate water-reducing agent to carry out stirring reaction.

7. The method for preparing a cement hydration accelerator according to claim 6, characterized in that: Includes at least one of the following technical features: (1) The stirring speed of the stirring reaction is 100-800 rpm; (2) The stirring reaction time is 18 to 120 hours; (3) The pH of the stirring reaction is 10.8-13.

0.

8. The method for preparing a cement hydration accelerator according to claim 6, characterized in that: The molar ratio of calcium in the calcium salt to silicon in the silicate is 0.2-1:

1.

9. The method for preparing a cement hydration accelerator according to claim 6, characterized in that: The calcium salt is added in the form of a calcium salt solution at a rate of 1-20 mL / min; And / or, the silicate is added in the form of a silicate solution at a rate of 1-20 mL / min.

10. A cement, characterized in that: A cement accelerator prepared by the preparation method of the cement hydration accelerator according to any one of claims 1 to 4 or the cement hydration accelerator according to any one of claims 5 to 9.

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