阅读说明：本技术 一种水泥助磨剂及其使用水泥助磨剂的高早强水泥 (Cement grinding aid and high early strength cement using same ) 是由 苏晓强 陈凤琪 王建朋 赵百顺 王涛 张露瑶 肖见祺 任建波 郑立曼 唐哲 王倩 于 2021-03-26 设计创作，主要内容包括：本申请涉及水泥助剂的技术领域,具体公开了一种水泥助磨剂及其使用水泥助磨剂的高早强水泥。一种水泥助磨剂包括乙二醇10-20份、丙二醇10-20份、稻壳灰5-10份、三乙醇胺10-20份、制冷剂5-10份和碳酸钠5-15份经过搅拌混合得到；其使用水泥助磨剂的高早强水泥包括上述水泥助磨剂制备获得,本申请的水泥助磨剂可用于水泥生产,其具有提高水泥早期强度的优点。(The application relates to the technical field of cement additives, and particularly discloses a cement grinding aid and high early strength cement using the same. A cement grinding aid comprises 10-20 parts of ethylene glycol, 10-20 parts of propylene glycol, 5-10 parts of rice hull ash, 10-20 parts of triethanolamine, 5-10 parts of refrigerant and 5-15 parts of sodium carbonate, and is obtained by stirring and mixing; the high early strength cement using the cement grinding aid is prepared by the cement grinding aid, and the cement grinding aid can be used for cement production and has the advantage of improving the early strength of the cement.)

1. The cement grinding aid is characterized by being prepared by stirring and mixing the following raw materials in parts by mass:

10-20 parts of ethylene glycol,

10-20 parts of propylene glycol,

5-10 parts of rice hull ash.

2. The cement grinding aid as claimed in claim 1, wherein: the grain size of the rice hull ash is 1-2 microns.

3. The cement grinding aid as claimed in claim 1, wherein: also comprises 10-20 parts of triethanolamine.

4. The cement grinding aid as claimed in claim 1, wherein: also comprises 5-10 parts of refrigerant.

5. The cement grinding aid as claimed in claim 4, wherein: the refrigerant is ammonium sulfate.

6. A cement grinding aid as claimed in claim 5, wherein: the particle size of the ammonium sulfate is 20-30 microns.

7. The cement grinding aid as claimed in claim 1, wherein: also comprises 5-15 parts of sodium carbonate.

8. A high early strength cement using a cement grinding aid, which is characterized in that: comprises the cement grinding aid preparation method of any one of the claims 1 to 7.

Technical Field

The application relates to the technical field of cement additives, in particular to a cement grinding aid and high early strength cement using the same.

Background

The cement grinding aid is added into the cement raw materials in the grinding process, and can be adsorbed on the surfaces of cement particles, so that the attraction among the cement particles is reduced, the flowability of the grinding is improved, and the grinding efficiency is obviously improved.

The existing cement grinding aid comprises liquid and solid, and can remarkably improve the yield of a mill, improve the product quality and reduce the power consumption of grinding.

Aiming at the related technologies, the inventor thinks that the cement grinding aid can effectively improve the grinding efficiency of cement particles, but the produced cement particles still have the phenomenon of uneven particle size, so that the hydration reaction is insufficient and the hydration reaction rate is not high, and the early strength of a cement product is not high.

Disclosure of Invention

In order to improve the grinding efficiency of the cement grinding aid and improve the early strength of a cement product, the application provides the cement grinding aid.

In order to obtain a high early strength cement, the present application provides a high early strength cement using a cement grinding aid.

The application provides a cement grinding aid adopts following technical scheme:

in a first aspect, the application provides a cement grinding aid, which adopts the following technical scheme:

the cement grinding aid is prepared by stirring and mixing the following raw materials in parts by mass:

10-20 parts of ethylene glycol,

10-20 parts of propylene glycol,

5-10 parts of rice hull ash.

By adopting the technical scheme, the cement raw materials can be broken by chemical bonds in the grinding process of the cement raw materials, and Ca is formed on the surfaces of particles²⁺、O^2-The unbalanced charge points attract each other, the fracture surfaces are bonded again or the particles are agglomerated together again to form large particles, and the large particles reduce the flowability and the grinding efficiency of the material; the ethylene glycol and the propylene glycol which are used as liquid grinding aids can be automatically and uniformly dispersed among cement particles, belong to small polar molecules and are easily adsorbed on the positions of unbalanced charge points on a new surface formed by grinding, so that the friction force among the cement particles is reduced, the flowability of powder is improved, the particle size of the prepared cement particles is more uniform, and the full hydration reaction of cement raw materials is facilitated; the dispersibility of the rice hull ash can be further improved by the ethylene glycol and the propylene glycol, the rice hull ash can be adsorbed on the surfaces of cement particles together with the ethylene glycol and the propylene glycol, the grinding aid effect of the grinding aid is further improved, in the cement blending process, a large amount of amorphous silica is contained in the rice hull ash, and the silica reacts with hydrationThe generated calcium hydroxide reacts to generate C-S-H gel, so that the strength of the cement product is improved, and the porous structure of the rice husk ash is favorable for the absorption of moisture to generate the volcanic ash reaction, so that the strength of the cement product is improved.

Preferably, the rice husk ash has a particle size of 1 to 2 μm.

By adopting the technical scheme, the grain size of the rice hull ash is smaller than that of the cement particles, the rice hull ash is more favorably adsorbed on the surfaces of the cement particles, the rice hull ash is adsorbed on the surfaces of the cement particles in the process of adding water into a cement raw material for mixing, the porous structure of the rice hull ash absorbs a large amount of water, the cement particles begin hydration reaction after being adsorbed by the rice hull ash particles with rich water on the surfaces, the generated CH continues to generate secondary hydration reaction with the rice hull ash particles in a rich water environment, the residual water in the rice hull ash particles is released along with the dissolution of the rice hull ash particles to further promote the hydration of tricalcium silicate, the hydration of the tricalcium silicate plays a leading role in the early strength of the cement, and therefore the early strength of the cement is improved.

Preferably, 10-20 parts of triethanolamine is also included.

By adopting the technical scheme, triethanolamine is added as a grinding aid in the grinding process, so that the aggregation of cement particles in the grinding process can be reduced, the flowability of cement is improved, the power consumption of a grinding machine is reduced, and the grinding efficiency is improved; triethanolamine is used as an alcamines substance with strong polarity, can chelate metal ions in cement, is a surfactant, plays a role of a catalyst in the cement hydration process, can accelerate the hydration of tricalcium silicate and the formation of ettringite, and can quickly improve the early strength of the cement.

Preferably, 5-10 parts of refrigerant is also included.

By adopting the technical scheme, as cement particles added with the grinding aid are finer, the hydration reaction rate is faster, the early strength of the cement is improved, but simultaneously the hydration heat released in unit time is increased, so that the finally prepared cement product has cracks, the hydration heat released during hydration can be absorbed by adding the refrigerant, the heat is absorbed by the reaction when the refrigerant is contacted with water, the condition that the cement has cracks due to high hydration heat is reduced, and the early strength of the cement is further improved.

Preferably, the refrigerant is ammonium sulfate.

By adopting the technical scheme, in the cement production process, structural defects and microcracks exist in cement raw material particles, ammonium sulfate serving as a grinding aid is added to enter the defect and microcrack positions like a wedge, strong expansion stress is formed among the raw material particles, so that the cement is easy to grind, the grinding aid effect is realized, the specific surface area of the cement is increased, the contact area of cement hydration reaction is increased, and the early strength of the cement is improved; simultaneously at cement raw materials mix in-process, ammonium sulfate can contact with water, and the ammonium sulfate can absorb the heat after dissolving in water to offset the heat of partial hydration reaction release, improve the early strength of cement.

Preferably, the particle size of the ammonium sulfate is 20-30 microns.

By adopting the technical scheme, the finer the particle size of ammonium sulfate is, the more grinding efficiency can be improved, but the too fine ammonium sulfate is not beneficial to improving the strength of the cement grinding aid in the hydration process after mixing, the particle size of the ammonium sulfate is close to that of the cement raw material after final grinding, the ammonium sulfate absorbs heat after being dissolved in water, and simultaneously the ammonium sulfate serves as a filler of cement when the cement is solidified, so that the early strength of the cement is improved.

Preferably, the detergent also comprises 5-15 parts of sodium carbonate.

Through adopting above-mentioned technical scheme, cement raw materials are at the in-process of carrying out the mix, have free calcium oxide in the cement raw materials, and free calcium oxide can influence the early strength of cement, and sodium carbonate can react with calcium oxide and generate calcium carbonate and deposit, fills the hole between cement granule, improves the early strength of cement.

In a second aspect, the present application provides a high early strength cement using a cement grinding aid, using the following technical scheme: a high early strength cement using a cement grinding aid, which is prepared by the cement grinding aid.

By adopting the technical scheme, the ethylene glycol and the propylene glycol which are used as the liquid grinding aids can be automatically and uniformly dispersed among cement particles, the flowability of powder is improved, the particle size of the prepared cement particles is more uniform, and the cement raw materials can be fully subjected to hydration reaction to generate calcium hydroxide; the dispersibility of the rice hull ash can be further improved by the ethylene glycol and the propylene glycol, the rice hull ash can be adsorbed on the surfaces of cement particles together with the ethylene glycol and the propylene glycol, the grinding aid effect of the grinding aid is further improved, and in the process of mixing the cement raw materials, a large amount of amorphous silicon dioxide contained in the rice hull ash reacts with calcium hydroxide to generate C-S-H gel, so that the strength of a cement product is improved; triethanolamine is added as a grinding aid in the grinding process, so that the aggregation of cement particles in the grinding process can be reduced, the fluidity of cement is improved, and the grinding efficiency is improved; the triethanolamine plays a role of a catalyst in the cement hydration process, can accelerate the hydration of tricalcium silicate and the formation of ettringite, and can quickly improve the early strength of cement; in the process of mixing cement raw materials, ammonium sulfate is contacted with water, and the ammonium sulfate can absorb heat after being dissolved in the water, so that the hydration heat released in hydration is absorbed, the condition that the cement cracks due to high hydration heat is reduced, and the early strength of the cement is further improved; the sodium carbonate can react with calcium oxide to generate calcium carbonate precipitate to fill the pores among cement particles, thereby improving the early strength of the cement.

In summary, the present application has the following beneficial effects:

1. because the rice hull ash is adopted, the rice hull ash can be adsorbed on the surfaces of cement particles together with ethylene glycol and propylene glycol, the grinding aid effect of the grinding aid is further improved, in the process of mixing cement, a large amount of amorphous silica is contained in the rice hull ash, and the silica reacts with calcium hydroxide generated by hydration reaction to generate C-S-H gel, so that the strength of a cement product is improved, and the porous structure of the rice hull ash is favorable for absorbing moisture to generate volcanic ash reaction, so that the early strength of the cement product is improved; 2. in the application, ammonium sulfate is preferably adopted, in the cement production process, all particles of cement raw materials have structural defects and microcracks, and after the ammonium sulfate is added as a grinding aid, the ammonium sulfate enters the positions of the defects and the microcracks like a wedge, so that strong expansion stress is formed among the raw material particles, the cement is more easily ground, the grinding aid effect is realized, the specific surface area of the cement is increased, the contact area of the cement hydration reaction is increased, and the early strength of the cement is improved; meanwhile, in the process of mixing the cement raw materials, the ammonium sulfate can be contacted with water, and the ammonium sulfate can absorb heat after being dissolved in the water, so that part of heat released by hydration reaction is offset, and the early strength of the cement is improved;

3. according to the method, the cement grinding aid and the cement raw materials are put into a ball mill for grinding, then the ground cement raw materials are mixed by adding water, the mixture is poured into a mold for pouring, and the cement with high early strength is obtained after pressurized steam curing.

Detailed Description

The raw material sources are as follows:

the ethylene glycol is a product sold in Shanghai-sourced leaf biotechnology and science and technology limited company in the market, and the mark is 107-21-1;

propylene glycol is a commercial product of Jinjinle chemical Co., Ltd, and the brand number is 57-55-6;

the rice hull ash is a product sold in the market of Nanyang Hongyun fertilizer industry Co Ltd;

triethanolamine is a commercially available product of Hezhou Huanyuan chemical Co., Ltd, and the brand number is 102-76-1;

ammonium sulfate is a commercially available product of Toonaceae Biotechnology Limited, and the brand number is 7783-20-2;

sodium carbonate is a commercially available product from sigma aldrich trade ltd under the designation 497-19-8.

Example 1

The cement grinding aid is prepared by stirring and mixing the following raw materials in parts by mass:

15 parts of ethylene glycol, namely 15 parts of ethylene glycol,

15 parts of propylene glycol, namely 15 parts of propylene glycol,

7 parts of rice hull ash, the average grain diameter is 1.5 microns,

15 parts of triethanolamine, namely 15 parts of triethanolamine,

8 parts of a refrigerant, namely 8 parts of refrigerant,

wherein the refrigerant is ammonium sulfate, the average grain diameter is 25 microns,

10 parts of sodium carbonate, the average grain diameter is 30 microns,

a high early strength cement using a cement grinding aid, which is prepared by the cement grinding aid,

s1: and (3) putting the cement grinding aid and the cement raw material into a ball mill according to the mass ratio of 1:250 for grinding for 30min to obtain the cement.

Wherein the cement raw material is obtained by mixing cement clinker, gypsum, limestone and slag according to the mass ratio of 10:1:1: 4.

Examples 2 to 5

A cement grinding aid is based on example 1, and is different in raw material dosage.

The amounts of the raw materials used in examples 1 to 5 are shown in the table below.

TABLE 1 raw material amounts for examples 1 to 5

Example 6

A cement grinding aid which is based on example 1 and differs therefrom in that the amount of rice husk ash is 0.

Example 7

A cement grinding aid is based on example 1, and is characterized in that the dosage of ethylene glycol and propylene glycol is 0.

The cements made using cement grinding aids of examples 1-5 and examples 6-7 were tested.

The test comprises the following steps:

1. compression test

Adding the cement grinding aid into a cement raw material for grinding, adding water into the ground cement for mixing, pouring the mixture into a mold for pouring after mixing, and performing steam curing to obtain a cement product.

The compressive strength of the high early strength cement product using the cement grinding aid was tested after standard curing for 7 days and 28 days, according to the method specified in GB/T17671-1999.

The test results are given in the table below.

TABLE II test results for high early strength cementitious articles using cement grinding aids of examples 1-5 and examples 6-7

The compressive strength of the embodiments 1 to 5 is superior to that of the embodiments 6 to 7, so that the ethylene glycol and the propylene glycol as the liquid grinding aid can be automatically and uniformly dispersed among cement particles, and the ethylene glycol and the propylene glycol belong to positions where small polar molecules are easily adsorbed on unbalanced valence bond force of a new surface formed by grinding, so that the friction force among the cement particles is reduced, the flowability of powder is improved, the particle size of the prepared cement particles is more uniform, and the full hydration reaction of cement raw materials is facilitated; and the dispersibility of the rice hull ash can be further improved by using the ethylene glycol and the propylene glycol, the rice hull ash can be adsorbed on the surfaces of cement particles together with the ethylene glycol and the propylene glycol, the grinding aid effect of the grinding aid is further improved, in the cement blending process, a large amount of amorphous silica is contained in the rice hull ash, the silica reacts with calcium hydroxide generated by hydration reaction to generate C-S-H gel, so that the strength of a cement product is improved, and the adsorption of the porous structure of the rice hull ash on water is favorable for the volcanic ash reaction, so that the strength of the cement product is improved.

Example 8

A cement grinding aid, based on example 1, differs in that the rice husk ash has a particle size of 50 μm.

Example 9

A cement grinding aid, based on example 1, is distinguished by the fact that triethanolamine is added in an amount of 0.

Example 10

A cement grinding aid, based on example 1, except that the amount of the refrigerant added was 0.

Example 11

A cement grinding aid, based on example 1, except that the refrigerant is ammonium chloride.

Example 12

A cement grinding aid, based on example 1, except that the refrigerant is acetonitrile.

The cement articles made using the cement grinding aids of examples 8-12 were tested.

The test results are given in the table below.

TABLE III test results for cement articles made using cement grinding aids of examples 8-12

	Example 8	Example 9	Example 10	Example 11	Example 12
						Compressive strength/MPa for 7 days	30.2	30.1	29.3	29.9	29.5
Compressive strength/MPa 28 days	45.3	44.4	40.2	42.3	41.2

Combining example 1 and example 8 and combining tables two and three, it can be seen that the compressive strength of the cement of example 1 is superior to that of example 8, so the particle size of the rice hull ash in the present application is smaller than that of the cement particles, which is more favorable for the rice hull ash to be adsorbed on the surfaces of the cement particles, during the process of adding water to the cement raw material for mixing, the rice hull ash is adsorbed on the surfaces of the cement particles, the porous structure of the rice hull ash absorbs a large amount of water, the cement particles begin to perform hydration reaction after being adsorbed by the rice hull ash particles with water-rich surfaces, the generated CH continues to perform secondary hydration reaction with the rice hull ash particles in the water-rich environment, with the dissolution of the rice hull ash particles, the release of the residual water in the interior can further promote the hydration of tricalcium silicate, the hydration of tricalcium silicate plays a leading role in the early strength of the cement, and thus the early strength.

By combining the example 1 and the example 9 and combining the second and third tables, it can be seen that the compressive strength of the cement in the example 1 is superior to that in the example 9, so that the triethanolamine serving as a grinding aid is added in the grinding process in the application, the aggregation of cement particles in the grinding process can be reduced, the flowability of the cement is improved, the power consumption of a grinding machine is reduced, and the grinding efficiency is improved; triethanolamine is used as an alcamines substance with strong polarity, can chelate metal ions in cement, is a surfactant, plays a role of a catalyst in the cement hydration process, can accelerate the hydration of tricalcium silicate and the formation of ettringite, and can quickly improve the early strength of the cement.

Combining example 1 and example 10 and combining tables two and three, it can be seen that the compressive strength of the cement of example 1 is better than that of example 10, so that in the application, cement particles after the grinding aid is added are finer, the hydration reaction rate is faster, and the early strength of the cement is improved, but at the same time, the hydration heat released in unit time is increased, so that the finally prepared cement product generates cracks, the hydration heat released during hydration can be absorbed by adding the refrigerant, the heat absorbed by the reaction of the refrigerant when the refrigerant is contacted with water is reduced, and the cracks generated in the cement due to the high hydration heat are reduced, so that the early strength of the cement is further improved.

Combining the example 1 and the examples 11-12 and combining the second and third tables, it can be seen that the compressive strength of the cement of the example 1 is superior to that of the example 11, so that ammonium sulfate is used as a grinding aid in the application, the ammonium sulfate is stable at normal temperature and is insensitive to striking, collision or friction, and during the cement production process, all particles of the cement raw material have structural defects and microcracks, and after the ammonium sulfate is added as the grinding aid, the ammonium sulfate enters the positions of the defects and microcracks like a wedge, so that strong expansion stress is formed among the raw material particles, the cement is more easily ground, the grinding aid effect is achieved, the specific surface area of the cement is increased, the contact area of the cement hydration reaction is increased, and the early strength of the cement is improved; simultaneously at cement raw materials mix in-process, ammonium sulfate can contact with water, and the ammonium sulfate can absorb the heat after dissolving in water to offset the heat of partial hydration reaction release, improve the early strength of cement.

Example 13

A cement grinding aid, based on example 1, differs in that the particle size of the ammonium sulfate is 100 microns.

Example 14

A cement grinding aid, based on example 1, except that sodium carbonate was used in an amount of 0.

The cement articles of examples 13-14 made using cement grinding aids were tested.

The test results are given in the table below.

TABLE IV, test results for cement articles made using cement grinding aids of examples 13-14

	Example 13	Example 14
			Compressive strength/MPa for 7 days	32.2	31.1
Compressive strength/MPa for 28 days	44.5	41.3

Combining example 1 and example 13 and combining tables two and four, it can be seen that the compressive strength of the cement of example 1 is better than that of example 13, so the finer the particle size of ammonium sulfate in the present application, the better the grinding efficiency, but the too fine ammonium sulfate is not beneficial to improving the strength of the cement grinding aid in the hydration process after mixing, the particle size of ammonium sulfate is similar to that of the cement raw material after final grinding, and the ammonium sulfate absorbs heat after dissolving in water and at the same time acts as a filler of the cement when the cement is solidified, which is beneficial to improving the early strength of the cement.

As can be seen by combining the example 1 and the example 14 and combining the tables II and IV, the compressive strength of the cement in the example 1 is better than that in the example 14, so that free calcium oxide exists in the cement raw materials in the mixing process of the cement raw materials in the application, the early strength of the cement is influenced by the free calcium oxide, and sodium carbonate can react with the calcium oxide to generate calcium carbonate precipitates to fill the pores among the cement particles, so that the early strength of the cement is improved.

The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.