CN115057636A

CN115057636A - Slag grinding aid, preparation method thereof and cement using same

Info

Publication number: CN115057636A
Application number: CN202210546073.5A
Authority: CN
Inventors: 张露瑶; 李尚普; 王新平; 唐哲; 王志刚; 刘广铎
Original assignee: Hebei Jinyu Dingxin Cement Co ltd; Tangshan Jidong Cement Admixture Co ltd; Bbmg Cement Co ltd
Current assignee: Hebei Jinyu Dingxin Cement Co ltd; Tangshan Jidong Cement Admixture Co ltd; Bbmg Cement Co ltd
Priority date: 2022-05-19
Filing date: 2022-05-19
Publication date: 2022-09-16
Anticipated expiration: 2042-05-19
Also published as: CN115057636B

Abstract

The application relates to the technical field of cement production, and particularly discloses a slag grinding aid, a preparation method thereof and cement prepared by using the grinding aid. The slag grinding aid comprises ethanol, polyalcohol, modified glucomannan and water; the preparation method comprises the following steps: mixing and stirring the trihydroxymethyl aminomethane, ethanol and water to prepare a mixed solution: and uniformly stirring the modified glucomannan and the mixed solution prepared by the S1 to form the slag grinding aid. The slag grinding aid can be used for grinding slag and has the advantage of improving the strength of prepared cement.

Description

Slag grinding aid, preparation method thereof and cement using slag grinding aid

Technical Field

The application relates to the technical field of cement production, in particular to a slag grinding aid, a preparation method thereof and cement using the slag grinding aid.

Background

As a powdery hydraulic inorganic cementing material, cement is widely used in civil engineering, water conservancy, national defense and other projects, and in the use process, water is usually added into the cement and stirred to form colloid, the colloid is mixed with sand, stone and other materials, then the cement is hardened in the air or water, and the sand, stone and other materials are cemented together, thereby achieving the construction effect.

The cement is prepared by adding cement clinker, gypsum and mixed material in proportion, crushing, mixing, calcining, grinding again and other steps. Because the slag has higher latent activity and hydraulicity, the slag is usually selected as a mixed material of cement so as to achieve the effects of improving the performance of the cement and reducing the production cost. However, in the process of grinding slag, because the slag is poor in grindability, when the slag and cement clinker are ground together, the fineness is often too coarse and the activity cannot be effectively exerted, so that the slag is usually mixed into other raw materials after being independently ground to a preset fineness, and the slag can exert greater activity.

In the related technology, after the slag is independently ground to a certain fineness, the surface energy of slag particles is increased, and each slag particle is agglomerated due to static electricity generated during grinding, so that the strength of the prepared cement is influenced.

Disclosure of Invention

In order to improve the strength of the prepared cement, the application provides a slag grinding aid, a preparation method thereof and cement using the slag grinding aid.

In a first aspect, the application provides a slag grinding aid, which adopts the following technical scheme:

the slag grinding aid comprises the following raw materials in parts by weight: 5-15 parts of ethanol, 30-40 parts of polyalcohol, 30-40 parts of modified glucomannan and 10-30 parts of water.

By adopting the technical scheme, the ethanol is used as an organic solvent in the raw materials, the contact area of each raw material in the slag grinding aid is increased, the reaction rate of the slag in the grinding process is improved, the hydrogen bond in the ethanol enables the ethanol to have deliquescence and absorb moisture in the air, so that the moisture in the grinding system is not easy to dissipate, other raw materials are easy to dissolve and disperse uniformly, meanwhile, the ethanol has volatility, and absorbs heat in the volatilization process, so that the temperature of the slag in the grinding process is not easy to rise, and the reaction in the grinding system is kept to be normally carried out.

The glucomannan molecule contains a large amount of hydroxyl, carbonyl and other hydrophilic groups, can be combined with a large amount of water, and the silicon dioxide contained in the slag is combined with the water to form gel, so that a glucomannan solution forms a net structure in the silicon dioxide gel, the water in a grinding system is kept in the net structure, and along with the reaction in the grinding system, the water is continuously released from the net structure, the reaction in the grinding system is kept to be continuously carried out, and the glucomannan can form an adhesive film with high density in the alkaline environment of the slag and is wrapped outside slag particles, so that the possibility of slag particle agglomeration is reduced, and the grinding efficiency and activity of the slag are improved.

The modified glucomannan is a product obtained by modifying the glucomannan, the viscosity of the glucomannan, which is increased due to strong water binding capacity, is reduced by the modification, the glucomannan is easier to be uniformly dispersed with other raw materials, glucose and mannose can be generated after the modified glucomannan is hydrolyzed, hydroxyl groups are contained in molecules of the glucose and the mannose, and the hydroxyl groups are mixed with polyhydric alcohols in the raw materials, so that the grinding efficiency of slag is improved.

The polyol is used as a common component of the slag grinding aid and is wrapped on the surface of the modified glucomannan in the slag grinding process, and at the moment, the slag surface is wrapped with two layers of films, so that the static electricity generated by increasing the specific surface energy of slag particles during grinding is further eliminated, the phenomenon of slag particle agglomeration is reduced, the grinding efficiency and activity of slag are improved, and the strength of the prepared cement is improved.

Preferably, the slag grinding aid comprises the following raw materials in parts by weight: 8-12 parts of ethanol, 33-37 parts of polyalcohol, 32-38 parts of modified glucomannan and 15-25 parts of water.

By adopting the technical scheme, the proportion of each raw material is optimized, so that the modified glucomannan is further combined with ethanol, polyhydric alcohol and water, and is wrapped on the surface of slag particles in the slag grinding process, the surface energy of the slag surface is reduced, the possibility of agglomeration of the slag particles in the grinding process is reduced, the slag activity is improved, and the strength of the prepared cement is improved.

Preferably, the modified glucomannan is prepared by mixing water, diatomite and glucomannan in a weight ratio of (1-3): (20-22): (10-14), and the preparation steps of the modified glucomannan are as follows:

a1, mixing glucomannan and diatomite to prepare glucomannan adsorbing diatomite;

and A2, adding water into the glucomannan which is prepared by the A1 and adsorbs the diatomite, and mixing to prepare the modified glucomannan.

By adopting the technical scheme, the diatomite and the glucomannan are mixed, at the moment, a part of the diatomite enters a porous structure of the glucomannan, meanwhile, a small part of the diatomite is adhered to the surface of the glucomannan, when water is added, the glucomannan with the surface not adhered with the diatomite is contacted with the water to form gel, the diatomite is wrapped inside the glucomannan, so that the diatomite positioned in pores of the glucomannan is not easy to separate from the porous structure, and when the glucomannan is mixed with other raw materials of the slag grinding aid, the dispersibility of the glucomannan is increased by the diatomite, so that all raw materials of the slag grinding aid are easier to be uniformly mixed; the diatomite is insoluble in water and can be used as an inorganic filler of cement to increase the strength of the cement, and the diatomite has a heat preservation effect, so that the early hydration heat of the cement prepared from slag added with the slag grinding aid is inhibited, the time required by the early hydration heat is prolonged, the later hydration heat of the prepared cement is fully carried out, and the later strength of the cement is improved.

Preferably, the diatomite is modified diatomite, and the modified diatomite is prepared from hydrochloric acid, mannase and diatomite in a weight ratio of (11-13): (5-7): (2-4), and the preparation method of the modified diatomite comprises the following steps:

b1, mixing the diatomite and the hydrochloric acid to prepare a mixture;

and B2, mixing the mixture prepared by the B1 with mannase to prepare the modified diatomite.

By adopting the technical scheme, the diatomite is modified by the hydrochloric acid, the aperture of the diatomite is increased, the mannase is completely adsorbed by the diatomite, meanwhile, impurities in the diatomite are removed in the process of mixing the hydrochloric acid and the diatomite, so that the specific surface area of the diatomite is further increased, when glucomannan is contacted with water, the diatomaceous earth brings the mannanase into the water, at which point the mannanase hydrolyzes the glucomannan and produces glucose and mannose, because the glucose molecule contains hydroxyl and aldehyde group, the glucose has the properties of polyalcohol and aldehyde, and the mannose molecule contains hydroxyl, when glucose and mannose are mixed with the polyol in the raw material of the slag grinding aid, the capability of the polyol for improving slag grinding performance is increased, the possibility of agglomeration of slag particles in the grinding process is reduced, the activity of slag is improved, and the strength of the prepared cement is improved; the hydrochloric acid has reducibility, can reduce the prepared glucose into hexanehexol, eliminates the influence of aldehyde group on a grinding system, and further improves the activity of slag.

Preferably, in the step B1, the mixing time is 30-50 min.

By adopting the technical scheme, the mixing time is controlled to be 30-50min, at the moment, the diatomite is fully modified by the hydrochloric acid, the aperture of the diatomite is increased, the specific surface area of the diatomite is increased, so that the diatomite can absorb more mannase, the glucomannan can be conveniently hydrolyzed to generate glucose and mannose, and the glucose and the mannose are mixed with the polyhydric alcohol, the slag grinding efficiency is improved, and the strength of the prepared cement is improved: when the mixing time is less than 30min, the hydrochloric acid is not fully mixed with the diatomite, the efficiency of the modified diatomite pore size is reduced, and the efficiency of the diatomite for adsorbing the mannanase is influenced: when the mixing time is longer than 50min, the efficiency of the hydrochloric acid modified diatomite is increased unchanged, and the mixing time is prolonged, so that the time waste is easily caused, and the modification efficiency is influenced.

Preferably, the concentration of the hydrochloric acid is 3-5 mol/L.

By adopting the technical scheme, 3-5mol hydrochloric acid is selected to modify the diatomite, the surface of the diatomite becomes rougher to form more grooves and holes, the specific surface area and the pore volume of particles are increased, the adsorption capacity of the diatomite is improved, more mannase is adsorbed, glucomannan is hydrolyzed to generate glucose and mannose, and the glucose and the mannose are mixed with polyhydric alcohol, so that the slag grinding efficiency is improved, and the strength of the prepared cement is improved; when the kieselguhr is modified by hydrochloric acid with the concentration of less than 3mol/L, the efficiency of modifying the kieselguhr by the hydrochloric acid is not increased to the maximum value, and the adsorption capacity of the kieselguhr is influenced; when the kieselguhr is modified by the hydrochloric acid with the concentration of more than 5mol/L, the efficiency of the hydrochloric acid modified kieselguhr is increased to the maximum value and tends to be stable, and at the moment, the efficiency of the hydrochloric acid modified kieselguhr is not increased by selecting the hydrochloric acid modified kieselguhr with the concentration of more than 5mol/L, so that the waste of the hydrochloric acid is easily caused.

Preferably, the polyol is tris (hydroxymethyl) aminomethane.

By adopting the technical scheme, the trihydroxymethyl aminomethane is selected as the polyalcohol, and the trihydroxymethyl aminomethane and the hexanehexol prepared by reducing glucose with hydrochloric acid are fully mixed, so that the grinding performance of the slag is further improved, the possibility of agglomeration is reduced while the specific surface area of each particle of the slag is improved in the grinding process, and the activity of the slag is improved, so that the cement strength is improved.

In a second aspect, the application provides a preparation method of a slag grinding aid, which adopts the following technical scheme:

a preparation method of a slag grinding aid comprises the following steps:

s1, mixing and stirring the tris (hydroxymethyl) aminomethane, the ethanol and the water to prepare a mixed solution:

and S2, uniformly stirring the mixed solution prepared from the modified glucomannan and the S1 to form the slag grinding aid.

By adopting the technical scheme, the trihydroxymethyl aminomethane, the ethanol, the water and the modified glucomannan are sequentially added and stirred to prepare the slag grinding aid, and the prepared slag grinding aid has the function of ensuring that the slag is not easy to agglomerate in the grinding process, so that the slag can be fully ground, the activity of the slag is increased, and the strength of the prepared cement is improved.

In a third aspect, the application provides cement using the slag grinding aid, and the following technical scheme is adopted:

a cement using the slag grinding aid, comprising the following steps:

mixing and grinding slag and a slag grinding aid to prepare a premix;

mixing the premix with gypsum and cement clinker and calcining to prepare a calcined material;

and grinding the calcined material again to obtain the cement.

By adopting the technical scheme, in the process of preparing cement from slag added with the slag grinding aid, the slag and the slag grinding aid are mixed and ground, so that the slag grindability of the slag grinding aid is improved in the slag grinding process, the activity of the slag is improved, gypsum, cement clinker and ground slag are mixed, calcined and ground to prepare the cement, the later strength of the cement prepared by adding the slag grinding aid is improved, and the strength of the prepared cement is improved.

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

1. the contact area of each raw material in the slag grinding aid is increased by the ethanol, the reaction rate of slag in the grinding process is improved, the moisture in the grinding system is not easy to dissipate due to the deliquescence of the ethanol, other raw materials are easy to dissolve and uniformly disperse, the ethanol absorbs heat during volatilization, the temperature is not easy to rise, and the normal reaction in the grinding system is kept; the modified glucomannan is easy to be uniformly dispersed with other raw materials, the modified glucomannan is combined with water to form a net structure, water is reserved in the net structure, the formed film is wrapped outside slag particles, the possibility of slag particle agglomeration is reduced, glucose and mannose generated after hydrolysis are mixed with polyhydric alcohol in the raw materials, and the slag grinding efficiency is improved; the polyol is also wrapped on the surface of the modified glucomannan in the slag grinding process, and the slag surface is wrapped with two films at the moment, so that the static electricity generated by increasing the specific surface energy of slag particles during grinding is further eliminated, the phenomenon of slag particle agglomeration is reduced, the grinding efficiency and activity of slag are improved, and the strength of the prepared cement is improved.

2. The diatomite increases the dispersibility of glucomannan, can be used as an inorganic filler of cement, increases the strength of the cement, has the heat preservation effect of the diatomite, inhibits the early hydration heat of the prepared cement, prolongs the time required by the early hydration heat, and fully carries out the later hydration heat of the prepared cement, thereby improving the later strength of the cement; the hydrochloric acid increases the aperture of the diatomite and removes impurities in the diatomite, and the specific surface area of the diatomite is increased, so that the diatomite adsorbs more mannanase; the mannase hydrolyzes glucomannan to generate glucose and mannose, and the glucose and the mannose are mixed with the polyol in the raw material of the slag grinding aid, so that the capability of the polyol for improving slag grinding performance is increased, the possibility of slag particle agglomeration in the grinding process is reduced, the activity of slag is improved, and the quality of the prepared cement is improved; the hydrochloric acid has reducibility, can reduce the prepared glucose into hexanehexol, eliminates the influence of aldehyde group on a grinding system, and further improves the slag activity.

3. The polyhydric alcohol is trihydroxymethyl aminomethane which is fully mixed with the hexanehexol prepared by reducing glucose with hydrochloric acid, so that the grinding performance of slag is further improved, the possibility of agglomeration is reduced while the specific surface area of each particle of the slag is increased in the grinding process, and the slag activity is improved, so that the cement strength is increased.

Detailed Description

The present application will be described in further detail with reference to examples.

Raw materials

The starting materials used in the examples are all commercially available.

Preparation examples

Preparation example 1

The preparation method of the modified diatomite comprises the following steps:

b1, stirring 2kg of diatomite and 11kg of hydrochloric acid for 30min to prepare a mixture;

and B2, mixing the mixture prepared by the B1 with 7kg of mannase, and stirring to prepare the modified diatomite.

Preparation examples 2 to 3

Different from preparation example 1, the raw material ratios, hydrochloric acid concentrations and stirring times of the modified diatomaceous earth prepared in preparation examples 2 to 3 were different, and the details are shown in table 1.

TABLE 1 raw material ratios, hydrochloric acid concentrations and stirring times of preparation examples 2 to 3

	Diatomaceous earth/kg	Hydrochloric acid/kg	Mannanase/kg	Hydrochloric acid concentration/mol	Stirring time/min
						Preparation example 1	2	11	7	3	30
Preparation example 2	3	12	6	4	40
						Preparation example 3	4	13	5	5	50

Preparation example 4

In contrast to preparation example 2, preparation example 4 used an equivalent amount of bentonite instead of diatomaceous earth.

Preparation example 5

In contrast to preparation 2, preparation 5 used an equivalent amount of sulfuric acid instead of hydrochloric acid.

Preparation example 6

The preparation method of the modified glucomannan comprises the following steps:

a1, mixing 10kg of glucomannan with 22kg of diatomite to prepare the glucomannan adsorbing the diatomite;

a2, adding 1kg of water into the glucomannan adsorbing the diatomite prepared by the A1 and mixing to prepare the modified glucomannan.

Preparation examples 7 to 8

Different from the preparation example 6, the raw materials for preparing the modified glucomannan in the preparation examples 7-8 have different ratios, and the details are shown in the table 2.

TABLE 2 raw material ratios of preparation examples 7 to 8

	Glucomannan/kg	Diatomite/kg	Water/kg
				Preparation example 6	10	22	1
Preparation example 7	12	21	2
				Preparation example 8	14	20	3

Preparation examples 9 to 13

In contrast to preparation 7, preparations 9 to 13 replaced the diatomaceous earth with the same amount of modified diatomaceous earth as from preparations 1 to 5.

Examples

Example 1

A preparation method of the slag grinding aid comprises the following steps:

s1, mixing 30kg of tris (hydroxymethyl) aminomethane, 15kg of ethanol and 10kg of water, and stirring to obtain a mixed solution:

s2, stirring 40kg of the modified glucomannan prepared in the preparation example 6 and the mixed solution prepared in the S1 uniformly to form the slag grinding aid.

Examples 2 to 5

Different from the example 1, the raw material proportion for preparing the slag grinding aid in the examples 2 to 5 is different, and the details are shown in the table 3.

TABLE 3 raw material ratios of examples 1-5

Examples 6 to 12

In contrast to example 3, the modified glucomannans of examples 6 to 12 were obtained in equal amounts from preparation examples 7 to 13.

Example 13

In example 13, trimethylolpropane is used in an equal amount in place of the tris (hydroxymethyl) aminomethane, unlike example 9.

Example 14

In contrast to example 9, in example 13 the same amount of triethanolamine is used instead of tris.

Comparative example

Comparative example 1

In contrast to example 3, the modified glucomannan was replaced by an equal amount of glucomannan in comparative example 1.

Comparative example 2

Unlike example 3, the modified glucomannan of comparative example 2 was added in an amount of 10 kg.

Comparative example 3

Unlike example 3, the modified glucomannan of comparative example 3 was added in an amount of 100 kg.

Application example

Application example 1

The preparation method of the cement comprises the following steps:

mixing and grinding slag and the slag grinding aid prepared in example 1 to prepare a premix;

and grinding the calcined material again to obtain the cement.

Application examples 2 to 14

Unlike application example 1, in application examples 2 to 14, cement was prepared using the same amount of each of the slag grinding aids obtained in examples 2 to 14.

Comparative application example

Comparative application examples 1 to 3

Unlike application example 1, comparative application examples 1 to 3 were each prepared using an equal amount of the slag grinding aid from comparative examples 1 to 3.

Performance test

The following performance tests were conducted for the cements obtained in application examples 1 to 14 and comparative application examples 1 to 3. The performance test comprises the compression strength and the breaking strength of the cement, and the test data are shown in a table 4.

1.28d compressive strength

The compression strength of the prepared cement is detected according to the detection standard of GB/T17671-1999 Cement mortar Strength test method (ISO method). Detecting the environment: at 22 ℃.

2.28d flexural strength

The flexural strength of the prepared cement is detected according to the detection standards of GB/T17671-1999 Cement mortar Strength test method (ISO method). Detecting the environment: at 22 ℃.

Table 4 table of performance testing data

The present application is described in detail below with reference to the test data provided in table 4.

Combining comparative application examples 1-3 and application examples 1-14, it was found that the cement produced in application examples 1-14 of the present application had both a 28d compressive strength and a 28d flexural strength superior to those of comparative application examples 1-3, indicating that the slag grinding aid of the present application performs better in increasing the 28d compressive strength and the 28d flexural strength of the produced cement.

The raw material adding ratios in application examples 1 to 5 are compared, and the results show that the cement obtained in application example 3 has higher 28d compressive strength and 28d flexural strength, which indicates that the raw material ratio of the slag grinding aid in application example 3 is better.

Combining application example 3 with comparative application examples 1-3, it is found that the cement obtained by using the same amount of glucomannan to replace the modified glucomannan in comparative application example 1 is lower than that obtained in application example 3 in terms of 28d compressive strength and 28d flexural strength; compared with the application example 2, the addition amount of the modified glucomannan is insufficient, and the obtained cement has the compressive strength of 28d and the flexural strength of 28d which are lower than those of the application example 3; in a comparative application example 3, the addition amount of the modified glucomannan in the raw materials is too much, and the obtained cement is lower than that of the application example 3 in the aspects of 28d compressive strength and 28d flexural strength; this shows that the modified glucomannan in the scope of the application achieves better effects in improving the 28d compressive strength and the 28d flexural strength of the cement.

By taking the application example 3 as a comparison, the application investigates the influence of different raw material ratios of the modified glucomannan in the application examples 6 and 7, and the result shows that the cement obtained in the application example 6 has higher 28d compressive strength and 28d flexural strength, which indicates that the raw material ratio of the modified glucomannan in the application example 6 is better.

The application examines the influence of the modified diatomite in application examples 8-12 by taking application example 6 as a contrast, and as a result, the cement prepared in application examples 8-12 is found to be superior to application example 6 in terms of 28d compressive strength and 28d flexural strength, which is probably because the addition of the mannanase in the modified diatomite hydrolyzes the glucomannan coated film on the surface of the diatomite, so that the diatomite in the glucomannan is released and used as a cement filler, and the 28d compressive strength and 28d flexural strength of the cement are increased.

In application examples 8 to 10 of the application, the influence of different proportions of the modified diatomite is examined, and as a result, the cement prepared in the application example 9 has higher 28d compressive strength and 28d flexural strength, which shows that the raw material proportion of the modified diatomite in the application example 9 is better.

Combining application examples 11 and 12 and application example 9, it was found that the cement prepared in application example 11 by replacing diatomaceous earth with the same amount of bentonite was lower in both 28d compressive strength and 28d flexural strength than in application example 9; in application example 12, hydrochloric acid was replaced with the same amount of sulfuric acid, and the obtained cement was lower in both 28d compressive strength and 28d flexural strength than application example 9, which indicates that the raw material of the modified diatomite selected in application example 9 has better effects in improving the 28d compressive strength and 28d flexural strength of the cement.

Combining application examples 13 and 14 and application example 9, it was found that when equal amount of trimethylolpropane is used in application example 13 instead of trimethylolaminomethane, the resulting cement was lower in both 28d compressive strength and 28d flexural strength than in application example 9; in application example 14, the same amount of triethanolamine is used to replace the tris, and the obtained cement has lower 28d compressive strength and 28d flexural strength than that of application example 9, which shows that the tris used in application example 9 has better effect in improving the 28d compressive strength and 28d flexural strength of the cement.

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.

Claims

1. The slag grinding aid is characterized by comprising the following raw materials in parts by weight: 5-15 parts of ethanol, 30-40 parts of polyalcohol, 30-40 parts of modified glucomannan and 10-30 parts of water.

2. The slag grinding aid of claim 1, wherein: the feed comprises the following raw materials in parts by weight: 8-12 parts of ethanol, 33-37 parts of polyalcohol, 32-38 parts of modified glucomannan and 15-25 parts of water.

3. The slag grinding aid of claim 1, wherein: the modified glucomannan is prepared from water, diatomite and glucomannan in a weight ratio of (1-3): (20-22): (10-14), and the preparation steps of the modified glucomannan are as follows:

4. The slag grinding aid of claim 3, wherein: the diatomite is modified diatomite which is prepared from hydrochloric acid, mannase and diatomite in a weight ratio of (11-13): (5-7): (2-4), and the preparation method of the modified diatomite comprises the following steps:

b1, mixing the diatomite and the hydrochloric acid to prepare a mixture;

5. The slag grinding aid according to claim 4, wherein the grinding aid is prepared from the following components in percentage by weight: in the step B1, the mixing time is 30-50 min.

6. The slag grinding aid according to claim 4, wherein the grinding aid is prepared from the following components in percentage by weight: the concentration of the hydrochloric acid is 3-5 mol/L.

7. The slag grinding aid of claim 1, wherein: the polyalcohol is trihydroxymethyl aminomethane.

8. The method for preparing a slag grinding aid according to any one of claims 1 to 7, which comprises the following steps:

9. A cement prepared using the slag grinding aid of any one of claims 1 to 8, comprising the steps of:

mixing and grinding slag and a slag grinding aid to prepare a premix;

and grinding the calcined material again to obtain the cement.