阅读说明：本技术 一种无水石膏自流平材料及其制备方法和用途 (Anhydrous gypsum self-leveling material and preparation method and application thereof ) 是由 吴阳 王姗 丁鑫 于 2021-09-01 设计创作，主要内容包括：本发明提供了一种无水石膏自流平材料及其制备方法和用途,所述自流平材料按重量份计包括以下组分：Ⅱ型无水石膏4000～6000份；掺合料2000～3000份；集料2000～3000份；减水剂3～50份；消泡剂5～20份；保水增稠剂3～15份。本发明所述自流平材料以Ⅱ型无水石膏为主料,辅以掺合料和集料,调节无水石膏的水化、凝结速率,提高强度,再通过减水剂、消泡剂及保水增稠剂等组分的添加,各组分相互配合,发挥协同作用,使其具备凝结时间短、流动性高、强度高、体积稳定性好、耐水性好的特点,性能优异；所述Ⅱ型无水石膏以磷石膏为原料,来源广泛,成本低,有助于实现磷石膏的资源化利用,避免磷石膏对环境的污染。(The invention provides an anhydrous gypsum self-leveling material, a preparation method and application thereof, wherein the self-leveling material comprises the following components in parts by weight: 4000-6000 parts of type II anhydrous gypsum; 2000-3000 parts of admixture; 2000-3000 parts of aggregate; 3-50 parts of a water reducing agent; 5-20 parts of a defoaming agent; 3-15 parts of a water-retaining thickener. The self-leveling material provided by the invention takes II type anhydrous gypsum as a main material, and is supplemented with an admixture and an aggregate, the hydration and coagulation rates of the anhydrous gypsum are adjusted, the strength is improved, and then the components are matched with each other through the addition of the water reducing agent, the defoaming agent, the water retention thickening agent and the like, so that the self-leveling material has the characteristics of short coagulation time, high fluidity, high strength, good volume stability, good water resistance and excellent performance; the type II anhydrous gypsum takes the phosphogypsum as a raw material, has wide source and low cost, is beneficial to realizing the resource utilization of the phosphogypsum and avoids the pollution of the phosphogypsum to the environment.)

1. The anhydrous gypsum self-leveling material is characterized by comprising the following components in parts by weight:

2. a self-leveling material according to claim 1, wherein the components of the self-leveling material further comprise an activator and a retarder, in parts by weight:

0-100 parts of an activator;

0-15 parts of retarder.

3. A self-levelling material according to claim 1 or claim 2, wherein the type ii anhydrite is prepared from phosphogypsum by calcination;

preferably, the fineness of the type II anhydrous gypsum is 500-1000 meshes;

preferably, the weight part ratio of the type II anhydrous gypsum to the admixture is (1.5-2.5): 1;

preferably, the admixture comprises alpha hemihydrate gypsum and/or beta hemihydrate gypsum.

4. A self-levelling material according to any one of claims 1 to 3, wherein the aggregate comprises any one of or a combination of at least two of river sand, machine-made sand or heavy calcium powder;

preferably, the fineness of the aggregate is 40-250 meshes.

5. The self-leveling material according to any one of claims 1 to 4, wherein the water reducing agent comprises any one of or a combination of at least two of a polycarboxylic acid-based water reducing agent, a naphthalene-based water reducing agent, a melamine-based water reducing agent, a phosphoric acid-based water reducing agent, or a sulfamic acid-based water reducing agent;

preferably, the defoamer comprises a silicone defoamer;

preferably, the water-retaining thickener comprises any one of hydroxypropyl methyl cellulose ether, hydroxyethyl methyl cellulose ether or carboxymethyl cellulose ether or a combination of at least two thereof.

6. A self-levelling material according to any one of claims 1 to 5, wherein the excitation agent comprises any one or a combination of at least two of potassium sulphate, aluminium sulphate, potassium aluminium sulphate or lithium sulphate;

preferably, the retarder includes any one of proteins, organic acid salts or basic phosphates or a combination of at least two thereof.

7. A method of making a self-levelling material according to any one of claims 1 to 6, comprising the steps of:

and mixing the components of the self-leveling material according to respective parts by weight to obtain the anhydrous gypsum self-leveling material.

8. The method according to claim 7, wherein the type II anhydrous gypsum in the components of the self-leveling material is subjected to a pulverization treatment to obtain type II anhydrous gypsum powder;

preferably, the pulverization treatment is carried out using a ball mill, preferably a tumbling ball mill;

preferably, the fineness of the II type anhydrous gypsum powder after the crushing treatment is 500-1000 meshes;

preferably, the type II anhydrous gypsum is obtained by calcining phosphogypsum;

preferably, the temperature of the calcination treatment is 600-900 ℃, and the time is 2-4 h.

9. A production method according to claim 7 or 8, characterized in that the mixing is performed in a compounding stirring apparatus;

preferably, the mixing and stirring device comprises a V-shaped mixer;

preferably, the mixing time is 10-20 min.

10. Use of a self-levelling material according to any one of claims 1 to 6 as a building material.

Technical Field

The invention belongs to the technical field of building materials, and relates to an anhydrous gypsum self-leveling material, and a preparation method and application thereof.

Background

With the rapid development of modern society, the demand of building materials is increasing, wherein self-leveling materials are common materials, and the self-leveling materials play an important role in improving the construction speed, saving manpower and material resources and reducing pollution. The traditional self-leveling material is mainly a cement-based self-leveling material, which is formed by taking cement as a base material, sand as an auxiliary material and adding an accelerator, a water reducer, a water-retaining agent and the like.

In order to overcome the defects of cement-based self-leveling materials, the research on novel self-leveling materials is continuously carried out, and the gypsum-based self-leveling material is one of the materials, has the advantages of high early strength, high construction speed, no cracking, no hollowing, environmental protection, energy conservation and the like, and still has the defects of low surface hardness, poor water resistance and wear resistance and the like.

CN 107324746A discloses a novel self-leveling mortar and a production process thereof, wherein the self-leveling mortar comprises the following components in percentage by weight: 3-60% of modified cement, 10-66% of modified hemihydrate gypsum, 0.1-8% of fly ash, 0.07-1.5% of cement modifier, 0.05-1.5% of gypsum modifier, 0.04-0.8% of set control agent, 0.01-0.1% of anti-swelling agent, 0.01-0.2% of stabilizer, 0.01-0.2% of defoaming agent, 0.2-0.4% of toner, 0.05-0.13% of slipping agent and 30-86% of aggregate; the self-leveling mortar uses the modified cement, the modified semi-hydrated gypsum and the fly ash together, the components are complex, the performance of the self-leveling mortar is difficult to accurately regulate and control, the pretreatment steps required for each raw material component are more, and the production process of the self-leveling mortar is complex.

CN 1693269a discloses a gypsum-based self-leveling floor leveling material, which comprises the following components in percentage by weight: 80-90% of natural anhydrous gypsum, 10-20% of alkaline activator, less than 1.5% of acidic activator, less than 0.1% of water-retaining agent, less than 1.5% of water-reducing agent and less than 0.5% of defoaming agent, wherein the alkaline activator is cement, namely the leveling material is the same as the natural anhydrous gypsum and the cement, the natural anhydrous gypsum has less reserve and higher cost, and the manufacturing cost of the leveling material for the self-leveling ground is improved.

In conclusion, for the selection of the components of the anhydrous gypsum self-leveling material, a proper matching component needs to be found, so that various performances of the self-leveling material are improved, the sources of the raw materials of the components are expanded, the cost is reduced, and the anhydrous gypsum self-leveling material is convenient to apply on a large scale.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide an anhydrous gypsum self-leveling material and a preparation method and application thereof, wherein the self-leveling material takes II type anhydrous gypsum as a main material, is supplemented with an admixture and an aggregate, adjusts the hydration rate and the condensation rate of the anhydrous gypsum, improves the strength, and further improves the performances of the anhydrous gypsum such as the fluidity, the strength and the water resistance by adding components such as a water reducing agent, a defoaming agent, a water retention thickening agent and the like through mutual matching and synergism; the self-leveling material has wide raw material source and low cost, and is beneficial to realizing the resource utilization of wastes.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the invention provides an anhydrous gypsum self-leveling material, which comprises the following components in parts by weight:

wherein, the weight portion of the II type anhydrous gypsum in the components can be selected from 4000 parts, 4500 parts, 5000 parts, 5500 parts or 6000 parts, the weight portion of the admixture can be selected from 2000 parts, 2200 parts, 2500 parts, 2700 parts or 3000 parts, the weight portion of the aggregate can be selected from 2000 parts, 2200 parts, 2500 parts, 2700 parts or 3000 parts, the weight portion of the water reducing agent can be selected from 3 parts, 10 parts, 20 parts, 30 parts, 40 parts or 50 parts, the weight portion of the defoaming agent can be selected from 5 parts, 8 parts, 10 parts, 15 parts or 20 parts, the weight portion of the water retention thickening agent can be selected from 3 parts, 5 parts, 8 parts, 10 parts, 12 parts or 15 parts, but not limited to the recited values, and other unrecited values in the respective value range are also applicable.

According to the composition of the anhydrous gypsum self-leveling material, the II type anhydrous gypsum, the admixture and the aggregate are three main components, wherein the II type anhydrous gypsum is used as a main material and is obtained by calcining dihydrate gypsum, so that the anhydrous gypsum self-leveling material has certain hydration performance but slow hydration rate, and the admixture and the aggregate are added to be matched for use, the admixture can adjust the hydration rate, promote the coagulation, improve the early strength of the anhydrous gypsum self-leveling material, and the micro-expansion performance of the admixture can adjust the micro-shrinkage performance of the anhydrous gypsum and increase the volume stability; the aggregate is used as a framework of the anhydrous gypsum self-leveling material, so that the stacking density of the self-leveling material can be reduced, and the fluidity and the volume stability of the self-leveling mortar are improved;

besides the main components, the self-leveling material also comprises a plurality of additive components, wherein the water reducing agent can reduce the water demand of the self-leveling material, so that the strength is increased, the self-leveling material keeps high flow property, and the construction is convenient; the defoaming agent can quickly eliminate bubbles generated after the self-leveling material is mixed with water, so that the surface of the self-leveling material is kept smooth, the pores are reduced, and the strength is increased; the water retention thickener can improve the water retention performance of the self-leveling material, increase the consistency and prevent bleeding; the self-leveling material has the characteristics of short setting time, high fluidity, high strength, good volume stability and good water resistance by the mutual matching of the components in the self-leveling material and the synergistic effect, and has excellent performance, convenient construction and lower cost when being used as a building material.

The following technical solutions are preferred technical solutions of the present invention, but not limited to the technical solutions provided by the present invention, and technical objects and advantageous effects of the present invention can be better achieved and achieved by the following technical solutions.

As a preferable technical scheme of the invention, the self-leveling material further comprises an exciting agent and a retarder, and the components in parts by weight are respectively as follows:

0-100 parts of an activator;

0-15 parts of retarder.

The activator can be selected from 0, 10, 30, 50, 60, 80 or 100 parts by weight, and the retarder can be selected from 0, 2, 15, 8, 10, 12 or 15 parts by weight, but the activator is not limited to the above-mentioned values, and other values not shown in the above-mentioned values are also applicable.

In the invention, the activator can improve the hydration rate of the self-leveling material so as to improve the strength, but if the addition amount of the activator is too large, the phenomenon of salt and alkali precipitation can occur when the self-leveling material is affected with damp, and meanwhile, the fluidity loss of the self-leveling material is increased, so that the construction is inconvenient; the retarder can reduce the fluidity loss of the self-leveling material and prolong the construction time, but if the addition amount of the retarder is too large, the setting time of the self-leveling material can be greatly prolonged, the strength is reduced, water secretion and surface skinning and powder falling are caused, and the improvement of the comprehensive performance of the self-leveling material is not facilitated.

According to the invention, the action of the exciting agent and the retarder is expressed, the action of the exciting agent and the action of the retarder are opposite in some aspects, so that the hydration rate is accelerated by adding the exciting agent, the problems that the setting time is difficult to control in a standard range, the fluidity of the material is poor, the later stage is likely to frost and grow hair and the like are easily caused when the setting is promoted, and the exciting agent and the retarder are reasonably proportioned by adding the retarder so as to regulate and control the setting time and reduce the adverse effect of the exciting agent.

As a preferable technical scheme of the invention, the type II anhydrous gypsum is prepared by calcining phosphogypsum.

In the invention, the type II anhydrous gypsum is from calcining of dihydrate gypsum, and the phosphogypsum is waste mainly composed of dihydrate gypsum and is easy to cause pollution problems, and the calcining treatment of the phosphogypsum can oxidize and decompose organic pollutants and solidify inorganic pollutants in the phosphogypsum, so that the anhydrous gypsum is obtained, and the resource utilization of the phosphogypsum waste is realized.

Preferably, the type ii anhydrite has a fineness of 500 to 1000 mesh, for example, 500 mesh, 600 mesh, 700 mesh, 800 mesh, 900 mesh, 1000 mesh, or the like, but is not limited to the recited values, and other values not recited in the range of the values are also applicable.

Preferably, the weight ratio of the anhydrous gypsum type II to the admixture is (1.5-2.5): 1, such as 1.5:1, 1.6:1, 1.8:1, 2:1, 2.2:1, 2.4:1 or 2.5:1, but not limited to the recited values, and other values not recited in the range of the values are also applicable.

In the invention, the weight ratio of the type II anhydrous gypsum to the admixture is an important factor influencing the performance of the self-leveling material. The addition of the admixture is beneficial to the excitation, hydration and coagulation of the type II anhydrous gypsum, and the early strength of the type II anhydrous gypsum is improved, so that the defect of insufficient excitation of the type II anhydrous gypsum is overcome, but if the addition amount of the admixture is too large, the volume stability of the self-leveling material is influenced, and the slurry is cracked due to nonuniform shrinkage in the coagulation process, so that the ratio of the type II anhydrous gypsum to the self-leveling material is controlled within a certain range, the hydration rate of the type II anhydrous gypsum can be adjusted, the coagulation is promoted, the early strength is improved, and the cracking phenomenon can be avoided.

Preferably, the admixture comprises alpha hemihydrate gypsum and/or beta hemihydrate gypsum.

As a preferred embodiment of the present invention, the aggregate comprises any one of river sand, machine-made sand or heavy calcium powder or a combination of at least two of them, as typical but non-limiting examples: the combination of river sand and machine-made sand, the combination of machine-made sand and coarse whiting powder, the combination of river sand, machine-made sand and coarse whiting powder and the like.

Preferably, the fineness of the aggregate is 40 to 250 mesh, for example, 40 mesh, 75 mesh, 100 mesh, 150 mesh, 200 mesh, or 250 mesh, but is not limited to the recited values, and other values not recited in the range of the values are also applicable.

As a preferred embodiment of the present invention, the water reducing agent includes any one or a combination of at least two of a polycarboxylic acid water reducing agent, a naphthalene water reducing agent, a melamine water reducing agent, a phosphoric acid water reducing agent, or a sulfamic acid water reducing agent, and the combination is typically, but not limited to, as follows: a combination of a polycarboxylic acid-based water reducing agent and a naphthalene-based water reducing agent, a combination of a melamine-based water reducing agent and a phosphoric acid-based water reducing agent, a combination of a polycarboxylic acid-based water reducing agent, a phosphoric acid-based water reducing agent and an aminosulfonic acid-based water reducing agent, a combination of a polycarboxylic acid-based water reducing agent, a naphthalene-based water reducing agent and a melamine-based water reducing agent, and the like.

Preferably, the defoamer comprises a silicone defoamer, the main component of which is a silicone oil silicone component.

Preferably, the water-retaining thickener comprises any one of, or a combination of at least two of, hydroxypropyl methyl cellulose ether, hydroxyethyl methyl cellulose ether, or carboxymethyl cellulose ether, typical but non-limiting examples of such combinations are: combinations of hydroxypropyl methylcellulose ether and hydroxyethyl methylcellulose ether, combinations of hydroxyethyl methylcellulose ether and carboxymethyl cellulose ether, combinations of hydroxypropyl methylcellulose ether, hydroxyethyl methylcellulose ether and carboxymethyl cellulose ether, and the like.

As a preferred technical solution of the present invention, the exciting agent comprises any one of potassium sulfate, aluminum sulfate, potassium aluminum sulfate or lithium sulfate or a combination of at least two of the foregoing, and typical but non-limiting examples of the combination are: combinations of potassium sulfate and aluminum sulfate, combinations of aluminum sulfate and potassium aluminum sulfate, combinations of potassium sulfate and lithium sulfate, combinations of aluminum sulfate, potassium aluminum sulfate and lithium sulfate, and the like.

Preferably, the retarder comprises any one of, or a combination of at least two of, proteins, organic acid salts, or basic phosphates, typical but non-limiting examples of which are: combinations of proteins and organic acid salts, combinations of organic acid salts and basic phosphates, combinations of proteins, organic acid salts and basic phosphates, and the like.

In a second aspect, the present invention provides a method for preparing the above self-leveling material, comprising the following steps:

and mixing the components of the self-leveling material according to respective parts by weight to obtain the anhydrous gypsum self-leveling material.

In a preferred embodiment of the present invention, the type ii anhydrous gypsum in the components of the self-leveling material is first pulverized to obtain type ii anhydrous gypsum powder.

Preferably, the pulverization treatment is carried out using a ball mill, preferably a tumbling ball mill.

In the invention, the II-type anhydrous gypsum obtained by calcination is easy to agglomerate and agglomerate, and a ball mill is required for crushing, so that the specific surface area of the II-type anhydrous gypsum is increased, and the activity of the material is improved.

Preferably, the fineness of the type II anhydrous gypsum powder after the pulverization treatment is 500 to 1000 mesh, for example, 500 mesh, 600 mesh, 700 mesh, 800 mesh, 900 mesh, 1000 mesh, etc., but not limited to the recited values, and other values not recited in the range of the values are also applicable.

Preferably, the type II anhydrous gypsum is obtained by calcining phosphogypsum.

Preferably, the temperature of the calcination treatment is 600 to 900 ℃, for example 600 ℃, 650 ℃, 700 ℃, 750 ℃, 800 ℃, 850 ℃, 900 ℃ or the like, but is not limited to the recited values, and other values not recited in the numerical range are also applicable; the time is 2 to 4 hours, for example, 2 hours, 2.5 hours, 3 hours, 3.5 hours, or 4 hours, but is not limited to the recited values, and other values not recited in the range of the values are also applicable.

As a preferred technical solution of the present invention, the mixing is performed in a mixing and stirring apparatus.

Preferably, the mixing and stirring device comprises a V-shaped mixer.

Preferably, the mixing time is 10-20 min, such as 10min, 12min, 14min, 15min, 16min, 18min or 20min, but not limited to the recited values, and other values not recited in the range of values are also applicable.

In a third aspect, the present invention provides the use of a self-levelling material as described above as a building material.

Compared with the prior art, the invention has the following beneficial effects:

(1) the self-leveling material provided by the invention takes II type anhydrous gypsum as a main material, and is supplemented with an admixture and an aggregate, the hydration rate and the condensation rate of the anhydrous gypsum are adjusted, the strength is improved, and then through the addition of components such as a water reducing agent, a defoaming agent, a water retention thickening agent and the like, the components are mutually matched to play a synergistic effect, so that the self-leveling material has the characteristics of short condensation time, high fluidity, high strength, good volume stability, good water resistance and excellent performance;

(2) the type II anhydrous gypsum in the self-leveling material takes the phosphogypsum as a raw material, has wide sources and low cost, is beneficial to realizing the resource utilization of phosphogypsum waste, and avoids the pollution of the phosphogypsum to the environment.

Detailed Description

In order to better illustrate the present invention and facilitate the understanding of the technical solutions of the present invention, the present invention is further described in detail below. However, the following examples are only simple examples of the present invention and do not represent or limit the scope of the present invention, which is defined by the claims.

The specific embodiment of the invention provides an anhydrous gypsum self-leveling material and a preparation method thereof, wherein the self-leveling material comprises the following components in parts by weight:

the preparation method comprises the following steps:

and mixing the components of the self-leveling material according to respective parts by weight to obtain the anhydrous gypsum self-leveling material.

The following are typical but non-limiting examples of the invention:

example 1:

the embodiment provides an anhydrous gypsum self-leveling material and a preparation method thereof, wherein the self-leveling material comprises the following components in parts by weight:

the fineness of the type II anhydrous gypsum is 700 meshes, and the fineness of the river sand is 100 meshes.

The water reducing agent is a polycarboxylic acid water reducing agent, the defoaming agent is an organic silicon defoaming agent, and the water retention thickening agent is hydroxypropyl methyl cellulose ether.

The excitant is aluminum potassium sulfate, and the retarder is amino acids.

The preparation method comprises the following steps:

(1) calcining phosphogypsum for 3 hours at 800 ℃, and then grinding by using a roller ball mill to obtain II-type anhydrous gypsum powder with the fineness of 700 meshes;

(2) and (3) mixing the components of the self-leveling material in parts by weight in a V-shaped mixer for 15min to obtain the anhydrous gypsum self-leveling material.

Example 2:

the embodiment provides an anhydrous gypsum self-leveling material and a preparation method thereof, wherein the self-leveling material comprises the following components in parts by weight:

the fineness of the type II anhydrous gypsum is 500 meshes, and the fineness of the machine-made sand is 200 meshes.

The water reducing agent is a melamine water reducing agent, the defoaming agent is an organic silicon defoaming agent, and the water-retaining thickening agent is hydroxyethyl methyl cellulose ether.

The excitant is potassium sulfate, and the retarder is protein.

The preparation method comprises the following steps:

(1) calcining phosphogypsum for 2 hours at 900 ℃, and then grinding by using a roller ball mill to obtain II-type anhydrous gypsum powder with the fineness of 500 meshes;

(2) and (3) mixing the components of the self-leveling material in parts by weight in a V-shaped mixer for 10min to obtain the anhydrous gypsum self-leveling material.

Example 3:

the embodiment provides an anhydrous gypsum self-leveling material and a preparation method thereof, wherein the self-leveling material comprises the following components in parts by weight:

the fineness of the type II anhydrous gypsum is 1000 meshes, and the fineness of the coarse whiting powder is 250 meshes.

The water reducing agent is a mixture of a polycarboxylic acid water reducing agent and a naphthalene water reducing agent, the defoaming agent is an organic silicon defoaming agent, and the water-retaining thickening agent is carboxymethyl cellulose ether.

The excitant is lithium sulfate, and the retarder is alkaline phosphate.

The preparation method comprises the following steps:

(1) calcining phosphogypsum for 4 hours at the temperature of 600 ℃, and then grinding by adopting a tubular ball mill to obtain II-type anhydrous gypsum powder with the fineness of 1000 meshes;

(2) and (3) mixing the components of the self-leveling material in parts by weight in a V-shaped mixer for 20min to obtain the anhydrous gypsum self-leveling material.

Example 4:

the embodiment provides an anhydrous gypsum self-leveling material and a preparation method thereof, wherein the self-leveling material comprises the following components in parts by weight:

the fineness of the type II anhydrous gypsum is 600 meshes, and the fineness of the machine-made sand is 75 meshes.

The water reducing agent is a mixture of a melamine water reducing agent and a phosphoric acid water reducing agent, the defoaming agent is an organic silicon defoaming agent, and the water-retaining thickening agent is hydroxypropyl methyl cellulose ether.

The preparation method comprises the following steps:

(1) calcining phosphogypsum for 3.5h at 700 ℃, and then grinding by adopting a tubular ball mill to obtain II-type anhydrous gypsum powder with the fineness of 600 meshes;

(2) and (3) mixing the components of the self-leveling material in parts by weight in a conical mixer for 12min to obtain the anhydrous gypsum self-leveling material.

Example 5:

the embodiment provides an anhydrous gypsum self-leveling material and a preparation method thereof, wherein the self-leveling material comprises the following components in parts by weight:

the fineness of the type II anhydrous gypsum is 800 meshes, and the fineness of the coarse whiting powder is 150 meshes.

The water reducing agent is a mixture of a polycarboxylic acid water reducing agent and an aminosulfonic acid water reducing agent, the defoaming agent is an organic silicon defoaming agent, and the water retention thickening agent is hydroxyethyl methyl cellulose ether.

The retarder is alkaline phosphate.

The preparation method comprises the following steps:

(1) calcining phosphogypsum for 2.5h at 750 ℃, and then grinding by adopting a roller ball mill to obtain II-type anhydrous gypsum powder with the fineness of 800 meshes;

(2) and (3) mixing the components of the self-leveling material in parts by weight in a V-shaped mixer for 18min to obtain the anhydrous gypsum self-leveling material.

Example 6:

the embodiment provides an anhydrous gypsum self-leveling material and a preparation method thereof, wherein the self-leveling material comprises the following components in parts by weight:

the fineness of the type II anhydrous gypsum is 900 meshes, and the fineness of the river sand is 50 meshes.

The water reducing agent is a polycarboxylic acid water reducing agent, the defoaming agent is an organic silicon defoaming agent, and the water retention thickening agent is hydroxypropyl methyl cellulose ether.

The exciting agent is aluminum sulfate.

The preparation method comprises the following steps:

(1) calcining phosphogypsum for 2.5h at 850 ℃, and then grinding by adopting a roller ball mill to obtain II-type anhydrous gypsum powder with the fineness of 900 meshes;

(2) and (3) mixing the components of the self-leveling material in parts by weight in a V-shaped mixer for 15min to obtain the anhydrous gypsum self-leveling material.

Comparative example 1:

this comparative example provides an anhydrous gypsum self-levelling material and a process for its preparation, the composition of which is as for the self-levelling material of example 1, except that: the admixture beta-hemihydrate gypsum is 1000 parts by weight, namely the addition amount of the admixture is too small.

Comparative example 2:

this comparative example provides an anhydrous gypsum self-levelling material and a process for its preparation, the composition of which is as for the self-levelling material of example 1, except that: the weight portion of the admixture beta-hemihydrate gypsum is 5000 portions, namely the addition amount of the admixture is excessive.

The anhydrous gypsum self-leveling materials prepared in examples 1-6 and comparative examples 1-2, respectively, were mixed with water at a standard consistency and then tested for performance using the test method in T/CBMF 82-2020, with the results shown in table 1.

Table 1 results of performance tests of the anhydrite self-leveling materials described in examples 1 to 6 and comparative examples 1 to 2

As can be seen from Table 1, the anhydrous gypsum self-leveling material is measured according to the standard consistency when being mixed with water, namely the water requirement of the self-leveling material; the components of the anhydrous gypsum self-leveling material in the embodiments 1 to 3 include all kinds, and the weight parts of the components are basically well matched, so that the obtained anhydrous gypsum self-leveling material has the advantages of adjustable setting time, high fluidity, high strength, good volume stability and good water resistance; in the embodiment 4, no excitant and retarder are added, but the other components are well mixed in parts by weight, so that the influence on the overall performance of the self-leveling material is small; in example 5, because of the lack of the activator, the performance of the activator for improving the hydration rate and the strength cannot be exerted, the setting time is relatively prolonged, and the strength is weakened; in example 6, the addition of only the activator and the absence of the retarder resulted in a greater loss of fluidity and a shorter setting time for the anhydrite self-leveling material.

In comparative example 1, the addition of the admixture is too small, so that the hydration rate of the type II anhydrous gypsum cannot be sufficiently improved, the early strength is too low, and the setting time is too long; in comparative example 2, the addition of the admixture resulted in a large loss of fluidity, too short setting time, easily affected the volume stability of the self-leveling material, and non-uniform shrinkage during setting, resulting in cracking of the self-leveling material.

It can be seen from the above examples and comparative examples that the self-leveling material of the present invention uses type II anhydrous gypsum as a main material, and uses an admixture and an aggregate as an auxiliary material to adjust the hydration rate and the setting rate of the anhydrous gypsum, and improve the strength, and then through the addition of the water reducing agent, the antifoaming agent, the water retention thickener, and other components, the components cooperate with each other to exert a synergistic effect, such that the self-leveling material has the characteristics of short setting time, high fluidity, high strength, good volume stability, good water resistance, and excellent performance; the type II anhydrous gypsum in the self-leveling material takes the phosphogypsum as a raw material, has wide sources and low cost, is beneficial to realizing the resource utilization of phosphogypsum waste, and avoids the pollution of the phosphogypsum to the environment.

The applicant states that the present invention is illustrated by the above examples to show the detailed products and methods of the present invention, but the present invention is not limited to the above detailed products and methods, i.e. it is not meant to imply that the present invention must rely on the above detailed products and methods for implementation. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions for the product of the present invention and the addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.