阅读说明：本技术 一种环保隔热型粉煤灰砖及其制备方法 (Environment-friendly heat-insulation fly ash brick and preparation method thereof ) 是由 孙伟 于 2021-07-20 设计创作，主要内容包括：本发明公开了一种环保隔热型粉煤灰砖及其制备方法,按重量份计,将20-25份粉煤灰、25-30份炉渣和2.5-3.5份铝矾土混合、研磨,制得混合料,之后加入2-5份磷石膏和0.1-0.3份木质素磺酸钙,加入水,继续混合研磨,之后静态压制成型,制得坯体；将坯体恒温恒压蒸压,制得粉煤灰砖体；制备出隔热涂料；将隔热涂料涂覆在粉煤灰砖体表面,控制涂覆厚度为0.5-2mm,制得环保隔热型粉煤灰砖；通过中间体3制备出基体树脂,制得的基体树脂侧链上含有含氟基团,朝外排列且不含极性基团,使得该基体树脂具有优异疏水性,赋予其优良的自清洁性能,不易被污料粘覆,进一步增强其防污性能。(The invention discloses an environment-friendly heat-insulating flyash brick and a preparation method thereof, wherein the environment-friendly heat-insulating flyash brick is prepared by mixing and grinding 20-25 parts of flyash, 25-30 parts of furnace slag and 2.5-3.5 parts of bauxite according to parts by weight to prepare a mixture, then adding 2-5 parts of phosphogypsum and 0.1-0.3 part of calcium lignosulfonate, adding water, continuously mixing and grinding, and then statically pressing and forming to prepare a blank; steaming and pressing the blank body at constant temperature and constant pressure to obtain a fly ash brick body; preparing the heat-insulating coating; coating the surface of the fly ash brick with a heat-insulating coating, and controlling the coating thickness to be 0.5-2mm to prepare the environment-friendly heat-insulating fly ash brick; the intermediate 3 is used for preparing the matrix resin, and the side chain of the prepared matrix resin contains fluorine-containing groups, is arranged outwards and does not contain polar groups, so that the matrix resin has excellent hydrophobicity, is endowed with excellent self-cleaning performance, is not easily adhered by dirt, and further enhances the antifouling performance.)

1. The environment-friendly heat-insulation flyash brick comprises a flyash brick body and a heat-insulation coating coated on the surface of the flyash brick body, and is characterized in that the heat-insulation coating is prepared by the following method:

step S1, adding perfluorohexanoic acid into N, N-dimethylformamide, heating in water bath at 40-45 ℃, stirring at constant speed and adding thionyl chloride, stirring at constant speed and reacting until no gas is generated, stopping the reaction, standing for layering, and distilling under reduced pressure to obtain an intermediate 1;

step S2, adding acrylic acid into a four-neck flask, sequentially adding ammonium chloride, a polymerization inhibitor and a catalyst, introducing nitrogen, stirring at a constant speed, heating to 85 ℃, dropwise adding propylene oxide, controlling the dropwise adding time to be 2 hours, evaporating redundant propylene oxide after the reaction is finished, removing the residual catalyst to obtain a crude product, and performing reduced pressure distillation to obtain an intermediate 2;

step S3, adding the intermediate 1 into the prepared intermediate 2 in an ice-water bath, heating to 60-70 ℃ after complete addition, uniformly stirring and reacting for 6h to obtain a product, and washing to obtain an intermediate 3;

step S4, uniformly mixing the intermediate 3, methyl methacrylate, butyl acrylate and acrylic acid, adding benzoyl peroxide, and heating and refluxing to prepare matrix resin;

and step S5, adding 35-55 parts by weight of matrix resin, 5-10 parts by weight of hollow glass beads and 3-5 parts by weight of pigment into a mixed solvent, uniformly dispersing, then adding 1.5-3.5 parts by weight of an auxiliary agent, dispersing and grinding to obtain the heat-insulating coating.

2. The environment-friendly heat-insulating flyash brick as claimed in claim 1, wherein the additive in step S5 is a mixture of a thickener, a leveling agent and an antifoaming agent in a weight ratio of 1: 0.5: 1.

3. The environment-friendly and heat-insulating flyash brick as claimed in claim 1, wherein the molar ratio of perfluorohexanoic acid to thionyl chloride in step S1 is controlled to 2: 1, the molar ratio of acrylic acid to propylene oxide in step S2 is 1: 1.10-1.15, the amount of catalyst is 2-3% by weight of acrylic acid, the amount of polymerization inhibitor is 0.1-0.2% by weight of acrylic acid, the amount of ammonium chloride is 1-2.5% by weight of acrylic acid, the molar ratio of intermediate 2 to intermediate 1 in step S3 is controlled to 1: 1, the molar ratio of intermediate 3, methyl methacrylate, butyl acrylate and acrylic acid in step S4 is 1: 1, and the amount of benzoyl peroxide is 3-5% by weight of intermediate 3.

4. The preparation method of the environment-friendly heat-insulating flyash brick as claimed in claim 1, comprising the following steps:

step S11, mixing and grinding 20-25 parts of fly ash, 25-30 parts of furnace slag and 2.5-3.5 parts of bauxite by weight to obtain a mixture, adding 2-5 parts of phosphogypsum and 0.1-0.3 part of calcium lignosulfonate, adding water, continuously mixing and grinding, and then statically pressing and forming to obtain a blank;

s12, steaming and pressing the blank at constant temperature and constant pressure for 8-12h at the temperature of 170-195 ℃ and the pressure of 0.8-1.5 MPa to obtain a fly ash brick body;

step S13, preparing a heat insulation coating;

and step S14, coating the thermal insulation coating on the surface of the fly ash brick body, and controlling the coating thickness to be 0.5-2mm to obtain the environment-friendly thermal insulation type fly ash brick.

5. The method for preparing the environment-friendly heat-insulating flyash brick as claimed in claim 4, wherein the static pressing forming condition is that the pressure is 15-25MPa, the pressing time is 5-10s, and the water content of the system is controlled to be 8-10%.

Technical Field

The invention relates to the technical field of heat insulation bricks, in particular to an environment-friendly heat insulation type fly ash brick and a preparation method thereof.

Background

In the field of building materials, the production technology of non-sintered flyash bricks has three types: non-steamed fly ash bricks, steam-cured fly ash bricks and autoclaved fly ash bricks. The non-steamed fly ash brick is naturally cured at normal temperature, the steam-cured fly ash brick is cured by common steam at the temperature of 90-100 ℃, and because the curing temperature is low, no matter what the proportion of the raw materials is, more hydration products with complete crystallization can not be generated, so the product has low strength, large shrinkage value, easy generation of shrinkage cracks, weak weather resistance and poor durability, and the product performance can not meet the requirements of building functions; the existing autoclaved fly ash brick is designed according to the strength theory on the basis of the traditional experience, the forming process is laggard, the curing temperature is still low, a few production plants adopt the pressure of 1.0MPa, the curing temperature is 179 ℃, and more complete-crystallization hydration products favorable for the product performance can not be generated, so that the fly ash doping amount is not high, the dry shrinkage value is still large, the durability is poor, and a plurality of problems are brought to the engineering quality.

Disclosure of Invention

The invention aims to provide an environment-friendly heat-insulation fly ash brick and a preparation method thereof, and the environment-friendly heat-insulation fly ash brick solves the following technical problems:

the fly ash brick produced by non-sintering at present is used as a heat insulation material of a building outer wall and the like, and the purpose of heat insulation is usually realized by preparing a hollow fly ash brick, but the heat insulation effect is greatly reduced due to gaps and micropores in the brick body, and the fly ash brick is polluted due to rainwater washing and dust accumulation when exposed in outdoor air for a long time, so that the attractiveness is influenced.

The purpose of the invention can be realized by the following technical scheme:

the environment-friendly heat-insulation fly ash brick comprises a fly ash brick body and a heat-insulation coating coated on the surface of the fly ash brick body, wherein the heat-insulation coating is prepared by the following method:

step S1, adding perfluorohexanoic acid into N, N-dimethylformamide, heating in water bath at 40-45 ℃, stirring at constant speed and adding thionyl chloride, stirring at constant speed and reacting until no gas is generated, stopping the reaction, standing for layering, and distilling under reduced pressure to obtain an intermediate 1, wherein the molar ratio of perfluorohexanoic acid to thionyl chloride is controlled to be 2: 1;

in step S1, perfluorohexanoic acid is added to N, N-dimethylformamide as a solvent, and the perfluorohexanoic acid reacts with thionyl chloride to generate intermediate 1, the reaction process is as follows:

step S2, adding acrylic acid into a four-neck flask, sequentially adding ammonium chloride, a polymerization inhibitor and a catalyst, introducing nitrogen, stirring at a constant speed, heating to 85 ℃, dropwise adding propylene oxide, controlling the dropwise adding time to be 2 hours, evaporating excessive propylene oxide after the reaction is finished, removing the residual catalyst to obtain a crude product, and performing reduced pressure distillation to obtain an intermediate 2, wherein the molar ratio of the acrylic acid to the propylene oxide is 1: 1.10-1.15, the dosage of the catalyst is 2-3% of the weight of the acrylic acid, the dosage of the polymerization inhibitor is 0.1-0.2% of the weight of the acrylic acid, and the dosage of the ammonium chloride is 1-2.5% of the weight of the acrylic acid;

in the step S2, acrylic acid and epoxypropane react to generate an intermediate 2, copper powder is used as a polymerization inhibitor, a catalyst is added, and the reaction process is as follows:

step S3, adding the intermediate 1 into the prepared intermediate 2 in an ice-water bath, heating to 60-70 ℃ after completely adding the intermediate, uniformly stirring and reacting for 6h to obtain a product, washing (washing for 2 times by using sodium bicarbonate with the mass fraction of 10% and deionized water respectively and then drying) to obtain an intermediate 3, and controlling the molar ratio of the intermediate 2 to the intermediate 1 to be 1: 1;

in the step S3, the intermediate 2 and the intermediate 1 react to generate the intermediate 3, and the reaction process is as follows:

step S4, uniformly mixing the intermediate 3, methyl methacrylate, butyl acrylate and acrylic acid, adding benzoyl peroxide, heating and refluxing to prepare matrix resin, wherein the molar ratio of the intermediate 3, the methyl methacrylate, the butyl acrylate and the acrylic acid is controlled to be 1: 1, and the dosage of the benzoyl peroxide is 3-5% of the weight of the intermediate 3;

in step S4, the intermediate 3 and the acrylate monomer are mixed, and benzoyl peroxide is used as an initiator to prepare the matrix resin, wherein the reaction process is as follows:

the intermediate 3 is introduced into the matrix resin, the intermediate 3 is a fluorine-containing organic monomer, the side chain of the prepared matrix resin contains fluorine-containing groups, and the fluorine-containing nonpolar groups are arranged outwards and do not contain polar groups, so that the matrix resin has excellent hydrophobicity and is endowed with excellent self-cleaning performance.

And step S5, adding 35-55 parts by weight of matrix resin, 5-10 parts by weight of hollow glass beads and 3-5 parts by weight of pigment into a mixed solvent, uniformly dispersing, then adding 1.5-3.5 parts by weight of an auxiliary agent, dispersing and grinding to obtain the heat-insulating coating.

As a further scheme of the invention: the auxiliary agent in the step S5 is formed by mixing a thickening agent, a flatting agent and a defoaming agent according to the weight ratio of 1: 0.5: 1.

A preparation method of an environment-friendly heat-insulation fly ash brick comprises the following steps:

step S11, mixing and grinding 20-25 parts of fly ash, 25-30 parts of furnace slag and 2.5-3.5 parts of bauxite by weight to obtain a mixture, adding 2-5 parts of phosphogypsum and 0.1-0.3 part of calcium lignosulfonate, adding water, continuously mixing and grinding, and then statically pressing and forming to obtain a blank;

s12, steaming and pressing the blank at constant temperature and constant pressure for 8-12h at the temperature of 170-195 ℃ and the pressure of 0.8-1.5 MPa to obtain a fly ash brick body;

step S13, preparing a heat insulation coating;

and step S14, coating the thermal insulation coating on the surface of the fly ash brick body, and controlling the coating thickness to be 0.5-2mm to obtain the environment-friendly thermal insulation type fly ash brick.

As a further scheme of the invention: the static pressing forming conditions are that the pressure is 15-25MPa, the pressing time is 5-10s, and the water content of the system is controlled to be 8-10%.

The invention has the beneficial effects that:

the invention relates to an environment-friendly heat-insulating flyash brick, which comprises a flyash brick body and a heat-insulating coating coated on the surface of the flyash brick body, wherein the heat-insulating coating is coated on the outer surface of the flyash brick body to realize the heat insulation, an intermediate 3 is prepared in the preparation process of the heat-insulating coating, then matrix resin is prepared from the intermediate 3, the intermediate 3 is a fluorine-containing organic monomer, the side chain of the prepared matrix resin contains fluorine-containing groups, the fluorine-containing nonpolar groups are arranged outwards and do not contain polar groups, so that the matrix resin has excellent hydrophobicity and is endowed with excellent self-cleaning performance, the matrix resin prepared from the fluorine-containing organic monomer and acrylate monomers has lower surface energy after the coating is prepared, is not easy to be adhered by dirt materials and further enhances the antifouling performance, in addition, hollow glass beads are added as fillers in the preparation process of the coating, the titanium dioxide is used as a reflective pigment, visible light and near infrared light can be reflected to the maximum degree, a heat insulation effect is achieved, the hollow glass beads can also achieve a heat insulation effect, the heat insulation effect is achieved through the synergistic heat insulation effect of the titanium dioxide and the hollow glass beads, the excellent heat insulation performance is endowed to the fly ash brick, in addition, heavy metal ions are not introduced in the preparation process, the coating is pollution-free, and the requirement of environmental protection is met.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

The heat insulation coating is prepared by the following method:

step S1, adding perfluorohexanoic acid into N, N-dimethylformamide, heating in water bath at 40 ℃, stirring at a constant speed, adding thionyl chloride, stirring at a constant speed, reacting until no gas is generated, stopping the reaction, standing for layering, and distilling under reduced pressure to obtain an intermediate 1, wherein the molar ratio of perfluorohexanoic acid to thionyl chloride is controlled to be 2: 1;

step S2, adding acrylic acid into a four-neck flask, sequentially adding ammonium chloride, copper powder and a VPO catalyst, introducing nitrogen, stirring at a constant speed, heating to 85 ℃, dropwise adding propylene oxide, controlling the dropwise adding time to be 2 hours, evaporating redundant propylene oxide after the reaction is finished, removing the residual catalyst to obtain a crude product, and carrying out reduced pressure distillation to obtain an intermediate 2, wherein the molar ratio of the acrylic acid to the propylene oxide is 1: 1.10, the dosage of the VPO catalyst is 2% of the weight of the acrylic acid, the dosage of the copper powder is 0.1% of the weight of the acrylic acid, and the dosage of the ammonium chloride is 1% of the weight of the acrylic acid;

step S3, adding the intermediate 1 into the prepared intermediate 2 in an ice-water bath, heating to 60 ℃ after completely adding the intermediate, uniformly stirring and reacting for 6 hours to obtain a product, washing the product for 2 times by using sodium bicarbonate with the mass fraction of 10% and deionized water respectively, and drying to obtain an intermediate 3, wherein the molar ratio of the intermediate 2 to the intermediate 1 is controlled to be 1: 1;

step S4, uniformly mixing the intermediate 3, methyl methacrylate, butyl acrylate and acrylic acid, adding benzoyl peroxide, heating and refluxing to prepare matrix resin, controlling the molar ratio of the intermediate 3, the methyl methacrylate, the butyl acrylate and the acrylic acid to be 1: 1, and controlling the using amount of the benzoyl peroxide to be 3% of the weight of the intermediate 3;

and step S5, adding 35 parts of matrix resin, 5 parts of hollow glass beads and 3 parts of titanium dioxide into the mixed solvent by weight parts for uniform dispersion, then adding 1.5 parts of auxiliary agent, dispersing and grinding to obtain the heat-insulating coating.

The auxiliary agent is formed by mixing hydroxyethyl cellulose, an acrylate flatting agent and a defoaming agent SD998 according to the weight ratio of 1: 0.5: 1.

The mixed solvent is prepared by mixing absolute ethyl alcohol and ethyl acetate according to the volume ratio of 1: 1.

Example 2

The heat insulation coating is prepared by the following method:

step S1, adding perfluorohexanoic acid into N, N-dimethylformamide, heating in water bath at 40 ℃, stirring at a constant speed, adding thionyl chloride, stirring at a constant speed, reacting until no gas is generated, stopping the reaction, standing for layering, and distilling under reduced pressure to obtain an intermediate 1, wherein the molar ratio of perfluorohexanoic acid to thionyl chloride is controlled to be 2: 1;

step S2, adding acrylic acid into a four-neck flask, sequentially adding ammonium chloride, copper powder and a VPO catalyst, introducing nitrogen, stirring at a constant speed, heating to 85 ℃, dropwise adding propylene oxide, controlling the dropwise adding time to be 2 hours, evaporating redundant propylene oxide after the reaction is finished, removing the residual catalyst to obtain a crude product, and carrying out reduced pressure distillation to obtain an intermediate 2, wherein the molar ratio of the acrylic acid to the propylene oxide is 1: 1.12, the dosage of the VPO catalyst is 2.5% of the weight of the acrylic acid, the dosage of the copper powder is 0.15% of the weight of the acrylic acid, and the dosage of the ammonium chloride is 1.5% of the weight of the acrylic acid;

step S3, adding the intermediate 1 into the prepared intermediate 2 in an ice-water bath, heating to 65 ℃ after completely adding the intermediate, uniformly stirring and reacting for 6 hours to obtain a product, washing for 2 times by using sodium bicarbonate with the mass fraction of 10% and deionized water respectively, and drying to obtain an intermediate 3, wherein the molar ratio of the intermediate 2 to the intermediate 1 is controlled to be 1: 1;

step S4, uniformly mixing the intermediate 3, methyl methacrylate, butyl acrylate and acrylic acid, adding benzoyl peroxide, heating and refluxing to prepare matrix resin, controlling the molar ratio of the intermediate 3, the methyl methacrylate, the butyl acrylate and the acrylic acid to be 1: 1, and controlling the using amount of the benzoyl peroxide to be 3.5% of the weight of the intermediate 3;

and step S5, adding 40 parts of matrix resin, 6 parts of hollow glass beads and 4 parts of titanium dioxide into the mixed solvent by weight parts for uniform dispersion, then adding 2.0 parts of auxiliary agent, dispersing and grinding to obtain the heat-insulating coating.

The auxiliary agent is formed by mixing hydroxyethyl cellulose, an acrylate flatting agent and a defoaming agent SD998 according to the weight ratio of 1: 0.5: 1.

The mixed solvent is prepared by mixing absolute ethyl alcohol and ethyl acetate according to the volume ratio of 1: 1.

Example 3

The heat insulation coating is prepared by the following method:

step S1, adding perfluorohexanoic acid into N, N-dimethylformamide, heating in a water bath at 45 ℃, stirring at a constant speed, adding thionyl chloride, stirring at a constant speed, reacting until no gas is generated, stopping the reaction, standing for layering, and distilling under reduced pressure to obtain an intermediate 1, wherein the molar ratio of perfluorohexanoic acid to thionyl chloride is controlled to be 2: 1;

step S2, adding acrylic acid into a four-neck flask, sequentially adding ammonium chloride, copper powder and a VPO catalyst, introducing nitrogen, stirring at a constant speed, heating to 85 ℃, dropwise adding propylene oxide, controlling the dropwise adding time to be 2 hours, evaporating redundant propylene oxide after the reaction is finished, removing the residual catalyst to obtain a crude product, and carrying out reduced pressure distillation to obtain an intermediate 2, wherein the molar ratio of the acrylic acid to the propylene oxide is 1: 1.14, the dosage of the VPO catalyst is 2.8% of the weight of the acrylic acid, the dosage of the copper powder is 0.18% of the weight of the acrylic acid, and the dosage of the ammonium chloride is 2.0% of the weight of the acrylic acid;

step S3, adding the intermediate 1 into the prepared intermediate 2 in an ice-water bath, heating to 70 ℃ after completely adding the intermediate, uniformly stirring and reacting for 6 hours to obtain a product, washing the product for 2 times by using sodium bicarbonate with the mass fraction of 10% and deionized water respectively, and drying to obtain an intermediate 3, wherein the molar ratio of the intermediate 2 to the intermediate 1 is controlled to be 1: 1;

step S4, uniformly mixing the intermediate 3, methyl methacrylate, butyl acrylate and acrylic acid, adding benzoyl peroxide, heating and refluxing to prepare matrix resin, controlling the molar ratio of the intermediate 3, the methyl methacrylate, the butyl acrylate and the acrylic acid to be 1: 1, and controlling the using amount of the benzoyl peroxide to be 4.5% of the weight of the intermediate 3;

and step S5, adding 50 parts of matrix resin, 8 parts of hollow glass beads and 4 parts of titanium dioxide into the mixed solvent by weight parts, uniformly dispersing, then adding 3 parts of auxiliary agent, dispersing and grinding to obtain the heat-insulating coating.

The auxiliary agent is formed by mixing hydroxyethyl cellulose, an acrylate flatting agent and a defoaming agent SD998 according to the weight ratio of 1: 0.5: 1.

The mixed solvent is prepared by mixing absolute ethyl alcohol and ethyl acetate according to the volume ratio of 1: 1.

Example 4

The heat insulation coating is prepared by the following method:

step S1, adding perfluorohexanoic acid into N, N-dimethylformamide, heating in a water bath at 45 ℃, stirring at a constant speed, adding thionyl chloride, stirring at a constant speed, reacting until no gas is generated, stopping the reaction, standing for layering, and distilling under reduced pressure to obtain an intermediate 1, wherein the molar ratio of perfluorohexanoic acid to thionyl chloride is controlled to be 2: 1;

step S2, adding acrylic acid into a four-neck flask, sequentially adding ammonium chloride, copper powder and a VPO catalyst, introducing nitrogen, stirring at a constant speed, heating to 85 ℃, dropwise adding propylene oxide, controlling the dropwise adding time to be 2 hours, evaporating redundant propylene oxide after the reaction is finished, removing the residual catalyst to obtain a crude product, and carrying out reduced pressure distillation to obtain an intermediate 2, wherein the molar ratio of the acrylic acid to the propylene oxide is 1: 1.15, the dosage of the VPO catalyst is 3% of the weight of the acrylic acid, the dosage of the copper powder is 0.2% of the weight of the acrylic acid, and the dosage of the ammonium chloride is 2.5% of the weight of the acrylic acid;

step S3, adding the intermediate 1 into the prepared intermediate 2 in an ice-water bath, heating to 70 ℃ after completely adding the intermediate, uniformly stirring and reacting for 6 hours to obtain a product, washing the product for 2 times by using sodium bicarbonate with the mass fraction of 10% and deionized water respectively, and drying to obtain an intermediate 3, wherein the molar ratio of the intermediate 2 to the intermediate 1 is controlled to be 1: 1;

step S4, uniformly mixing the intermediate 3, methyl methacrylate, butyl acrylate and acrylic acid, adding benzoyl peroxide, heating and refluxing to prepare matrix resin, controlling the molar ratio of the intermediate 3, the methyl methacrylate, the butyl acrylate and the acrylic acid to be 1: 1, and controlling the using amount of the benzoyl peroxide to be 5% of the weight of the intermediate 3;

and step S5, adding 55 parts of matrix resin, 10 parts of hollow glass beads and 5 parts of titanium dioxide into the mixed solvent by weight parts for uniform dispersion, then adding 3.5 parts of auxiliary agent, dispersing and grinding to obtain the heat-insulating coating.

The auxiliary agent is formed by mixing hydroxyethyl cellulose, an acrylate flatting agent and a defoaming agent SD998 according to the weight ratio of 1: 0.5: 1.

The mixed solvent is prepared by mixing absolute ethyl alcohol and ethyl acetate according to the volume ratio of 1: 1.

Comparative example 1

This comparative example compares to example 1 with an acrylic resin instead of the matrix resin.

Comparative example 2

Compared with the embodiment 1, the comparison example does not add hollow glass beads, and replaces titanium dioxide with carbon black.

The coatings prepared in examples 1-4 and comparative examples 1-2 were tested according to the requirements of GB/T-25261-2010 reflective thermal insulation coating for buildings, and the results are shown in the following Table 1:

TABLE 1

	Drying time h	Water resistance h	Pollution resistance%	Resistance to scouring/scouring	Solar reflectance
						Example 1	≤2	175	15	2000	0.88
Example 2	≤2	174	15	2000	0.87
						Example 3	≤2	175	15	2000	0.88
Example 4	≤2	173	14	2000	0.88
						Comparative example 1	≤2	120	25	2000	0.87
Comparative example 2	≤2	172	15	2000	0.37

As can be seen from Table 1 above, the drying times of examples 1 to 4 were all 2 hours or less, the drying times of 173- "175 hours" in the water resistance test, the contamination resistance was 14 to 15%, the wash-out resistance test was 2000 times, the solar reflectance was 0.87 to 0.88, the drying times of comparative examples 1 to 2 were all 2 hours or less, the water resistance test was 120- "172 hours", the contamination resistance was 15 to 25%, the wash-out resistance test was 2000 times, and the solar reflectance was 0.37 to 0.87.

Example 5

A preparation method of an environment-friendly heat-insulation fly ash brick comprises the following steps:

step S11, mixing and grinding 20 parts of fly ash, 25 parts of furnace slag and 2.5 parts of bauxite according to parts by weight to obtain a mixture, adding 2 parts of phosphogypsum and 0.1 part of calcium lignosulfonate, adding water, continuously mixing and grinding, and then performing static compression molding to obtain a blank, wherein the static compression molding conditions are that the pressure is 15MPa, the compression time is 5S, and the water content is controlled to be 8%;

step S12, steaming and pressing the blank at the constant temperature and the constant pressure for 8 hours at the temperature of 170 ℃ and under the pressure of 0.8MPa to obtain a fly ash brick body;

step S13, preparing a thermal insulation coating according to example 1;

and step S14, coating the thermal insulation coating on the surface of the fly ash brick body, and controlling the coating thickness to be 0.5mm to obtain the environment-friendly thermal insulation type fly ash brick.

Example 6

A preparation method of an environment-friendly heat-insulation fly ash brick comprises the following steps:

step S11, mixing and grinding 22 parts of fly ash, 28 parts of furnace slag and 3 parts of bauxite according to parts by weight to obtain a mixture, adding 3 parts of phosphogypsum and 0.2 part of calcium lignosulfonate, adding water, continuously mixing and grinding, and then performing static compression molding to obtain a blank, wherein the static compression molding conditions are that the pressure is 15MPa, the compression time is 5S, and the water content is controlled to be 8%;

step S12, steaming and pressing the blank at the constant temperature and the constant pressure for 8 hours at the temperature of 170 ℃ and under the pressure of 0.8MPa to obtain a fly ash brick body;

step S13, preparing a thermal insulation coating according to example 1;

and step S14, coating the thermal insulation coating on the surface of the fly ash brick body, and controlling the coating thickness to be 0.5-2mm to obtain the environment-friendly thermal insulation type fly ash brick.

Example 7

A preparation method of an environment-friendly heat-insulation fly ash brick comprises the following steps:

step S11, mixing and grinding 25 parts of fly ash, 30 parts of furnace slag and 3.5 parts of bauxite according to parts by weight to obtain a mixture, adding 5 parts of phosphogypsum and 0.3 part of calcium lignosulfonate, adding water, continuously mixing and grinding, and then performing static compression molding to obtain a blank, wherein the static compression molding conditions are that the pressure is 25MPa, the compression time is 10S, and the water content is controlled to be 10%;

step S12, steaming and pressing the blank at constant temperature and constant pressure for 12 hours at 195 ℃ and 1.5MPa to obtain a fly ash brick body;

step S13, preparing a thermal insulation coating according to example 1;

and step S14, coating the heat-insulating coating on the surface of the fly ash brick body, and controlling the coating thickness to be 2mm to obtain the environment-friendly heat-insulating fly ash brick.

Comparative example 3

This comparative example is a fly ash brick produced by a commercially available company.

The mechanical properties of examples 5 to 7 and comparative example 3 were tested according to the test method of GB5101, and the results are shown in table 2 below:

TABLE 2

	Example 5	Example 6	Example 7	Comparative example 3
					Compressive strength MPa	24.5	24.6	24.3	22.8
Flexural strength MPa	4.9	4.8	4.8	4.6

As can be seen from Table 2 above, the compressive strengths of examples 5 to 7 were 24.3 to 24.6MPa, the flexural strengths were 4.8 to 4.9MPa, and the compressive strength of comparative example 3 was 22.8MPa, and the flexural strength was 4.6 MPa.

While one embodiment of the present invention has been described in detail, the description is only a preferred embodiment of the present invention and should not be taken as limiting the scope of the invention. All equivalent changes and modifications made within the scope of the present invention shall fall within the scope of the present invention.