Additives for non-fired bricks made primarily of phosphorus tailings and titanium ash and their preparation method

Abstract

This invention discloses an admixture for non-fired bricks made primarily of phosphorus tailings and titanium dioxide, and its preparation method. The admixture, by weight, comprises: 120-180 parts of a slurry-raising and dispersing agent, 2-8 parts of a long-chain alkylamine, 10-20 parts of a polyhydroxy alcohol, 10-20 parts of a maleic acid-acrylic acid copolymer, 15-30 parts of sodium diacetate of amino acids, 40-80 parts of a C-S-H microcrystalline dispersing agent, 8-12 parts of a polyglycoside ester-polyol amine ester-carboxylic acid ester polymer, and 650-795 parts of deionized water. This admixture can be widely applied to various types of cement-fired bricks made primarily of phosphorus tailings and titanium dioxide, effectively improving the strength, performance, and quality of the bricks. It also increases the comprehensive utilization rate and added value of phosphorus tailings and titanium dioxide in the bricks.

Description

Technical Field

[0001] This invention relates to the field of cement-free brick admixtures, specifically to an admixture for free-fired bricks made primarily of phosphorus tailings and titanium ash, and its preparation method. Background Technology

[0002] Sintered bricks have a history of over 2000 years in my country and continue to this day. However, with increasing demands for environmental and resource protection, higher restrictions have been placed on red bricks, which were originally the main building wall material. This has led to the increased attention and development of cement-free bricks. Cement-free bricks are a new type of wall material made primarily from cement, fly ash, coal slag, waste residue, natural sand, and gravel, without the need for high-temperature firing. As a mainstream material, cement-free bricks, compared to traditional sintered bricks, save land resources, have a simpler production process, lower cost, lower energy consumption, meet environmental protection requirements, and can be immediately demolded without deformation, making them suitable for stacking. However, they also have some shortcomings, such as a relatively loose structure that affects strength, insufficient adhesion leading to brittleness, and insufficient tensile and crack resistance. These shortcomings can be addressed by using admixtures. The introduction of admixtures not only improves the overall performance of cement-free bricks but also increases the comprehensive utilization rate and added value of industrial waste residue admixtures in the bricks.

[0003] Patent CN103951338A discloses a method for preparing non-metallic powder bricks from waste printed circuit boards. The method utilizes non-metallic powder from waste printed circuit boards with cement, sand, lime, etc. to prepare a mixture. The method uses an aqueous solution of sodium sulfate and calcium lignosulfonate as an additive to solve the problem of unstable quality in the current production technology and to reuse the non-metallic powder from waste printed circuit boards.

[0004] Patent CN105461264A discloses a manganese slag non-fired brick and its preparation method, which is made by mixing acid-leached manganese slag, natural river sand, quicklime, cement, water and additives. The additives are composed of one or more of triethanolamine, calcium chloride, sodium sulfate and sodium lignosulfonate, which reduces the amount of cement used in the non-fired brick, while improving the compressive strength of the non-fired brick and saving costs.

[0005] Patent CN104692720A discloses a copper tailings non-fired brick and its preparation method, which is composed of copper tailings powder, cement, aggregate, water and admixtures, wherein the admixtures are composed of common naphthalene-based, polycarboxylate-based or lignin-based water-reducing agents and alkaline activators.

[0006] Patent CN112551932A discloses an admixture for non-fired bricks based on waste slag and its application method. The admixture uses mineral powder, dolomite, metakaolin, steelmaking slag, sodium sulfate, lignin sulfonate, potassium permanganate, aluminum ferric sulfate and water as the main raw materials. At the same time, it prepares and uses modified polyacrylate to enhance the bonding, dispersion, oxidation and early strength effects of the aforementioned materials.

[0007] Patent CN108383475A discloses a method for preparing non-fired bricks made from aluminum ash, which includes additives such as silicates, oxides, borates, sulfates, phosphates, halogen salts, and lignin sulfonates.

[0008] Similar patents or literature report that the admixtures for non-fired bricks are all made by compounding ordinary water-reducing agents and cement activators. To date, no universal admixture has been developed that can simultaneously solve the problems of strength of non-fired bricks and the application of industrial waste residue as admixture. Summary of the Invention

[0009] To address the shortcomings of existing technologies, the inventors have provided an admixture for non-fired bricks, with phosphorus tailings and titanium ash as the main materials, and its preparation method, in order to improve the strength of cement-fired non-fired bricks and at the same time improve the comprehensive utilization rate and added value of phosphorus tailings and titanium ash in non-fired bricks.

[0010] According to a first aspect, the present invention provides an admixture for non-fired bricks, mainly composed of phosphorus tailings and titanium ash, comprising, by weight: 120-180 parts of a slurry dispersant, 2-8 parts of a long-chain alkylamine, 10-20 parts of a polyhydroxy alcohol, 10-20 parts of a maleic acid-acrylic acid copolymer, 15-30 parts of sodium diacetate of amino acids, 40-80 parts of a CSH microcrystalline dispersant, 8-12 parts of a polyglycoside ester-polyol amine ester-carboxylic acid ester polymer, and 650-795 parts of deionized water.

[0011] Further, the slurry dispersant, by weight, is polymerized from 90-120 parts of hydroxyethyl acrylate, 90-120 parts of hydroxypropyl acrylate, 10-20 parts of sodium dodecyl diphenyl ether disulfonate, 8-15 parts of alkyl polyglucoside, 3-8 parts of ammonium persulfate, 6-12 parts of mercaptopropanol, 0.2-2 parts of ferrous sulfate, and 703-792 parts of water.

[0012] Furthermore, the CSH microcrystalline dispersant comprises, by weight: 78-90 parts calcium nitrate tetrahydrate, 30-40 parts sodium silicate nonahydrate, 16-25 parts sodium hydroxide, and 845-876 parts deionized water.

[0013] Furthermore, the long-chain alkylamine is a C8-C22 straight-chain aliphatic amine.

[0014] Furthermore, the polyhydroxy alcohol is at least one of glycerol, pentaerythritol, pentanediol, hexanediol, and heptahydrol.

[0015] Furthermore, the sodium diacetate of the amino acid is at least one of tetrasodium diacetate of glutamic acid, tetrasodium diacetate of aspartic acid, and trisodium diacetate of methylglycine.

[0016] Furthermore, the molecular weight of the polyglycolic ester-polyolamine ester-carboxylic ester polymer is 1200-2400, and it includes at least one of maltose acrylate-diethanolamine acrylate-acrylic polymer, glucose maleate-triethanolamine acrylate-acrylic polymer, and maltose acrylate-diethanolamine maleate monoisopropanolamine acrylate-acrylic polymer.

[0017] Furthermore, the average molecular weight of the maleic acid-acrylic acid copolymer is 582.

[0018] According to a second aspect, the present invention also provides a method for preparing an admixture for cement-free bricks, comprising:

[0019] Preparation steps of the slurry-enhancing dispersant: By weight, add 703-792 parts of water to the reactor, start stirring, then add 10-20 parts of sodium dodecyl diphenyl ether disulfonate and 8-15 parts of alkyl polyglucoside and stir to dissolve for 30 minutes. Then add 90-120 parts of hydroxyethyl acrylate and 90-120 parts of hydroxypropyl acrylate and stir for 10 minutes. Then add 6-12 parts of mercaptopropanol, 0.2-2 parts of ferrous sulfate and 3-8 parts of ammonium persulfate in sequence and stir for 10 minutes. Then raise the temperature to 60°C and let it stand for 12 hours. After cooling to room temperature, the slurry-enhancing dispersant is obtained.

[0020] Preparation steps of CSH microcrystalline dispersant: By weight, dissolve 78-90 parts of calcium nitrate tetrahydrate in deionized water, heat to 80℃ and stir for 20 min, wherein the mass ratio of calcium nitrate tetrahydrate to deionized water is 1:6; dissolve 30-40 parts of sodium silicate nonahydrate in deionized water, heat to 80℃ and stir for 20 min, wherein the mass ratio of sodium silicate nonahydrate to deionized water is 1:11-13; under constant temperature of 80℃, add the above sodium silicate nonahydrate aqueous solution dropwise to the stirred calcium nitrate tetrahydrate aqueous solution, the addition time is 2 h, after the addition is completed, continue to keep warm for 120 h, after the temperature is completed, cool to room temperature and add 16-25 parts of sodium hydroxide, stir for 1 h to obtain CSH microcrystalline dispersant;

[0021] Stirring steps: At room temperature, by weight, add 650-795 parts of deionized water, 120-180 parts of slurry dispersant, 2-8 parts of long-chain alkylamine, 10-20 parts of polyhydroxy alcohol, 10-20 parts of maleic acid-acrylic acid copolymer, 15-30 parts of tetrasodium diacetate of glutamic acid, 40-80 parts of CSH microcrystalline dispersant, and 8-12 parts of maltose acrylate-diethanolamine acrylate-acrylic acid polymer to a stirred reactor in sequence, and stir evenly to obtain the additive for non-fired bricks.

[0022] The mechanism of this invention is as follows:

[0023] This invention directly uses hydroxyethyl acrylate and hydroxypropyl acrylate to form a slurry dispersant through static polymerization. Hydroxyethyl acrylate and hydroxypropyl acrylate, as monomers in this reaction, have high activity. Under static, medium-temperature, and high-chain-transfer agent conditions, they form a three-dimensional network structure with entangled long molecular chains and dense hydroxyl groups. At the same time, the three-dimensional network structure can encapsulate surfactants within it. Due to interfacial activity, it can effectively form an interface between water, air, and cementitious particles, thereby improving the fullness of the slurry in non-fired bricks.

[0024] Long-chain alkylamines and polyhydroxy alcohols possess strong molecular polarity. Polyhydroxy alcohol molecules adsorb onto the surface of cement particles via hydroxyl groups, significantly reducing the surface energy and adhesion of the cementitious particles and promoting the dispersion of cement, phosphorus tailings, and titanium dioxide particles. Long-chain alkylamines form a sparse hydrophobic layer on the surface of cement, phosphorus tailings, and titanium dioxide particles through van der Waals forces. The presence of this hydrophobic layer prevents water from accumulating in the gaps between solid particles, enhancing the permeability of the unfired bricks.

[0025] Maleic acid-acrylic acid copolymer and sodium diacetate can chelate calcium ions in cement, phosphorus tailings, and titanium dioxide, reducing the calcium ion concentration in the hydration system and inhibiting the rapid growth of ettringite. This optimizes the structure of non-fired bricks made primarily of phosphorus tailings and titanium dioxide, improving their durability. The dispersing effect of the maleic acid-acrylic acid copolymer can fix soluble alkali metal ions in phosphorus tailings and titanium dioxide, thereby suppressing the efflorescence phenomenon in non-fired bricks.

[0026] The silica and alumina content in phosphorus tailings and titanium ash is extremely low, preventing the formation of hydrates. CSH microcrystalline dispersant, through the polymerization reaction of calcium nitrate, sodium silicate nonahydrate, and sodium hydroxide, forms a nanoscale semi-crystalline polymer. This polymer, through nucleation and adsorption effects, stimulates the reactivity of phosphorus tailings and titanium ash at low temperatures, promoting the hydration process. This results in uniform growth of hydration products throughout the system, promoting the development of gel strength and compressive strength in the early stages of hydration, leading to a denser and harder unfired brick structure.

[0027] Polyglycosyl ester-polyolamine ester-carboxylic acid ester polymer contains alkanolamine structures, polyhydroxy and carboxyl groups, which improves the adsorption and dispersion capacity of cement, phosphorus tailings and titanium ash particles, and stimulates the hydration activity of the unfired bricks, which only act as fillers, allowing them to fully exert their strength.

[0028] Beneficial effects:

[0029] (1) The admixture for non-fired bricks prepared by the present invention has versatility and can be widely used in various types of cement non-fired bricks with phosphorus tailings and titanium ash as the main materials.

[0030] (2) The additives for non-fired bricks prepared by the present invention can improve the strength of cement non-fired bricks, improve the properties such as permeability, adsorption capacity, and dispersion capacity, suppress the efflorescence phenomenon, stabilize the quality, and at the same time improve the comprehensive utilization rate and added value of phosphorus tailings and titanium ash in non-fired bricks.

[0031] (3) By using appropriate phosphorus tailings and titanium ash in combination and with the help of additives, cement can be reduced or eliminated while ensuring the strength of the bricks. This is conducive to the resource utilization of industrial solid waste, the use of water-reducing cement, and makes building materials more environmentally friendly. Detailed Implementation

[0032] The present invention will be further described in detail below through embodiments.

[0033] Example 1

[0034] Add 746g of water to the reactor and start stirring. Then add 10g of sodium dodecyl diphenyl ether disulfonate and 15g of alkyl polyglucoside and stir to dissolve for 30 minutes. Then add 90g of hydroxyethyl acrylate and 120g of hydroxypropyl acrylate and stir for 10 minutes. After that, add 12g of mercaptopropanol, 1g of ferrous sulfate and 6g of ammonium persulfate in sequence and stir for 10 minutes. Then raise the temperature to 60℃ and let it stand for 12 hours. After cooling to room temperature, the slurry extractor is obtained.

[0035] Dissolve 90g of calcium nitrate tetrahydrate in 540g of deionized water, heat to 80℃ and stir for 20min; dissolve 30g of sodium silicate nonahydrate in 336g of deionized water, heat to 80℃ and stir for 20min; under constant temperature of 80℃, add the sodium silicate nonahydrate aqueous solution dropwise to the stirred calcium nitrate tetrahydrate aqueous solution over 2h, and continue to keep warm for 120h after the addition is complete. After the temperature is completed, cool to room temperature and add 25g of sodium hydroxide. Stir for 1h to obtain the CSH microcrystalline dispersant.

[0036] At room temperature, 751g of deionized water, 120g of slurry dispersant, 2g of C22 linear fatty amine, 20g of glycerol, 20g of maleic acid-acrylic acid copolymer, 15g of tetrasodium diacetate of glutamic acid, 60g of CSH microcrystalline dispersant, and 12g of maltose acrylate-diethanolamine acrylate-acrylic acid polymer are added sequentially into a stirred reactor and stirred evenly to obtain an additive for non-fired bricks with phosphorus tailings and titanium ash as the main materials.

[0037] Example 2

[0038] Add 751g of water to the reactor and start stirring. Then add 20g of sodium dodecyl diphenyl ether disulfonate and 8g of alkyl polyglucoside and stir to dissolve for 30 minutes. Then add 105g of hydroxyethyl acrylate and 105g of hydroxypropyl acrylate and stir for 10 minutes. After stirring, add 6g of mercaptopropanol, 2g of ferrous sulfate and 3g of ammonium persulfate in sequence and stir for 10 minutes. Then raise the temperature to 60℃ and let it stand for 12 hours. After cooling to room temperature, the slurry extractor is obtained.

[0039] Dissolve 78g of calcium nitrate tetrahydrate in 468g of deionized water, heat to 80℃ and stir for 20min; dissolve 35g of sodium silicate nonahydrate in 408g of deionized water, heat to 80℃ and stir for 20min; under constant temperature of 80℃, add the sodium silicate nonahydrate aqueous solution dropwise to the stirred calcium nitrate tetrahydrate aqueous solution over 2h, and continue to keep warm for 120h after the addition is complete. After the temperature is completed, cool to room temperature and add 20g of sodium hydroxide. Stir for 1h to obtain the CSH microcrystalline dispersant.

[0040] At room temperature, 718g of deionized water, 180g of slurry dispersant, 5g of C18 linear fatty amine, 5g of pentaerythritol, 5g of pentanediol, 15g of maleic acid-acrylic acid copolymer, 22g of tetrasodium diacetate aspartate, 40g of CSH microcrystalline dispersant, and 10g of maleic acid glucose ester-triethanolamine acrylate-acrylic acid polymer are sequentially added to a stirred reactor and stirred evenly to obtain an additive for non-fired bricks with phosphorus tailings and titanium ash as the main materials.

[0041] Example 3

[0042] Add 746g of water to the reactor and start stirring. Then add 15g of sodium dodecyl diphenyl ether disulfonate and 12g of alkyl polyglucoside and stir to dissolve for 30 minutes. Then add 120g of hydroxyethyl acrylate and 90g of hydroxypropyl acrylate and stir for 10 minutes. Then add 9g of mercaptopropanol, 0.2g of ferrous sulfate and 8g of ammonium persulfate in sequence and stir for 10 minutes. Then raise the temperature to 60℃ and let it stand for 12 hours. After cooling to room temperature, the slurry extractor is obtained.

[0043] Dissolve 84g of calcium nitrate tetrahydrate in 504g of deionized water, heat to 80℃ and stir for 20min; dissolve 30g of sodium silicate nonahydrate in 352g of deionized water, heat to 80℃ and stir for 20min; under constant temperature of 80℃, add the sodium silicate nonahydrate aqueous solution dropwise to the stirred calcium nitrate tetrahydrate aqueous solution over 2h, and continue to keep warm for 120h after the addition is complete. After the temperature is completed, cool to room temperature and add 16g of sodium hydroxide. Stir for 1h to obtain the CSH microcrystalline dispersant.

[0044] At room temperature, 689g of deionized water, 150g of slurry dispersant, 4g of C8 linear fatty amine, 4g of C12 linear fatty amine, 15g of hexanediol, 20g of maleic acid-acrylic acid copolymer, 30g of trisodium methylglycine diacetate, 80g of CSH microcrystalline dispersant, and 8g of maltose acrylate-maleic acid diethanolamine monoisopropanol ester-acrylic acid polymer are sequentially added to a stirred reactor and stirred evenly to obtain an additive for non-fired bricks with phosphorus tailings and titanium ash as the main materials.

[0045] Comparative Example 1

[0046] No additives are added, only deionized water is used.

[0047] Comparative Example 2

[0048] Based on Example 1, no slurry dispersant was added.

[0049] Comparative Example 3

[0050] Based on Example 1, maleic acid-acrylic acid copolymer and sodium diacetate of amino acids were not added.

[0051] Comparative Example 4

[0052] Based on Example 1, without adding CSH microcrystalline dispersant.

[0053] According to the relevant testing methods in national standards JC422-91 "Non-sintered Common Clay Bricks" and GBT2542-2012 "Test Methods for Masonry Bricks", the performance of the non-fired bricks prepared in this invention was tested. The proportions of cement, phosphorus tailings and titanium ash, aggregates, and admixtures were as follows: cement accounted for 10% of the raw material mass, phosphorus tailings and titanium ash accounted for 60%, aggregates accounted for 30%, and admixtures accounted for 0.2%.

[0054] Titanium ash is the chimney ash produced during the production of titanium dioxide from titanium ore, with a specific surface area of ​​600-850 m². 2 / kg, mainly composed of 59.3%–62.8% calcium carbonate, 12.4%–15.7% iron oxide, 6.2%–8.4% silicon dioxide, and 2.1%–3.6% titanium dioxide. Phosphate tailings are chimney ash produced during phosphate rock production, with a specific surface area of ​​600-800 m². 2 / kg, mainly composed of 60.1%–62.0% calcium oxide, 14.2%–15.3% silicon oxide, 5.9%–7.2% aluminum oxide, 1.9%–2.8% iron oxide, and 1.5%–2.1% phosphorus pentoxide.

[0055] Table 1 Results of compressive and flexural strength tests on unfired bricks

[0056]

[0057] As shown in Table 1, compared with Comparative Example 1, the data from Examples 1-3 demonstrate that the admixture for non-fired bricks prepared in this invention, primarily composed of phosphorus tailings and titanium dioxide, can significantly improve the compressive and flexural strength of cement-fired bricks. Compared with Example 1, Comparative Example 2 (without slurry-enhancing dispersant), Comparative Example 3 (without maleic acid-acrylic acid copolymer, sodium amino acid diacetate), and Comparative Example 4 (without CSH microcrystalline dispersant) all showed negative performance. This is mainly because slurry-enhancing dispersants can improve the fullness of the slurry, thereby increasing the strength of the non-fired bricks; maleic acid-acrylic acid copolymer and sodium amino acid diacetate can optimize the structure of the non-fired bricks; and CSH microcrystalline dispersant promotes cement hydration.

[0058] Table 2 Results of the Efflorescence Test for Non-fired Bricks

[0059] Frosting Example 1 No blooming—salting out was barely visible on the test surface. Example 2 No blooming—salting out was barely visible on the test surface. Example 3 No blooming—salting out was barely visible on the test surface. Comparative Example 1 Moderate blooming—obvious salt precipitation appears on the surface and edges of the test area. Comparative Example 2 No blooming—salting out was barely visible on the test surface. Comparative Example 3 Moderate blooming—obvious salt precipitation appears on the surface and edges of the test area. Comparative Example 4 No blooming—salting out was barely visible on the test surface.

[0060] As shown in Table 2, maleic acid-acrylic acid copolymer and sodium diacetate of amino acids have dispersing and chelating effects, which can fix soluble alkali metal ions in phosphorus tailings and titanium ash, thereby inhibiting the efflorescence phenomenon of non-fired bricks.

[0061] Table 3. Generality Test of Admixtures for Non-fired Bricks Based on Phosphorus Tailings and Titanium Ash

[0062]

[0063] Note: The admixture used in this experiment is from Example 1, and the admixture accounts for 0.2% of the raw material mass.

[0064] As can be seen from the data in Table 3, the admixture for non-fired bricks prepared by this invention has versatility and can be widely used in various types of cement-fired bricks with phosphorus tailings and titanium ash as the main materials; it can improve the comprehensive utilization rate and added value of phosphorus tailings and titanium ash in non-fired bricks; by using appropriate phosphorus tailings, titanium ash or other industrial solid wastes in combination and with the help of the admixture, the amount of cement can be reduced while ensuring the strength of the brick.

Claims

1. An admixture for non-fired bricks, primarily composed of phosphorus tailings and titanium ash, characterized in that, For the preparation of non-fired bricks mainly composed of phosphorus tailings and titanium ash, the additives, by weight, include: 120-180 parts of slurry dispersant, 2-8 parts of long-chain alkylamine, 10-20 parts of polyhydroxy alcohol, 10-20 parts of maleic acid-acrylic acid copolymer, 15-30 parts of sodium diacetate of amino acids, 40-80 parts of CSH microcrystalline dispersant, 8-12 parts of polyglycoside ester-polyol amine ester-carboxylic acid ester polymer, and 650-795 parts of deionized water; The pulping dispersant, by weight, is composed of 90-120 parts of hydroxyethyl acrylate, 90-120 parts of hydroxypropyl acrylate, 10-20 parts of sodium dodecyl diphenyl ether disulfonate, 8-15 parts of alkyl polyglucoside, 3-8 parts of ammonium persulfate, 6-12 parts of mercaptopropanol, 0.2-2 parts of ferrous sulfate, and 703-792 parts of water. The CSH microcrystalline dispersant comprises, by weight: 78-90 parts calcium nitrate tetrahydrate, 30-40 parts sodium silicate nonahydrate, 16-25 parts sodium hydroxide, and 845-876 parts deionized water.

2. The admixture for non-fired bricks as described in claim 1, characterized in that, The long-chain alkylamine is a C8~C22 straight-chain aliphatic amine.

3. The admixture for non-fired bricks as described in claim 1, characterized in that, The polyhydroxy alcohol is at least one of glycerol, pentaerythritol, hexanediol, and heptahydrol.

4. The admixture for non-fired bricks, mainly composed of phosphorus tailings and titanium ash, as described in claim 1, and its preparation method, characterized in that... The sodium diacetate of the amino acid is at least one of tetrasodium diacetate of glutamic acid, tetrasodium diacetate of aspartic acid, and trisodium diacetate of methylglycine.

5. The admixture for non-fired bricks as described in claim 1, characterized in that, The polyglycolic ester-polyolamine ester-carboxylic ester polymer has a molecular weight of 1200-2400, and includes at least one of maltose acrylate-diethanolamine acrylate-acrylic polymer, glucoamyl maleate-triethanolamine acrylate-acrylic polymer, and maltose acrylate-diethanolamine maleate monoisopropanolamine acrylate-acrylic polymer.

6. The admixture for non-fired bricks as described in claim 1, characterized in that, The average molecular weight of the maleic acid-acrylic acid copolymer is 582.

7. A method for preparing an admixture for non-fired bricks, primarily composed of phosphorus tailings and titanium ash, characterized in that, Includes the following steps: Preparation steps of slurry-enhancing dispersant: Add 703-792 parts of water to the reactor, start stirring, then add 10-20 parts of sodium dodecyl diphenyl ether disulfonate and 8-15 parts of alkyl polyglucoside and stir to dissolve for 30 minutes. Then add 90-120 parts of hydroxyethyl acrylate and 90-120 parts of hydroxypropyl acrylate and stir for 10 minutes. Then add 6-12 parts of mercaptopropanol, 0.2-2 parts of ferrous sulfate and 3-8 parts of ammonium persulfate in sequence and stir for 10 minutes. Then heat to 60℃ and let stand for 12 hours. After cooling to room temperature, the slurry-enhancing dispersant is obtained. Preparation steps of CSH microcrystalline dispersant: Dissolve 78-90 parts of calcium nitrate tetrahydrate in deionized water, heat to 80℃ and stir for 20 min, wherein the mass ratio of calcium nitrate tetrahydrate to deionized water is 1:6; Dissolve 30-40 parts of sodium silicate nonahydrate in deionized water, heat to 80℃ and stir for 20 min, wherein the mass ratio of sodium silicate nonahydrate to deionized water is 1:11~13; Under constant temperature of 80℃, add the above sodium silicate nonahydrate aqueous solution dropwise to the stirred calcium nitrate tetrahydrate aqueous solution over 2 h, and continue to keep warm for 120 h after the addition is completed. After the temperature is completed, cool to room temperature and add 16-25 parts of sodium hydroxide, stir for 1 h to obtain CSH microcrystalline dispersant; Stirring steps: At room temperature, add 650-795 parts of deionized water, 120-180 parts of slurry dispersant, 2-8 parts of long-chain alkylamine, 10-20 parts of polyhydroxy alcohol, 10-20 parts of maleic acid-acrylic acid copolymer, 15-30 parts of tetrasodium diacetate of glutamic acid, 40-80 parts of CSH microcrystalline dispersant, and 8-12 parts of maltose acrylate-diethanolamine acrylate-acrylic acid polymer to a stirred reactor in sequence, and stir evenly to obtain the additive for non-fired bricks.

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