A preparation method of gypsum-based tile adhesive material

Abstract

The present invention relates to a preparation method of a gypsum-based tile adhesive material, wherein the raw materials of the gypsum-based tile adhesive material include gypsum-based gel material, gypsum sand, dispersible latex powder, and cellulose ether; wherein the content of the gypsum-based gel material is within 40%. Compared with the existing scheme, the technical scheme of the present invention can be controlled to be 30-45% by developing a gypsum-based gel material and using gypsum sand as an aggregate. Moreover, due to the specially formulated gypsum-based gel material and gypsum sand in a water environment, the aluminum and silicon compounds in the raw materials undergo a ceramic reaction in an alkaline environment to form an ettringite structure (AFT) and / or hydrated calcium aluminate (C-S-H), thereby improving the density and water resistance of the tile adhesive solidification slurry, and having water-resistant properties in a real sense.

Description

Technical Field

[0001] The present invention relates to the field of building materials, and in particular to a method for preparing a gypsum-based tile adhesive material. Background Art

[0002] Tile adhesive is currently widely used for attaching tiles, with cement-based tile adhesive being the most popular. Cement-based tile adhesive is a dry powder mixture composed primarily of cement, graded sand, and organic additives. It is mixed with water to form a gel. It is used to bond decorative materials such as ceramic tiles, facing tiles, and floor tiles. It is widely used in decorative areas such as walls, floors, and kitchens. Tile adhesive is characterized by its ease of application and high bond strength, making it a highly effective adhesive.

[0003] With the development of the building materials industry, the water absorption of tiles is decreasing. Cement-based tile adhesives, due to high shrinkage stress, can cause rigidity failure, leading to hollowing and spalling between tiles and the adhesive layer. Furthermore, the production of cement consumes significant resources and releases large amounts of greenhouse gases, which is inconsistent with the dual carbon development goals. In recent years, the government has introduced numerous important environmental improvement measures. Using new building cementitious materials and reducing cement use is a key development direction for the construction industry. Gypsum, one of the three major cementitious materials, is abundant and a ubiquitous resource. For example, desulfurization gypsum produced by flue gas desulfurization in thermal power plants and phosphogypsum, a byproduct of the phosphate compound fertilizer industry, are all sources of gypsum. However, compared to cement, gypsum is currently used less in the construction industry due to its lack of strength. In recent years, gypsum wall materials such as gypsum-based self-leveling cement, gypsum-based plaster mortar, stucco gypsum, and gypsum board have experienced rapid growth.

[0004] Gypsum is a monoclinic crystal with a high degree of cleavage, easily cracking into thin flakes. Hemihydrate gypsum is obtained by heating gypsum to 100-200°C, which loses some of its crystal water. It is an air-hardening cementitious material with two forms, α and β, both of which are rhombohedral crystals but have different physical properties. α-type hemihydrate gypsum is well-crystallized and solid; β-type hemihydrate gypsum is a flaky, cracked crystal with very fine crystals and a much larger specific surface area than α-type hemihydrate gypsum. Its shrinkage is one-tenth of that of cement materials. Gypsum-based tile adhesives can effectively solve the problem of hollowing and falling tiles. However, the biggest drawback of gypsum-based tile adhesives is that they are not water-resistant and easily powderize in humid environments, losing their adhesive properties.

[0005] Numerous researchers have conducted research on gypsum-based tile adhesives, achieving fruitful results. Patent CN110510970A discloses a gypsum-based ceramic tile adhesive and its preparation method. The adhesive comprises 50%-80% gypsum, 15%-25% sand, 0.0%-0.5% retarder, 0.0%-0.5% anti-sagging, 0.0%-1% waterproofing, 2%-8% water-reducing, 0.0%-0.5% water-retaining, and 0.0%-8% thickening agent. The adhesive exhibits a tensile bond strength of 1.0 MPa and, after immersion in water, a tensile bond strength exceeding 0.56 MPa.

[0006] Patent CN113998975A discloses a gypsum-based tile adhesive material and its preparation method, belonging to the field of building materials technology. The raw materials of the gypsum-based tile adhesive material include, by weight, 50-55 parts of hemihydrate gypsum, 20-30 parts of steel slag or nickel slag aggregate, 10-15 parts of fly ash, 8-12 parts of cement, 2-4 parts of glue powder, 0.2-0.4 parts of water retaining agent, 0.4-0.6 parts of waterproofing agent, 0.05-0.15 parts of water reducing agent and 0.05-0.1 parts of retarder. All the raw materials are mixed evenly to prepare the gypsum-based tile adhesive material. The gypsum-based tile adhesive material has high early strength, good volume stability and good water resistance. Most of the raw materials used are industrial solid waste, which reduces the pressure on the ecological environment, realizes the recycling of industrial solid waste, and promotes the green transformation of building materials. Patent CN109336537B provides a tile adhesive comprising or consisting of the following components, by weight: 300-350 parts α-hemihydrate gypsum, 650-700 parts graded sand, 3-4 parts cellulose ether, 5-17 parts dispersible latex powder, 1-3 parts water reducer, 0.5-1 part gypsum retarder, 0-1 part starch ether, and 4-6 parts silicone hydrophobic agent. The gypsum-based tile adhesive material provided by the present invention, which uses α-hemihydrate gypsum as a binder, exhibits excellent bonding properties, meeting the technical requirements for tile adhesives.

[0007] The aforementioned prior arts require high levels of gypsum cementitious materials, essentially using hemihydrate gypsum or α-hemihydrate gypsum. Patents CN110510970A and CN113998975A both require gypsum cementitious materials at levels exceeding 50%. This increased proportion of fine components in tile adhesives can increase the risk of cracking. Patent CN109336537B utilizes α-hemihydrate gypsum, but its poor water resistance limits its application. Using gypsum in tile adhesives requires modification with appropriate admixtures and additives. Furthermore, tile adhesives formulated with α-hemihydrate gypsum offer no cost advantage over cement-based tile adhesives.

[0008] Therefore, it is a technical problem to be solved urgently to provide a method for preparing a gypsum-based tile adhesive material that can effectively utilize gypsum and at the same time meet the strength requirements of tile paving. Summary of the Invention

[0009] In response to the above-mentioned defects, the present invention provides a method for preparing a gypsum-based tile adhesive material, wherein a gypsum-based tile adhesive that meets the standards of ordinary cement-based tile adhesive (tile adhesive industry standard "Ceramic Tile Adhesive" JC / T 547-2017) is prepared by using a gypsum-based gel material, gypsum sand and functional additives. The method effectively solves the shortcomings of cement-based tile adhesive, such as large shrinkage and easy cracking and hollowing. It also makes the use of industrial by-product gypsum more extensive, complies with the national resource recycling economy concept, and expands the advantages of gypsum.

[0010] The invention provides a preparation method of a gypsum-based tile adhesive material. The raw materials of the gypsum-based tile adhesive material include gypsum-based gel material, gypsum sand, dispersible latex powder and cellulose ether; wherein the content of the gypsum-based gel material is within 40%.

[0011] Furthermore, the preparation method of the gypsum-based gel material includes:

[0012] Based on the total mass of the raw materials, the raw material percentage content of the gypsum-based gel material is: gypsum 65%-70%, slag 9.4%-24.8%, lime 2%-5%, mineral powder 8%-15%, water-soluble sulfate 0.05%-0.15%, water-soluble hydroxide 0.05%-0.2%, silicate 0.05%-0.2%, silicon phosphate 0.02%-0.05%, and zeolite 0.2-2%;

[0013] The preparation method comprises: uniformly mixing gypsum, slag, lime, mineral powder, water-soluble sulfate, water-soluble hydroxide, silicate, silicon phosphate and zeolite in proportion, grinding the mixture to a particle size of ≤0.037 mm, and preparing a gypsum-based gel material.

[0014] Furthermore, the gypsum is any one of desulfurized gypsum, phosphogypsum, fluorinated gypsum, titanium gypsum or other industrial by-product gypsums, or a combination of any two or more thereof.

[0015] Furthermore, the slag is any one of coal power plant slag and other industrial slag, or a combination of any two or more thereof.

[0016] Furthermore, the mineral powder is any one of powders obtained from fluorite tailings, nickel tailings, iron tailings or other tailings as raw materials, or a combination of any two or more thereof.

[0017] Furthermore, the water-soluble sulfate is any one of sodium sulfate, potassium sulfate, zinc sulfate or magnesium sulfate, or a combination of any two or more thereof.

[0018] Furthermore, the water-soluble hydroxide is sodium hydroxide or potassium hydroxide.

[0019] Furthermore, the silicate is any one of sodium silicate, potassium silicate or lithium silicate, or a combination of any two or more thereof.

[0020] Furthermore, the preparation method of the gypsum sand includes:

[0021] Based on the total mass of the raw materials, the percentage content of the raw materials of the gypsum sand is as follows: parent particles account for 5%-10%, main material 1 accounts for 65%-80%, main material 2 accounts for 10%-15%, auxiliary materials account for 2%-5%, ball-forming materials account for 3%-5%, and the balance is dispersant;

[0022] Mother particle: perlite filter aid with particle size ≤0.102mm;

[0023] Main material 1: any one of natural gypsum, desulfurized gypsum, phosphogypsum, fluorinated gypsum, titanium gypsum or other industrial by-product gypsum, or a mixture of any two or more;

[0024] Main material 2: any one of aluminate compounds, silica-alumina minerals, kaolin minerals, dolomite, soluble oxides, and aluminum oxide, or a mixture of any two or more thereof;

[0025] Auxiliary materials: active calcium, slaked lime, or a mixture of the two;

[0026] Pelletizing material: clay, lignin, cellulose or bentonite, or a mixture of any two or more, with particle size ≤ 0.048mm;

[0027] The preparation method comprises:

[0028] (1) Grinding: Grind the main material 1, main material 2, auxiliary material, and ball-forming material to 0.037±0.005mm respectively;

[0029] (2) Mud reaction: add the main material 1, main material 2, auxiliary material, and ball forming material into a suitable amount of water and put them into a stirring kettle for thorough stirring at a speed of 50-300 r / min for 5-10 minutes. At this time, all materials are fully dispersed in the water to form a slurry, and all materials can be fully contacted and mixed evenly.

[0030] (3) Dehydration: After the slurry reaction, the slurry is dehydrated by centrifugation, adsorption, and extrusion, and then dried at 150-250° C. to control the water content of the slurry to below 3% by mass to obtain a bulk material;

[0031] (4) Powdering: Grinding the bulk material into powder of 0.037±0.005 mm using a high-speed grinder at a speed of 3000-6000 r / min;

[0032] (5) Mother ball formation: the mother granules are poured into a round pot granulator, and water is sprayed through the water spray assembly of the granulator to form particles A. 1 / 3-1 / 2 of the total weight of the powder is added to the particles A, and the particles are continuously rotated rapidly in the ball mill to form mother balls;

[0033] (6) Sphere formation: The mother ball is continuously sprayed with water mist in the granulator while the remaining powder is added. As the ball mill rotates rapidly, the mother ball gradually grows larger to form a first sphere. No more water spraying is required at this point. Then, the dispersant is added to form a second spherical particle.

[0034] (7) Sieving: removing the coarse particles from the second spherical particles obtained in step (6) and leaving the particles with a mesh size of 40-140 for later use;

[0035] (8) Spheroidization: The 40-140 mesh particles obtained in step (7) are subjected to a spheroidization operation again to form a more rounded sphere, and the sphericity of the rounded sphere after the shaping operation reaches more than 98%;

[0036] (9) Curing: The round sphere obtained in step (8) is sent to a curing bin for curing, which is carried out in two stages: water spray curing and dry curing;

[0037] (10) The spherical particles obtained in step (9) are sieved to obtain gypsum sand, wherein the gypsum sand has a specification of 0.106 mm to 0.425 mm and an internal bulk density of 600 kg / m 3 -1400kg / m 3 , other indicators meet the requirements of GB / T 14684-2022 "Construction Sand".

[0038] Furthermore, in step (6), the particle size of the first sphere is 20-140 mesh.

[0039] Furthermore, in step (6), particles with a particle size of ≥0.425 mm are removed.

[0040] Furthermore, the curing in step (9) is as follows: the water mist curing lasts for 4-7 days, each water spraying lasts for 4 hours, once a day, and the curing chamber temperature is 15-25 degrees Celsius; the curing is transferred to the next curing chamber for dry curing, and the room temperature is maintained for dry curing for 11-14 days. The principle of the curing stage is: the gypsum in the raw materials and the gypsum reactant (main material 2) undergo a ceramic reaction to form ceramic spherical particles, so that the product has high strength and water resistance. The mass loss rate of the ceramic spherical particles is 5% (high strength), which meets the Class I standard requirements of GB / T 14684-2022 "Construction Sand". The softening coefficient is 0.76, which has high water resistance and has a high tensile strength effect when forming tile adhesive later.

[0041] Furthermore, the preparation method of the gypsum-based tile adhesive material includes:

[0042] Based on the total mass of the raw materials, the percentage content of the raw materials of the gypsum-based tile adhesive material is: 30%-40% of the gypsum-based gel material, 48.6%-69.5% of the gypsum sand, 0.3%-6% of the dispersed latex powder, and 0.2%-0.45% of the cellulose ether; the gypsum-based tile adhesive material is dry-mixed.

[0043] Furthermore, the dispersible latex powder is selected from any one of ethylene / vinyl acetate copolymer, vinyl acetate / versatate copolymer or acrylic acid copolymer, or a combination of any two thereof.

[0044] Furthermore, the cellulose ether is selected from any one of hydroxyethyl methyl cellulose, carboxymethyl cellulose, ethyl cellulose, benzyl cellulose, hydroxyethyl cellulose or hydroxypropyl methyl cellulose, or a combination of any two thereof.

[0045] Furthermore, during the use of the gypsum-based tile adhesive material, the gypsum-based gel material reacts with water to form a mullite structure and an ettringite phase, and the obtained tile adhesive layer has water-resistant properties. Its tensile bonding strength after immersion in water is greater than or equal to 1.3 MPa. The tensile bonding strength of ordinary cement-based tile adhesive of the same grade after immersion in water is 0.6-0.8 MPa.

[0046] The beneficial effects of the present invention are:

[0047] (1) The existing technologies basically use hemihydrate gypsum or α-hemihydrate gypsum, and the dosage of gypsum gel material reaches more than 50% (generally 50-80%). In order to solve the water resistance problem, waterproof components or water repellent components are introduced. This solution solves the water resistance problem, but does not limit the entry of moisture into the tile adhesive curing body. Therefore, as long as moisture enters, the water resistance strength of the tile adhesive will inevitably decrease;

[0048] Compared with the existing solutions, the technical solution of the present invention develops a gypsum-based gel material and uses gypsum sand as an aggregate. The dosage of the gypsum-based gel material in the final gypsum-based tile adhesive can be controlled at 30-45%. In addition, since the specially formulated gypsum-based gel material and gypsum sand are in a water environment, the aluminum and silicon compounds in the raw materials undergo a ceramic reaction in an alkaline environment to form ettringite structure (AFT) and / or calcium aluminate hydrate (CSH), thereby improving the density and water resistance of the tile adhesive curing slurry, and truly possessing water-resistant properties.

[0049] (2) The gypsum-based gel material and gypsum sand independently developed in the present invention achieve an ultra-high utilization rate of gypsum. The gypsum utilization rate in the preparation of the gypsum sand of the present invention reaches more than 70%, while the existing teaching materials on gypsum point out that the gypsum utilization rate is only 60%. Combined with the gypsum-based gel material independently developed in the present invention, the overall comprehensive utilization rate of gypsum in the gypsum-based tile adhesive of the present invention is more than 66%, which is much higher than the common 40-50% in the existing technology.

[0050] (3) The gypsum-based tile adhesive prepared from the gypsum sand and gypsum-based gel material in the present invention has significantly improved tensile bonding strength after immersion in water during use compared to the existing technical solutions. The tensile bonding strength of the gypsum-based tile adhesive in the technical solution of the present invention after immersion in water is above 1.2 MPa, while that of the existing technical solution is only 0.5 MPa, and even worse, it is lower than 0.5 MPa.

[0051] (4) The gypsum-based tile adhesive prepared from the gypsum sand and gypsum-based gel material of the present invention has a significantly lower recovery rate than the cement-based tile adhesive of the same grade. The shrinkage of the tile adhesive of the technical solution of the present invention is less than 0.15%, while that of the cement-based is more than 0.25%. Example

[0052] The invention is described in detail below with reference to the embodiments:

[0053] Example 1 A method for preparing a gypsum-based tile adhesive material, wherein the raw materials of the gypsum-based tile adhesive material include 35% gypsum-based gel material, 63.8% gypsum sand, 1% dispersible latex powder, and 0.2% cellulose ether; dry mixing is performed to form the gypsum-based tile adhesive material;

[0054] The preparation method of the gypsum-based gel material comprises:

[0055] The raw material percentage content of the gypsum-based gel material is as follows: desulfurized gypsum 70%, power plant blast furnace slag 10.4%, lime 5%, S95 slag 12%, potassium sulfate 0.15%, potassium hydroxide 0.2%, potassium silicate 0.2%, silicon phosphate 0.05%, and zeolite 2%, based on the total weight of the raw materials.

[0056] The preparation method includes uniformly mixing gypsum, slag, lime, mineral powder, water-soluble sulfate, water-soluble hydroxide, silicate, silicon phosphate, and zeolite in appropriate proportions, and grinding the mixture to a particle size of ≤0.037 mm to prepare a gypsum-based gel material. Upon reaction with water, the gel material forms mullite and ettringite phases, exhibiting waterproof properties, a 28-day compressive strength of ≥45 MPa, and a flexural strength of ≥2.5 MPa.

[0057] The preparation method of the gypsum sand comprises:

[0058] Based on the total mass of the raw materials, the percentage content of the raw materials of the gypsum sand is as follows: parent particles account for 8%, main material 1 accounts for 70%, main material 2 accounts for 12%, auxiliary materials account for 2%, ball-forming materials account for 5%, and the balance is a dispersant, and the dispersant is heavy calcium powder;

[0059] Mother particle: 8% of perlite filter aid with particle size ≤ 0.102mm;

[0060] Main material 1: desulfurization gypsum;

[0061] Main material 2: aluminate cement;

[0062] Auxiliary materials: active calcium;

[0063] Pellet material: lignin cellulose, particle size ≤ 0.048mm;

[0064] The preparation method comprises:

[0065] (1) Grinding: Grind the main material 1, main material 2, auxiliary material, and ball-forming material to 0.037 mm respectively;

[0066] (2) Mud reaction: add the main material 1, main material 2, auxiliary material, and ball forming material into a suitable amount of water and put them into a stirring kettle for thorough stirring at a speed of 100 r / min for 7 minutes. At this time, all materials are fully dispersed in the water to form a slurry, and all materials can be fully contacted and mixed evenly.

[0067] (3) Dehydration: After the slurry reaction, the slurry is dehydrated by centrifugation, adsorption, and extrusion, and then dried at 170° C. to control the water content of the slurry to below 3% by mass to obtain a bulk material;

[0068] (4) Powdering: Grinding the bulk material into powder of 0.037 mm using a high-speed grinder at a speed of 3000 r / min;

[0069] (5) Mother ball formation: the mother granules are poured into a round pot granulator, and water is sprayed through the water spray assembly of the granulator to form particles A. 1 / 3 of the total weight of the powder is added to the particles A, and the particles are continuously rotated rapidly in the ball mill to form mother balls;

[0070] (6) Sphere formation: The mother ball is continuously sprayed with water mist in the granulator while the remaining powder is added. As the ball mill rotates rapidly, the mother ball gradually grows larger to form a first sphere. No more water spraying is required at this point. Then, the dispersant is added to form a second spherical particle.

[0071] (7) Sieving: removing particles with a particle size of ≥0.425 mm from the second spherical particles obtained in step (6), and leaving particles with a size of 40-140 mesh for later use;

[0072] (8) Spheroidization: The 40-140 mesh particles obtained in step (7) are subjected to a spheroidization operation again to form a more rounded sphere, and the sphericity of the rounded sphere after the shaping operation reaches more than 98%;

[0073] (9) Curing: The round sphere obtained in step (8) is sent to a curing bin for curing, which is carried out in two stages: water spray curing and dry curing;

[0074] (10) The spherical particles obtained in step (9) are sieved to obtain gypsum sand, wherein the gypsum sand has a specification of 0.106 mm to 0.425 mm and an internal bulk density of 600 kg / m 3 -1400kg / m 3 . Other indicators meet the requirements of GB / T 14684-2022 "Construction Sand".

[0075] The curing in step (9) is as follows: the water mist curing lasts for 4 days, each water spraying lasts for 4 hours, and the curing chamber temperature is 15 degrees Celsius; the curing chamber is transferred to the next curing chamber for dry curing, and the room temperature is maintained for dry curing for 14 days. The principle of the curing stage is: the main material 1 and the main material 2 (which acts as a gypsum reactant) in the raw materials undergo a ceramic reaction to form ceramic spherical particles, so that the product has high strength and water resistance. The mass loss rate of the ceramic spherical particles is 5% (high strength), which meets the Class I standard requirements of GB / T 14684-2022 "Construction Sand". The softening coefficient is 0.76, which has high water resistance and has a high tensile strength when forming tile adhesive later.

[0076] Example 2 A method for preparing a gypsum-based tile adhesive material, wherein the raw materials of the gypsum-based tile adhesive material include 35% gypsum-based gel material, 63.8% gypsum sand, 1% dispersible latex powder, and 0.2% cellulose ether; dry mixing is performed to form the gypsum-based tile adhesive material;

[0077] The preparation method of the gypsum-based gel material comprises:

[0078] The raw material percentage content of the gypsum-based gel material is as follows: 65% phosphogypsum, 8.4% power plant blast furnace slag, 12% lime, 12% S95 mineral powder, 0.15% sodium sulfate, 0.2% sodium hydroxide, 0.2% sodium silicate, 0.05% silicon phosphate, and 2% zeolite, based on the total mass of the raw materials.

[0079] The preparation method includes uniformly mixing phosphogypsum, power plant blast furnace slag, lime, S95 mineral powder, sodium sulfate, sodium hydroxide, sodium silicate, and zeolite in appropriate proportions, and grinding the mixture to a particle size of ≤0.037 mm to prepare a gypsum-based gel material. Upon reaction with water, the gel material forms mullite and ettringite phases, exhibiting waterproof properties, a 28-day compressive strength of ≥45 MPa, and a flexural strength of ≥2.5 MPa.

[0080] The preparation method of the gypsum sand comprises:

[0081] Based on the total mass of the raw materials, the percentage content of the raw materials of the gypsum sand is as follows: parent particles account for 5%, main material 1 accounts for 70%, main material 2 accounts for 15%, auxiliary materials account for 2%, ball-forming materials account for 5%, and the balance is a dispersant, and the dispersant is heavy calcium powder;

[0082] Mother particle: particle size ≤ 0.102mm perlite filter aid 5%;

[0083] Main material 1: phosphogypsum;

[0084] Main material 2: Dolomite;

[0085] Auxiliary materials: calcium hydroxide;

[0086] Ball forming material: bentonite, particle size ≤0.048mm;

[0087] The preparation method comprises:

[0088] (1) Grinding: Grind the main material 1, main material 2, auxiliary material, and ball-forming material to 0.037 mm respectively;

[0089] (2) Mud reaction: add the main material 1, main material 2, auxiliary material, and ball forming material into a suitable amount of water and put them into a stirring kettle for thorough stirring at a speed of 300 r / min for 10 minutes. At this time, all materials are fully dispersed in the water to form a slurry, and all materials can be fully contacted and mixed evenly.

[0090] (3) Dehydration: After the slurry reaction, the slurry is dehydrated by centrifugation, adsorption, and extrusion, and then dried at 240° C. to control the water content of the slurry to below 3% by mass to obtain a bulk material;

[0091] (4) Powdering: Grinding the bulk material into powder of 0.037 mm using a high-speed grinder at a rotation speed of 4500 r / min;

[0092] (5) Mother ball formation: the mother granules are poured into a round pot granulator, and water is sprayed through the water spray assembly of the granulator to form particles A. 1 / 2 of the total weight of the powder is added to the particles A, and the particles are continuously rotated rapidly in the ball mill to form mother balls;

[0093] (6) Sphere formation: The mother ball is continuously sprayed with water mist in the granulator while the remaining powder is added. As the ball mill rotates rapidly, the mother ball gradually grows larger to form a first sphere. No more water spraying is required at this point. Then, the dispersant is added to form a second spherical particle.

[0094] (7) Sieving: removing particles with a particle size of ≥0.425 mm from the second spherical particles obtained in step (6), and leaving particles with a size of 40-140 mesh for later use;

[0095] (8) Spheroidization: The 40-140 mesh particles obtained in step (7) are subjected to a spheroidization operation again to form a more rounded sphere, and the sphericity of the rounded sphere after the shaping operation reaches more than 98%;

[0096] (9) Curing: The round sphere obtained in step (8) is sent to a curing bin for curing, which is carried out in two stages: water spray curing and dry curing;

[0097] (10) The spherical particles obtained in step (9) are sieved to obtain gypsum sand, wherein the gypsum sand has a specification of 0.106 mm to 0.425 mm and an internal bulk density of 600 kg / m 3 -1400kg / m 3 , other indicators meet the requirements of GB / T 14684-2022 "Construction Sand".

[0098] The curing in step (9) is as follows: the water mist curing lasts for 5 days, each water spraying lasts for 4 hours, and the curing chamber temperature is 25 degrees Celsius; the curing is transferred to the next curing chamber for dry curing, and the room temperature is maintained for dry curing for 12 days; the principle of the curing stage is: the gypsum in the raw material and the gypsum reactant (main material 2) undergo a ceramic reaction to form ceramic spherical particles, so that the product has high strength and water resistance, the mass loss rate of the ceramic spherical particles is 5% (high strength), which meets the Class I standard requirements of GB / T14684-2022 "Construction Sand", and the softening coefficient is 0.76 with high water resistance, which has a high tensile strength effect when forming tile adhesive later.

[0099] Example 3 A method for preparing a gypsum-based tile adhesive material, wherein the raw materials of the gypsum-based tile adhesive material include 35% gypsum-based gel material, 63.8% gypsum sand, 1% dispersible latex powder, and 0.2% cellulose ether; dry mixing is performed to form the gypsum-based tile adhesive material;

[0100] The preparation method of the gypsum-based gel material comprises:

[0101] The raw material percentage content of the gypsum-based gel material is as follows: 65% fluorgypsum, 8.4% power plant blast furnace slag, 12% lime, 12% mineral powder, 0.15% magnesium sulfate, 0.2% potassium hydroxide, 0.2% lithium silicate, 0.05% silicon phosphate, and 2% zeolite, based on the total weight of the raw materials.

[0102] The preparation method includes uniformly mixing fluorgypsum, power plant blast furnace slag, lime, mineral powder, magnesium sulfate, potassium hydroxide, lithium silicate, and zeolite in appropriate proportions, and grinding the mixture to a particle size of ≤0.037 mm to prepare a gypsum-based gel material. Upon reaction with water, the gel material forms mullite and ettringite phases, exhibiting waterproof properties, a 28-day compressive strength of ≥45 MPa, and a flexural strength of ≥2.5 MPa.

[0103] The preparation method of the gypsum sand comprises:

[0104] Based on the total mass of the raw materials, the percentage content of the raw materials of the gypsum sand is as follows: parent particles account for 5%, main material 1 accounts for 70%, main material 2 accounts for 12%, auxiliary materials account for 5%, ball-forming materials account for 5%, and the balance is a dispersant, and the dispersant is heavy calcium powder;

[0105] Mother particle: particle size ≤ 0.102mm perlite filter aid 5%;

[0106] Main material 1: phosphogypsum;

[0107] Main material 2: Dolomite;

[0108] Auxiliary materials: calcium hydroxide;

[0109] Ball forming material: bentonite, particle size ≤0.048mm;

[0110] The preparation method comprises:

[0111] (1) Grinding: Grind the main material 1, main material 2, auxiliary material, and ball-forming material to 0.037 mm respectively;

[0112] (2) Mud reaction: add the main material 1, main material 2, auxiliary material, and ball forming material into a suitable amount of water and put them into a stirring kettle for thorough stirring at a speed of 300 r / min for 10 minutes. At this time, all materials are fully dispersed in the water to form a slurry, and all materials can be fully contacted and mixed evenly.

[0113] (3) Dehydration: After the slurry reaction, the slurry is dehydrated by centrifugation, adsorption, and extrusion, and then dried at 240° C. to control the water content of the slurry to below 3% by mass to obtain a bulk material;

[0114] (4) Powdering: Grinding the bulk material into powder of 0.037 mm using a high-speed grinder at a rotation speed of 4500 r / min;

[0115] (5) Mother ball formation: the mother granules are poured into a round pot granulator, and water is sprayed through the water spray assembly of the granulator to form particles A. 1 / 2 of the total weight of the powder is added to the particles A, and the particles are continuously rotated rapidly in the ball mill to form mother balls;

[0116] (6) Sphere formation: The mother ball is continuously sprayed with water mist in the granulator while the remaining powder is added. As the ball mill rotates rapidly, the mother ball gradually grows larger to form a first sphere. No more water spraying is required at this point. Then, the dispersant is added to form a second spherical particle.

[0117] (7) Sieving: removing particles with a particle size of ≥0.425 mm from the second spherical particles obtained in step (6), and leaving particles with a size of 40-140 mesh for later use;

[0118] (8) Spheroidization: The 40-140 mesh particles obtained in step (7) are subjected to a spheroidization operation again to form a more rounded sphere, and the sphericity of the rounded sphere after the shaping operation reaches more than 98%;

[0119] (9) Curing: The round sphere obtained in step (8) is sent to a curing bin for curing, which is carried out in two stages: water spray curing and dry curing;

[0120] (10) The spherical particles obtained in step (9) are sieved to obtain gypsum sand, wherein the gypsum sand has a specification of 0.106 mm to 0.425 mm and an internal bulk density of 600 kg / m 3 -1400kg / m 3 , other indicators meet the requirements of GB / T 14684-2022 "Construction Sand".

[0121] The curing in step (9) is as follows: the water mist curing lasts for 5 days, each water spraying lasts for 4 hours, and the curing chamber temperature is 25 degrees Celsius; the curing is transferred to the next curing chamber for dry curing, and the room temperature is maintained for dry curing for 12 days; the principle of the curing stage is: the gypsum in the raw material and the gypsum reactant (main material 2) undergo a ceramic reaction to form ceramic spherical particles, so that the product has high strength and water resistance, the mass loss rate of the ceramic spherical particles is 5% (high strength), which meets the Class I standard requirements of GB / T14684-2022 "Construction Sand", and the softening coefficient is 0.76 with high water resistance, which has a high tensile strength effect when forming tile adhesive later.

[0122] Comparative Example 1

[0123] A cement-based tile adhesive has the following formula: 35% of PO42.5 ordinary Portland cement, 63.7% of graded river sand, 1% of dispersible latex powder, and 0.3% of cellulose ether.

[0124] Comparative Example 2

[0125] A gypsum-based tile adhesive has the following formula: 56.5% gypsum component, 25% river sand component, 0.5% animal protein retarder, 0.5% bentonite, 1% silicone waterproofing agent, 8% polycarboxylic acid, 0.5% hydroxymethyl cellulose ether with a viscosity of 60,000-100,000, and 8% polyvinyl alcohol.

[0126] The performance comparison is as follows:

[0127] project index Example 1 Example 2 Example 3 Comparison column 1 Comparison column 2 Tensile bond strength ≥0.5 0.98 1.21 0.98 0.88 0.89 Air-drying ≥20min, tensile bonding strength ≥0.5 0.77 0.78 0.79 0.62 0.57 Tensile bond strength after heat aging ≥0.5 1.02 1.34 1.01 0.90 0.92 Tensile bond strength after immersion in water ≥0.5 0.76 0.73 0.79 0.66 0.56 Tensile bond strength after freeze-thaw cycles ≥0.5 0.83 0.80 0.84 0.79 0.64 Shrinkage rate‰ 1.03 1.01 1.06 2.6 1.02

[0128] Based on the contents of the above table, it can be seen that the samples of the present invention have the following advantages compared with similar products of the comparative example:

[0129] 1) The gypsum-based tile adhesive of the present invention solves the water resistance problem of existing gypsum-based tile adhesives, and its water resistance is 0.2 MPa higher than that of the prior art;

[0130] (2) The utilization rate of industrial waste gypsum by the gypsum-based tile adhesive of the present invention reaches more than 85%. Gypsum sand and gypsum-based gel materials cooperate with each other and are utilized together, ultimately achieving a gypsum-based gel material content in the overall material within 40%;

[0131] (3) The shrinkage rate of the gypsum-based tile adhesive of the present invention is significantly lower than that of the cement-based tile adhesive, with a shrinkage rate of more than 78% lower than that of the cement-based adhesive and a strength of more than 0.4 MPa higher;

[0132] (4) The gypsum-based tile adhesive of the present invention adopts a new preparation process, gypsum sand, and gypsum cementitious material. These two materials are prepared through compatibility design and have good controllability.

[0133] The above description is merely a preferred embodiment of the present invention and does not constitute any other form of limitation to the present invention. Any modification or equivalent variation based on the technical essence of the present invention shall still fall within the scope of protection claimed by the present invention.

Claims

1. A method for preparing a gypsum-based tile adhesive material, characterized in that: The raw materials of the gypsum-based tile adhesive material include gypsum-based gel material, gypsum sand, dispersible latex powder, and cellulose ether; wherein the content of the gypsum-based gel material is within 40%; Based on the total mass of the raw materials, the raw material percentage content of the gypsum-based gel material is: gypsum 65%-70%, slag 9.4%-24.8%, lime 2%-5%, mineral powder 8%-15%, water-soluble sulfate 0.05%-0.15%, water-soluble hydroxide 0.05%-0.2%, silicate 0.05%-0.2%, silicon phosphate 0.02%-0.05%, zeolite 0.2%-2%, and the sum of the above raw materials is 100%; Based on the total mass of the raw materials, the percentage content of the raw materials of the gypsum sand is as follows: parent particles account for 5%-10%, main material 1 accounts for 65%-80%, main material 2 accounts for 10%-15%, auxiliary materials account for 2%-5%, ball-forming materials account for 3%-5%, and the balance is dispersant; Mother particle: perlite filter aid with particle size ≤0.102mm; Main material 1: any one of natural gypsum, desulfurized gypsum, phosphogypsum, fluorinated gypsum, titanium gypsum or other industrial by-product gypsum, or a mixture of any two or more; Main material 2: any one of aluminate compounds, silica-alumina minerals, kaolin minerals, dolomite, soluble oxides, and aluminum oxide, or a mixture of any two or more thereof; Auxiliary materials: active calcium, slaked lime, or a mixture of the two; Pelletizing material: any one of clay, lignin cellulose or bentonite, or a mixture of any two or more thereof, with particle size ≤0.048mm.

2. The preparation method according to claim 1, characterized in that The preparation method of the gypsum-based gel material comprises: Gypsum, slag, lime, mineral powder, water-soluble sulfate, water-soluble hydroxide, silicate, silicon phosphate and zeolite are uniformly mixed according to proportion, and ground to a particle size of ≤0.037 mm to prepare a gypsum-based gel material.

3. The preparation method according to claim 2, characterized in that The gypsum is any one of desulfurized gypsum, phosphogypsum, fluorinated gypsum, titanium gypsum or other by-product gypsums of other industries, or a combination of any two or more thereof.

4. The preparation method according to claim 2, characterized in that The slag is any one of coal power plant slag and other industrial slags, or a combination of any two or more thereof.

5. The preparation method according to claim 2, characterized in that The mineral powder is any one of powders obtained from fluorite tailings, nickel tailings, iron tailings or other tailings as raw materials, or a combination of any two or more of them.

6. The preparation method according to claim 2, characterized in that The water-soluble sulfate is any one of sodium sulfate, potassium sulfate, zinc sulfate or magnesium sulfate, or a combination of any two or more thereof.

7. The preparation method according to claim 2, characterized in that The water-soluble hydroxide is sodium hydroxide or potassium hydroxide.

8. The preparation method according to claim 2, characterized in that The silicate is any one of sodium silicate, potassium silicate or lithium silicate, or a combination of any two or more thereof.

9. The preparation method according to claim 2, characterized in that The preparation method of the gypsum sand comprises: (1) Grinding: Grind the main material 1, main material 2, auxiliary material, and ball-forming material to 0.037±0.005mm respectively; (2) Mud reaction: add the main material 1, main material 2, auxiliary material, and ball forming material into a suitable amount of water and put them into a stirring kettle for full stirring at a speed of 50-300 r / min for 5-10 minutes. At this time, all kinds of materials are fully dispersed in the water to form a slurry, and all materials can be fully contacted and mixed evenly. (3) Dehydration: After the slurry reaction, the slurry is dehydrated by centrifugation, adsorption, and extrusion, and then dried at 150-250°C to control the water content of the slurry to be below 3% by mass to obtain a bulk material; (4) Powdering: Grind the bulk material into powder of 0.037±0.005 mm by a high-speed grinder at a speed of 3000-6000 r / min; (5) Mother ball formation: the mother granules are poured into a round pot granulator, and water is sprayed through the water spray assembly of the granulator to form particles A. 1 / 3-1 / 2 of the total weight of the powder is added to the particles A, and the particles are continuously rotated rapidly in the ball mill to form mother balls; (6) Sphere formation: The mother ball is continuously sprayed with water mist in the granulator while the remaining powder is added. As the ball mill rotates rapidly, the mother ball gradually grows larger to form the first sphere. No more water spraying is required at this point. Then, the dispersant is added to form the second spherical particles. (7) Sieving: removing the coarse particles from the second spherical particles obtained in step (6) and leaving the particles with a mesh size of 40-140 for later use; (8) Spheroidization: The 40-140 mesh particles obtained in step (7) are subjected to a spheroidization operation again to form a more rounded sphere. The sphericity of the rounded sphere after the shaping operation reaches more than 98%; (9) Curing: The round sphere obtained in step (8) is sent to the curing bin for curing, which is carried out in two stages: water spray curing and dry curing; (10) The spherical particles obtained in step (9) are sieved to obtain gypsum sand, wherein the gypsum sand has a specification of 0.106 mm to 0.425 mm and an internal bulk density of 600 kg / m 3 -1400kg / m 3 .

10. The preparation method according to claim 9, characterized in that The particle size of the first sphere in step (6) is 20-140 mesh.

11. The preparation method according to claim 9, characterized in that In the step (6), particles with a particle size of ≥0.425 mm are removed.

12. The preparation method according to claim 9, characterized in that The curing in step (9) is as follows: the water mist curing lasts for 4-7 days, each water spraying lasts for 4 hours, and the curing chamber temperature is 15-25 degrees Celsius; the curing is transferred to the next curing chamber for dry curing, and the dry curing is maintained at room temperature for 11-14 days; the principle of the curing stage is: the main material 1 and the main material 2 in the raw materials undergo a ceramic reaction to form ceramic spherical particles, the mass loss rate of the ceramic spherical particles is 5%, and the softening coefficient is 0.

76.

13. The preparation method according to claim 9, characterized in that The preparation method of the gypsum-based tile adhesive material comprises: Based on the total mass of the raw materials, the percentage content of the raw materials of the gypsum-based tile adhesive material is: 30%-40% of the gypsum-based gel material, 48.6%-69.5% of the gypsum sand, 0.3%-6% of the dispersed latex powder, and 0.2%-0.45% of the cellulose ether; the gypsum-based tile adhesive material is dry-mixed.