Toughened compression-resistant gypsum batten and preparation method thereof

Abstract

The invention discloses a toughened compression-resistant gypsum batten and a preparation method thereof.The gypsum batten is prepared from phosphogypsum, light calcium carbonate, semi-hydrated phosphogypsum, modified diatomite, modified elastomer particles, composite fibers, a retarder, a water reducing agent and water. The preparation method of the gypsum batten comprises the following steps that S1, the modified diatomite is prepared; the preparation method comprises the following steps: S1, preparing phosphogypsum, S2, preparing modified elastic particles, S3, preparing composite fibers, S4, stirring the phosphogypsum, light calcium carbonate, semi-hydrated phosphogypsum, the modified diatomite, the modified elastomer particles, the composite fibers, a retarder, a water reducing agent and water into uniform mixed slurry, pouring the mixed slurry into a mold, and carrying out extrusion molding, solidification, cutting, drying and edge sawing to obtain the toughened compression-resistant gypsum batten. Through filling and adsorption effects of the light calcium carbonate, the semi-hydrated phosphogypsum and the modified diatomite and a three-dimensional network structure of the composite fibers, the compactness and the compression resistance of the gypsum batten are jointly improved.

Description

Technical Field

[0001] The invention relates to the technical field of gypsum strip boards, and in particular to a toughened compression-resistant gypsum strip board and a preparation method thereof. Background Art

[0002] Phosphogypsum is a by-product of phosphate fertilizer production. Its main component is calcium sulfate hemihydrate (CaSO 4 1 / 2H 2 O). Due to its wide source and low cost, phosphogypsum is widely used as a building material, especially for the preparation of gypsum strips. However, the traditional gypsum strips prepared with phosphogypsum have the disadvantage of insufficient strength. The compressive strength and flexural strength of the traditional phosphogypsum strips are low. The reason is that phosphogypsum is a by-product of the production process of phosphate fertilizers. Its chemical composition contains a certain amount of impurities, such as unreacted phosphates, fluorides, etc. These impurities may affect the integrity of gypsum crystals and the mechanical properties of the strips. At the same time, due to the irregular crystal morphology of phosphogypsum, the uneven size and distribution of phosphogypsum crystals will lead to uneven internal structure of the strips, thereby affecting its strength. Therefore, in order to increase the structural strength of the phosphogypsum strips, fiber materials will be added in appropriate amounts or the phosphogypsum will be modified during the production of the phosphogypsum strips to increase the toughness and compressive resistance of the phosphogypsum.

[0003] Based on the above situation, in the prior art, the patent with publication number CN117985995A discloses a lightweight reinforced gypsum board and a preparation method thereof, wherein the preparation method comprises: (1) weighing phosphogypsum, desulfurized gypsum, talcum powder, light calcium carbonate, expanded vermiculite, modified starch, fiber powder, tourmaline, activated carbon, citric acid, water reducer and water for later use; (2) mixing phosphogypsum with desulfurized gypsum, talcum powder and light calcium carbonate, then adding water, stirring and mixing evenly, The mixed slurry A is obtained; (3) adding expanded vermiculite, modified starch, fiber powder and citric acid to the mixed slurry A obtained in step (2), heating to 55-65°C, stirring and mixing evenly, keeping the mixture at a temperature of 1-2 hours, then adding tourmaline, activated carbon and a water reducing agent, stirring and mixing evenly, and obtaining gypsum slurry; (4) pouring the gypsum slurry obtained in step (3) into a template, curing it, heating and drying it, and after the moisture is completely removed, the lightweight reinforced gypsum board is obtained.

[0004] However, the gypsum board in the above patent still has some shortcomings when used. The above gypsum board has the problem of insufficient structural strength. Although the addition of lightweight fillers such as expanded vermiculite helps to reduce the overall density, the particles of expanded vermiculite, talcum powder and light calcium carbonate are large and cannot effectively fill the gaps left after the crystallization of phosphogypsum and desulfurized gypsum, resulting in insufficient overall density of the gypsum board. When the gypsum board is subjected to greater pressure, these lightweight fillers may easily deform or break, thereby affecting the overall compressive resistance. At the same time, additives such as modified starch and fiber powder can improve the toughness of the gypsum board to a certain extent, but these two materials cannot effectively form a network structure in the gypsum board, thereby limiting the improvement of the toughness of the gypsum board. Summary of the invention

[0005] In view of the technical defects existing in the background technology, the present invention proposes a toughened and compressive gypsum board and a preparation method thereof, which solves the above technical problems and meets the actual needs. The specific technical solution is as follows: A toughened and compression-resistant gypsum strip board comprises the following components in parts by weight: 80-90 parts of phosphogypsum, 20-30 parts of light calcium carbonate, 20-30 parts of hemihydrate phosphogypsum, 10-15 parts of modified diatomaceous earth, 15-20 parts of modified elastomer particles, 5-10 parts of composite fibers, 0.1-5 parts of retarder, 0.1-5 parts of water reducer, and 50-200 parts of water. The composite fibers are prepared by cross-linking glass fibers and chitosan fibers modified by amino coupling agents through glutaraldehyde, and the modified elastomer particles comprise elastic particles and magnetic particles loaded on the surfaces of the elastic particles.

[0006] Furthermore, the metal oxide is selected from one or more of iron oxide, magnesium oxide, zinc oxide or lanthanum oxide, and the metal oxide is preferably zinc oxide.

[0007] Furthermore, the elastic particles are selected from one or more of EPDM rubber, nitrile rubber, TPE, and polyurethane, and the elastic particles are preferably nitrile rubber. The magnetic particles are nano-ferrosoferric oxide particles.

[0008] Furthermore, the water reducer is selected from one or more of polycarboxylate water reducer, melamine water reducer, naphthalenesulfonate water reducer, aminosulfonate high-efficiency water reducer and melamine water reducer, and the retarder is selected from one or more of sodium hexametaphosphate, sodium polyphosphate, citric acid, sodium citrate, tartaric acid and potassium tartrate.

[0009] A method for manufacturing a toughened and compressive gypsum board comprises the following steps: S1. Prepare modified diatomite, put diatomite into a metal salt solution, slowly add sodium hydroxide solution under stirring, filter after the reaction is completed to obtain a diatomite intermediate, wash and calcine the diatomite intermediate to obtain modified diatomite.

[0010] S2. Prepare modified elastic particles, dissolve the amino coupling agent in a methanol aqueous solution, then add nano-ferroferric oxide particles to obtain a magnetic solution, spray the magnetic solution on the surface of the elastomer particles to obtain an elastic particle intermediate, dry the elastic particle intermediate, and obtain modified elastic particles.

[0011] S3. Preparation of composite fibers, S31. Etching the glass fiber with a sodium hydroxide solution to obtain an etched glass fiber, dissolving the amino coupling agent in an aqueous solution of methanol to obtain an aqueous solution of the amino coupling agent in methanol, adding the etched glass fiber to the aqueous solution of the amino coupling agent in methanol and stirring for a period of time, then filtering out the etched glass fiber, washing it, and obtaining a modified glass fiber.

[0012] S32. Place chitosan fiber and modified glass fiber into a beaker containing deionized water, heat, adjust pH to 8-9.5, then drop glutaraldehyde solution, wait for the reaction to complete, filter, and obtain a composite fiber intermediate. The composite fiber intermediate is washed and dried to obtain a composite fiber.

[0013] S4. The phosphogypsum, light calcium carbonate, hemihydrate phosphogypsum, modified diatomaceous earth, modified elastomer particles, composite fiber, retarder, water and water are stirred into a uniform mixed slurry, and the mixed slurry is poured into a mold with a vibrator, and then electromagnets are respectively installed at the top and bottom positions of the mold, and the vibrator and the electromagnet are turned on at the same time. Under the attraction of the electromagnets, the modified elastic particles are respectively concentrated to the top and bottom positions of the mold, and the mixed slurry in the mold is extruded, solidified, cut, dried, and sawed to obtain a gypsum strip board.

[0014] Furthermore, in step S2 and step S31, the amino coupling agent is selected from any one of 3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane or 3-aminopropyltriethoxysilane.

[0015] Further, in step S1, a 1.0-3.0 mol / L metal salt solution is prepared, diatomaceous earth with a particle size of 100-200 microns is placed in the metal salt solution, and 0.1-0.5 mol / L sodium hydroxide solution is slowly added dropwise under stirring conditions. After the reaction is completed, it is filtered to obtain a diatomaceous earth intermediate, and the diatomaceous earth intermediate is washed with 2-3 times the volume of deionized water, and then calcined at 200-500° C. to obtain modified diatomaceous earth; the metal salt solution is any one of a ferric nitrate solution, a magnesium nitrate solution, a zinc nitrate solution, and a lanthanum nitrate solution, and the volume ratio of the diatomaceous earth to the metal salt solution is 1:10-20.

[0016] Furthermore, in step S2, the particle size of the elastomeric particles obtained by crushing is 200-500 microns, the weight percentage of each component in the magnetic solution is: amino coupling agent 1%-5%, methanol 67%-79%, deionized water 10%-15%, nano-ferrosoferric oxide 5%-10%, and the drying method of the elastic particle intermediate is: drying at room temperature for 12-24 hours, and then drying at 200°C for 1-2 hours.

[0017] Furthermore, in step S31, the glass fiber and the sodium hydroxide solution are heated and immersed in a beaker, the mass ratio of the glass fiber ball to the sodium hydroxide solution is 1:100-200, the concentration of the sodium hydroxide solution is 0.2-1.0 mol / L, the heating temperature is 70-100°C, and the immersion time is 60-120 min; the etched glass fiber is added to 5-10 times the volume of the aqueous solution of amino coupling agent in methanol, and stirred and immersed for 30-60 min, and then the etched glass fiber is filtered out, washed, and dried to obtain modified glass fiber, and the weight percentage of each component in the aqueous solution of amino coupling agent in methanol is: amino coupling agent 1%-5%, methanol 80%-85%, deionized water 10%-5%.

[0018] Furthermore, in step S32, 2.0 g of chitosan fiber and modified glass fiber are respectively weighed, put into a beaker containing 100 ml of deionized water, stirred and heated to 50°C, 0.1 mol / L sodium hydroxide solution is used to adjust the pH to 8.0, and then 5-10 ml of a 40-50% mass fraction glutaraldehyde aqueous solution is slowly added under stirring conditions, reacted for 5-10 hours, filtered, and a composite fiber intermediate is obtained. The composite fiber intermediate is washed and dried to obtain a composite fiber.

[0019] The beneficial effects of the present invention are: The modified diatomaceous earth of the present invention can effectively capture phosphate ions, hydrogen phosphate ions and fluoride ions in phosphogypsum, and prevent them from combining with calcium ions in phosphogypsum to generate insoluble substances, thereby avoiding the adhesion of insoluble substances on the surface of phosphogypsum particles, thereby reducing the dispersed particle size of phosphogypsum particles in water, and significantly improving the density and compressive strength of gypsum strips; the modified elastic particles of the present invention not only retain the flexibility of the original elastic particles, but also have magnetic properties, so that in the process of forming the gypsum strips, the modified elastic particles can be concentratedly distributed on the upper and lower surfaces of the strips under the action of the magnetic field, thereby further enhancing the compressive performance of the material; the present invention The composite fiber is formed by cross-linking glass fiber modified by an amino coupling agent and chitosan fiber through glutaraldehyde, and can construct a three-dimensional network structure in the gypsum matrix, effectively improving the toughness of the material and providing additional strength and durability for the gypsum board; the semi-hydrated phosphogypsum of the present invention is converted into dihydrate calcium sulfate during the hydration process, which can effectively fill the gaps left between the phosphogypsum during the solidification process, further improving the density and compressive resistance of the gypsum board; the addition of light calcium carbonate not only reduces the density of the overall material, but also further enhances the density and compressive resistance of the gypsum board through its micro-aggregate effect and filling effect. DETAILED DESCRIPTION

[0020] The implementation mode of the present invention is described below in conjunction with relevant embodiments. The implementation mode of the present invention is not limited to the following embodiments, and the present invention relates to relevant necessary components in the technical field, which should be regarded as the known technology in the technical field and can be known and mastered by the technical personnel in the technical field.

[0021] A toughened and compression-resistant gypsum strip board comprises the following components in parts by weight: 80-90 parts of phosphogypsum, 20-30 parts of light calcium carbonate, 20-30 parts of hemihydrate phosphogypsum, 10-15 parts of modified diatomaceous earth, 15-20 parts of modified elastomer particles, 5-10 parts of composite fibers, 0.1-5 parts of retarder, 0.1-5 parts of water reducer, and 50-200 parts of water. The composite fibers are prepared by cross-linking glass fibers and chitosan fibers modified by amino coupling agents through glutaraldehyde, and the modified elastomer particles comprise elastic particles and magnetic particles loaded on the surfaces of the elastic particles.

[0022] The present invention utilizes the adsorption effect of modified diatomaceous earth on harmful ions such as phosphate ions, hydrogen phosphate ions and fluoride ions in phosphogypsum, effectively avoiding the reaction of these ions with calcium ions to generate insoluble substances, thereby maintaining the good dispersibility of gypsum particles in water and increasing the density of the gypsum matrix. The introduction of modified elastomer particles not only retains the flexibility of the elastic particles, but also realizes concentrated distribution on the upper and lower surfaces of the gypsum strips during the molding process through their magnetic properties, thereby enhancing the resistance of the gypsum strips when under pressure. At the same time, the flexibility of the elastic particles also provides the gypsum strips with additional deformation resistance, making it less likely to undergo brittle fracture when subjected to external forces. The dihydrated calcium sulfate formed after the hemihydrate phosphogypsum is hydrated further fills the gaps generated during the solidification process, thereby improving the overall structure of the material. The composite fiber is made of glass fiber modified by amino coupling agent and chitosan fiber cross-linked by glutaraldehyde. The composite fiber forms a three-dimensional network structure in the gypsum board, which can effectively disperse and absorb external force impact, improve the crack resistance and toughness of the material, and light calcium carbonate is used as a filler. Through its micro-aggregate effect and filling effect, it reduces the porosity in the gypsum matrix and improves the density of the material. The synergistic effect of modified diatomaceous earth, modified elastomer particles and composite fibers further refines the microstructure of the material, so that the gypsum board can maintain high strength and toughness while maintaining a low density. The addition of retarder and water reducer can optimize the fluidity and workability of the gypsum slurry, making the material smoother during mixing, pouring and molding, reducing the processing difficulty and improving production efficiency.

[0023] The present invention uses phosphogypsum and hemihydrate gypsum as the main components of the gypsum strip board, providing the main structural support. The phosphogypsum forms a hard skeleton structure during the hydration process. At the same time, through the adsorption of modified diatomite, the influence of harmful ions is reduced, and the smooth progress of the hydration process is guaranteed. The hemihydrate phosphogypsum has a high hydration activity and can react with water quickly to generate calcium sulfate dihydrate. In this process, calcium sulfate dihydrate crystals gradually grow and fill between phosphogypsum particles to form a dense phosphogypsum system, thereby improving the density and strength of the gypsum strip board. The modified diatomite has a large specific surface area and rich pore structure, and can adsorb and fix harmful ions such as phosphate ions, hydrogen phosphate ions and fluoride ions. At the same time, the load of metal oxides further enhances its adsorption capacity, so that the modified diatomite plays a purification role in the gypsum strip board.

[0024] Light calcium carbonate as a filler not only reduces the overall density of the material, but also enhances the density and compressive resistance of the gypsum board. Light calcium carbonate particles are small and uniform. On the one hand, they can fill the larger gaps between gypsum particles, reduce porosity, and increase the density of the material. On the other hand, because of its own hardness, it can improve the hardness of the gypsum board to a certain extent. At the same time, its micro-aggregate effect can disperse stress and prevent local stress concentration, thereby improving compressive resistance.

[0025] The modified elastomer particles not only retain the flexibility of the elastic particles, but also achieve concentrated distribution during the molding process through magnetic effects, thereby enhancing the compressive resistance and toughness of the gypsum strips. The nano-iron tetroxide particles give the elastic particles magnetism, so that under the action of electromagnets, the modified elastic particles can be directionally arranged on the upper and lower surfaces of the gypsum strips. The upper and lower surfaces are the areas where the force is most concentrated, thereby improving the compressive resistance of the material as a whole.

[0026] The composite fibers form a three-dimensional network structure in the gypsum matrix, effectively improving the toughness and crack resistance of the material. The composite fibers are made of glass fibers modified by amino coupling agents and chitosan fibers cross-linked by glutaraldehyde, and have good mechanical properties and chemical stability. They are intertwined in the gypsum matrix to form a three-dimensional network structure, which can effectively prevent the expansion and extension of cracks, thereby improving the toughness and crack resistance of the gypsum board.

[0027] As one of the preferred embodiments of the present invention, the metal oxide is selected from one or more of iron oxide, magnesium oxide, zinc oxide or lanthanum oxide, and the metal oxide is preferably zinc oxide.

[0028] The modified diatomite prepared by the present invention is a composite material of diatomite loaded with zinc oxide. Diatomite itself is a porous natural mineral material with a high specific surface area. The microporous structure on its surface provides a large number of active sites for the adsorption of phosphate radicals. Zinc oxide is loaded on the surface of diatomite by a coprecipitation method to form a diatomite-zinc oxide composite adsorbent, thereby increasing the adsorption capacity for particles such as phosphate radicals. The introduction of zinc oxide not only increases the active sites of the adsorbent, but also may enhance the adsorption capacity for phosphate radicals by changing the charge properties of the diatomite surface or forming a new adsorption mechanism. The Zn on the surface of zinc oxide 2+ It can form a coordination bond with the oxygen atom in the phosphate group, thereby achieving the adsorption of the phosphate group.

[0029] As one of the preferred embodiments of the present invention, the elastic particles are selected from one or more of EPDM rubber, nitrile rubber, TPE, and polyurethane, the elastic particles are preferably nitrile rubber, and the magnetic particles are nano-ferrosoferric oxide particles.

[0030] The modified elastic particles prepared by the present invention are composite materials of nitrile rubber particles loaded with nano-ferroferric oxide. The nitrile rubber (NBR) has good elasticity and toughness, and can provide effective stress dispersion and energy absorption in the gypsum strip board, thereby enhancing the crack resistance and impact resistance of the entire material. At the same time, the nitrile rubber has good chemical corrosion resistance and can resist the corrosion of oils, solvents and some acidic and alkaline substances, which enables the nitrile rubber to maintain stable performance in the gypsum strip board and is not easy to age or degrade. The nano-ferroferric oxide (Fe 3 O 4 ) particles have excellent magnetic responsiveness and can move and position quickly under the action of an external magnetic field. In the preparation process of gypsum strips, this characteristic enables the modified elastic particles to be concentrated on the upper and lower surfaces of the gypsum strips under the action of electromagnets, forming an enhanced boundary layer, thereby improving the overall compressive performance of the material. At the same time, nano-iron tetroxide particles have a higher specific surface area and surface activity, and can form a stronger binding force with the surface of elastic particles, improving the stability and durability of the modified elastic particles.

[0031] As one of the preferred embodiments of the present invention, the water reducer is selected from one or more of polycarboxylate water reducer, melamine water reducer, naphthalenesulfonate water reducer, aminosulfonate high-efficiency water reducer and melamine water reducer, and the retarder is selected from one or more of sodium hexametaphosphate, sodium polyphosphate, citric acid, sodium citrate, tartaric acid and potassium tartrate.

[0032] The water reducer is preferably a polycarboxylate water reducer, and the retarder is sodium hexametaphosphate. Sodium hexametaphosphate is used to adjust the setting time of the gypsum slurry to ensure the smooth progress of the pouring and molding process. Sodium hexametaphosphate can slow down the rate of hydration reaction in the gypsum slurry, thereby extending the setting time. This allows construction personnel to have enough time to perform pouring, vibration and molding operations, and improve the quality of the gypsum strips. The polycarboxylate water reducer is used to improve the fluidity and workability of the gypsum slurry, reduce water consumption, and improve the density and strength of the gypsum strips. The polycarboxylate water reducer can be adsorbed on the surface of the gypsum particles to form a lubricating film, reduce the friction and resistance between the particles, and make the gypsum slurry smoother during stirring and pouring. At the same time, the water reducer can also reduce water consumption and improve the density and strength of the material.

[0033] A method for manufacturing a toughened and compressive gypsum board comprises the following steps: S1. Prepare modified diatomite, put diatomite into a metal salt solution, slowly add sodium hydroxide solution under stirring, filter after the reaction is completed to obtain a diatomite intermediate, wash and calcine the diatomite intermediate to obtain modified diatomite.

[0034] S2. Prepare modified elastic particles, dissolve the amino coupling agent in a methanol aqueous solution, then add nano-ferroferric oxide particles to obtain a magnetic solution, spray the magnetic solution on the surface of the elastomer particles to obtain an elastic particle intermediate, dry the elastic particle intermediate, and obtain modified elastic particles.

[0035] S3. Preparation of composite fibers, S31. Etching the glass fiber with a sodium hydroxide solution to obtain an etched glass fiber, dissolving the amino coupling agent in an aqueous solution of methanol to obtain an aqueous solution of the amino coupling agent in methanol, adding the etched glass fiber to the aqueous solution of the amino coupling agent in methanol and stirring for a period of time, then filtering out the etched glass fiber, washing it, and obtaining a modified glass fiber.

[0036] S32. Place chitosan fiber and modified glass fiber into a beaker containing deionized water, heat, adjust pH to 8-9.5, then drop glutaraldehyde solution, wait for the reaction to complete, filter, and obtain a composite fiber intermediate. The composite fiber intermediate is washed and dried to obtain a composite fiber.

[0037] S4. The phosphogypsum, light calcium carbonate, hemihydrate phosphogypsum, modified diatomaceous earth, modified elastomer particles, composite fiber, retarder, water and water are stirred into a uniform mixed slurry, and the mixed slurry is poured into a mold with a vibrator, and then electromagnets are respectively installed at the top and bottom positions of the mold, and the vibrator and the electromagnet are turned on at the same time. Under the attraction of the electromagnets, the modified elastic particles are respectively concentrated to the top and bottom positions of the mold, and the mixed slurry in the mold is extruded, solidified, cut, dried, and sawed to obtain a gypsum strip board.

[0038] As one of the preferred embodiments of the present invention, in step S2 and step S31, the amino coupling agent is any one of 3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane or 3-aminopropyltriethoxysilane.

[0039] The amino coupling agent is preferably 3-aminopropyltriethoxysilane. In step S2, 3-aminopropyltriethoxysilane acts as a film-forming material. 3-aminopropyltriethoxysilane is dissolved in an aqueous solution of methanol, and then nano-ferroferric oxide particles are added to obtain a magnetic solution. The magnetic solution is sprayed on the surface of the elastomer particles to obtain an elastic particle intermediate. The elastic particle intermediate is dried to allow 3-aminopropyltriethoxysilane to react with moisture and oxygen in the air to hydrolyze hydroxyl groups. Among these hydroxyl groups, some hydroxyl groups are condensed with each other, and the other part of the hydroxyl groups are chemically bonded with the nano-ferroferric oxide particles, thereby forming a magnetic film layer on the surface of the elastomer particles, and the nano-ferroferric oxide particles are loaded onto the surface of the elastomer particles through 3-aminopropyltriethoxysilane, thereby obtaining modified elastic particles.

[0040] In step S31, 3-aminopropyltriethoxysilane reacts with hydroxyl groups on the surface of the etched glass fiber, so that the surface of the etched glass fiber is grafted with amino groups through 3-aminopropyltriethoxysilane, and the amino groups react with glutaraldehyde solution to achieve crosslinking with chitosan fiber.

[0041] As one of the preferred embodiments of the present invention, in step S1, a 1.0-3.0 mol / L metal salt solution is prepared, diatomaceous earth with a particle size of 100-200 microns is placed in the metal salt solution, and 0.1-0.5 mol / L sodium hydroxide solution is slowly added dropwise under stirring conditions. After the reaction is completed, it is filtered to obtain a diatomaceous earth intermediate, and the diatomaceous earth intermediate is washed with 2-3 times the volume of deionized water, and then calcined at 200-500° C. to obtain modified diatomaceous earth; the metal salt solution is any one of a ferric nitrate solution, a magnesium nitrate solution, a zinc nitrate solution, and a lanthanum nitrate solution, and the volume ratio of the diatomaceous earth to the metal salt solution is 1:10-20.

[0042] In step S1, first prepare a 1.0 mol / L zinc nitrate solution, put diatomaceous earth with a particle size of 200 microns into the zinc nitrate solution, the volume ratio of diatomaceous earth to zinc nitrate solution is 1:20, and slowly add 0.1 mol / L sodium hydroxide solution under stirring conditions. After the reaction is completed, filter to obtain a diatomaceous earth intermediate, wash the diatomaceous earth intermediate with 3 times the volume of deionized water, and then calcine at 200° C. for 12 hours to obtain modified diatomaceous earth.

[0043] As one of the preferred embodiments of the present invention, in step S2, the particle size of the elastomeric particles obtained by crushing is 200-500 microns, the weight percentage of each component in the magnetic solution is: amino coupling agent 1%-5%, methanol 67%-79%, deionized water 10%-15%, nano-ferrosoferric oxide 5%-10%, and the drying method of the elastic particle intermediate is: drying at room temperature for 12-24 hours, and then drying at 200°C for 1-2 hours.

[0044] In step S2, the elastomer is crushed by a pulverizer to a particle size of 300 μm, and the elastic particles are modified. A magnetic solution is prepared according to a weight ratio of 1% amino coupling agent, 79% methanol, 15% deionized water, and 5% nano-ferroferric oxide. The amino coupling agent is dissolved in an aqueous solution of methanol, and then nano-ferroferric oxide particles are added to obtain a magnetic solution. The magnetic solution is sprayed on the surface of the elastomer particles to obtain an elastic particle intermediate. The elastic particle intermediate is dried at room temperature for 24 hours, and then dried at 200°C for 1 hour to obtain modified elastic particles.

[0045] As one of the preferred embodiments of the present invention, in step S31, the glass fiber and the sodium hydroxide solution are heated and immersed in a beaker, the mass ratio of the glass fiber ball to the sodium hydroxide solution is 1:100-200, the concentration of the sodium hydroxide solution is 0.2-1.0 mol / L, the heating temperature is 70-100°C, and the immersion time is 60-120 min; the etched glass fiber is added to an aqueous solution of 5-10 times the volume of the amino coupling agent in methanol, and stirred and immersed for 30-60 min, and then the etched glass fiber is filtered out, washed, and dried to obtain a modified glass fiber, and the amino coupling agent in methanol is added to the aqueous solution of 5-10 times the volume of the amino coupling agent in methanol. The weight percentages of the components in the aqueous solution are: 1%-5% amino coupling agent, 80%-90% methanol, and 10%-5% deionized water; in step S32, 2.0 g of chitosan fiber and modified glass fiber are weighed respectively, put into a beaker containing 100 ml of deionized water, stirred and heated to 50°C, 0.1 mol / L sodium hydroxide solution is used to adjust the pH to 8.0, and then 5-10 ml of a 40-50% mass fraction glutaraldehyde aqueous solution is slowly added under stirring conditions, reacted for 5-10 hours, filtered, and a composite fiber intermediate is obtained. The composite fiber intermediate is washed and dried to obtain a composite fiber.

[0046] In step S31, a glass fiber with a diameter of 30 microns and a length of 15 mm and a sodium hydroxide solution are heated and immersed in a beaker, the mass ratio of the glass fiber to the sodium hydroxide solution is 1: 200, the concentration of the sodium hydroxide solution is 0.2 mol / L, the heating temperature is 70°C, and the immersion time is 60 min; the etched glass fiber is added to an aqueous solution of 10 times the volume of an amino coupling agent in methanol, and stirred and immersed for 30 min, and then the etched glass fiber is filtered out, washed, and dried to obtain a modified glass fiber, and the weight percentage of each component in the aqueous solution of amino coupling agent in methanol is: 1% amino coupling agent, 89% methanol, and 10% deionized water; in step S32, The diameter of the chitosan fiber is 20 microns and the length is 10 mm. 2.0 g of chitosan fiber and modified glass fiber are weighed respectively, put into a beaker containing 100 ml of deionized water, stirred and heated to 50°C, and 0.1 mol / L sodium hydroxide solution is used to adjust the pH to 8.0. Then, 5 ml of a 50% by mass glutaraldehyde aqueous solution is slowly added under stirring, reacted for 10 hours, filtered, and a composite fiber intermediate is obtained. The composite fiber intermediate is washed and dried to obtain a composite fiber.

[0047] Example 1

[0048] 80 parts of phosphogypsum, 20 parts of light calcium carbonate, 20 parts of hemihydrate phosphogypsum, 10 parts of modified diatomaceous earth, 15 parts of modified elastomer particles, 5 parts of composite fiber, 0.1 part of retarder, 0.1 part of water reducer and 100 parts of water are mixed and stirred into a uniform mixed slurry, and the mixed slurry is poured into a mold with a vibrator, and then electromagnets are respectively installed at the top and bottom positions of the mold, and the vibrator and the electromagnet are turned on at the same time. Under the attraction of the electromagnets, the modified elastic particles are respectively concentrated to the top and bottom positions of the mold, and the mixed slurry in the mold is extruded, solidified, cut, dried, and sawed to obtain a gypsum strip board, and then the gypsum strip board is subjected to a compression test. The test method is GB / T9775-2008, and the thickness of the tested gypsum strip board is 1 cm.

[0049] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that modified diatomaceous earth is not added in Comparative Example 1, and the remaining preparation steps are the same as those of Example 1.

[0050] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that no modified elastic particles are added in Comparative Example 2, and the remaining preparation steps are the same as those of Example 1.

[0051] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that no composite fiber is added in Comparative Example 3, and the remaining preparation steps are the same as those in Example 1.

[0052] Comparative Example 4 The difference between Comparative Example 4 and Example 1 is that hemihydrate phosphogypsum is not added in Comparative Example 4, and the remaining preparation steps are the same as those in Example 1.

[0053] The compression test results of Example 1 and Comparative Examples 1-4 are shown in the following table.

[0054] By comparing Example 1 and Comparative Example 1, it can be seen that after the modified diatomite is not added, the flexural strength (transverse and longitudinal), hardness and shear force of the gypsum strip board are all reduced. This shows that the modified diatomite plays an important role in enhancing the compressive performance, hardness and flexural strength of the gypsum strip board. The modified diatomite adsorbs harmful ions (such as phosphate ions, hydrogen phosphate ions and fluoride ions) in the phosphogypsum, reducing the possibility of them reacting with calcium ions to generate insoluble substances, thereby improving the density and overall strength of the gypsum strip board. By comparing the data of Example 1 and Comparative Example 2, it can be seen that after the modified elastomer particles are not added, the flexural strength, hardness and shear force of the gypsum strip board are significantly reduced. This proves that the concentrated distribution caused by the magnetic effect of the modified elastomer particles has a significant effect on enhancing the compressive performance and toughness of the gypsum strip board. The modified elastomer particles not only retain the flexibility of the elastic particles, but also achieve concentrated distribution on the upper and lower surfaces of the gypsum strip board through magnetic action, thereby further improving the compressive performance of the material. By comparing Example 1 and Comparative Example 3, without adding composite fibers, the mechanical properties of the gypsum board decrease, especially the flexural strength and hardness. This fully illustrates the important role of composite fibers in gypsum boards. Composite fibers can form a three-dimensional network structure in the gypsum matrix, effectively improving the toughness and overall strength of the material. The data comparison between Example 1 and Comparative Example 4 shows that the addition of hemihydrate phosphogypsum has a positive effect on the compressive properties and hardness of the gypsum board. Hemihydrate phosphogypsum forms calcium sulfate dihydrate through hydration, which can fill the gaps between phosphogypsum particles and increase the density and compressive properties of the gypsum board.

[0055] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A toughened and compressive gypsum board, It is characterized in that The invention comprises the following components in parts by weight: 80-90 parts of phosphogypsum, 20-30 parts of light calcium carbonate, 20-30 parts of hemihydrate phosphogypsum, 10-15 parts of modified diatomaceous earth, 15-20 parts of modified elastomer particles, 5-10 parts of composite fibers, 0.1-5 parts of retarder, 0.1-5 parts of water reducer and 50-200 parts of water. The composite fibers are prepared by cross-linking glass fibers and chitosan fibers modified by amino coupling agents through glutaraldehyde. The modified elastomer particles comprise elastic particles and magnetic particles loaded on the surface of the elastic particles.

2. The toughened and compressive gypsum board according to claim 1, It is characterized in that The metal oxide is selected from one or more of iron oxide, magnesium oxide, zinc oxide or lanthanum oxide, and the metal oxide is preferably zinc oxide.

3. The toughened and compressive gypsum board according to claim 1, It is characterized in that The elastic particles are selected from one or more of EPDM, nitrile rubber, TPE, and polyurethane. The elastic particles are preferably nitrile rubber. The magnetic particles are nano-ferrosoferric oxide particles.

4. The toughened and compressive gypsum board according to claim 1, It is characterized in that The water reducer is selected from one or more of polycarboxylate water reducer, melamine water reducer, naphthalenesulfonate water reducer, aminosulfonate high-efficiency water reducer and melamine water reducer, and the retarder is selected from one or more of sodium hexametaphosphate, sodium polyphosphate, citric acid, sodium citrate, tartaric acid and potassium tartrate.

5. A method for manufacturing the toughened compression-resistant gypsum board according to any one of claims 1 to 4, It is characterized in that The following steps are involved: S1. preparing modified diatomaceous earth, placing diatomaceous earth in a metal salt solution, slowly dropping a sodium hydroxide solution under stirring conditions, filtering after the reaction is completed to obtain a diatomaceous earth intermediate, and washing and calcining the diatomaceous earth intermediate to obtain modified diatomaceous earth; S2. preparing modified elastic particles, dissolving an amino coupling agent in an aqueous solution of methanol, and then adding nano-iron tetroxide particles to obtain a magnetic solution, spraying the magnetic solution on the surface of the elastomer particles to obtain an elastic particle intermediate, and drying the elastic particle intermediate to obtain a modified elastic particle; S3. Preparation of composite fibers, S31. The glass fiber is etched using a sodium hydroxide solution to obtain an etched glass fiber, the amino coupling agent is dissolved in an aqueous solution of methanol to obtain an aqueous solution of the amino coupling agent in methanol, the etched glass fiber is added to the aqueous solution of the amino coupling agent in methanol and stirred for a period of time, and then the etched glass fiber is filtered out and washed to obtain a modified glass fiber; S32. The chitosan fiber and the modified glass fiber were placed in a beaker containing deionized water, heated, adjusted to pH = 8-9.5, and then glutaraldehyde solution was added dropwise, and the reaction was completed, filtered to obtain a composite fiber intermediate, the composite fiber intermediate was washed and dried to obtain a composite fiber; S4. The phosphogypsum, light calcium carbonate, hemihydrate phosphogypsum, modified diatomaceous earth, modified elastomer particles, composite fiber, retarder, water and water are stirred into a uniform mixed slurry, and the mixed slurry is poured into a mold with a vibrator, and then electromagnets are respectively installed at the top and bottom positions of the mold, and the vibrator and the electromagnet are turned on at the same time. Under the attraction of the electromagnets, the modified elastic particles are respectively concentrated to the top and bottom positions of the mold, and the mixed slurry in the mold is extruded, solidified, cut, dried, and sawed to obtain a gypsum strip board.

6. The method for manufacturing the toughened compression-resistant gypsum board according to claim 5, It is characterized in that In step S2 and step S31, the amino coupling agent is any one of 3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane or 3-aminopropyltriethoxysilane.

7. The method for manufacturing the toughened compression-resistant gypsum board according to claim 5, It is characterized in that In step S1, a 1.0-3.0 mol / L metal salt solution is prepared, diatomaceous earth with a particle size of 100-200 microns is placed in the metal salt solution, and a 0.1-0.5 mol / L sodium hydroxide solution is slowly added dropwise under stirring conditions. After the reaction is completed, the diatomaceous earth intermediate is filtered to obtain the diatomaceous earth intermediate, and the diatomaceous earth intermediate is washed with 2-3 times the volume of deionized water, and then calcined at 200-500° C. to obtain modified diatomaceous earth; The metal salt solution is any one of ferric nitrate solution, magnesium nitrate solution, zinc nitrate solution and lanthanum nitrate solution, and the volume ratio of the diatomaceous earth to the metal salt solution is 1:10-20.

8. The method for manufacturing the toughened compression-resistant gypsum board according to claim 5, It is characterized in that In step S2, the particle size of the crushed elastomer particles is 200-500 microns, the weight percentage of each component in the magnetic solution is: amino coupling agent 1%-5%, methanol 67%-79%, deionized water 10%-15%, nano-ferrosoferric oxide 5%-10%, and the drying method of the elastic particle intermediate is: drying at room temperature for 12-24 hours, and then drying at 200°C for 1-2 hours.

9. The method for manufacturing the toughened compression-resistant gypsum board according to claim 6, It is characterized in that In step S31, the glass fiber and the sodium hydroxide solution are heated and immersed in a beaker, the mass ratio of the glass fiber ball to the sodium hydroxide solution is 1:100-200, the concentration of the sodium hydroxide solution is 0.2-1.0 mol / L, the heating temperature is 70-100° C., and the immersion time is 60-120 min; The etched glass fiber is added to an aqueous solution of amino coupling agent in methanol with a volume of 5-10 times, and stirred and immersed for 30-60 minutes, and then the etched glass fiber is filtered out, washed, and dried to obtain a modified glass fiber, wherein the weight percentage of each component in the aqueous solution of amino coupling agent in methanol is: 1%-5% amino coupling agent, 80%-85% methanol, and 10%-5% deionized water.

10. The method for manufacturing the toughened and compressive gypsum board according to claim 6, It is characterized in that In step S32, 2.0 g of chitosan fiber and modified glass fiber are weighed respectively, put into a beaker containing 100 ml of deionized water, stirred and heated to 50°C, 0.1 mol / L sodium hydroxide solution is used to adjust the pH to 8.0, and then 5-10 ml of a 40-50% mass fraction glutaraldehyde aqueous solution is slowly added under stirring conditions, reacted for 5-10 hours, filtered, and a composite fiber intermediate is obtained. The composite fiber intermediate is washed and dried to obtain a composite fiber.

Images