Fiber polymer titanium gypsum mortar and preparation method thereof

Abstract

The invention discloses fiber polymer titanium gypsum mortar and a preparation method thereof. The fiber polymer titanium gypsum mortar is prepared from the following raw materials in parts by weight: 40 to 60 parts of titanium gypsum, 40 to 60 parts of sand, 10 to 15 parts of alkaline additive, 0.5 to 1 part of sodium sulfate, 2 to 3 parts of quick lime, 0.1 to 3 parts of plant fiber, 1 to 2 parts of cellulose ether, 0.2 to 2 parts of water reducing agent, 1 to 5 parts of redispersible latex powder and 0.1 to 2 parts of retarder. The doped plant fiber raw material is wide in source, so that the impermeability and the crack resistance of the gypsum mortar are effectively improved, and meanwhile, the construction performance is improved. The titanium gypsum is only dried and does not need to be calcined, certain additives and plant fibers are added, the high-water-resistance gypsum mortar with the titanium gypsum as a main cementing material is obtained, an energy-saving and environment-friendly product with good mechanical properties is provided, and meanwhile the high-water-resistance gypsum mortar has the advantages of being low in production cost, wide in raw material source and good in water resistance.

Description

Technical Field

[0001] This invention belongs to the field of building materials technology, and relates to the technology for the resource utilization of titanium gypsum waste, specifically to a fiber polymer titanium gypsum mortar and its preparation method. Background Technology

[0002] In industry, quicklime is typically added to neutralize the acidic wastewater generated during titanium dioxide production, resulting in a large amount of titanium gypsum, an industrial byproduct. This titanium gypsum is almost never utilized, not only occupying a large amount of land but also easily polluting the surrounding environment, posing serious environmental problems.

[0003] Currently, desulfurized gypsum, phosphogypsum, and fluorogypsum are generally used as cementing materials to produce gypsum mortar. Chemically modified titanium gypsum and fibers are rarely used to produce titanium gypsum mortar. Moreover, it generally requires long-term high-temperature calcination, which often results in high energy consumption, many impurities, and poor water resistance of the product, making it difficult to apply widely.

[0004] Chinese patent application CN201610663138 discloses a titanium gypsum straw fiber lightweight aggregate concrete and its preparation method. It uses titanium gypsum, cement, fly ash, quicklime, straw fiber, expanded perlite, polycarboxylic acid, and sodium polyacrylate as raw materials to prepare a straw fiber concrete with simple manufacturing process, low density, and good thermal insulation performance. However, the straw fiber concrete has insufficient waterproofing, crack resistance, and impact resistance. In addition, the industrial by-product titanium gypsum contains certain impurities and needs to be harmlessly treated before it can be comprehensively utilized as a resource. Summary of the Invention

[0005] The technical problem to be solved by the present invention is that existing titanium gypsum cannot be directly used as building cement mortar, and has the disadvantages of low strength and high energy consumption in the calcination process. In addition, the water resistance and crack resistance of general titanium gypsum mortar are poor. Therefore, a high water resistance titanium gypsum building cement mortar and its preparation method are provided.

[0006] To solve the above problems, the present invention is achieved through the following technical solution: A fiber polymer titanium plaster mortar, comprising the following raw materials in parts by weight: Titanium plaster: 40-60 parts Sand: 40-60 parts Alkaline additive: 10-15 parts Sodium sulfate: 0.5-1 part quicklime: 2-3 parts Plant fiber: 0.1-3 parts Cellulose ether: 1-2 parts Water-reducing agent: 0.2-2 parts Redispersible latex: 1-5 parts Retarder: 0.1-2 parts.

[0007] The titanium gypsum mentioned is a byproduct of titanium dioxide production, a waste residue mainly composed of calcium sulfate dihydrate. It is produced through washing, chemical modification, filtration, drying, crushing, grinding, and sieving to form titanium gypsum powder. Initial washing separates impurities such as iron, magnesium, and aluminum salts. Then, citric acid is added to react with ferric ions to generate ferrous ions, further reducing the iron ion concentration, causing the titanium gypsum to gradually turn white. The filtered titanium gypsum is dried at 80℃-250℃ for 4-8 hours to reduce its moisture content. It is then ground in a ball mill at 3000-8000 rpm for 3-6 hours, passing through a sieve of 300 mesh or finer, with an attached water content ≤1%.

[0008] The main components of the titanium gypsum, by mass percentage, are: SiO2 2.23%, Fe2O3 7.92%, Al2O3 1.34%, CaO 28.7%, MgO 2.45%, SO3 36.7%, TiO2 1.36%, with a loss of 19.3%.

[0009] The fineness of the manufactured sand is between 100 and 120 mesh.

[0010] The alkaline additives mentioned are ordinary silicate cement and sulfoaluminate cement.

[0011] The lime, whose main component is CaO, is an alkaline activator, and sodium sulfate is a sulfate activator. Both help to improve the early strength of gypsum mortar.

[0012] The plant fiber mentioned is one of bamboo fiber, sisal fiber, ramie fiber, flax fiber, and abaca fiber, with a length of 5mm-10mm.

[0013] The cellulose ether is one of hydroxypropyl methylcellulose, hydroxyethyl methylcellulose, hydroxyethyl cellulose, and sodium carboxymethyl cellulose.

[0014] The redispersible latex powder is one of ethylene-vinyl acetate latex powder, vinyl acetate-ethylene tert-carbonate latex powder, and acrylic latex powder.

[0015] The retarder is one of sodium hexametaphosphate, citric acid, and sodium citrate.

[0016] The water-reducing agent is one of the following: sodium lignosulfonate water-reducing agent, naphthalene-based high-efficiency water-reducing agent, aliphatic high-efficiency water-reducing agent, amino high-efficiency water-reducing agent, and polycarboxylate high-efficiency water-reducing agent.

[0017] A method for preparing a fiber polymer titanium gypsum mortar includes the following steps: Step (1): Weigh and set aside: Weigh out titanium gypsum powder, sand, alkaline additives, plant fiber, sodium sulfate, quicklime, purified water, cellulose ether, water-reducing agent, redispersible latex powder, and retarder in sequence according to the proportions. Step (2): Mixing and stirring: Add the titanium gypsum powder, sand, sodium sulfate, quicklime and alkaline additive prepared in step (1) evenly to the mixer, start the motor and stir for about 10 minutes to make the materials evenly mixed; then add the cellulose ether, water-reducing agent, redispersible latex powder, retarder and purified water selected in step (1) to the mixer, control the water-cement ratio at 0.3-0.6, start the motor and stir for about 5 minutes; finally add the plant fiber prepared in step (1) to the mixer, start the motor and stir at low speed for about 5 minutes, then stir at high speed for about 10 minutes to make the materials evenly mixed.

[0018] Step (3): Product shaping: The materials prepared in step (2) are packaged and shaped to obtain the product.

[0019] This invention has the following characteristics: (1) This invention adopts non-calcination modification technology, removes impurities in titanium gypsum waste residue through chemical modification and filtration and washing, and obtains titanium gypsum powder through drying, crushing, grinding and sieving. It is an energy-saving, environmentally friendly, low-cost and low-risk technology product.

[0020] (2) The fiber polymer titanium gypsum mortar of the present invention has good workability and water retention; the plaster layer hardens quickly and has a short curing cycle; after construction, it has strong adhesion, does not shrink, does not hollow, and has a smooth and flat surface.

[0021] (3) The plant fibers added in this invention can effectively improve the mechanical properties of mortar, enhance its crack resistance and impermeability, and improve its water resistance, toughness, and adhesion. The flexibility of the fibers themselves and the three-dimensional network structure formed after mixing with other materials can effectively reduce the drying shrinkage of mortar during the drying process, thereby improving the crack resistance of the mortar. In addition, the three-dimensional spatial structure can lock 2-6 times its own weight of water in the middle, which has a certain water retention effect; at the same time, it has good thixotropy. When subjected to external force (such as scraping or stirring), the structure will change and align along the direction of movement, releasing water, reducing viscosity, and improving workability, which can improve construction performance and effectively solve the problems of cracking and water seepage caused by poor water resistance in traditional mortar. It reduces the generation and development of cracks and improves the overall performance of mortar. Detailed Implementation

[0022] Specific embodiments of the present invention are described below.

[0023] Example 1 A fiber polymer titanium plaster mortar, comprising the following components in parts by weight: Titanium plaster: 40 parts; Sand: 40 parts; Ordinary Portland cement: 10 parts; Bamboo fiber: 2 parts; length 5mm-10mm; Sodium sulfate: 0.5 parts; Quicklime: 2 parts; Cellulose ether (hydroxypropyl methylcellulose): 0.5 parts; Polycarboxylate superplasticizer: 1 part; Redispersible latex (acrylic latex powder): 3.5 parts Retarder (citric acid): 0.5 parts.

[0024] The preparation method of this fiber polymer titanium gypsum mortar includes the following steps: Step (1): Using industrial byproducts, mainly CaSO4·2H2O, obtained during the titanium dioxide production process as raw materials, gypsum and impurities such as iron, magnesium, and aluminum salts are separated through preliminary washing. Then, citric acid is added to react with ferric ions to generate ferrous ions, further reducing the iron ion concentration, and the titanium gypsum gradually turns white. The filtered titanium gypsum is dried at 130℃ for 5 hours to reduce its moisture content. Titanium gypsum powder was obtained by grinding in a ball mill at 4000 rpm for 2 hours and passing through a 400-mesh sieve. Its main components by mass percentage are: SiO2 2.23%, Fe2O3 7.92%, Al2O3 1.34%, CaO 28.7%, MgO 2.45%, SO3 36.7%, TiO2 1.36%, with a loss of 19.3%. Cement and sand were crushed in a pulverizer at 3200 rpm for 2.5 hours and passed through a 300-mesh sieve to obtain sand and cement powder with a specific surface area of ​​415 m³ / kg, respectively. Step (2): Weighing for later use: Weigh out titanium gypsum powder, sand, alkaline additives, plant fiber, sodium sulfate, quicklime, purified water, cellulose ether, water-reducing agent, redispersible latex powder, and retarder in sequence according to the proportions. Step (3): Mixing and stirring: Add the titanium gypsum powder, sand, sodium sulfate, quicklime and alkaline additive prepared in step (1) evenly to the mixer, start the motor and stir for about 10 minutes to make the materials evenly mixed; then add the cellulose ether, water-reducing agent, redispersible latex powder, retarder and purified water selected in step (1) to the mixer, control the water-cement ratio at 0.5, start the motor and stir for about 5 minutes; finally add the plant fiber prepared in step (1) to the mixer, start the motor and stir at low speed for about 5 minutes, then stir at high speed for about 10 minutes to make the materials evenly mixed.

[0025] Step (4): Product shaping: Package the material prepared in step (3) into shape to obtain the product.

[0026] Example 2 A fiber polymer titanium plaster mortar, comprising the following components in parts by weight: Titanium plaster: 45 parts; Sand: 35 parts; Ordinary Portland cement: 10 parts; Sisal fiber: 1 part; length 5mm-10mm; Sodium sulfate: 0.5 parts; Quicklime: 2 parts; Cellulose ether (hydroxypropyl methylcellulose): 1 part; Polycarboxylate superplasticizer: 0.5 parts; Redispersible latex (acrylic latex powder): 3 parts Retarder (citric acid): 1 part.

[0027] The preparation method of this fiber polymer titanium gypsum mortar includes the following steps: Step (1): Using industrial byproducts mainly composed of CaSO4·2H2O obtained during the production of titanium dioxide as raw materials, gypsum and impurities such as iron salts, magnesium salts, and aluminum salts are separated through preliminary washing. Then, citric acid is added to react with ferric ions to generate ferrous ions, further reducing the iron ion concentration, and the titanium gypsum gradually turns white. The filtered titanium gypsum is dried at 130℃ for 5 hours to reduce its moisture content. It is then ground in a ball mill at 3500 rpm for 3 hours and passed through a 400-mesh sieve to obtain titanium gypsum powder. Cement and sand are pulverized in a pulverizer at 3500 rpm for 3 hours and passed through a 300-mesh sieve to obtain sand and cement powder with a specific surface area of ​​415 m³ / Kg, respectively. Step (2): Weighing for later use: Weigh out titanium gypsum powder, sand, alkaline additives, plant fiber, sodium sulfate, quicklime, purified water, cellulose ether, water-reducing agent, redispersible latex powder, and retarder in sequence according to the proportions. Step (3): Mixing and stirring: Add the titanium gypsum powder, sand, sodium sulfate, quicklime and alkaline additive prepared in step (1) evenly to the mixer, start the motor and stir for about 10 minutes to make the materials evenly mixed; then add the cellulose ether, water-reducing agent, redispersible latex powder, retarder and purified water selected in step (1) to the mixer, control the water-cement ratio at 0.4, start the motor and stir for about 4 minutes; finally add the plant fiber prepared in step (1) to the mixer, start the motor and stir at low speed for about 4 minutes, then stir at high speed for about 8 minutes to make the materials evenly mixed.

[0028] Step (4): Product shaping: Package the material prepared in step (3) into shape to obtain the product.

[0029] Example 3 A fiber polymer titanium plaster mortar, comprising the following components in parts by weight: Titanium plaster: 45 parts; Sand: 42.5 parts; Ordinary Portland cement: 10 parts; Flax fiber: 2 parts; length 5mm-10mm; Sodium sulfate: 0.5 parts; Quicklime: 2 parts; Cellulose ether (hydroxypropyl methylcellulose): 0.3 parts; Polycarboxylate superplasticizer: 0.5 parts; Redispersible latex (acrylic latex powder): 2 parts Retarder (citric acid): 0.2 parts The preparation method of this fiber polymer titanium gypsum mortar includes the following steps: Step (1): Using industrial byproducts mainly composed of CaSO4·2H2O obtained during the production of titanium dioxide as raw materials, gypsum and impurities such as iron salts, magnesium salts, and aluminum salts are separated through preliminary washing. Then, citric acid is added to react with ferric ions to generate ferrous ions, further reducing the iron ion concentration, and the titanium gypsum gradually turns white. The filtered titanium gypsum is dried at 180℃ for 2 hours to reduce its moisture content. It is then ground in a ball mill at 4000 rpm for 2 hours and passed through a 300-mesh sieve to obtain titanium gypsum powder. Cement and sand are pulverized in a pulverizer at 3400 rpm for 0 hours and passed through a 300-mesh sieve to obtain sand and cement powder with a specific surface area of ​​400 m³ / Kg, respectively. Step (2): Weighing for later use: Weigh out titanium gypsum powder, sand, alkaline additives, plant fiber, sodium sulfate, quicklime, purified water, cellulose ether, water-reducing agent, redispersible latex powder, and retarder in sequence according to the proportions. Step (3): Mixing and stirring: Add the titanium gypsum powder, sand, sodium sulfate, quicklime and alkaline additive prepared in step (1) evenly to the mixer, start the motor and stir for about 10 minutes to make the materials evenly mixed; then add the cellulose ether, water-reducing agent, redispersible latex powder, retarder and purified water selected in step (1) to the mixer, control the water-cement ratio at 0.6, start the motor and stir for about 7 minutes; finally add the plant fiber prepared in step (1) to the mixer, start the motor and stir at low speed for about 5 minutes, then stir at high speed for about 12 minutes to make the materials evenly mixed.

[0030] Step (4): Product shaping: Package the material prepared in step (3) into shape to obtain the product.

[0031] Comparative Example 1 A titanium gypsum straw fiber lightweight aggregate concrete comprises the following components in parts by weight: Titanium plaster: 50 parts Cement: 20 parts fly ash: 5 parts quicklime: 3 parts Straw fiber: 3 parts, length 20mm-25mm Expanded perlite: 1 part Polycarboxylic acid: 0.5 parts Sodium polyacrylate: 0.5 parts.

[0032] The titanium gypsum has a water content of 50% and a CaSO4·H2O mass percentage of 70%. The cement is 42.5 ordinary Portland cement with a fineness (80 μm) of 2.5% and a specific surface area of ​​375 m². 2 / kg. The fly ash is Class I fly ash for power plants, with a fineness (80μm) of 8.5% and a loss on ignition of 3.51%. The quicklime has a mass percentage of ≥90.0%, an overburning rate of ≤10%, and a fineness of 150 mesh.

[0033] Specifically, the steps include the following: Step (1) Wet the expanded perlite with water for 24 hours; Step (2) Add cement, fly ash, quicklime, straw fiber and sodium polyacrylate into a mixer and mix for 2 minutes. Then add titanium gypsum and polycarboxylate and mix for 2 minutes. Finally add the expanded perlite obtained in step 1 and mix for 2 minutes to obtain titanium gypsum straw fiber lightweight aggregate concrete.

[0034] Comparative Example 2 The only difference is that the plant fiber is replaced with straw fiber (20mm-25mm in length), and the rest of the components and processes are the same as in Example 2.

[0035] The bamboo fiber, sisal fiber, and other plant fibers used in this invention have higher tensile strength than traditional straw fibers. The shorter length of these plant fibers can fill the pores in the titanium gypsum mortar material, preventing cracking and thus improving the tensile bond strength of the titanium gypsum mortar. The plant fibers used in this invention have numerous pores on their surface; after uniform mixing, they can effectively inhibit the drying shrinkage of the titanium gypsum mortar, thus preventing cracking and ensuring early water permeability. Furthermore, excessively long or excessive amounts of straw fibers can lead to clumping and balling, resulting in insufficient binding material in the titanium gypsum mortar, thereby affecting the product's mechanical properties.

[0036] Performance testing: According to GB / T 28627-2012 and JGJ / T 70-2009, the titanium gypsum mortar materials prepared by the above embodiments were subjected to strength tests, and the performance of the obtained samples is shown in Table 1.

[0037] Table 1 Performance test results of titanium gypsum mortar The titanium gypsum used in this invention undergoes chemical modification and filtration / washing to remove impurities from the titanium gypsum waste. The filtered titanium gypsum is then dried at 130℃ for 5 hours to reduce its moisture content. The plant fibers added in this invention effectively improve the mechanical properties of the mortar, enhance its crack resistance and impermeability, increase its water resistance, toughness, and adhesion, reduce the generation and development of cracks, and improve the overall performance of the mortar.

[0038] As shown in Table 1, the fiber polymer titanium gypsum mortar of this invention possesses good mechanical properties, water retention rate, and bonding performance, improving workability and effectively solving problems such as easy cracking and water seepage caused by poor water resistance in traditional gypsum mortar. It provides an effective way for the resource utilization of titanium gypsum waste and can be widely applied in the field of building materials.

[0039] The embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A fiber polymer titanium gypsum mortar, characterized in that, The raw materials, by weight, include: titanium gypsum: 40-60 parts, sand: 40-60 parts, alkaline additives: 10-15 parts, sodium sulfate: 0.5-1 parts, quicklime: 2-3 parts, plant fiber: 0.1-3 parts, cellulose ether: 1-2 parts, water-reducing agent: 0.2-2 parts, redispersible latex powder: 1-5 parts, and retarder: 0.1-2 parts.

2. The fiber polymer titanium gypsum mortar according to claim 1, characterized in that, The titanium gypsum is a powder made from industrial by-products, mainly CaSO4·2H2O, obtained during the production of titanium dioxide. The powder is produced through washing, chemical modification, filtration, drying, crushing, grinding, and sieving. Its main components, by mass percentage, include: SiO2 2.23%, Fe2O3 7.92%, Al2O3 1.34%, CaO 28.7%, MgO 2.45%, SO3 36.7%, TiO2 1.36%, with a loss of 19.3%.

3. The fiber polymer titanium gypsum mortar according to claim 2, characterized in that, The preparation method of the titanium gypsum includes the following steps: using industrial by-products mainly composed of CaSO4·2H2O obtained during the production of titanium dioxide as raw materials, iron salts, magnesium salts and aluminum salts are separated by preliminary washing, and then citric acid is added to react with ferric ions to generate ferrous ions, further reducing the iron ion concentration, and the titanium gypsum gradually turns white; after filtration, it is dried at 80℃-250℃ for 4-8 hours to reduce its moisture content; the ball mill is used for grinding at a speed of 3000-8000 rpm for 3-6 hours, and then passed through a sieve of 300 mesh or larger.

4. The fiber polymer titanium gypsum mortar according to claim 1, characterized in that, The alkaline additive is ordinary silicate cement or sulfoaluminate cement.

5. The fiber polymer titanium gypsum mortar according to claim 1, characterized in that, The plant fiber mentioned is one of bamboo fiber, sisal fiber, ramie fiber, flax fiber, and abaca fiber, with a length of 5mm-10mm.

6. The fiber polymer titanium gypsum mortar according to claim 1, characterized in that, The cellulose ether is one of hydroxypropyl methylcellulose, hydroxyethyl methylcellulose, hydroxyethyl cellulose, and sodium carboxymethyl cellulose.

7. The fiber polymer titanium gypsum mortar according to claim 1, characterized in that, The redispersible latex powder is one of ethylene-vinyl acetate latex powder, vinyl acetate-ethylene tert-carbonate latex powder, and acrylic latex powder.

8. The fiber polymer titanium gypsum mortar according to claim 1, characterized in that, The retarder is one of sodium hexametaphosphate, citric acid, and sodium citrate.

9. The fiber polymer titanium gypsum mortar according to claim 1, characterized in that, The water-reducing agent is one of the following: sodium lignosulfonate water-reducing agent, naphthalene-based high-efficiency water-reducing agent, aliphatic high-efficiency water-reducing agent, amino high-efficiency water-reducing agent, and polycarboxylate high-efficiency water-reducing agent.

10. The method for preparing a fiber polymer titanium gypsum mortar according to claim 1, characterized in that, Includes the following steps: Step (1) Weighing for later use: Weigh out titanium gypsum, sand, alkaline additives, plant fiber, sodium sulfate, quicklime, purified water, cellulose ether, water-reducing agent, redispersible latex powder, and retarder separately according to the proportions; Step (2) Mixing and stirring: Add the titanium gypsum, sand, sodium sulfate, quicklime and alkaline additives prepared in step (1) evenly to the mixer, start the motor and stir for 10 minutes to make the materials evenly mixed; then add cellulose ether, water reducing agent, redispersible latex powder, retarder and purified water to the mixer, control the water-cement ratio at 0.3-0.6, start the motor and stir for 5 minutes; finally add plant fiber to the mixer, start the motor and stir at low speed for 5 minutes, then stir at high speed for 10 minutes to make the materials evenly mixed. Step (3) Product shaping: The materials prepared in step (2) are packaged and shaped to obtain the product.

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