High-strength household environment-friendly ceramic and preparation method thereof

Abstract

The application discloses a kind of high-strength domestic environment-friendly ceramic and preparation method thereof, comprising the following steps: S1, preparation of modified red mud;S2, preparation of modified coal gangue powder;S3, preparation of ceramic green body;S4, preparation of environment-friendly glaze;S5, preparation of high-strength environment-friendly ceramic.The application uses high proportion of industrial solid waste as main raw material, through multi-component synergistic modification and in-situ self-generated reinforcing phase method, successfully prepares high-performance daily-use ceramic with high mechanical strength and excellent environmental protection characteristics;The application changes traditional low-efficiency inert waste materials such as red mud and coal gangue into in-situ precursors of reinforcing phase in ceramic matrix, solves the technical problems such as frosting, cracking and low strength easily occurred in high solid waste content ceramic, the process route design is reasonable, the cost is low, waste is turned into treasure, and provides a new, practical industrialization prospect solution for high-value utilization of bulk industrial solid waste.

Description

Technical Field

[0001] This invention belongs to the field of ceramic preparation technology, specifically relating to a high-strength household environmentally friendly ceramic and its preparation method. Background Technology

[0002] As an indispensable part of people's daily lives, the market demand for daily-use ceramics continues to grow. Traditional production of daily-use ceramics mainly relies on high-grade natural mineral resources such as clay, feldspar, and quartz. However, with the increasing depletion of high-quality mineral resources and the continuous rise in mining costs, the ceramics industry faces a severe raw material crisis. At the same time, with the increasing awareness of environmental protection, reducing production energy consumption and increasing product added value have become important directions for technological upgrading in the industry. Therefore, utilizing industrial solid waste to replace some natural raw materials in ceramic production has become a research hotspot in the fields of materials science and environmental engineering.

[0003] Among the many industrial solid wastes, red mud and coal gangue have attracted much attention due to their huge output, large storage space, and easy environmental pollution. Theoretically, applying these two solid wastes to ceramic preparation has significant economic and environmental benefits. However, in practical applications, the existing technology still faces the following technical bottlenecks that are difficult to overcome: (1) The high alkalinity and high iron content of red mud lead to application limitations. Red mud contains a large amount of free alkali (such as Na2O and K2O), which makes it easy for frost to occur during firing and use when it is introduced into ceramic body using traditional methods, even after simple water washing, seriously affecting the appearance and durability of the product. In addition, the high content of ferric oxide (Fe2O3) in red mud will make the ceramics dark red or brownish-red, which limits its application in white or light-colored daily ceramics, and is generally considered to be a harmful impurity that affects the high-temperature performance of ceramics. (2) The inertness and poor plasticity of coal gangue lead to process problems. Although coal gangue has a certain chemical activity after calcination, it is still essentially an inert and non-plastic aggregate. After replacing clay in large quantities in ceramic formulations, the plasticity of the green body will decrease sharply, making it difficult to form and resulting in low green body strength. It is also prone to cracking during drying and firing, thus limiting its effective dosage in the formulation. (3) Research on the composite utilization of multiple solid wastes is mostly limited to the level of simple physical mixing, i.e., technology stacking. Various solid waste components are merely used as cheap fillers, each performing its own function, without forming an effective chemical synergy, resulting in mediocre performance of the final product. It can usually only be used to prepare low-value-added building ceramsite, permeable bricks, etc.

[0004] Therefore, the development of a high-strength household environmentally friendly ceramic and its preparation method is of great significance in order to realize the high-value and functional utilization of industrial solid waste in the field of environmentally friendly daily ceramics. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a high-strength environmentally friendly household ceramic and its preparation method.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A method for preparing high-strength environmentally friendly household ceramic includes the following steps:

[0008] S1. Preparation of modified red mud: After washing the red mud with water to remove impurities, it is added to a phytic acid aqueous solution and stirred under ultrasonic conditions. After the reaction is completed, it is filtered and dried to obtain modified red mud.

[0009] S2. Preparation of modified coal gangue powder: Coal gangue and rice husk ash are mixed evenly to obtain a mixed powder. Then, sodium hydroxide solution is added to the mixed powder and ball milled to obtain a pretreated powder. The pretreated powder is added to water, followed by papermaking black liquor, and heated to react. After the reaction is completed, the mixture is filtered and dried to obtain modified coal gangue powder.

[0010] S3. Preparation of ceramic green body: Take albite, waste glass powder, wollastonite, modified coal gangue and modified red mud and mix them evenly to obtain green body powder. Then add bio-based grinding aid and water, and after wet ball milling and iron removal by sieving, obtain slurry. Then, through slurry casting or pressing, dry to obtain ceramic green body.

[0011] S4. Preparation of environmentally friendly glaze: By weight, potassium feldspar, calcite, calcined talc, boron mud, zinc oxide, zirconium silicate and water are mixed and ball-milled to obtain environmentally friendly glaze, which is then applied to the surface of the ceramic green body by spraying or dipping.

[0012] S5. Preparation of high-strength environmentally friendly ceramics: The glazed body is sent into a kiln for sintering. After sintering, it is naturally cooled to room temperature in the kiln to obtain high-strength environmentally friendly household ceramics.

[0013] In this invention, various industrial and agricultural solid wastes, such as red mud, coal gangue, rice husk ash, waste glass powder, papermaking black liquor, and waste molasses, are used as core raw materials to prepare high-strength environmentally friendly household ceramics through a combination of chemical modification and formula design. Each solid waste component plays a different structural function in the green body: modified red mud provides iron-aluminum plastic components, modified coal gangue powder provides highly active silicon-aluminum aggregates, and waste glass powder acts as a low-temperature flux to promote liquid-phase sintering, synergistically achieving densification of the green body. Compared with traditional ceramic formulas using pure natural minerals as raw materials, this solution not only effectively utilizes multiple types of solid wastes, but also, through reasonable raw material ratios and sintering process control, enables ceramic products to obtain good mechanical properties and appearance quality, achieving the dual goals of resource utilization and product functionality.

[0014] Preferably, in step S1, the mass concentration of the phytic acid aqueous solution is 1-2%, the mass ratio of the red mud to the phytic acid aqueous solution is 1:8-10, the ultrasonic power is 200-300W, the stirring reaction temperature is 40-50℃, and the time is 2-3h.

[0015] Red mud contains a large amount of free alkali components, which can lead to excessive alkali content and affect the stability of ceramic bodies when used directly. This invention modifies the red mud using a phytic acid aqueous solution. The six phosphate groups in the phytic acid molecule can react with the Fe atoms on the surface of the red mud. 3+ Al 3+ When metal ions coordinate and complex, a dense organic phosphate chelate layer is formed on the particle surface, which effectively seals the alkaline active sites of red mud and reduces its risk of alkali leaching. The surface hydrophilicity of red mud modified with phytic acid is improved, and its compatibility with other raw material components is enhanced, which helps to improve the uniformity and molding stability of the green body.

[0016] Preferably, in step S2, the mass ratio of coal gangue to rice husk ash is 7-7.5:2.5-3, the mass concentration of sodium hydroxide solution is 2-3%, the mass ratio of mixed powder to sodium hydroxide solution is 100:15-20, the ball milling speed is 300-400 r / min, and the time is 2-3 h.

[0017] Preferably, in step S2, the mass ratio of the pretreated powder, water, and papermaking black liquor is 100:500-700:1.5-2, the heating reaction temperature is 50-60℃, and the time is 1-2 hours.

[0018] Although coal gangue possesses a certain degree of pozzolanic activity, the reactivity of its active silica-alumina phase remains limited, resulting in insignificant sintering-promoting effects when used directly. This invention pre-treats rice husk ash with calcined coal gangue using a ball milling process with sodium hydroxide solution. The amorphous SiO2 abundant in the rice husk ash serves as a highly active silicon source, not only adjusting the SiO2 / Al2O3 molar ratio of the system but also promoting phase reorganization during sintering and improving the composition and viscosity of the liquid phase. Alkaline ball milling further disrupts the ordered structure of residual kaolinite in the coal gangue, enhancing the chemical activity of the aluminosilicate components. Subsequently, papermaking black liquor is introduced, where lignin sulfonate acts as an anionic surfactant component, adsorbing onto the surface of the powder particles and improving particle dispersion. Simultaneously, the organic matter in the black liquor, remaining between particles after drying, undergoes pyrolysis and gasification during the sintering heating stage, producing a slight activation effect on the contact area between particles, which helps promote neck formation and densification in the early stages of sintering.

[0019] Preferably, in step S3, the amounts of each raw material by weight are: 25-30 parts of albite, 10-15 parts of waste glass powder, 10-15 parts of wollastonite, 30-35 parts of modified coal gangue, and 15-20 parts of modified red mud. The amount of bio-based grinding aid added is 0.5-0.8% of the mass of the green powder, and the amount of water added is 0.8-1.2 times the mass of the green powder.

[0020] Preferably, in step S3, the preparation method of the bio-based grinding aid is as follows: by weight, 55-65 parts of waste molasses, 25-35 parts of water glass and 5-15 parts of sodium oleate are mixed evenly to obtain the product.

[0021] During wet ball milling, the powder particles have high surface energy and are prone to agglomeration, affecting the milling efficiency and slurry uniformity. This invention prepares a bio-based grinding aid by compounding waste molasses, water glass, and sodium oleate. The three play a synergistic role in the grinding process. The polyhydroxy organic compounds (sucrose, glucose, etc.) in the waste molasses can be adsorbed on the surface of newly formed cracks, reducing the surface energy of the particles and inhibiting the agglomeration of fine powder. The silicate ions provided by water glass can form an adsorption layer on the particle surface, enhancing the electrostatic repulsion between particles. Sodium oleate, as an anionic surfactant, further improves the fluidity and stability of the slurry. This grinding aid uses waste molasses from the food industry as the main raw material, achieving functionality while also taking into account the resource utilization of solid waste.

[0022] Preferably, in step S3, the wet ball milling time is 5-7 hours, the pressing pressure is 15-25 MPa, the drying temperature is 100-120°C, and the drying is carried out until the moisture content of the green body is less than 1%.

[0023] Preferably, in step S4, the amount of each raw material by weight is: 30-35 parts potassium feldspar, 15-20 parts calcite, 10-15 parts calcined talc, 8-12 parts boron mud, 5-8 parts zinc oxide, 3-5 parts zirconium silicate, and 40-50 parts water, and the ball milling time is 6-8 hours.

[0024] Preferably, in step S5, the sintering process is as follows: the temperature is increased to 400-600℃ at 3-5℃ / min and held for 1-2 hours; then the temperature is increased to 1150-1200℃ at 8-10℃ / min and held for 2-3 hours.

[0025] This invention also protects a high-strength, environmentally friendly household ceramic prepared by the method described above.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) The high-strength household environmentally friendly ceramics provided by the present invention use a high proportion of industrial solid waste as the main raw material. Through multi-component synergistic modification and in-situ self-generation of reinforcing crystal phase, high-performance daily ceramics with high mechanical strength and excellent environmental protection properties are successfully prepared. The present invention transforms traditional inefficient inert wastes such as red mud and coal gangue into in-situ precursors of reinforcing phases in ceramic matrix, solving the technical problems of frost, cracking and low strength that are easy to occur in ceramics with high solid waste content. The process route of this method is reasonably designed, low cost, and turns waste into treasure. It provides a brand-new solution with practical industrial prospects for the high-value utilization of bulk industrial solid waste.

[0028] (2) The high-strength household environmentally friendly ceramic provided by the present invention introduces phytic acid to perform ultrasonic-assisted chemical modification of red mud. On the one hand, the multiple phosphate groups on the phytic acid molecule can react with Fe on the surface of the red mud. 3+ Al 3+ High-valence metal ions undergo strong multidentate chelation to form a stable macromolecular chelate coating layer, effectively inhibiting the aggregation of red mud particles in the aqueous medium and improving their dispersion uniformity in the subsequent slurry system; simultaneously, phytic acid reacts with Fe on the surface of the red mud. 3+ Al 3+ A dense chelated coating layer is formed, which physically hinders the outward migration of alkaline components, thus eliminating the generation of blooming defects at the source. On the other hand, phytic acid molecules, as a phosphorus-containing organic compound, serve as an in-situ reinforcing phase precursor during the subsequent high-temperature sintering process, laying the foundation for the formation of specific high-strength crystalline phases.

[0029] (3) The high-strength household environmentally friendly ceramics provided by this invention achieve deep activation of the activity and improvement of the process performance of coal gangue through a two-step method of alkali activation and organic coating. First, the inert silicon-oxygen and aluminum-oxygen bonds in calcined coal gangue are destroyed by sodium hydroxide solution during the mechanochemical ball milling process, forming a large number of chemically reactive broken bonds and non-bridged oxygen, which significantly improves the ability of aluminum-silicon components to participate in high-temperature solid-phase reactions. Then, papermaking black liquor is introduced, in which large molecular organic matter such as sodium lignin sulfonate is adsorbed and coated on the surface of active powder, which effectively improves the dispersibility and slurry flowability of high proportion coal gangue powder in the pulping process, and solves the process problems of poor rheological properties and insufficient uniformity of green body forming in slurry with high solid waste content. Finally, the coal gangue powder modified by the above two steps can achieve high efficiency in the sintering stage (1150-11800 rpm). At 0℃, the phytic acid, along with components such as albite, wollastonite, and waste glass powder in the system, participates in a high-temperature liquid-phase reaction. Low-melting-point components such as waste glass powder form the liquid phase first, filling the pores between particles and driving the densification of the green body. At the same time, the phytic acid introduced in the early stage decomposes in the high-temperature liquid-phase environment to release highly active phosphate ions, which can react in situ with various high-valence metal cations in the system to generate a diffusely distributed high-strength microcrystalline reinforcing phase. These in-situ generated microcrystalline reinforcing phases are uniformly distributed in the ceramic matrix and intertwine and pin together with various needle-like or plate-like crystals formed by recrystallization of various components in the matrix during high-temperature sintering, constructing a dense microscopic composite reinforcing network. This effectively hinders the initiation and propagation of microcracks. It is this multi-component synergistic and in-situ self-generated composite reinforcing mechanism that endows the final ceramic product with excellent flexural strength and fracture toughness. Detailed Implementation

[0030] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0031] Unless otherwise specified, all chemical reagents and materials in this invention are purchased from the market or synthesized from raw materials purchased from the market.

[0032] In this invention, the red mud is a byproduct of the Bayer process for aluminum smelting, obtained by washing and drying. Its main chemical components, by mass percentage, include: Fe2O3 20-50%, Al2O3 10-25%, and SiO2 5-20%. The coal gangue is rock waste generated during the coal washing process, obtained by ball milling after calcination at 800°C for two hours. Its main chemical components, by mass percentage, include: SiO2 40-65% and Al2O3 15-35%. The papermaking black liquor is cooking waste liquor generated during the sulfate pulping process of wood pulp or bamboo pulp, wherein the mass fraction of lignin is 25-45%, and the solid content is 30-60%. Example 1

[0033] A method for preparing high-strength environmentally friendly household ceramic includes the following steps:

[0034] S1. After washing the red mud to remove impurities, add it to a 1.5% phytic acid aqueous solution with a mass ratio of 1:9. Stir and react at 45°C for 2.5 hours under ultrasonic conditions with a power of 250W. After the reaction is completed, filter and dry to obtain modified red mud.

[0035] S2. Coal gangue and rice husk ash are mixed evenly at a mass ratio of 7:3 to obtain a mixed powder. Then, a 2.5% sodium hydroxide solution is added to the mixed powder, with a mass ratio of 100:18 between the mixed powder and the sodium hydroxide solution. The mixture is ball-milled at 350 r / min for 2.5 h to obtain a pretreated powder. 1 kg of the pretreated powder is added to 6 kg of water, followed by 18 g of papermaking black liquor. The mixture is reacted at 55 °C for 1.5 h. After the reaction is completed, the mixture is filtered and dried to obtain modified coal gangue powder.

[0036] S3. By weight, take 25 parts of albite, 13 parts of waste glass powder, 12 parts of wollastonite, 32 parts of modified coal gangue, and 18 parts of modified red mud and mix them evenly to obtain green body powder. Then add 0.7% of the weight of the green body powder of bio-based grinding aid and 1 times the weight of the green body powder of water. After wet ball milling for 6 hours, after sieving to remove iron, obtain slurry, press it into shape at 20 MPa, and dry it at 110℃ until the moisture content of the green body is less than 1% to obtain ceramic green body.

[0037] S4. By weight, take 33 parts potassium feldspar, 17 parts calcite, 13 parts calcined talc, 10 parts boron mud, 7 parts zinc oxide, 4 parts zirconium silicate, and 45 parts water, mix and ball mill for 7 hours to obtain an environmentally friendly glaze slurry, and apply it to the surface of the ceramic green body by spraying or dipping.

[0038] S5. The glazed body is sent into the kiln for sintering. The sintering process is as follows: the temperature is increased to 500℃ at 4℃ / min and held for 1.5h; then the temperature is increased to 1180℃ at 9℃ / min and held for 2.5h. After sintering, the body is naturally cooled to room temperature in the kiln to obtain high-strength household environmentally friendly ceramics.

[0039] The preparation method of the bio-based grinding aid is as follows: 60 parts by weight of waste molasses, 30 parts by weight of water glass and 10 parts by weight of sodium oleate are mixed evenly to obtain the final product. Example 2

[0040] A method for preparing high-strength environmentally friendly household ceramic includes the following steps:

[0041] S1. After washing the red mud to remove impurities, add it to a 1% phytic acid aqueous solution with a mass ratio of 1:8. Stir and react at 40°C for 3 hours under ultrasonic conditions with a power of 200W. After the reaction is completed, filter and dry to obtain modified red mud.

[0042] S2. Coal gangue and rice husk ash are mixed evenly at a mass ratio of 7:3 to obtain a mixed powder. Then, a 2% sodium hydroxide solution is added to the mixed powder, with a mass ratio of 100:20 between the mixed powder and the sodium hydroxide solution. The mixture is ball-milled at 300 r / min for 3 hours to obtain a pretreated powder. 1 kg of the pretreated powder is added to 5 kg of water, followed by 15 g of papermaking black liquor. The mixture is reacted at 50°C for 2 hours. After the reaction is completed, the mixture is filtered and dried to obtain modified coal gangue powder.

[0043] S3. By weight, take 20 parts of albite, 10 parts of waste glass powder, 10 parts of wollastonite, 30 parts of modified coal gangue, and 15 parts of modified red mud and mix them evenly to obtain green body powder. Then add 0.5% of the weight of the green body powder of bio-based grinding aid and 0.8 times the weight of the green body powder of water. After wet ball milling for 5 hours, after sieving to remove iron, obtain slurry, press it into shape at 15 MPa, and dry it at 110℃ until the moisture content of the green body is less than 1% to obtain ceramic green body.

[0044] S4. By weight, take 30 parts potassium feldspar, 15 parts calcite, 10 parts calcined talc, 8 parts boron mud, 5 parts zinc oxide, 3 parts zirconium silicate, and 40 parts water, mix and ball mill for 6 hours to obtain an environmentally friendly glaze slurry, and apply it to the surface of the ceramic green body by spraying or dipping.

[0045] S5. The glazed body is sent into the kiln for sintering. The sintering process is as follows: the temperature is increased to 400℃ at 3℃ / min and held for 2 hours; then the temperature is increased to 1150℃ at 8℃ / min and held for 3 hours. After sintering, the body is naturally cooled to room temperature in the kiln to obtain high-strength household environmentally friendly ceramics.

[0046] The preparation method of the bio-based grinding aid is as follows: 55 parts by weight of waste molasses, 25 parts by weight of water glass and 5 parts by weight of sodium oleate are mixed evenly to obtain the final product. Example 3

[0047] A method for preparing high-strength environmentally friendly household ceramic includes the following steps:

[0048] S1. After washing the red mud to remove impurities, add it to a 2% phytic acid aqueous solution with a mass ratio of 1:10. Stir and react at 50°C for 2 hours under ultrasonic conditions with a power of 300W. After the reaction is completed, filter and dry to obtain modified red mud.

[0049] S2. Coal gangue and rice husk ash are mixed evenly at a mass ratio of 7.5:2.5 to obtain a mixed powder. Then, a 3% sodium hydroxide solution is added to the mixed powder, with a mass ratio of 100:15 between the mixed powder and the sodium hydroxide solution. The mixture is ball-milled at 400 r / min for 2 hours to obtain a pretreated powder. 1 kg of the pretreated powder is added to 7 kg of water, followed by 20 g of papermaking black liquor. The mixture is reacted at 60℃ for 1 hour. After the reaction is completed, the mixture is filtered and dried to obtain modified coal gangue powder.

[0050] S3. By weight, take 30 parts of albite, 15 parts of waste glass powder, 15 parts of wollastonite, 35 parts of modified coal gangue, and 20 parts of modified red mud and mix them evenly to obtain green body powder. Then add 0.8% of the green body powder mass of bio-based grinding aid and 1.2 times the mass of the green body powder of water. After wet ball milling for 7 hours, after sieving to remove iron, obtain slurry, press it into shape at 25 MPa, and dry it at 110℃ until the moisture content of the green body is less than 1% to obtain ceramic green body.

[0051] S4. By weight, take 35 parts potassium feldspar, 20 parts calcite, 15 parts calcined talc, 12 parts boron mud, 8 parts zinc oxide, 5 parts zirconium silicate, and 50 parts water, mix and ball mill for 8 hours to obtain an environmentally friendly glaze slurry, and apply it to the surface of the ceramic green body by spraying or dipping.

[0052] S5. The glazed body is sent into the kiln for sintering. The sintering process is as follows: the temperature is increased to 600℃ at 5℃ / min and held for 1 hour; then the temperature is increased to 1200℃ at 10℃ / min and held for 2 hours. After sintering, the body is naturally cooled to room temperature in the kiln to obtain high-strength household environmentally friendly ceramics.

[0053] The preparation method of the bio-based grinding aid is as follows: 65 parts by weight of waste molasses, 35 parts by weight of water glass and 15 parts by weight of sodium oleate are mixed evenly to obtain the final product. Comparative Example 1

[0054] A method for preparing high-strength environmentally friendly household ceramic includes the following steps:

[0055] S1. After washing the red mud to remove impurities, add it to a 1.5% hydrochloric acid aqueous solution with a mass ratio of 1:9. Stir and react at 45°C for 2.5 hours under ultrasonic conditions with a power of 250W. After the reaction is completed, filter and dry to obtain modified red mud.

[0056] S2. Coal gangue and rice husk ash are mixed evenly at a mass ratio of 7:3 to obtain a mixed powder. Then, a 2.5% sodium hydroxide solution is added to the mixed powder, with a mass ratio of 100:18 between the mixed powder and the sodium hydroxide solution. The mixture is ball-milled at 350 r / min for 2.5 h to obtain a pretreated powder. 1 kg of the pretreated powder is added to 6 kg of water, followed by 18 g of papermaking black liquor. The mixture is reacted at 55 °C for 1.5 h. After the reaction is completed, the mixture is filtered and dried to obtain modified coal gangue powder.

[0057] S3. By weight, take 25 parts of albite, 13 parts of waste glass powder, 12 parts of wollastonite, 32 parts of modified coal gangue, and 18 parts of modified red mud and mix them evenly to obtain green body powder. Then add 0.7% of the weight of the green body powder of bio-based grinding aid and 1 times the weight of the green body powder of water. After wet ball milling for 6 hours, after sieving to remove iron, obtain slurry, press it into shape at 20 MPa, and dry it at 110℃ until the moisture content of the green body is less than 1% to obtain ceramic green body.

[0058] S4. By weight, take 33 parts potassium feldspar, 17 parts calcite, 13 parts calcined talc, 10 parts boron mud, 7 parts zinc oxide, 4 parts zirconium silicate, and 45 parts water, mix and ball mill for 7 hours to obtain an environmentally friendly glaze slurry, and apply it to the surface of the ceramic green body by spraying or dipping.

[0059] S5. The glazed body is sent into the kiln for sintering. The sintering process is as follows: the temperature is increased to 500℃ at 4℃ / min and held for 1.5h; then the temperature is increased to 1180℃ at 9℃ / min and held for 2.5h. After sintering, the body is naturally cooled to room temperature in the kiln to obtain high-strength household environmentally friendly ceramics.

[0060] The preparation method of the bio-based grinding aid is as follows: 60 parts by weight of waste molasses, 30 parts by weight of water glass and 10 parts by weight of sodium oleate are mixed evenly to obtain the final product.

[0061] Compared with Example 1, this comparative example replaces phytic acid in step S1 with hydrochloric acid. Comparative Example 2

[0062] A method for preparing high-strength environmentally friendly household ceramic includes the following steps:

[0063] S1. After washing the red mud to remove impurities, add it to a 1.5% phytic acid aqueous solution with a mass ratio of 1:9. Stir and react at 45°C for 2.5 hours under ultrasonic conditions with a power of 250W. After the reaction is completed, filter and dry to obtain modified red mud.

[0064] S2. Mix coal gangue and rice husk ash evenly at a mass ratio of 7:3 to obtain a mixed powder. Then add a sodium hydroxide solution with a mass concentration of 2.5% to the mixed powder. The mass ratio of the mixed powder to the sodium hydroxide solution is 100:18. Ball mill at a speed of 350 r / min for 2.5 h to obtain modified coal gangue powder.

[0065] S3. By weight, take 25 parts of albite, 13 parts of waste glass powder, 12 parts of wollastonite, 32 parts of modified coal gangue, and 18 parts of modified red mud and mix them evenly to obtain green body powder. Then add 0.7% of the weight of the green body powder of bio-based grinding aid and 1 times the weight of the green body powder of water. After wet ball milling for 6 hours, after sieving to remove iron, obtain slurry, press it into shape at 20 MPa, and dry it at 110℃ until the moisture content of the green body is less than 1% to obtain ceramic green body.

[0066] S4. By weight, take 33 parts potassium feldspar, 17 parts calcite, 13 parts calcined talc, 10 parts boron mud, 7 parts zinc oxide, 4 parts zirconium silicate, and 45 parts water, mix and ball mill for 7 hours to obtain an environmentally friendly glaze slurry, and apply it to the surface of the ceramic green body by spraying or dipping.

[0067] S5. The glazed body is sent into the kiln for sintering. The sintering process is as follows: the temperature is increased to 500℃ at 4℃ / min and held for 1.5h; then the temperature is increased to 1180℃ at 9℃ / min and held for 2.5h. After sintering, the body is naturally cooled to room temperature in the kiln to obtain high-strength household environmentally friendly ceramics.

[0068] The preparation method of the bio-based grinding aid is as follows: 60 parts by weight of waste molasses, 30 parts by weight of water glass and 10 parts by weight of sodium oleate are mixed evenly to obtain the final product.

[0069] Compared with Example 1, no papermaking black liquor was introduced in step S2 of this comparative example. Comparative Example 3

[0070] A method for preparing high-strength environmentally friendly household ceramic includes the following steps:

[0071] S1. After washing the red mud to remove impurities, add it to a 1.5% phytic acid aqueous solution with a mass ratio of 1:9. Stir and react at 45°C for 2.5 hours under ultrasonic conditions with a power of 250W. After the reaction is completed, filter and dry to obtain modified red mud.

[0072] S2. Add a 2.5% sodium hydroxide solution to the coal gangue, with a mass ratio of coal gangue to sodium hydroxide solution of 100:18. Ball mill at 350 r / min for 2.5 h to obtain pretreated powder. Add 1 kg of pretreated powder to 6 kg of water, then add 18 g of papermaking black liquor. React at 55 °C for 1.5 h. After the reaction is complete, filter and dry to obtain modified coal gangue powder.

[0073] S3. By weight, take 25 parts of albite, 13 parts of waste glass powder, 12 parts of wollastonite, 32 parts of modified coal gangue, and 18 parts of modified red mud and mix them evenly to obtain green body powder. Then add 0.7% of the weight of the green body powder of bio-based grinding aid and 1 times the weight of the green body powder of water. After wet ball milling for 6 hours, after sieving to remove iron, obtain slurry, press it into shape at 20 MPa, and dry it at 110℃ until the moisture content of the green body is less than 1% to obtain ceramic green body.

[0074] S4. By weight, take 33 parts potassium feldspar, 17 parts calcite, 13 parts calcined talc, 10 parts boron mud, 7 parts zinc oxide, 4 parts zirconium silicate, and 45 parts water, mix and ball mill for 7 hours to obtain an environmentally friendly glaze slurry, and apply it to the surface of the ceramic green body by spraying or dipping.

[0075] S5. The glazed body is sent into the kiln for sintering. The sintering process is as follows: the temperature is increased to 500℃ at 4℃ / min and held for 1.5h; then the temperature is increased to 1180℃ at 9℃ / min and held for 2.5h. After sintering, the body is naturally cooled to room temperature in the kiln to obtain high-strength household environmentally friendly ceramics.

[0076] The preparation method of the bio-based grinding aid is as follows: 60 parts by weight of waste molasses, 30 parts by weight of water glass and 10 parts by weight of sodium oleate are mixed evenly to obtain the final product.

[0077] Compared with Example 1, rice husk ash was not introduced in step S2 of this comparative example. Comparative Example 4

[0078] A method for preparing high-strength environmentally friendly household ceramic includes the following steps:

[0079] S1. After washing the red mud to remove impurities, add it to a 1.5% phytic acid aqueous solution with a mass ratio of 1:9. Stir and react at 45°C for 2.5 hours under ultrasonic conditions with a power of 250W. After the reaction is completed, filter and dry to obtain modified red mud.

[0080] S2. Coal gangue and rice husk ash are mixed evenly at a mass ratio of 7:3 to obtain a mixed powder. Then, a 2.5% sodium hydroxide solution is added to the mixed powder, with a mass ratio of 100:18 between the mixed powder and the sodium hydroxide solution. The mixture is ball-milled at 350 r / min for 2.5 h to obtain a pretreated powder. 1 kg of the pretreated powder is added to 6 kg of water, followed by 18 g of papermaking black liquor. The mixture is reacted at 55 °C for 1.5 h. After the reaction is completed, the mixture is filtered and dried to obtain modified coal gangue powder.

[0081] S3. By weight, take 25 parts of albite, 13 parts of waste glass powder, 12 parts of wollastonite, 32 parts of modified coal gangue, and 18 parts of modified red mud and mix them evenly to obtain green body powder. Then add 0.7% waste molasses and 1 times the weight of water of the green body powder. After wet ball milling for 6 hours, remove iron by sieving to obtain slurry. Press it into shape at 20 MPa and dry it at 110℃ until the moisture content of the green body is less than 1% to obtain ceramic green body.

[0082] S4. By weight, take 33 parts potassium feldspar, 17 parts calcite, 13 parts calcined talc, 10 parts boron mud, 7 parts zinc oxide, 4 parts zirconium silicate, and 45 parts water, mix and ball mill for 7 hours to obtain an environmentally friendly glaze slurry, and apply it to the surface of the ceramic green body by spraying or dipping.

[0083] S5. The glazed body is sent into the kiln for sintering. The sintering process is as follows: the temperature is increased to 500℃ at 4℃ / min and held for 1.5h; then the temperature is increased to 1180℃ at 9℃ / min and held for 2.5h. After sintering, the body is naturally cooled to room temperature in the kiln to obtain high-strength household environmentally friendly ceramics.

[0084] Compared to Example 1, the biological grinding aid in this comparative example is only waste molasses. Comparative Example 5

[0085] A method for preparing high-strength environmentally friendly household ceramic includes the following steps:

[0086] S1. Mix coal gangue and rice husk ash evenly at a mass ratio of 7:3 to obtain a mixed powder;

[0087] S2. By weight, take 25 parts of albite, 13 parts of waste glass powder, 12 parts of wollastonite, 32 parts of mixed powder, and 18 parts of red mud and mix them evenly to obtain green body powder. Then add 0.7% of the weight of the green body powder of bio-based grinding aid and 1 times the weight of the green body powder of water. After wet ball milling for 6 hours, after sieving to remove iron, obtain slurry, press it into shape at 20 MPa, and dry it at 110℃ until the moisture content of the green body is less than 1% to obtain ceramic green body.

[0088] S3. By weight, take 33 parts potassium feldspar, 17 parts calcite, 13 parts calcined talc, 10 parts boron mud, 7 parts zinc oxide, 4 parts zirconium silicate, and 45 parts water, mix and ball mill for 7 hours to obtain an environmentally friendly glaze slurry, and apply it to the surface of the ceramic green body by spraying or dipping.

[0089] S4. The glazed body is sent into the kiln for sintering. The sintering process is as follows: the temperature is increased to 500℃ at 4℃ / min and held for 1.5h; then the temperature is increased to 1180℃ at 9℃ / min and held for 2.5h. After sintering, the body is naturally cooled to room temperature in the kiln to obtain high-strength household environmentally friendly ceramics.

[0090] The preparation method of the bio-based grinding aid is as follows: 60 parts by weight of waste molasses, 30 parts by weight of water glass and 10 parts by weight of sodium oleate are mixed evenly to obtain the final product.

[0091] Compared with Example 1, this comparative example did not modify the red mud and coal gangue.

[0092] The high-strength household environmentally friendly ceramics prepared in Examples 1-3 and Comparative Examples 1-5 were subjected to performance tests. Fracture toughness was tested according to standard GB / T 23806-2009; flexural strength was tested according to standard GB / T 6569-2006; water absorption rate was tested by taking 5 ceramic fragments, washing and drying them, weighing them separately, then separating the fragments and placing them in distilled water, boiling for 3 hours, during which the water level was kept at least 10 mm above the fragments. Afterwards, the fragments were removed, the water adhering to the surface was wiped off with a water-saturated cloth, and their weight was quickly measured. The average water absorption rate of the 5 fragments was calculated to obtain the water absorption rate of the ceramic product; apparent porosity was tested according to standard GB / T 2997-2015; the temperature of the environmental chamber for the efflorescence test was 45-50℃, and the relative humidity was 85-90%RH; the test results are shown in Table 1 below.

[0093] Table 1

[0094]

[0095] As can be seen from Table 1 above, the high-strength environmentally friendly household ceramics prepared by this invention have good mechanical properties and good application prospects.

[0096] The above description is a further detailed explanation of the present invention in conjunction with specific implementation examples. It should not be considered that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present invention, and all such deductions or substitutions should be considered to fall within the protection scope of the present invention.

[0097] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit 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 present invention.

Claims

1. A method for preparing high-strength environmentally friendly household ceramic, characterized in that, Includes the following steps: S1. After washing the red mud to remove impurities, add it to a phytic acid aqueous solution and stir the reaction under ultrasonic conditions. After the reaction is completed, filter and dry to obtain modified red mud. S2. Mix coal gangue and rice husk ash evenly to obtain a mixed powder. Then add sodium hydroxide solution to the mixed powder and ball mill it to obtain a pretreated powder. The pretreated powder was added to water, followed by papermaking black liquor, and heated to react. After the reaction was completed, the mixture was filtered and dried to obtain modified coal gangue powder. S3. Take albite, waste glass powder, wollastonite, modified coal gangue and modified red mud and mix them evenly to obtain green body powder. Then add bio-based grinding aid and water, and after wet ball milling and iron removal by sieving, obtain slurry. Then, obtain ceramic green body by slurry casting or pressing and drying. S4. By weight, take potassium feldspar, calcite, calcined talc, boron mud, zinc oxide, zirconium silicate, and water, mix and ball mill to obtain an environmentally friendly glaze slurry, and apply it to the surface of the ceramic green body by spraying or dipping. S5. The glazed body is sent into the kiln for sintering. After sintering, it is naturally cooled to room temperature in the kiln to obtain high-strength environmentally friendly household ceramics. In step S3, the preparation method of the bio-based grinding aid is as follows: by weight, 55-65 parts of waste molasses, 25-35 parts of water glass and 5-15 parts of sodium oleate are mixed evenly to obtain the product.

2. The preparation method according to claim 1, characterized in that, In step S1, the mass concentration of the phytic acid aqueous solution is 1-2%, the mass ratio of the red mud to the phytic acid aqueous solution is 1:8-10, the ultrasonic power is 200-300W, the stirring reaction temperature is 40-50℃, and the time is 2-3h.

3. The preparation method according to claim 1, characterized in that, In step S2, the mass ratio of coal gangue to rice husk ash is 7-7.5:2.5-3, the mass concentration of sodium hydroxide solution is 2-3%, the mass ratio of mixed powder to sodium hydroxide solution is 100:15-20, the ball milling speed is 300-400 r / min, and the time is 2-3 h.

4. The preparation method according to claim 1, characterized in that, In step S2, the mass ratio of the pretreated powder, water, and papermaking black liquor is 100:500-700:1.5-2, the heating reaction temperature is 50-60℃, and the time is 1-2 hours.

5. The preparation method according to claim 1, characterized in that, In step S3, the amounts of each raw material by weight are as follows: 25-30 parts of albite, 10-15 parts of waste glass powder, 10-15 parts of wollastonite, 30-35 parts of modified coal gangue, and 15-20 parts of modified red mud. The amount of bio-based grinding aid added is 0.5-0.8% of the mass of the green powder, and the amount of water added is 0.8-1.2 times the mass of the green powder.

6. The preparation method according to claim 1, characterized in that, In step S3, the wet ball milling time is 5-7 hours, the pressing pressure is 15-25 MPa, the drying temperature is 100-120℃, and the drying is carried out until the moisture content of the green body is less than 1%.

7. The preparation method according to claim 1, characterized in that, In step S4, the amounts of each raw material by weight are: 30-35 parts potassium feldspar, 15-20 parts calcite, 10-15 parts calcined talc, 8-12 parts boron mud, 5-8 parts zinc oxide, 3-5 parts zirconium silicate, and 40-50 parts water. The ball milling time is 6-8 hours.

8. The preparation method according to claim 1, characterized in that, In step S5, the sintering process is as follows: the temperature is increased to 400-600℃ at 3-5℃ / min and held for 1-2 hours; then the temperature is increased to 1150-1200℃ at 8-10℃ / min and held for 2-3 hours.

9. A high-strength, environmentally friendly household ceramic prepared by the method described in any one of claims 1-8.

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