A high tensile strength ceramic body, ceramic tile and method of manufacture

Abstract

The application provides a high tensile strength ceramic body, a ceramic tile and a preparation method, and raw materials of the ceramic body include, in parts by weight, 25-30 parts of raw clay, 15-25 parts of sodium feldspar, 25-35 parts of potassium feldspar, 5-10 parts of wollastonite and 2-4 parts of magnesia soil. The application introduces wollastonite into the ceramic body formula, increases the calcium content in the formula, controls the proportion of sodium feldspar, adjusts the types and proportions of clay, thereby enhancing the mechanical strength of the body, improving the tensile strength of the body, improving the tensile stability of the ceramic tile, and thereby making the ceramic tile less likely to be damaged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ceramic production, and particularly relates to a high tensile strength ceramic body, a ceramic tile and a preparation method. BACKGROUND

[0002] With the development of the building ceramic market, consumers have higher requirements for the quality of building ceramics, and the production labor cost of ceramic enterprises is rising, and the manufacturing raw materials are becoming more and more scarce, resulting in increasing production cost of ceramics. Therefore, ceramic enterprises can only reduce the production cost by improving the production capacity and reducing the firing temperature.

[0003] Because of the continuous improvement of production capacity, the reduction of firing temperature, the shortening of firing cycle, and the faster and faster pressing forming of the press, the speed of filling the powder in the press is also continuously accelerated, which reduces the uniformity of the press material, and finally may cause the tensile stability of the ceramic tile to decrease significantly. If the tensile stability is poor, a large number of broken corners, cutting cracks and the like may occur in the ceramic paving process, that is, the ceramic tile may be damaged during paving and transportation.

[0004] Therefore, the prior art has defects and needs to be improved and developed. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a high tensile strength ceramic body, a ceramic tile and a preparation method aiming at the above-mentioned defects of the prior art, so as to solve the problem of poor tensile stability of the ceramic tile in the prior art, and further to cause the ceramic tile to be easily damaged.

[0006] The technical solution adopted by the present application to solve the technical problem is as follows:

[0007] The first aspect of the present application provides a high tensile strength ceramic body, wherein the raw materials of the ceramic body include, by weight:

[0008] 25-30 parts of raw clay, 15-25 parts of sodium feldspar, 25-35 parts of potassium feldspar, 5-10 parts of wollastonite and 2-4 parts of magnesia soil.

[0009] In an embodiment of the present application, the chemical composition of the wollastonite includes, by mass percentage:

[0010] 53-56% of SiO2, 0.5-1.5% of Al2O3, 0.3-0.5% of Fe2O3, 41-43% of CaO, 0.8-1.2% of MgO, and 1-2% of ignition loss.

[0011] In an embodiment of the present application, the chemical composition of the raw clay includes, by mass percentage:

[0012] SiO2 65-70%, Al2O3 22-27%, Fe2O3 1.2-2.0%, K2O 1.0-1.5%, ignition loss 2-5%;

[0013] The chemical composition of the albite includes, by mass percentage:

[0014] SiO2 70-75%, Al2O3 13-15%, Fe2O3 0.5-1.5%, CaO 0.3-0.5%, MgO 0.5-1.0%, K2O 1.0-3.0%, Na2O 6.0-8.0%, ignition loss 1-3%;

[0015] The chemical composition of the potassium feldspar includes, by mass percentage:

[0016] SiO2 65-70%, Al2O3 15-20%, Fe2O3 0.5-1.5%, K2O 3.0-6.0%, Na2O 1.0-2.0%, ignition loss 1.5-5.5%;

[0017] The chemical composition of the magnesia soil includes, by mass percentage:

[0018] SiO2 64-68%, MgO 22-26%, Al2O3 2.2-2.5%, Fe2O3 1.4-1.6%, CaO 0.5-1.0%, ignition loss 2-5%.

[0019] The second aspect embodiment of the application provides a preparation method of a ceramic body, wherein the preparation method of the ceramic body includes:

[0020] The raw clay, the albite, the potassium feldspar, the wollastonite and the magnesia soil are mixed in a weight ratio of 25-30:15-25:25-35:5-10:2-4, and then water glass and a body debonding agent are added and ball milled to obtain a slurry;

[0021] The slurry is screened and de-ironed, and then aged, and the aged slurry is spray dried to obtain a powder;

[0022] The powder is screened and de-ironed, and then aged, and the aged powder is pressed into a ceramic body under a predetermined forming pressure.

[0023] In an embodiment of the application, the moisture content of the slurry is controlled to be 33%-36%, the fineness of the slurry is controlled to be 2.0%-2.4% on a 325 mesh screen, and the specific gravity of the slurry is greater than or equal to 1.68.

[0024] In an embodiment of the present application, the water content of the powder is 6.8% to 7.3%, and the particle size of the powder is 40 mesh, accounting for 45% to 50%; the predetermined forming pressure is 30 to 32 MPa.

[0025] The third aspect of the present application provides a ceramic tile, wherein the ceramic tile comprises the high tensile strength ceramic body as described above, and / or the ceramic body prepared by the preparation method as described above.

[0026] The fourth aspect of the present application provides a preparation method of the ceramic tile as described above, wherein the preparation method of the ceramic tile comprises:

[0027] The ceramic body is dried, and a glaze slurry is applied on the dried ceramic body to obtain a glazed body;

[0028] The glazed body is fired at a firing temperature of 1210 to 1230℃ and a firing period of 40 to 45 minutes to obtain the ceramic tile.

[0029] In the firing process, the oxidation decomposition zone of the kiln is heated from 950℃ to 1100℃, and the heating time of the oxidation decomposition zone is 20 to 30 minutes; the sintering zone is heated from 1100℃ to 1210℃, and the heating time of the sintering zone is 10 to 15 minutes.

[0030] In an embodiment of the present application, the chemical composition of the glaze slurry comprises, by mass percentage:

[0031] SiO2 46 to 50%, Al2O3 14 to 18%, CaO 3 to 6%, MgO 2 to 4%, BaO 3 to 6%, K2O 1 to 2%, Na2O 2 to 4%, ZnO 2 to 4%, and ZrO2 6 to 10%.

[0032] In an embodiment of the present application, the tensile strength of the ceramic tile is not less than 38 MPa.

[0033] The embodiments of the present application achieve the beneficial effects:

[0034] The present application provides a high tensile strength ceramic body, a ceramic tile and a preparation method, the raw materials of the ceramic body comprise, by weight fraction: 25 to 30 parts of raw clay, 15 to 25 parts of sodium feldspar, 25 to 35 parts of potassium feldspar, 5 to 10 parts of wollastonite, and 2 to 4 parts of magnesia. By introducing wollastonite into the ceramic body formula, increasing the calcium content in the formula, controlling the proportion of sodium feldspar, adjusting the type and proportion of clay, the mechanical strength of the body is enhanced, the tensile strength of the body is improved, the tensile stability of the ceramic tile is improved, and the ceramic tile is not easy to break. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 is a flow chart of a preferred embodiment of a method of preparing a ceramic body in the present invention.

[0036] Figure 2 is a process block diagram of a preferred embodiment of a method of preparing a ceramic body in the present invention. DETAILED DESCRIPTION

[0037] In order to make the objects, technical solutions and advantages of the present invention clearer and more explicit, the present invention is further described in detail below with reference to the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present invention and do not limit the present invention.

[0038] In ceramic production, the following problems are often encountered:

[0039] First, the lack of high-quality ceramic raw materials: due to the over-exploitation of resources in the early stage, the high-quality clay gradually decreases. At present, the clay has high silica sand content, which will lead to poor powder forming, and the powder forming will be damaged during the spray drying process of the slurry. The large damage of the powder forming will cause the low bulk density of the powder, and the production capacity is getting larger and larger, so it is difficult to adjust the powder forming in time, which seriously affects the continuity of the press production.

[0040] Second, the tensile strength of the product is low and the stability is poor: the production capacity is getting faster and faster, and the product is getting larger and larger, from the size of 500*500mm to the size of 1600*3200mm, etc. The pressing speed of the former press is 1 minute for 4-5 pieces of brick body, and the total time for feeding and exhausting is 12-15 seconds when pressing one piece of brick body. The pressing speed now has been done to 1 minute for 8-9 pieces of brick body, and the total time for feeding and exhausting is 6.5-7.5 seconds when pressing one piece of brick body. Therefore, the pressing process of the press will appear the problems of body delamination, edge cracking, and hidden cracking, etc. At the same time, due to the low bulk density of the powder, the uneven powder particles, etc., the uneven feeding of the press will cause the problems of low tensile strength and uneven tensile strength of the product. The tensile strength does not meet the standard, and the internal quality of the product is degraded over time, which will cause cracks and cutting cracks during the processing or paving process, and the product will also have problems of rotten corners and edges during the transportation process, which seriously affects the product quality and easily causes great loss.

[0041] Third, the various specifications of the product impact: to meet market demand, ceramic manufacturers need to produce different thickness different size specifications of ceramic tiles, such as 10.0mm, 9.0mm thickness, 900*900mm, 900*1800mm size specifications and other products. For example: in 10.0mm, 9.0mm different thickness specifications conversion production, the product tensile strength of the former body formula is low (less than 30MPa), the tensile strength is unstable, a piece of tile takes multiple test points to test the tensile strength, the difference is more than 10MPa, the transfer damage rate is high, the corner and edge is as high as 6%, the product cutting crack is very serious, therefore, it is particularly important to improve the tensile strength of the ceramic tile.

[0042] The application embodiment in 10.0mm, 9.0mm different thickness specifications conversion production, through the body formula adjustment, the product tensile strength is higher than 38MPa, the tensile strength of the conventional formula product is higher than 10MPa, and the tensile strength is stable, a piece of tile takes multiple test points to test the tensile strength, the difference is within 5MPa, the product transfer damage rate is reduced by 80%, the corner and edge is greatly improved compared with the conventional formula, the ceramic tile with corner and edge is within 2%, the corner and edge is reduced by 80%, the product cutting crack problem is completely solved, the product quality is greatly improved, the transportation damage loss can be reduced by 80%, the transportation damage loss fee can be saved by more than 1 million yuan per year.

[0043] The application provides a high tensile strength ceramic body, raw materials of the ceramic body include, by weight parts:

[0044] Raw clay 25-30 parts, sodium feldspar 15-25 parts, potassium feldspar 25-35 parts, wollastonite 5-10 parts, magnesia 2-4 parts.

[0045] Specifically, the application embodiment increases the content of calcium in the formula, enhances the mechanical strength of the body, improves the tensile strength of the body and the body cutting crack problem. Wollastonite contains 41%-43% CaO, during the body sintering process, a part of wollastonite and kaolinite in clay react to generate anorthite and cristobalite, the anorthite crystal is needle-shaped, forms an interlaced network structure in the body, can effectively improve the mechanical strength and toughness of the body, and improve the tensile strength of the body.

[0046] The application solves the problem of narrow sintering range of the formula, improves the production stability. Wollastonite as an alkaline earth metal silicate can play a fluxing role in ordinary ceramic body, and can reduce the sintering temperature of the body. Therefore, the application embodiment reduces part of sodium feldspar and magnesia and other fluxing raw materials, widens the sintering range of the body and adjusts the sintering temperature of the body, increases the content of part of clay, increases the content of Al2O3 in the body formula, promotes the generation of mullite crystals in the body, further improves the mechanical strength of the body, and improves the tensile strength of the body.

[0047] The formula of the embodiment of the present application introduces 5-10 parts of acicular wollastonite raw material, which increases the calcium content in the formula, controls the proportion of sodium feldspar, adjusts the type and proportion of clay, and further enhances the mechanical strength of the body and improves the tensile strength of the body. The acicular wollastonite crystals are arranged in a cross pattern in the body, forming an interwoven network structure. This structure is similar to the steel bars in reinforced concrete, enhancing the skeleton strength of the body, allowing the body to better maintain its shape during drying and firing, and reducing deformation and cracking. Moreover, the needle-shaped crystals of wollastonite are interwoven with other particles, increasing the bonding force between particles. This enhanced bonding force allows the body to better disperse stress when subjected to external forces, thereby improving overall strength.

[0048] The reason why wollastonite can improve the tensile strength of the brick body is that it can improve the flexibility of the brick body. The flexibility of the ceramic body refers to the ability of the body to resist external forces (such as bending, stretching, compression) without breaking or producing irreversible deformation during processes such as forming, drying, and firing. Specifically, wollastonite has a certain solubility effect on quartz stone during high-temperature firing. Wollastonite produces mullite after high-temperature firing, thus improving the flexibility of the body. The brick body made of the conventional formula has strong steel, and after adding a certain amount of wollastonite, the brick body has enhanced toughness compared to the brick body made of the conventional formula.

[0049] In the embodiment of the present application, the chemical composition of the wollastonite includes, by mass percentage:

[0050] SiO2 53-56%, Al2O3 0.5-1.5%, Fe2O3 0.3-0.5%, CaO 41-43%, MgO 0.8-1.2%, and loss on ignition 1-2%.

[0051] Among them, SiO2 is the main component of the ceramic body, which reacts with CaO to form minerals such as anorthite, forming a dense network structure, enhancing the mechanical strength and hardness of the ceramic. The synergistic effect of SiO2 and CaO can reduce the firing temperature and shorten the firing period. CaO is a key fluxing component in wollastonite, which can reduce the firing temperature of the ceramic and promote the formation of liquid phase. Al2O3 can stabilize the crystal structure of the ceramic, improve the thermal shock resistance and chemical stability, and reduce deformation and cracking during firing. Al2O3 can optimize the microstructure of the ceramic, enabling the product to withstand special mechanical processing such as sawing and drilling. Low content of Fe2O3 can ensure the pure color of the ceramic tile. MgO can adjust the thermal expansion coefficient of the ceramic, reduce the shrinkage difference during firing, and avoid cracking and deformation.

[0052] The embodiment of the present application can achieve the effects of reducing the firing temperature, improving the tensile strength, and reducing the production cost by introducing wollastonite.

[0053] In the embodiment of the present application, the chemical composition of the raw ore mud includes, by mass percentage:

[0054] SiO2 65-70%, Al2O3 22-27%, Fe2O3 1.2-2.0%, K2O 1.0-1.5%, loss on ignition 2-5%;

[0055] The chemical composition of the albite includes, by mass percentage:

[0056] SiO2 70-75%, Al2O3 13-15%, Fe2O3 0.5-1.5%, CaO 0.3-0.5%, MgO 0.5-1.0%, K2O 1.0-3.0%, Na2O 6.0-8.0%, loss on ignition 1-3%;

[0057] The chemical composition of the potassium feldspar includes, by mass percentage:

[0058] SiO2 65-70%, Al2O3 15-20%, Fe2O3 0.5-1.5%, K2O 3.0-6.0%, Na2O 1.0-2.0%, loss on ignition 1.5-5.5%;

[0059] The chemical composition of the magnesian clay includes, by mass percentage:

[0060] SiO2 64-68%, MgO 22-26%, Al2O3 2.2-2.5%, Fe2O3 1.4-1.6%, CaO 0.5-1.0%, loss on ignition 2-5%.

[0061] The raw ore mud refers to the purple clay material that is naturally mined from a mining area without chemical addition or artificial modification, and retains natural mineral components such as quartz, clay, mica, and iron elements. The albite is a sodium aluminosilicate mineral, which, as a barren raw material, reduces drying shrinkage and deformation, improves drying performance, and shortens drying time; fills the green body during firing, and improves density and light transmittance. The potassium feldspar is a potassium aluminosilicate mineral, which can reduce firing temperature, and improve mechanical strength and translucency of the green body. The magnesian clay is a clay mineral containing a relatively high content of magnesium oxide.

[0062] The embodiment of the present application can enhance the mechanical strength of the green body and improve the tensile strength of the green body by mixing wollastonite with the raw ore mud, the albite, the potassium feldspar, and the magnesian clay to obtain the ceramic green body.

[0063] Referring to Figure 1 The present application also provides a preparation method of the ceramic green body, which includes:

[0064] Step S100, by weight parts, the raw clay 25-30 parts, feldspar 15-25 parts, 25-35 parts of potassium feldspar, wollastonite 5-10 parts, 2-4 parts of magnesium soil are mixed, and water glass and green body debonding agent are added and ball milled to obtain slurry;

[0065] Step S200, the slurry is sieved and de-ironed, and then aged, and the aged slurry is spray dried to obtain a powder;

[0066] Step S300, the powder is sieved and de-ironed, and then aged, and the aged powder is pressed into a ceramic green body under a predetermined forming pressure.

[0067] Specifically, in step S100, the ball mill is prepared according to the green body formula; 0.8-1.0% of water glass and 0.04-0.08% of green body debonding agent are added according to the mass percentage. In step S200, the slurry is sieved and de-ironed to reduce the defects such as blistering, melting hole and spot impurities caused by coarse particles and iron impurities; the ball milled slurry is batched in a slurry pool, aged for 24 hours, and then spray dried to obtain a powder. In step S300, the powder is sieved and de-ironed, and then aged for 24 hours in the warehouse. According to the actual production needs, the powder is sent to the press distribution system through the powder feeding system for pressing, wherein the predetermined forming pressure is 30-32 MPa.

[0068] The embodiment of the present application introduces wollastonite into the ceramic green body formula, increases the calcium content in the formula, controls the proportion of sodium feldspar, and adjusts the type and proportion of clay to prepare a ceramic green body, thereby enhancing the mechanical strength of the green body and improving the tensile strength of the green body.

[0069] In one embodiment of the present application, the moisture content of the slurry is controlled at 33-36%, and the fineness of the slurry is controlled at 2.0-2.4% on a 325 mesh screen; the specific gravity of the slurry is greater than or equal to 1.68.

[0070] Specifically, the moisture content of the slurry is controlled at 33-36%, the fineness of the slurry is controlled at 2.0-2.4% on a 325 mesh screen, the specific gravity of the slurry is greater than or equal to 1.68, and the flow rate of the slurry is 100±30 seconds.

[0071] The slurry moisture control of the embodiment of the present application is 33% to 36%, which can balance the slurry fluidity and the ball milling efficiency, ensures that the raw material reaches the target fineness within the target time, and at the same time avoids the particle agglomeration caused by excessive grinding. Too low moisture (<33%) will cause the slurry viscosity to be too high, the friction between the ball milling medium (such as alumina ball) and the raw material to be insufficient, the particle refinement efficiency to be reduced, the ball milling time to be prolonged by 20% to 30%, and the energy consumption to be increased. Too high moisture (>36%) will reduce the slurry density, reduce the particle collision frequency, and also affect the refinement effect, and easily cause the slurry to be stratified, affecting the uniformity of the composition. Moreover, the slurry moisture control of the embodiment of the present application is 33% to 36%, which can guarantee the spray drying effect and improve the green body pressing performance.

[0072] The fineness control of the slurry of the embodiment of the present application is 2.0% to 2.4% of the 325 mesh screen residue, which can ensure that the raw material particles are uniformly refined, the glass phase fully fills the gap between the particles during sintering, the green body porosity is reduced, and the bending strength is improved.

[0073] The specific gravity of the slurry of the embodiment of the present application is greater than or equal to 1.68, the proportion of solid particles in the slurry is reasonable, the spray drying thermal efficiency is improved, the water content of the powder is stable, and it is suitable for continuous production.

[0074] In the embodiment of the present application, the water content of the powder is 6.8% to 7.3%, and the proportion of the particle size of 40 mesh of the powder is 45% to 50%; the predetermined forming pressure is 30 to 32 MPa.

[0075] The water content of the powder in the embodiment of the present application is 6.8% to 7.3%, which can balance the lubricity and exhaust performance of the powder. Specifically, the water forms a water film to reduce particle friction, while avoiding gas sealing, so that the green body density uniformity is improved and the bending strength is improved. The proportion of the particle size of 40 mesh of the powder in the embodiment of the present application is 45% to 50%, which can form a close-packed structure, the green body porosity is reduced, and the bending strength is improved. The forming pressure of 30 to 32 MPa can increase the green body density and improve the bending strength, while avoiding overpressure layer cracking.

[0076] The present application also provides a ceramic tile comprising a high tensile strength ceramic green body as described above, and / or a ceramic green body prepared by the preparation method of the ceramic green body as described above.

[0077] The present application also provides a preparation method of a ceramic tile as described above, which comprises:

[0078] Drying the ceramic green body, applying glaze slurry on the dried ceramic green body to obtain a glazed green body;

[0079] Firing the glazed green body at a firing temperature of 1210 to 1230℃ and a firing period of 40 to 45 minutes to obtain a ceramic tile.

[0080] During the firing, the oxidation-decomposition zone of the kiln is heated from 950℃ to 1100℃, and the heating time of the oxidation-decomposition zone is 20min-30min; the sintering zone is heated from 1100℃ to 1210℃, and the heating time of the sintering zone is 10min-15min.

[0081] The oxidation-decomposition zone is a key stage in the ceramic firing process, in which the organic matter, carbon, sulfide and other impurities in the body are oxidized, the carbonates and sulfates are decomposed, and the quartz undergoes a crystal transformation, accompanied by mass loss and strength reduction. The effects of the oxidation-decomposition zone include: (1) complete oxidation and decomposition: ensure that the carbon, sulfide and other impurities in the body are completely burned through the oxidation atmosphere, avoiding defects such as bubbles and smoke in the glaze due to gas sealing in the subsequent high-temperature stage; (2) structural water removal: the structural water in clay minerals is removed at this stage, reducing the risk of cracking caused by rapid water evaporation at high temperatures; (3) crystal transformation buffer: the crystal transformation of quartz at 573℃ has been completed, but the heating rate needs to be controlled at this stage to avoid residual stress.

[0082] The sintering zone is the stage at which the body is densified by high temperature to form a hard ceramic body. In this stage, a large amount of liquid phase is generated, the contact area between particles is expanded, the pores are gradually isolated and reduced, the body density approaches the theoretical value, and the mechanical strength is significantly improved. The effects of the sintering zone include: (1) liquid phase promotes sintering: the flux raw materials such as feldspar melt to form a liquid phase, filling the crystal boundary voids, accelerating particle rearrangement and material migration, and reducing the sintering temperature; (2) mullite generation: the decomposition products of kaolinite react with the liquid phase to generate needle-like mullite, enhancing the thermal stability and mechanical strength of the body; (3) glass phase solidification: the liquid phase is converted into glass phase after cooling, which bonds the ceramic body particles and imparts gloss.

[0083] Because some wollastonite raw ore contains a small amount of carbonate minerals, the heating rate of the oxidation-decomposition zone of the kiln needs to be reduced during firing, so that the body has enough time to remove the organic matter and the gas generated by the oxidation and decomposition of carbonates before the glaze begins to melt, avoiding defects such as closed bubbles, dissolution cavities and glaze pinholes. The oxidation-decomposition zone of the conventional potassium and sodium body formulation is heated from 980℃ to 1150℃ for 15min-20min, and the sintering zone is heated from 1150℃ to 1210℃ for 20min-25min. The oxidation-decomposition zone of the high-tensile-strength body formulation of the present application is heated from 950℃ to 1100℃ for 20min-30min, and the sintering zone is heated from 1100℃ to 1210℃ for 10min-15min.

[0084] In the embodiment of the present application, the production process of the ceramic tile is specifically: raw material homogenization, formula batching, ball milling, screening and iron removal, spray drying, pressing, drying, glazing, inkjet printing or printing, kiln firing, edge grinding, grading, and packaging, as shown in the following table. Figure 2

[0085] In one specific embodiment, the pressed ceramic body is dried in a drying kiln at a temperature of 100-120℃ for 50-60 minutes, which can completely remove free water, avoid firing defects, promote the combination between particles, improve the strength of the body, control the shrinkage rate, and improve the size accuracy of the product.

[0086] In the embodiment of the present application, the chemical composition of the glaze slurry includes, by mass percentage:

[0087] SiO2 46-50%, Al2O3 14-18%, CaO 3-6%, MgO 2-4%, BaO 3-6%, K2O 1-2%, Na2O 2-4%, ZnO 2-4%, and ZrO2 6-10%.

[0088] Specifically, the performance parameters of the glaze slurry include: a 325 mesh residue of 0.2%-0.4%, a glaze slurry viscosity of 25-35 seconds, a specific gravity of 1.7-1.8, and a glazing amount of 500-550 g / m 2 .

[0089] ​In the embodiments of the present application, SiO2 can significantly improve the wear resistance, hardness and chemical stability of the glaze layer, while reducing the thermal expansion coefficient to reduce the risk of cracking, and the content is controlled at 46-50% to balance the melting temperature and high temperature viscosity, avoiding the increase of firing temperature due to too high content. Al2O3 can enhance the thermal shock resistance of the glaze surface by improving the mechanical strength and chemical corrosion resistance of the glaze layer. The synergistic effect of Al2O3 and SiO2 can optimize the thermal expansion coefficient of the glaze, ensuring the expansion matching with the body, and preventing glaze cracking. CaO can reduce the viscosity of the glaze and improve the fluidity, promoting the smoothness of the glaze surface. MgO can effectively alleviate the stress concentration at the glaze-body junction by reducing the thermal expansion coefficient of the glaze layer, and the formation of magnesium aluminate spinel structure by MgO and Al2O3 can enhance the anti-cracking performance of the glaze surface and improve the wear resistance and acid and alkali corrosion resistance. BaO can significantly improve the gloss and chemical stability of the glaze surface, and can form high refractive index crystal phase in building ceramic glaze, enhancing light reflection effect, and the synergistic effect of BaO and SiO2 can widen the firing temperature range of the glaze and improve the process adaptability. K2O and Na2O as alkali oxides, both can reduce the melting temperature and high temperature viscosity of the glaze, promote the uniform melting of the glaze layer, K2O performs better in improving the hardness and water resistance of the glaze surface, while Na2O can enhance the transparency of the glaze layer, and the ratio control of the two can balance the fluidity and thermal stability of the glaze. ZnO can improve the process controllability by reducing the melting temperature of the glaze and expanding the firing range. ZrO2 as a high stability oxide, can significantly improve the chemical corrosion resistance and thermal stability of the glaze layer, and by forming zirconite crystal phase, it can enhance the hardness and wear resistance of the glaze surface, while improving the bonding strength between the glaze layer and the body, reducing the risk of peeling.

[0090] In the embodiments of the present application, the tensile strength of the ceramic tile is not less than 38 MPa. In a specific embodiment, the tensile strength of the ceramic tile is 38-51 MPa. By improving the tensile strength of the ceramic tile, the ceramic tile can withstand higher impact energy, reducing the risk of cracking or breaking; the ceramic tile needs to withstand its own weight and construction stress during paving, and the brick body flexural strength (positively correlated with tensile strength) of the tile with tensile strength not less than 38 MPa can reach 60-80 MPa (usually represented by fracture modulus), which is much higher than the requirement of national standard fracture modulus not less than 35 MPa, and can avoid deformation or cracking caused by stress concentration, especially suitable for paving large size ceramic tiles (such as 1200x2400mm). In addition, the ceramic tile will produce thermal stress when the temperature changes suddenly (such as winter floor heating on / off), and the thermal expansion coefficient matching of the tile with tensile strength not less than 38 MPa is more optimal, which can reduce the risk of glaze cracking or body cracking.

[0091] Tensile strength: refers to the stress value of the material when it bears the maximum tensile force in the tensile test. It reflects the ability of the material to resist fracture under the action of tensile force. When the material is subjected to tensile force, the distance between the atoms or molecules inside the material will gradually increase, and when it reaches a certain extent, the material will break, and the tensile strength is the maximum tensile stress that the material can withstand before breaking.

[0092] Bending strength: refers to the stress value of the material when it bears the maximum bending moment in the bending test. It reflects the ability of the material to resist fracture under the action of bending force. When the material is subjected to bending force, bending stress will occur inside the material, and the upper and lower parts of the material will be subjected to compression and tension, respectively, and the bending strength is the maximum bending stress that the material can withstand during bending.

[0093] The high tensile strength body formula provided by the embodiments of the present application is compared with the conventional formula product. The tensile strength of the conventional formula product is between 20-35 MPa at 8 detection points of the same brick, and the tensile strength stability of each detection point is poor. The ceramic product with the addition of selected wollastonite in the body formula of the embodiments of the present application is tested for tensile strength, and the test result is not less than 38 MPa, the tensile strength of 8 detection points is between 38-41 MPa, the tensile strength value of the detection points is stable, and the difference between the maximum value and the minimum value is less than 5 MPa. Since the tensile strength value is more stable, the damage rate is smaller, therefore, the embodiments of the present application can reduce the product damage rate.

[0094] The embodiments of the present application are tested as follows:

[0095] First, the product obtained by the embodiments of the present application has stable tensile strength, and the use of water knives, alloy knives and cutting knives for cutting tests will cut the product into different specifications, and the product is completely free of cutting cracks.

[0096] Second, the use of selected wollastonite in the embodiments of the present application solves the problem of narrow body firing range. The test kiln firing temperature is changed from 1210 degrees to 1230 degrees, the product water absorption rate is maintained at 0.04-0.05%, and the product brick type and endosperm detection are stable, therefore, the present application improves the production stability and continuity.

[0097] Third, the product loading and transportation test is also carried out in the embodiments of the present application, and the product integrity rate is improved by 80% in various road transportation tests, greatly reducing the transportation damage problem.

[0098] The following specific embodiments are listed for illustration.

[0099] Embodiment one:

[0100] The body formula described in this embodiment comprises, by weight:

[0101] Raw ore slurry 29 parts, sodium feldspar 23 parts, potassium feldspar 34 parts, wollastonite 10 parts, magnesia 4 parts.

[0102] The chemical composition of the wollastonite includes, by mass percentage:

[0103] SiO2 54%, Al2O3 1.3%, Fe2O3 0.5%, CaO 42%, MgO 1.2%, loss on ignition 1%.

[0104] The preparation process of the ceramic tile includes the following steps:

[0105] Step A1, raw ore slurry 29 parts, sodium feldspar 23 parts, potassium feldspar 34 parts, wollastonite 10 parts, magnesia 4 parts are mixed, and water glass and body debonding agent are added for ball milling to obtain a slurry; the moisture content of the slurry is controlled at 33%-36%, the fineness of the slurry is controlled at 2.0%-2.4% of the 325 mesh screen residue, and the specific gravity of the slurry is greater than or equal to 1.68;

[0106] Step A2, the slurry is sieved and de-ironed, and then aged, the aged slurry is pumped into a spray tower for spray drying to obtain a powder with a moisture content of 6.8%-7.3% and a particle size of 40 mesh accounting for 45%-50%;

[0107] Step A3, the powder is sieved and de-ironed, and then aged, and the aged powder is pressed into a ceramic body at 30 MPa;

[0108] Step A4, the ceramic body is dried in a drying kiln at a temperature of 100℃ for 60 minutes, and a glaze paste is applied to the dried ceramic body to obtain a glazed body;

[0109] Step A5, the oxidation decomposition zone of the kiln is heated from 950℃ to 1100℃, the heating time of the oxidation decomposition zone is 20-30 minutes; the sintering zone is heated from 1100℃ to 1210℃, the heating time of the sintering zone is 10-15 minutes; the glazed body is fired at a firing temperature of 1210-1230℃ for a firing period of 40 minutes to obtain a ceramic tile; the tensile strength of the ceramic tile is not less than 38 MPa.

[0110] Example Two:

[0111] The body formula of the present embodiment includes, by weight parts:

[0112] Raw ore slurry 28 parts, sodium feldspar 25 parts, potassium feldspar 35 parts, wollastonite 8 parts, magnesia 4 parts.

[0113] The chemical composition of the wollastonite includes, by mass percentage:

[0114] SiO2 55.1%, Al2O3 0.8%, Fe2O3 0.3%, CaO 42%, MgO 0.8%, ignition loss 1%.

[0115] The preparation process steps of the ceramic tile include:

[0116] Step A1, by weight parts, mix raw clay 28%, albite 25%, potassium feldspar 35%, wollastonite 8%, magnesia 4%, and add water glass and body debonder, then ball mill to obtain a slurry; the moisture content of the slurry is controlled at 33%-36%, the fineness of the slurry is controlled at 2.0%-2.4% of 325 mesh screen residue, and the specific gravity of the slurry is greater than or equal to 1.68;

[0117] Step A2, sieve and remove iron from the slurry, then age, and then pump the aged slurry into a spray tower for spray drying to obtain a powder with a moisture content of 6.8%-7.3% and a particle size of 40 mesh accounting for 45%-50%;

[0118] Step A3, sieve and remove iron from the powder, then age, and then press the aged powder into a ceramic body at 32 MPa;

[0119] Step A4, dry the ceramic body in a drying kiln at a temperature of 120℃ for 50 minutes, and then apply glaze slurry to the dried ceramic body to obtain a glazed body;

[0120] Step A5, raise the oxidation decomposition zone of the kiln from 950℃ to 1100℃, the oxidation decomposition zone is raised for 20-30 minutes; raise the sintering zone from 1100℃ to 1210℃, the sintering zone is raised for 10-15 minutes; and then sinter the glazed body at a firing temperature of 1210-1230℃ for a firing period of 45 minutes to obtain a ceramic tile; the tensile strength of the ceramic tile is not less than 38 MPa.

[0121] The application provides a high-tensile-strength ceramic body, a ceramic tile and a preparation method.

[0122] It should be understood that the application is not limited to the above examples, and can be improved or changed according to the above description by those skilled in the art, and all these improvements and changes should belong to the protection scope of the appended claims of the application.

Claims

1. A high tensile strength ceramic green body, characterized in that, The raw materials for the ceramic green body, by weight, include: 25-30 parts of raw mud, 15-25 parts of sodium feldspar, 25-35 parts of potassium feldspar, 5-10 parts of wollastonite, and 2-4 parts of magnesia. The chemical composition of the wollastonite, by mass percentage, includes: SiO2 53-56%, Al2O3 0.5-1.5%, Fe2O3 0.3-0.5%, CaO 41-43%, MgO 0.8-1.2%, loss on ignition 1-2%; The chemical composition of the raw ore slime, by mass percentage, includes: SiO2 65~70%, Al2O3 22~27%, Fe2O3 1.2~2.0%, K2O 1.0~1.5%, loss on ignition 2~5%; The chemical composition of the albite, by mass percentage, includes: SiO2 70~75%, Al2O3 13~15%, Fe2O3 0.5~1.5%, CaO 0.3~0.5%, MgO 0.5~1.0%, K2O 1.0~3.0%, Na2O 6.0~8.0%, loss on ignition 1~3%; The chemical composition of the potassium feldspar, by mass percentage, includes: SiO2 65~70%, Al2O3 15~20%, Fe2O3 0.5~1.5%, K2O 3.0~6.0%, Na2O 1.0~2.0%, loss on ignition 1.5~5.5%; The chemical composition of the magnesian earth, by mass percentage, includes: SiO2 64~68%, MgO 22~26%, Al2O3 2.2~2.5%, Fe2O3 1.4~1.6%, CaO 0.5~1.0%, loss on ignition 2~5%; The wollastonite is acicular wollastonite. The acicular wollastonite crystals are arranged in a cross pattern in the ceramic body to form an interwoven network structure, which helps the ceramic body maintain its shape during drying and firing. The acicular wollastonite crystals are interwoven with other particles in the ceramic body to increase the bonding force between particles. The tensile strength of the ceramic product obtained by the ceramic blank is not less than 38 MPa, and the difference between the maximum and minimum tensile strength values ​​at the test points on the ceramic product obtained by the ceramic blank is less than 5 MPa.

2. A method for preparing a ceramic green body, characterized in that, The method for preparing the ceramic green body includes: By weight, 25-30 parts of raw ore slime, 15-25 parts of sodium feldspar, 25-35 parts of potassium feldspar, 5-10 parts of wollastonite, and 2-4 parts of magnesia are mixed, and water glass and a deflocculant for billets are added before ball milling to obtain slurry. After the mud is sieved and iron is removed, it is aged, and the aged mud is spray-dried to obtain powder. The powder is sieved and iron-removed, then aged, and the aged powder is pressed into a ceramic blank under a predetermined molding pressure. The chemical composition of the wollastonite, by mass percentage, includes: SiO2 53-56%, Al2O3 0.5-1.5%, Fe2O3 0.3-0.5%, CaO 41-43%, MgO 0.8-1.2%, loss on ignition 1-2%; The chemical composition of the raw ore slime, by mass percentage, includes: SiO2 65~70%, Al2O3 22~27%, Fe2O3 1.2~2.0%, K2O 1.0~1.5%, loss on ignition 2~5%; The chemical composition of the albite, by mass percentage, includes: SiO2 70~75%, Al2O3 13~15%, Fe2O3 0.5~1.5%, CaO 0.3~0.5%, MgO 0.5~1.0%, K2O 1.0~3.0%, Na2O 6.0~8.0%, loss on ignition 1~3%; The chemical composition of the potassium feldspar, by mass percentage, includes: SiO2 65~70%, Al2O3 15~20%, Fe2O3 0.5~1.5%, K2O 3.0~6.0%, Na2O 1.0~2.0%, loss on ignition 1.5~5.5%; The chemical composition of the magnesian earth, by mass percentage, includes: SiO2 64~68%, MgO 22~26%, Al2O3 2.2~2.5%, Fe2O3 1.4~1.6%, CaO 0.5~1.0%, loss on ignition 2~5%; The wollastonite is acicular wollastonite. The acicular wollastonite crystals are arranged in a cross pattern in the ceramic body to form an interwoven network structure, which helps the ceramic body maintain its shape during drying and firing. The acicular wollastonite crystals are interwoven with other particles in the ceramic body to increase the bonding force between particles. The tensile strength of the ceramic product obtained by the ceramic blank is not less than 38 MPa, and the difference between the maximum and minimum tensile strength values ​​at the test points on the ceramic product obtained by the ceramic blank is less than 5 MPa.

3. The method for preparing a ceramic green body according to claim 2, characterized in that, The moisture content of the mud is controlled at 33% to 36%, the fineness of the mud is controlled at 2.0% to 2.4% residue on a 325-mesh sieve, and the specific gravity of the mud is greater than or equal to 1.

68.

4. The method for preparing a ceramic green body according to claim 2, characterized in that, The moisture content of the powder is 6.8% to 7.3%, and the predetermined molding pressure is 30 to 32 MPa.

5. A ceramic tile, characterized in that, The ceramic brick comprises the high tensile strength ceramic green body as described in claim 1, or a ceramic green body prepared by the method for preparing the ceramic green body as described in any one of claims 2 to 4.

6. A method for preparing ceramic tiles as described in claim 5, characterized in that, The method for preparing the ceramic brick includes: The ceramic blank is dried, and a glaze slurry is applied to the dried ceramic blank to obtain a glazed blank; The oxidation decomposition zone of the kiln is heated from 950℃ to 1100℃ for 20-30 minutes, and the sintering zone is heated from 1100℃ to 1210℃ for 10-15 minutes. The glaze blank is then fired at a firing temperature of 1210-1230℃ for 40-45 minutes to obtain ceramic bricks.

7. The method for preparing ceramic bricks according to claim 6, characterized in that, The chemical composition of the glaze slurry, by mass percentage, includes: SiO2 46~50%, Al2O3 14~18%, CaO 3~6%, MgO 2~4%, BaO 3~6%, K2O 1~2%, Na2O 2~4%, ZnO 2~4%, ZrO26~10%.

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