Method for preparing cordierite microcrystalline glass combined aluminum silicate ceramic material by utilizing low-grade natural minerals and product thereof

Abstract

The invention discloses a method for preparing a cordierite microcrystalline glass combined aluminum silicate ceramic material by using low-grade natural minerals and a product thereof. The cordierite microcrystalline glass combined aluminum silicate ceramic material is prepared from a base material and a binding agent, the base material is prepared from the following raw materials in percentage by weight: 10 to 25 percent of cordierite-based microcrystalline glass powder, 10 to 30 percent of mullite aggregate, 30 to 60 percent of corundum aggregate and 10 to 20 percent of clay powder, and the cordierite-based microcrystalline glass powder is prepared from the following raw materials in percentage by weight: 55 to 60 percent of low-grade iron-titanium-rich clay mineral, 30 to 35 percent of magnesium mineral, 5 to 10 percent of quartz and 0.5 to 1 percent of Li2O. According to the invention, cordierite microcrystalline glass prepared from low-grade natural minerals is used as a sintering aid, and cordierite crystals are introduced into microcrystalline glass in an aluminum silicate ceramic matrix in an in-situ synthesis manner, so that a low-temperature sintering aid is provided, and the performance of an aluminum silicate ceramic material is effectively improved; and the preparation method has important significance in overcoming the problems existing in application of microcrystalline glass in the prior art and improving the cost performance of the aluminum silicate ceramic material, so that the preparation method has wide market prospects and is beneficial to popularization and application and progress and development of industrial technologies.

Description

Technical Field

[0001] The present invention relates to the technical field of ceramic materials, and in particular to a method for preparing cordierite glass-ceramics combined with aluminum silicate ceramic materials by utilizing low-grade natural minerals and products thereof. Background Art

[0002] Clay is an important non-metallic mineral resource in my country. Its application scope is constantly expanding, and its demand is also increasing year by year. However, clay is a non-renewable resource. With the expansion of its application field, the resource is in short supply, and the price is rising accordingly. In particular, high-quality and high-end clay processed products are far from meeting the needs of market consumption. The ceramic industry has higher requirements for clay quality than other industries, so my country's ceramic industry is facing the dilemma of decreasing high-quality raw materials, which has become a bottleneck restricting the healthy and sustainable development of the industry and has become a hot issue in recent years. Therefore, many scientists have begun to look for low-grade clay to replace high-quality clay and its possible application in the ceramic industry.

[0003] However, low-grade clay has a high impurity content and a whiteness of less than 80%. Its content of colorant elements such as iron (Fe) and titanium (Ti) is relatively higher than that of ordinary clay. The groups formed by the calcination of Fe or Ti elements act as strong colorants, which significantly reduce the whiteness of the porcelain body. When the ratio of Fe and Ti elements reaches a certain ratio, the compounds they form have greater coloring ability. Therefore, in the ceramic industry, the content of impurities such as Fe and Ti must be strictly controlled, and only a small amount of medium and low-grade clay can be used in the building ceramics industry. The ceramic industry generally has higher requirements for clay than other industries, so low-grade kaolin is currently difficult to be directly used in the ceramic industry. In addition to impurities such as Fe and Ti, low-grade clay also contains some alkaline earth metal oxides and alkali metal oxides, which makes it difficult to use in refractory materials.

[0004] Low-grade clay contains more impurities, which is helpful for melting and preparing glass-ceramics. In addition, the presence of various oxides helps the low-temperature viscous flow of glass. In this way, glass-ceramics prepared from low-grade clay or natural minerals are expected to be used as a sintering aid with excellent performance. If the target crystals and the number of crystals are further controlled through the heat treatment process of glass-ceramics, it will help the products to obtain the required performance. So far, there has been no report on the use of low-grade natural minerals to prepare glass-ceramics for use as a low-temperature sintering aid or for the preparation of aluminum silicate ceramic materials. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for preparing cordierite glass-ceramics combined with aluminum silicate ceramic materials using low-grade natural minerals, using natural low-grade minerals as raw materials to prepare cordierite glass-ceramics as a sintering aid for aluminum silicate ceramics, introducing low expansion phases such as cordierite by phase separation and crystallization and in-situ synthesis, and by complementing the sintering properties of glass and ceramic matrix, thereby obtaining an aluminum silicate ceramic material with high density and better thermal shock resistance. Another purpose of the present invention is to provide a product obtained based on the above method for preparing cordierite glass-ceramics combined with aluminum silicate ceramic materials using low-grade natural minerals.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] The present invention provides a method for preparing a cordierite glass-ceramic combined with an aluminum silicate ceramic material by using low-grade natural minerals. The ceramic material is prepared from a base material and a binder; the raw material composition of the base material is 10-25wt% of cordierite-based glass-ceramic powder, 10-30wt% of mullite aggregate, 30-60wt% of corundum aggregate, and 10-20wt% of clay powder, wherein the raw material composition of the cordierite-based glass-ceramic powder is 55-60wt% of low-grade iron-titanium-rich clay mineral, 30-35wt% of magnesia mineral, 5-10wt% of quartz, and 0.5-1wt% of Li2O; the amount of the binder is 8-12wt% of the base material; the preparation method comprises the following steps:

[0008] (1) mixing the raw materials of the cordierite-based microcrystalline glass powder according to the composition ratio, melting them into glass liquid, then pouring the glass liquid into water to quench to obtain a frit, and then ball milling to obtain the cordierite-based microcrystalline glass powder;

[0009] (2) mixing the base materials according to the raw material composition ratio, adding a binder and mixing evenly, and then pressing and molding, and drying to obtain a green body;

[0010] (3) The green body is sintered in two stages, i.e., a low-temperature sintering is performed at 900-1000°C for a period of ≥10 hours, and then the temperature is raised to 1200-1300°C for a second high-temperature sintering for a period of 3-5 hours; and then naturally cooled to room temperature to obtain a cordierite glass-ceramic combined with aluminum silicate ceramic material.

[0011] Furthermore, the chemical composition of the iron-titanium-rich clay mineral of the present invention is SiO2 42-45%, Al2O3 35-37%, Fe2O3+TiO2 8-9%, RO 0.2-0.4%, R2O 1-1.5%, IL 8.6-11.5%. The particle size of the cordierite microcrystalline glass powder is 10-75 μm, the particle size of the mullite aggregate is 40-325 mesh, the particle size of the corundum aggregate is 40-500 mesh, and the particle size of the clay powder is 25-75 μm. The binder is a PVA solution with a concentration of 5wt%. The clay powder is a combination of two or more of kaolin, ball clay, and bauxite powder; the magnesia mineral is talc and / or serpentine.

[0012] In the above scheme, the melting temperature in step (1) of the present invention is 1500-1600°C and the melting time is 2-3 hours. The moisture content of the green body after drying in step (2) is less than 1%.

[0013] The product obtained by the method of preparing cordierite glass-ceramics combined with aluminum silicate ceramic material using low-grade natural minerals has a water absorption rate of ≤5.5% and a thermal expansion coefficient of ≤3.85×10 -6 ℃ -1 , glass crystallinity ≥91%, flexural strength >70MPa.

[0014] The present invention has the following beneficial effects:

[0015] (1) The present invention utilizes low-grade clay minerals as the main raw material to produce high-quality cordierite glass-ceramics, providing a feasible solution for the high-value resource utilization of low-grade clay minerals. At the same time, the impurities in natural minerals are used to increase the low-temperature viscous flow of glass, promote the crystallization behavior of glass, and improve the crystallinity, thereby improving product performance.

[0016] (2) The present invention uses natural minerals to prepare cordierite glass-ceramics that produce viscous flow at low temperature as a sintering aid, and low-temperature sintering and phase separation are carried out simultaneously. Through long-term heat preservation at low temperature, various aggregates and powders are wrapped with glass powder with good fluidity, which promotes the removal of pores inside the blank, reduces the porosity, and achieves the purpose of lowering the firing temperature of aluminum silicate ceramics. At the same time, long-term heat preservation, combined with the rich Fe and Ti in low-grade clay, promotes phase separation inside the glass frit, and utilizes the local component deviation caused by phase separation and the formed interface, combined with the surface defects of the frit powder, to jointly promote crystallization behavior and improve crystallinity.

[0017] (3) The introduction of Li2O in the present invention can enhance the low-temperature viscous flow of glass, increase the low-temperature sintering property of glass, and help improve the density of the product. Moreover, since impurities in low-grade clay promote crystallization, only a small amount of Li2O can form a low-expansion spodumene phase in situ in the glass, which helps to reduce the thermal expansion coefficient and form a 4-level thermal expansion coefficient gradient with cordierite, mullite, and corundum, thereby effectively improving the thermal shock resistance of the product.

[0018] (4) The present invention designs a firing system that complements the sintering properties of glass and ceramic blanks. Since clay will expel structural water at low temperatures to form pores, the low-temperature viscous flow of glass frit powder near its transition temperature point is used to offset the pore-forming effect; when the high-temperature crystallization heat treatment is performed, the expansion effect of crystallization causes the overall structure of the product to become loose, and the fine clay powder is used to generate liquid phase flow to promote shrinkage, offsetting this part of the expansion effect, thereby omitting the high-temperature (>1400°C) firing process.

[0019] (5) The present invention avoids the crystallization temperature of the glass by keeping the temperature at a low temperature for a long time, thereby preventing crystallization from reducing the amount of viscous flow, thereby solving the problem that high sintering temperature causes crystallization to weaken the sinterability of the glass, thereby causing poor sintering effect.

[0020] (6) The present invention utilizes impurities (such as CaO, K2O, Na2O) rich in low-grade clay minerals, combined with the introduction of Li2O, to enhance the low-temperature viscous flow of glass, so that the glass and the ceramic body are partially wetted well, and the ion migration ability of the glass is enhanced. Combined with the high activity of another part of the clay and the effect of impurities, the glass is promoted to absorb part of the clay powder and corundum during the high-temperature crystallization process, supplementing the lack of Al2O3 and SiO2 in the glass, making its composition closer to the chemical composition of cordierite and spodumene, and improving the crystallinity of the glass.

[0021] (7) The process of the present invention is simple and the firing temperature is low. It is of great significance for the high-value resource utilization of low-grade clay minerals, improving the quality of aluminum silicate ceramic materials, and overcoming various problems in the application of microcrystalline glass. Therefore, it has broad market prospects and is conducive to the promotion and application and the progress and development of industry technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings:

[0023] Figure 1 This is the XRD spectrum of the cordierite glass-ceramics combined with aluminum silicate ceramic material prepared in the embodiment of the present invention;

[0024] Figure 2This is a microstructure diagram of the phase separation and crystallization of the glass-ceramics portion of the ceramic material of the present invention after acid corrosion (after HF acid corrosion for 60 seconds, scanning electron microscope secondary electron image). DETAILED DESCRIPTION

[0025] Embodiment 1:

[0026] The present embodiment discloses a method for preparing cordierite glass-ceramics combined with aluminum silicate ceramic material by using low-grade natural minerals, which is prepared by base material and binder; the raw material composition of the base material is cordierite-based glass-ceramics powder (particle size 75 μm) 25wt%, mullite aggregate 30wt% (including 15wt% of particle size 40 mesh, 5wt% of particle size 80 mesh, and 10wt% of particle size 325 mesh), corundum aggregate 30wt% (including 15wt% of particle size 40 mesh, 5wt% of particle size 120 mesh, and 10wt% of particle size 400 mesh), and clay powder (particle size 25 μm) 15wt% (including 7.5wt% of kaolin and 7.5wt% of bauxite); the raw material composition of the cordierite-based glass-ceramics powder is low-grade iron-titanium-rich clay mineral (whose chemical composition is SiO245%, Al2O335%, Fe2O3+TiO29%, RO 0.4%, R2O 1.5%, IL9.1%) 55wt%, talc 35wt%, quartz 9.5wt%, Li2O0.5wt%; the binder is a 5wt% PVA solution, and its amount is 12wt% of the base material; the preparation method comprises the following steps:

[0027] (1) mixing the raw materials of the cordierite-based microcrystalline glass powder according to the composition ratio, placing them in an electric furnace at a temperature of 1600° C. for 2 h to melt them into glass liquid, then pouring the glass liquid into water to quench and obtain a frit, and then ball milling to obtain cordierite-based microcrystalline glass powder;

[0028] (2) After mixing the above base materials according to the raw material composition ratio, adding a binder and mixing evenly, then pressing and molding, and drying at a temperature of 110° C. to obtain a green body with a moisture content of less than 1%;

[0029] (3) The green body is sintered in two stages, i.e., a low-temperature sintering is performed at 900°C for 11 hours, and then the temperature is raised to 1200°C for a second high-temperature sintering for 4 hours; and then naturally cooled to room temperature to obtain cordierite glass-ceramics combined with aluminum silicate ceramic material.

[0030] Embodiment 2:

[0031] The present embodiment discloses a method for preparing a cordierite glass-ceramic combined with an aluminum silicate ceramic material using low-grade natural minerals, which is prepared from a base material and a binder; the base material comprises 10 wt% of cordierite-based glass-ceramic powder (particle size 10 μm), 20 wt% of mullite aggregate (including 10 wt% of 40-mesh particle size and 10 wt% of 80-mesh particle size), 50 wt% of corundum aggregate (including 30 wt% of 40-mesh particle size, 10 wt% of 250-mesh particle size and 10 wt% of 500-mesh particle size), and 20 wt% of clay powder (particle size 50 μm) (including 10 wt% of ball clay and 10 wt% of bauxite); the raw material composition of the cordierite-based glass-ceramic powder is a low-grade iron-titanium-rich clay mineral (whose chemical composition is SiO2 42%, Al2O3 37%, Fe2O3+TiO2 8%, RO 0.2%, R2O1.3%, IL11.5%) 60wt%, talc 17wt%, serpentine 17wt%, quartz 5wt%, Li2O 1wt%; the binder is a 5wt% PVA solution, and its amount is 8wt% of the base material; the preparation method comprises the following steps:

[0032] (1) mixing the raw materials of the cordierite-based microcrystalline glass powder according to the composition ratio, placing them in an electric furnace at a temperature of 1500° C. for 3 hours to melt them into glass liquid, then pouring the glass liquid into water to quench and obtain a fused block, and obtaining cordierite-based microcrystalline glass powder after ball milling;

[0033] (2) After mixing the above base materials according to the raw material composition ratio, adding a binder and mixing evenly, then pressing and molding, and drying at 100° C. to obtain a green body with a moisture content of less than 1%;

[0034] (3) The green body is sintered in two stages, i.e., a low-temperature sintering is performed at 950°C for 11 hours, and then the temperature is raised to 1250°C for a second high-temperature sintering for 4 hours; and then naturally cooled to room temperature to obtain cordierite glass-ceramics combined with aluminum silicate ceramic material.

[0035] Embodiment three:

[0036] The present embodiment provides a method for preparing a cordierite glass-ceramic combined with an aluminum silicate ceramic material using low-grade natural minerals, which is prepared from a base material and a binder; the raw material composition of the base material is cordierite-based glass-ceramic powder (particle size 35 μm) 15wt%, mullite aggregate (particle size 80 mesh) 10wt%, corundum aggregate 60wt% (including 30wt% of 40 mesh, 10wt% of 325 mesh, and 20wt% of 500 mesh), and clay powder (particle size 68 μm) 15wt% (including 5wt% kaolin, 5wt% bauxite, and 5wt% ball clay); the raw material composition of the cordierite-based glass-ceramic powder is a low-grade iron-titanium-rich clay mineral (whose chemical composition is SiO2 43%, Al2O3 36%, Fe2O3+TiO2 8.5%, RO 0.3%, R2O 1%, IL11.2%) 60wt%, serpentine 30wt%, quartz 9wt%, Li2O 1wt%; the binder is a 5wt% PVA solution, and its amount is 10wt% of the base material; the preparation method comprises the following steps:

[0037] (1) mixing the raw materials of the cordierite-based microcrystalline glass powder according to the composition ratio, placing them in an electric furnace at a temperature of 1550° C. for 2.5 hours to melt them into glass liquid, then pouring the glass liquid into water to quench and obtain a fused block, and obtaining cordierite-based microcrystalline glass powder after ball milling;

[0038] (2) After mixing the above base materials according to the raw material composition ratio, adding a binder and mixing evenly, then pressing and molding, and drying at a temperature of 110° C. to obtain a green body with a moisture content of less than 1%;

[0039] (3) The green body is sintered in two stages, i.e., a low-temperature sintering is performed at 1000°C for 10 hours, and then the temperature is raised to 1300°C for a second high-temperature sintering for 3 hours; and then naturally cooled to room temperature to obtain cordierite glass-ceramics combined with aluminum silicate ceramic material.

[0040] Embodiment 4:

[0041] The present embodiment provides a method for preparing cordierite glass-ceramics combined with aluminum silicate ceramic materials using low-grade natural minerals, which is prepared from a base material and a binder; the raw material composition of the base material is cordierite-based glass-ceramics powder (particle size 35 μm) 20wt%, mullite aggregate (particle size 80 mesh) 30wt%, corundum aggregate 40wt% (including 30wt% of 40 mesh particle size and 10wt% of 325 mesh particle size), and clay powder (particle size 75 μm) 10wt% (including 5wt% kaolin and 5wt% bauxite); the raw material composition of the cordierite-based glass-ceramics powder is a low-grade iron-titanium-rich clay mineral (whose chemical composition is SiO2 44%, Al2O3 37%, Fe2O3+TiO2 8.8%, RO 0.2%, R2O1.4%, IL8.6%) 56.25wt%, talc 33wt%, quartz 10wt%, Li2O 0.75wt%; the binder is a 5wt% PVA solution, and its amount is 11wt% of the base material; the preparation method comprises the following steps:

[0042] (1) mixing the raw materials of the cordierite-based microcrystalline glass powder according to the composition ratio, placing them in an electric furnace at a temperature of 1575° C. for 3 hours to melt them into glass liquid, then pouring the glass liquid into water to quench and obtain a frit, and then ball milling to obtain cordierite-based microcrystalline glass powder;

[0043] (2) After mixing the above base materials according to the raw material composition ratio, adding a binder and mixing evenly, then pressing and molding, and drying at a temperature of 110° C. to obtain a green body with a moisture content of less than 1%;

[0044] (3) The green body is sintered in two stages, i.e., a low-temperature sintering is performed at 975°C for 12 hours, and then the temperature is raised to 1300°C for a second high-temperature sintering for 4 hours; and then naturally cooled to room temperature to obtain cordierite glass-ceramics combined with aluminum silicate ceramic material.

[0045] Comparative Examples 1, 2, 3 and 4 are respectively prepared by not using low-grade natural minerals to prepare glass-ceramics (the original MAS oxide composition in the glass-ceramics is replaced by high-purity MgO, Al2O3 and SiO2), not adding clay powder (i.e. replacing clay with mullite of the same particle size), not keeping warm at low temperature for a long time (i.e. the keeping time for a low-temperature sintering is 3h), and not adding Li2O to the glass-ceramics (the remaining MAS oxide composition is according to the original ratio) (other conditions are the same as those in Example 1).

[0046] Comparative Example 5 is a method in which no clay powder is added (i.e., clay is replaced by mullite of the same particle size) and no low-grade natural minerals are used to prepare microcrystalline glass (the original MAS oxide composition in the microcrystalline glass is replaced by high-purity MgO, Al2O3, and SiO2) (other conditions are the same as those in Example 2).

[0047] Comparative Example 6 is in which no clay powder is added (i.e., mullite of the same particle size is used to replace clay), no low-grade natural minerals are used to prepare microcrystalline glass (the original MAS oxide composition in the microcrystalline glass is replaced by high-purity MgO, Al2O3, and SiO2), and no long-term low-temperature insulation (i.e., the insulation time for one period of low-temperature sintering is 3h) (other conditions are the same as those in Example 2).

[0048] The various properties and glass crystallinity of the ceramic materials prepared in the examples of the present invention and the comparative examples are shown in Table 1.

[0049] Table 1 Performance and glass crystallinity of ceramic materials obtained in the embodiments of the present invention and the comparative examples

[0050]

[0051] The glass crystallinity was calculated by the internal standard method (with corundum as reference) and the MDI Jade 6.5 software to calculate the amount of cordierite and spodumene in the blank, and then divided by the amount of added glass.

[0052] It can be seen from Table 1 that the cordierite glass-ceramics combined with the aluminum silicate ceramic material prepared in the embodiments of the present invention have low water absorption, low thermal expansion coefficient, high crystallinity and high strength.

[0053] By comparing the data of Example 1 with that of Comparative Example 1, it can be seen that when low-grade natural minerals are not used as the main raw materials for preparing microcrystalline glass, the water absorption rate of the product increases, the thermal expansion coefficient increases, and the crystallinity decreases. Because of the lack of impurities of natural minerals such as low-grade clay (including K2O, Na2O, CaO, TiO2, Fe2O3), the low-temperature sintering ability and crystallization tendency of the glass decrease, the density and the crystallinity of cordierite and spodumene are reduced, and the thermal expansion coefficient is also increased. By comparing the data of Example 1 with that of Comparative Example 2, it can be seen that clay powder is not added as part of the ceramic body, and the product The water absorption rate of the product increases, the thermal expansion coefficient increases, and the crystallinity decreases. Because the high-temperature sintering effect of clay is lacking, the effect of glass crystallization expansion is not offset. At the same time, the lack of high-activity clay integrated into the glass reduces the crystallinity of cordierite and spodumene, and also increases the thermal expansion coefficient. By comparing the data of Example 1 with Comparative Example 3, it can be seen that the water absorption rate of the product increases, the thermal expansion coefficient increases, and the crystallinity decreases due to the lack of long-term low-temperature insulation. This is because, on the one hand, the low-temperature viscous flow of the glass is lacking, which increases the number of pores; on the other hand, the lack of a long-term low-temperature insulation step causes the separation. The number of phases is small, and the number of glass phases and interfaces are missing, which is not conducive to crystallization; compared with the data of Example 1 and Comparative Example 4, it can be seen that Li2O is not added to the microcrystalline glass, the sintering effect of the microcrystalline glass is reduced, and the crystallinity is reduced. Because of the lack of Li2O, the fluidity of the glass is reduced, and spodumene cannot be precipitated. At the same time, it is not easy to absorb clay fine powder, resulting in a decrease in crystallinity. At the same time, there is a lack of a gradient of the 4-level thermal expansion coefficient, which is not conducive to thermal shock resistance; compared with the data of Example 2 and Comparative Example 5, it can be seen that low-grade natural minerals are not used as the main raw materials to prepare microcrystalline glass, and clay powder is not added as the ceramic body The comprehensive performance of the product is reduced because of the lack of the beneficial effects of low-grade natural minerals and clay on improving the sintering property and crystallinity of glass. By comparing the data of Example 2 with Comparative Example 6, it can be seen that low-grade natural minerals are not used as the main raw materials to prepare microcrystalline glass, clay is not added as part of the ceramic body, and the product is not kept at low temperature for a long time. The comprehensive performance of the product is greatly reduced. In addition to the lack of the beneficial effects of low-grade natural minerals and clay, the beneficial effects of long-term low-temperature insulation on viscous flow, such as promoting particle rearrangement, eliminating pores, and promoting phase separation, are also lacking.

[0054] The cordierite glass-ceramics prepared in the embodiment of the present invention are combined with aluminum silicate ceramic materials, such as Figure 1 As shown, it contains the crystal phases of corundum, mullite, cordierite and spodumene; Figure 2 As shown in the figure, after HF acid corrosion, the protrusions are not easily corroded and separated, while the crystals mainly grow on a large scale at the interface or edge of the separated phases, which illustrates the importance of separation to crystallization.

Claims

1. A method for preparing cordierite glass-ceramics combined with aluminum silicate ceramic materials using low-grade natural minerals, characterized in that: The ceramic material is prepared from a base material and a binder; the raw material composition of the base material is 10-25wt% of cordierite-based microcrystalline glass powder, 10-30wt% of mullite aggregate, 30-60wt% of corundum aggregate, and 10-20wt% of clay powder, wherein the raw material composition of the cordierite-based microcrystalline glass powder is 55-60wt% of low-grade iron-titanium-rich clay mineral, 30-35wt% of magnesia mineral, 5-10wt% of quartz, and 0.5-1wt% of Li2O; the amount of the binder is 8-12wt% of the base material; the preparation method comprises the following steps: (1) mixing the raw materials of the cordierite-based microcrystalline glass powder according to the composition ratio, melting them into glass liquid, then pouring the glass liquid into water to quench to obtain a frit, and then ball milling to obtain the cordierite-based microcrystalline glass powder; (2) mixing the base materials according to the raw material composition ratio, adding a binder and mixing evenly, and then pressing and molding, and drying to obtain a green body; (3) The green body is sintered in two stages, i.e., a low-temperature sintering is performed at 900-1000°C for a period of ≥10 hours, and then the temperature is raised to 1200-1300°C for a second high-temperature sintering for a period of 3-5 hours; and then naturally cooled to room temperature to obtain a cordierite glass-ceramic combined with aluminum silicate ceramic material.

2. The method for preparing cordierite glass-ceramics combined with aluminum silicate ceramic materials using low-grade natural minerals according to claim 1, characterized in that: The chemical composition of the iron-titanium-rich clay mineral is SiO2 42-45%, Al2O3 35-37%, Fe2O3+TiO2 8-9%, RO 0.2-0.4%, R2O 1-1.5%, and IL 8.6-11.5%.

3. The method for preparing cordierite glass-ceramics combined with aluminum silicate ceramic materials using low-grade natural minerals according to claim 1, characterized in that: The particle size of the cordierite microcrystalline glass powder is 10-75 μm, the particle size of the mullite aggregate is 40-325 meshes, the particle size of the corundum aggregate is 40-500 meshes, and the particle size of the clay powder is 25-75 μm.

4. The method for preparing cordierite glass-ceramics combined with aluminum silicate ceramic materials using low-grade natural minerals according to claim 1, characterized in that: The binder is a PVA solution with a concentration of 5 wt%.

5. The method for preparing cordierite glass-ceramics combined with aluminum silicate ceramic materials using low-grade natural minerals according to claim 1, characterized in that: The clay powder is a combination of two or more of kaolin, ball clay and bauxite powder; the magnesium mineral is talc and / or serpentine.

6. The method for preparing cordierite glass-ceramics combined with aluminum silicate ceramic materials using low-grade natural minerals according to claim 1, characterized in that: In the step (1), the melting temperature is 1500-1600° C. and the melting time is 2-3 hours.

7. The method for preparing cordierite glass-ceramics combined with aluminum silicate ceramic materials using low-grade natural minerals according to claim 1, characterized in that: The moisture content of the green body after drying in step (2) is less than 1%.

8. A product obtained by the method for preparing cordierite glass-ceramics combined with aluminum silicate ceramic materials using low-grade natural minerals as described in any one of claims 1 to 7.

9. The product according to claim 8, characterized in that: The cordierite glass-ceramics combined with the aluminum silicate ceramic material has a water absorption rate of ≤5.5% and a thermal expansion coefficient of ≤3.85×10 -6 ℃ -1 , glass crystallinity ≥91%, flexural strength >70MPa.

Images