CN115180932B - Mullite porous ceramic based on high-sodium industrial alumina in-situ synthesis and preparation method thereof - Google Patents
Mullite porous ceramic based on high-sodium industrial alumina in-situ synthesis and preparation method thereof Download PDFInfo
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Abstract
The invention relates to an in-situ synthesis mullite porous ceramic based on high-sodium industrial alumina and a preparation method thereof. The technical proposal is as follows: mixing the high-sodium industrial alumina fine powder and the tertiary alumina fine powder in the mass ratio of 1:2.3-3.3 in a ball mill to obtain a mixture; adding 10-20wt% of polyvinyl alcohol solution into the mixture, and mixing to obtain ceramic powder; molding ceramic powder under 80-150 MPa, and drying at 100-110 ℃; then placing the ceramic in a muffle furnace, preserving heat for 2-3 hours in the air atmosphere at 1550-1650 ℃, and cooling to obtain the mullite porous ceramic based on high-sodium industrial alumina in-situ synthesis. The main chemical components of the high-sodium industrial alumina fine powder are as follows: al (Al) 2 O 3 ≥98wt％，Na 2 O is more than or equal to 1.2wt%; the invention has low cost, energy conservation and environmental protection; the prepared product has good thermal shock resistance, good air permeability, excellent mechanical property and remarkable economic benefit.
Description
Technical Field
The invention belongs to the technical field of mullite porous ceramics. In particular to mullite porous ceramic synthesized in situ based on high-sodium industrial alumina and a preparation method thereof.
Background
Industrial alumina is often used in the field of refractory materials as a primary raw material for the production of corundum. At present, 95% of industrial alumina in the world is produced by the Bayer process, and because NaOH solution is required to be added in the production process to dissolve out the alumina, part of Na exists in the calcined industrial alumina product 2 O, as shown in formula (1), 1% Na as an impurity 2 O will react with Al at high temperature 2 O 3 16% of beta-Al is generated 2 O 3 ，β-Al 2 O 3 Is far more brittle than alpha-Al 2 O 3 The mechanical properties of the material are thus significantly reduced. And industrial alumina has a large number of pores left by mother salt decomposition, and a large number of natural pores exist in the structure due to phase change or dehydration reaction and the like in the sintering process.
The mullite porous ceramic is a ceramic material which is sintered at high temperature and has a large number of interconnected or isolated pores inside. Industrial alumina is often used as an alumina source to synthesize mullite porous ceramics.
(1) Wang Tao et al (Wang Tao et al. Preparation of high-strength porous ceramic Material by in-situ mullite Synthesis with silica fume [ J ]]Silicate report, 2013, 32 (11): 2244-2248.) mullite porous ceramics were prepared by in situ reaction using silica micropowder with industrial alumina as starting material. Although porous ceramics of mullite crystal-interlaced structure were prepared, al using industrial alumina 2 O 3 The content is 99.75 percent, and the impurity content is extremely small, so the raw material impurity removal cost is high. And the pore-forming agent is added, so that the natural pore structure of the industrial alumina mother salt artefact is not effectively utilized, the cost is increased, and the environment is polluted.
(2) Chen Gangling (Chen Gangling. Preparation of high-strength porous mullite support by in-situ reaction sintering [ J ]. Rare metal materials and engineering, 2008, 37 (z 1): 74-77.) the porous mullite support is prepared by in-situ reaction sintering using clay mineral and industrial alumina as raw materials, and has the advantages that the prepared mullite support has good pore structure and higher mechanical properties, but has the disadvantages that: feldspar is added in the sintering process to provide a liquid phase environment for mullite growth, more impurities are introduced into the system, meanwhile, the pore structure of the mullite crystal column mainly comprises mullite crystal columns, along with the increase of the sintering temperature, the densification process of the material is accelerated, the pore size is reduced, and the advantages of high strength and high porosity cannot be achieved.
The high sodium industrial alumina fine powder is low-grade industrial alumina which is not treated by sodium removal process, and Na in the industrial alumina 2 O is generally considered a detrimental impurity and is also severely limited in Na within the alumina product standards (GB/T24487-2009) 2 Content of O (Na 2 O<0.7 wt%). Thus in order to reduce Na in industrial alumina 2 O content, a lot of resources and energy are consumed (e.g. by reacting beta-Al 2 O 3 High temperature calcination to convert to gas phase to reduce Na 2 O content), but for high Na 2 The industrial alumina with O content is not disclosed and reported for synthesizing mullite porous ceramics.
Disclosure of Invention
The invention aims to overcome the defects of the prior art, and aims to provide a preparation method for synthesizing mullite porous ceramic in situ based on high-sodium industrial alumina, which is low in cost and environment-friendly; the mullite porous ceramic prepared by the method and based on the in-situ synthesis of high-sodium industrial alumina has the advantages of good thermal shock resistance, good air permeability, excellent mechanical property and remarkable economic benefit.
In order to achieve the above purpose, the invention adopts the following technical scheme:
mixing the high-sodium industrial alumina fine powder and the tertiary alumina fine powder according to the mass ratio of 1:2.3-3.3, and placing the high-sodium industrial alumina fine powder and the tertiary alumina fine powder in a ball mill to mix for 1-2 hours to obtain a mixture; and adding 10-20wt% of polyvinyl alcohol solution into the mixture, and uniformly mixing to obtain the ceramic powder.
Placing the ceramic powder into a die, performing mechanical press forming under the condition of 80-150 MPa, and drying for 20-24 hours at the temperature of 100-110 ℃; and then placing the ceramic in a muffle furnace, preserving heat for 2-3 hours in an air atmosphere at 1550-1650 ℃, and cooling to obtain the mullite porous ceramic synthesized in situ based on high-sodium industrial alumina.
The high-sodium industrial alumina fine powder refers to industrial alumina which is not treated by a sodium removal process, and the main chemical components of the high-sodium industrial alumina fine powder are as follows: al (Al) 2 O 3 ≥98wt%，Na 2 O is more than or equal to 1.2wt%; the granularity of the high-sodium industrial alumina micro powder is 0.05-0.1 mm.
The three-stage alumina fine powder comprises the following components: al (Al) 2 O 3 The content is 45-60wt%, al 2 O 3 ∶SiO 2 The mass ratio of (2) is 1-1.8:1; the granularity of the tertiary alumina fine powder is less than or equal to 0.01mm.
The polyvinyl alcohol solution is a mixed solution of analytically pure polyvinyl alcohol and deionized water; wherein: the mass ratio of the analytically pure polyvinyl alcohol to the deionized water is 0.05-0.06:1.
The grinding balls of the ball mill are corundum balls.
By adopting the technical scheme, compared with the prior art, the invention has the following positive effects:
(1) The liquid phase forming temperature of the three-stage bauxite is lower than that of beta-Al 2 O 3 The formation temperature of Na on the mother salt artefact particles 2 O does not form beta-Al 2 O 3 And absorbed by the liquid phase formed by the uniformly dispersed tertiary alumina fine powder. The method is obtained by calculating the Factsag thermodynamic software: the composition evolution diagram of the three-stage alumina and the high-sodium industrial alumina in the prepared mullite porous ceramic based on the in-situ synthesis of the high-sodium industrial alumina in the sintering process is shown; the component evolution diagram of the low-sodium industrial alumina in-situ synthesized mullite porous ceramic in the sintering process is shown. Thus, it is known that the mullite formation amount and the liquid phase content of the high-sodium industrial alumina and the low-sodium industrial alumina are not significantly different in the sintering process. In addition, as known from calculation of the FactSAge thermodynamic software, na is found in industrial alumina 2 Increase of O content, liquidThe viscosity of the phase decreases. The results indicate more Na 2 O is dissolved in liquid phase to permeate into the gaps of mother salt false marks, so that the reactivity is increased. Meanwhile, the reduction of the viscosity provides a liquid phase environment of the mullite crystal column, promotes the growth of the mullite crystal column, enables the crystal size of the mullite crystal column to be larger, and improves the mechanical property of the mullite porous ceramic synthesized in situ based on high-sodium industrial alumina.
(2) According to the invention, the large-granularity high-sodium industrial alumina fine powder with the mother salt false structure is blended with the small-granularity tertiary alumina fine powder, and the porous framework structure with large-size aperture of the high-sodium industrial alumina is effectively reserved by utilizing the pore structure characteristics of the mother salt false structure material, so that the tertiary alumina fine powder is uniformly distributed around the structural framework of the high-sodium industrial alumina.
(3) According to the mullite crystal column formed in the liquid phase sintering process of the mullite porous ceramic based on the high-sodium industrial alumina in-situ synthesis, the solid phase sintering alumina crystal grains with lower structural strength are replaced, the original pore structure is expanded through the growth of the mullite crystal column, and the pore size and the air permeability of the mullite porous ceramic based on the high-sodium industrial alumina in-situ synthesis are remarkably improved. The mullite crystal columns are all supported by the mother salt false skeleton of the high-sodium industrial alumina, and the original loose mother salt false structure is converted into the inter-column crossed structure of the mullite crystal columns, so that the thermal shock resistance of the mullite porous ceramic synthesized in situ based on the high-sodium industrial alumina can be improved.
(4) The invention adopts high Na 2 The industrial alumina with the O content has rich sources and low cost. Especially, the high-temperature calcination treatment in the sodium removal process is not needed, and the resources and energy sources can be saved. Therefore, reasonably apply high Na 2 The industrial alumina with the O content is beneficial to improving the utilization efficiency of energy and resources, realizes the high value-added conversion of low-value raw materials, and has remarkable economic benefit.
The in-situ synthesis mullite porous ceramic based on high-sodium industrial alumina prepared by the invention is detected by the following steps: the main phase is mullite phase, and the pore-forming structure is in a through state; the volume density is 1.82-2.10 g/cm 3 The apparent porosity is 33 to 40 percent, and the averageThe aperture is 35-50 mu m, and the cold state compressive strength is 90-110 MPa.
Therefore, the invention has low cost, energy conservation and environmental protection; the prepared mullite porous ceramic based on the in-situ synthesis of high-sodium industrial alumina has the advantages of good thermal shock resistance, good air permeability, excellent mechanical property and remarkable economic benefit.
Drawings
FIG. 1 is a schematic diagram of the composition evolution of two raw materials, namely high sodium industrial alumina and tertiary alumina, in the in-situ synthesis of mullite porous ceramic based on high sodium industrial alumina, prepared by the invention in the sintering process;
FIG. 2 is a schematic diagram showing the composition evolution of the prepared low-sodium industrial alumina in-situ synthesized mullite porous ceramic in the sintering process;
FIG. 3 shows different Na values in industrial alumina 2 Schematic diagram of influence of O content on liquid phase viscosity of in-situ synthesized mullite porous ceramic;
FIG. 4 is a graph of the microscopic morphology of the high sodium commercial alumina feedstock employed in the present invention under high temperature conditions;
fig. 5 is a microscopic morphology picture of mullite porous ceramic prepared by the invention and based on high-sodium industrial alumina in-situ synthesis.
Detailed Description
The invention is further described in connection with the drawings and the detailed description which follow, without limiting the scope thereof.
In this embodiment:
the high-sodium industrial alumina fine powder is industrial alumina which is not treated by a sodium removal process, and the granularity of the high-sodium industrial alumina fine powder is 0.05-0.1 mm;
the granularity of the tertiary alumina fine powder is less than or equal to 0.01mm;
the grinding balls of the ball mill are corundum balls.
The embodiments are not described in detail.
Example 1
An in-situ synthesis mullite porous ceramic based on high-sodium industrial alumina and a preparation method thereof. The preparation method of the embodiment is as follows:
mixing the high-sodium industrial alumina fine powder and the tertiary alumina fine powder according to the mass ratio of 1:2.3, and placing the high-sodium industrial alumina fine powder and the tertiary alumina fine powder into a ball mill to mix for 1 hour to obtain a mixture; and adding 10wt% polyvinyl alcohol solution of the mixture, and uniformly mixing to obtain the ceramic powder.
Placing the ceramic powder into a die, performing mechanical press forming under the condition of 80MPa, and drying for 24 hours at the temperature of 110 ℃; then placing the ceramic in a muffle furnace, preserving heat for 3 hours under the conditions of air atmosphere and 1550 ℃, and cooling to obtain the mullite porous ceramic based on high-sodium industrial alumina in-situ synthesis.
The main chemical components of the high-sodium industrial alumina fine powder are as follows: al (Al) 2 O 3 98.2wt% of Na 2 O was 1.2wt%.
The three-stage alumina fine powder comprises the following components: al (Al) 2 O 3 The content is 48wt%, al 2 O 3 ∶SiO 2 1.3:1.
The polyvinyl alcohol solution is a mixed solution of analytically pure polyvinyl alcohol and deionized water; wherein: the mass ratio of the analytically pure polyvinyl alcohol to the deionized water is 0.05:1.
The in-situ synthesis mullite porous ceramic based on high sodium industrial alumina prepared in the embodiment is detected: the main phase is mullite phase, and the pore-forming structure is in a through state; bulk density of 1.82g/cm 3 The apparent porosity was 38%, the average pore diameter was 50. Mu.m, and the cold compressive strength was 110MPa.
Example 2
An in-situ synthesis mullite porous ceramic based on high-sodium industrial alumina and a preparation method thereof. The preparation method of the embodiment is as follows:
mixing the high-sodium industrial alumina fine powder and the tertiary alumina fine powder according to the mass ratio of 1:2.5, and placing the high-sodium industrial alumina fine powder and the tertiary alumina fine powder into a ball mill to mix for 1 hour to obtain a mixture; and adding 13wt% polyvinyl alcohol solution into the mixture, and uniformly mixing to obtain the ceramic powder.
Placing the ceramic powder into a die, performing mechanical press forming under the condition of 100MPa, and drying for 22 hours under the condition of 110 ℃; then placing the ceramic in a muffle furnace, preserving heat for 3 hours in the air atmosphere at 1600 ℃, and cooling to obtain the mullite porous ceramic based on high-sodium industrial alumina in-situ synthesis.
The main chemical components of the high-sodium industrial alumina fine powder are as follows: al (Al) 2 O 3 98.5wt% of Na 2 O was 1.3wt%.
The three-stage alumina fine powder comprises the following components: al (Al) 2 O 3 The content is 52wt%, al 2 O 3 ∶SiO 2 1.5:1.
The polyvinyl alcohol solution is a mixed solution of analytically pure polyvinyl alcohol and deionized water; wherein: the mass ratio of the analytically pure polyvinyl alcohol to the deionized water is 0.05:1.
The in-situ synthesis mullite porous ceramic based on high sodium industrial alumina prepared in the embodiment is detected: the main phase is mullite phase, and the pore-forming structure is in a through state; bulk density of 2.03g/cm 3 The apparent porosity was 38%, the average pore diameter was 42. Mu.m, and the cold compressive strength was 98MPa.
Example 3
An in-situ synthesis mullite porous ceramic based on high-sodium industrial alumina and a preparation method thereof. The preparation method of the embodiment is as follows:
mixing the high-sodium industrial alumina fine powder and the tertiary alumina fine powder according to the mass ratio of 1:2.7, and placing the high-sodium industrial alumina fine powder and the tertiary alumina fine powder into a ball mill to mix for 1.5 hours to obtain a mixture; and adding a polyvinyl alcohol solution with 15wt% of the mixture, and uniformly mixing to obtain the ceramic powder.
Placing the ceramic powder into a die, performing mechanical press forming under the condition of 120MPa, and drying for 20 hours at the temperature of 110 ℃; then placing the ceramic in a muffle furnace, preserving heat for 3 hours in an air atmosphere at the temperature of 1650 ℃, and cooling to obtain the mullite porous ceramic based on high-sodium industrial alumina in-situ synthesis.
The main chemical components of the high-sodium industrial alumina fine powder are as follows: al (Al) 2 O 3 98.2wt% of Na 2 O was 1.5wt%.
The tertiary alumFine powder of soil: al (Al) 2 O 3 The content is 55wt%, al 2 O 3 ∶SiO 2 1.4:1.
The polyvinyl alcohol solution is a mixed solution of analytically pure polyvinyl alcohol and deionized water; wherein: the mass ratio of the analytically pure polyvinyl alcohol to the deionized water is 0.05:1.
The in-situ synthesis mullite porous ceramic based on high sodium industrial alumina prepared in the embodiment is detected: the main phase is mullite phase, and the pore-forming structure is in a through state; bulk density of 1.96g/cm 3 The apparent porosity was 40%, the average pore diameter was 47. Mu.m, and the cold compressive strength was 102MPa.
Example 4
An in-situ synthesis mullite porous ceramic based on high-sodium industrial alumina and a preparation method thereof. The preparation method of the embodiment is as follows:
mixing the high-sodium industrial alumina fine powder and the tertiary alumina fine powder according to the mass ratio of 1:3, and placing the high-sodium industrial alumina fine powder and the tertiary alumina fine powder into a ball mill to mix for 1.5 hours to obtain a mixture; and adding a polyvinyl alcohol solution with 17wt% of the mixture, and uniformly mixing to obtain the ceramic powder.
Placing the ceramic powder into a die, performing mechanical press forming under 140MPa, and drying at 100 ℃ for 24 hours; then placing the ceramic in a muffle furnace, preserving heat for 2.5 hours in an air atmosphere at the temperature of 1650 ℃, and cooling to obtain the mullite porous ceramic based on high-sodium industrial alumina in-situ synthesis.
The main chemical components of the high-sodium industrial alumina fine powder are as follows: al (Al) 2 O 3 98.3wt% of Na 2 O was 1.4wt%.
The three-stage alumina fine powder comprises the following components: al (Al) 2 O 3 The content is 48wt%, al 2 O 3 ∶SiO 2 1.5:1.
The polyvinyl alcohol solution is a mixed solution of analytically pure polyvinyl alcohol and deionized water; wherein: the mass ratio of the analytically pure polyvinyl alcohol to the deionized water is 0.06:1.
Mullite poly prepared in this example and based on in-situ synthesis of high sodium industrial aluminaThe pore ceramic was tested: the main phase is mullite phase, and the pore-forming structure is in a through state; bulk density of 2.08g/cm 3 The apparent porosity was 33%, the average pore diameter was 38. Mu.m, and the cold compressive strength was 90MPa.
Example 5
An in-situ synthesis mullite porous ceramic based on high-sodium industrial alumina and a preparation method thereof. The preparation method of the embodiment is as follows:
mixing the high-sodium industrial alumina fine powder and the tertiary alumina fine powder according to the mass ratio of 1:3.3, and placing the high-sodium industrial alumina fine powder and the tertiary alumina fine powder into a ball mill to mix for 2 hours to obtain a mixture; and adding a polyvinyl alcohol solution with the weight of 20% of the mixture, and uniformly mixing to obtain the ceramic powder.
Placing the ceramic powder into a die, performing mechanical press forming under 150MPa, and drying at 100 ℃ for 22 hours; then placing the ceramic in a muffle furnace, preserving heat for 2 hours in an air atmosphere at the temperature of 1650 ℃, and cooling to obtain the mullite porous ceramic based on high-sodium industrial alumina in-situ synthesis.
The main chemical components of the high-sodium industrial alumina fine powder are as follows: al (Al) 2 O 3 98.1wt% of Na 2 O was 1.5wt%.
The three-stage alumina fine powder comprises the following components: al (Al) 2 O 3 The content is 50wt%, al 2 O 3 ∶SiO 2 1.2:1.
The polyvinyl alcohol solution is a mixed solution of analytically pure polyvinyl alcohol and deionized water; wherein: the mass ratio of the analytically pure polyvinyl alcohol to the deionized water is 0.06:1.
The in-situ synthesis mullite porous ceramic based on high sodium industrial alumina prepared in the embodiment is detected: the main phase is mullite phase, and the pore-forming structure is in a through state; bulk density of 2.10g/cm 3 The apparent porosity was 35%, the average pore diameter was 35. Mu.m, and the cold compressive strength was 100MPa.
Compared with the prior art, the specific embodiment has the following positive effects:
(1) The embodiment has low liquid phase forming temperature through three stages of aluminasIn beta-Al 2 O 3 The formation temperature of Na on the mother salt artefact particles 2 O does not form beta-Al 2 O 3 And absorbed by the liquid phase formed by the uniformly dispersed tertiary alumina fine powder. And obtaining the composition change comparison diagrams shown in the figures 1-3 through calculation of the Factsag thermodynamic software. FIG. 1 is a schematic diagram showing the component evolution of the three-stage alumina and the high sodium industrial alumina in the in-situ synthesis of mullite porous ceramic based on the high sodium industrial alumina prepared in example 1 during sintering; fig. 2 is a schematic diagram of component evolution of a low-sodium industrial alumina in-situ synthesized mullite porous ceramic in a sintering process, wherein the low-sodium industrial alumina in-situ synthesized mullite porous ceramic is prepared by using low-sodium industrial alumina instead of high-sodium industrial alumina, and the rest of the low-sodium industrial alumina in-situ synthesized mullite porous ceramic obtained by the same preparation method as that of example 1, namely the schematic diagram of component evolution of three-stage alumina and low-sodium industrial alumina in the sintering process of the low-sodium industrial alumina in-situ synthesized mullite porous ceramic shown in fig. 2; from the calculation of the viscosity module of the pictvage thermodynamic software of fig. 1 and 2 (abscissa is the mass of high sodium/low sodium industrial alumina involved in the reaction), it can be seen that there is no significant difference in the mullite formation and in the variation of the liquid phase content during sintering of the high sodium industrial alumina and the low sodium industrial alumina.
FIG. 3 shows different Na values in industrial alumina 2 The influence of the O content on the liquid phase viscosity of the in-situ synthesized mullite porous ceramic is shown in fig. 3: with Na in industrial alumina 2 The increase of the O content reduces the viscosity of the liquid phase. The results indicate more Na 2 O is dissolved in liquid phase to permeate into the gaps of mother salt false marks, so that the reactivity is increased. Meanwhile, the reduction of the viscosity provides a liquid phase environment of the mullite crystal column, promotes the growth of the mullite crystal column, enables the crystal size of the mullite crystal column to be larger, and improves the mechanical property of the mullite porous ceramic synthesized in situ based on high-sodium industrial alumina.
(2) The specific embodiment utilizes the pore structure characteristics (shown in figure 4) of the mother salt artefact structural material to effectively reserve the porous framework structure of the large-size aperture of the high-sodium industrial alumina by blending the large-granularity high-sodium industrial alumina fine powder with the small-granularity three-stage alumina fine powder with the mother salt artefact structure, so that the three-stage alumina fine powder is uniformly distributed around the structural framework of the high-sodium industrial alumina.
(3) The in-situ synthesized mullite porous ceramic based on high-sodium industrial alumina prepared in the specific embodiment is shown in fig. 5, fig. 5 is a microstructure picture of the in-situ synthesized mullite porous ceramic based on high-sodium industrial alumina prepared in example 1, and it can be seen from fig. 5: the mullite crystal column formed in the liquid phase sintering process replaces solid phase sintering alumina crystal grains with lower structural strength, the growth of the mullite crystal column expands the original pore structure, and the pore size and the air permeability of the mullite porous ceramic synthesized in situ based on high-sodium industrial alumina are obviously improved. It can also be seen from fig. 5 that: the generated mullite crystal columns are all supported by a mother salt false framework of the high-sodium industrial alumina, and the original loose mother salt false structure is converted into an inter-column crossed structure of the mullite crystal columns, so that the thermal shock resistance of the mullite porous ceramic synthesized in situ based on the high-sodium industrial alumina can be improved;
(4) High Na employed in this embodiment 2 The industrial alumina with the O content has rich sources and low cost. Especially, the high-temperature calcination treatment in the sodium removal process is not needed, and the resources and energy sources can be saved. Therefore, reasonably apply high Na 2 The industrial alumina with the O content is beneficial to improving the utilization efficiency of energy and resources, realizes the high value-added conversion of low-value raw materials, and has remarkable economic benefit.
The in-situ synthesized mullite porous ceramic based on high-sodium industrial alumina prepared by the specific embodiment is detected: the main phase is mullite phase, and the pore-forming structure is in a through state; the volume density is 1.82-2.10 g/cm 3 The apparent porosity is 33-40%, the average pore diameter is 35-50 μm, and the cold compressive strength is 90-110 MPa.
Therefore, the specific implementation mode is low in cost, energy-saving and environment-friendly; the prepared mullite porous ceramic based on the in-situ synthesis of high-sodium industrial alumina has the advantages of good thermal shock resistance, good air permeability, excellent mechanical property and remarkable economic benefit.
Claims (6)
1. A preparation method for synthesizing mullite porous ceramic in situ based on high-sodium industrial alumina is characterized by comprising the following steps:
mixing the high-sodium industrial alumina fine powder and the tertiary alumina fine powder according to the mass ratio of 1:2.3-3.3, and placing the high-sodium industrial alumina fine powder and the tertiary alumina fine powder in a ball mill to mix for 1-2 hours to obtain a mixture; adding 10-20wt% of polyvinyl alcohol solution into the mixture, and uniformly mixing to obtain ceramic powder;
placing the ceramic powder into a die, performing mechanical press forming under the condition of 80-150 MPa, and drying for 20-24 hours at the temperature of 100-110 ℃; then placing the ceramic in a muffle furnace, preserving heat for 2-3 hours in an air atmosphere at 1550-1650 ℃, and cooling to obtain the mullite porous ceramic synthesized in situ based on high-sodium industrial alumina;
the main chemical components of the high-sodium industrial alumina fine powder are as follows: al (Al) 2 O 3 ≥98wt%，Na 2 O≥1.2wt%。
2. The method for preparing the mullite porous ceramic based on the in-situ synthesis of the high-sodium industrial alumina, which is disclosed in claim 1, wherein the granularity of the high-sodium industrial alumina fine powder is 0.05-0.1 mm.
3. The method for preparing the mullite porous ceramic based on the in-situ synthesis of high sodium industrial alumina according to claim 1, wherein the three-stage alumina fine powder is characterized in that: al (Al) 2 O 3 The content is 45-60wt%, al 2 O 3 ∶SiO 2 The mass ratio of (2) is 1-1.8:1; the granularity of the tertiary alumina fine powder is less than or equal to 0.01mm.
4. The method for preparing the mullite porous ceramic based on the in-situ synthesis of the high sodium industrial alumina, which is characterized in that the polyvinyl alcohol solution is a mixed solution of analytically pure polyvinyl alcohol and deionized water; wherein: the mass ratio of the analytically pure polyvinyl alcohol to the deionized water is 0.05-0.06:1.
5. The method for preparing the mullite porous ceramic based on the high sodium industrial alumina in-situ synthesis of claim 1, wherein the grinding balls of the ball mill are corundum balls.
6. The high-sodium industrial alumina-based in-situ synthesized mullite porous ceramic is characterized in that the high-sodium industrial alumina-based in-situ synthesized mullite porous ceramic is prepared by the preparation method of the high-sodium industrial alumina-based in-situ synthesized mullite porous ceramic according to any one of claims 1-5.
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