Cordierite ceramic material, method for producing the same and use thereof

Abstract

The application belongs to the technical field of preparing cordierite materials, and particularly relates to a cordierite ceramic material, a preparation method and application thereof. The preparation method of the cordierite ceramic material comprises the following steps: 1) mixing chromium-iron waste residue and fly ash according to a mass ratio of (3-5):(5-7), heating to obtain a molten mixture, and then performing water quenching treatment to obtain a clinker raw material; 2) mixing the obtained clinker raw material with SnO2 according to a mass ratio of (95-99):(1-5), grinding, and then performing calcination treatment to obtain the cordierite ceramic material; the calcination treatment comprises preheating, first calcination and second calcination, and the heating rate from preheating to first calcination is 8-12 DEG C / min. The whole process is matched, the cordierite ceramic material obtained has high mass content of cordierite phase, and has low thermal expansion coefficient, high bending strength, excellent thermal stability, good high-temperature performance and mechanical performance.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of preparing cordierite materials, and particularly relates to a cordierite ceramic material and a preparation method and application thereof. BACKGROUND

[0002] Magnesium aluminate spinel (MgAl2O4) is a cubic spinel oxide, and Al 3+ and Mg 2+ occupy the oxygen octahedral and tetrahedral interstitial sites respectively to form a three-dimensional oxygen dense packing framework, which endows the material with excellent high-temperature stability (melting point > 2100℃) and chemical inertness. However, magnesium aluminate spinel is often generated during the crystallization of cordierite ceramic (Mg2Al4Si5O 18 ), and its formation mechanism is closely related to the deviation of the Mg / Al molar ratio in the cordierite precursor from the theoretical value, the local temperature gradient, and the uneven mixing of raw materials. This by-product can significantly deteriorate the macroscopic performance of the material, and has become a core bottleneck restricting the industrialization of high-end cordierite-based materials. Experimental data show that when the volume fraction of spinel is > 5%, the flexural strength of cordierite decreases by 28%-32%, and the thermal shock resistance deteriorates by 35%-40%. The essential mechanism is that the covalent bond energy of Si-O bonds (> 800kJ / mol) in the cordierite structure is significantly higher than that of Al-O (511kJ / mol) and Mg-O bonds (394kJ / mol), which leads to the preferential occupation of magnesium aluminate spinel at Al 3+ / Mg 2+ coordination sites, blocking the construction of Si-O-Al / Mg networks and forming a kinetic barrier. Although the existing external flux method (such as adding B2O3, Li2O, TiO2) for preparing cordierite ceramic materials can promote the decomposition of magnesium aluminate spinel, the introduced borate glass phase will reduce the refractoriness (≥200℃) of the material and form a low-melting-point region in the microstructure, thereby damaging the high-temperature performance. SUMMARY

[0003] Therefore, the technical problem to be solved by the present application is to overcome the defects of the existing cordierite ceramic material, such as the low mass content of cordierite phase and the poor high-temperature performance and mechanical performance, so as to provide a cordierite ceramic material, a preparation method and application thereof.

[0004] The present application provides a preparation method of a cordierite ceramic material, comprising the following steps:

[0005] 1) mixing chromium-iron waste residue and fly ash at a mass ratio of (3-5):(5-7), heating to obtain a molten mixture, and then performing water quenching treatment to obtain a clinker raw material;

[0006] 2) mixing the frit raw material obtained in step 1) with SnO2 in a mass ratio of (95-99):(1-5), grinding, and then obtaining the cordierite ceramic material through calcination treatment;

[0007] The calcination treatment comprises preheating, first calcination, and second calcination, and the temperature increasing rate from preheating to first calcination is 8-12℃ / min.

[0008] Preferably, the mass of the chromium-iron waste residue in step 1) accounts for 30%-50% of the total mass of the chromium-iron waste residue and fly ash;

[0009] Preferably, the mass of the fly ash in step 1) accounts for 50%-70% of the total mass of the chromium-iron waste residue and fly ash;

[0010] Preferably, the heating temperature is 1500-1650℃, and the heating time is 1-4h.

[0011] Optionally, the heating is performed in an oxidizing atmosphere.

[0012] Further optionally, the heating is performed in an air atmosphere.

[0013] Optionally, the heating step further comprises a clarification step.

[0014] Preferably, the components of the frit raw material in step 1) comprise, in terms of mass percentage: 40-50% SiO2, 28-30% Al2O3, 3-5% Fe2O3, 2-4% CaO, 8-15% MgO, 3-6% Cr2O3, <2% KNaO, <2% TiO2, <1% SO3, and the balance is loss on ignition.

[0015] Optionally, the components of the chromium-iron waste residue comprise, in terms of mass percentage: 25-30% SiO2, 25-30% Al2O3, 3-5% Fe2O3, 3-5% CaO, 28-32% MgO, 8-10% Cr2O3, <1% KNaO, <1% TiO2, <0.5% SO3, and the balance is loss on ignition.

[0016] Optionally, the components of the fly ash comprise, in terms of mass percentage: 55-60% SiO2, 28-32% Al2O3, 3-5% Fe2O3, 2-4% CaO, <1% MgO, <2.5% KNaO, <2% TiO2, <0.5% SO3, and the balance is loss on ignition.

[0017] Optionally, in the mixed particles formed by mixing the chromium-iron waste residue and the fly ash in step 1), more than 90wt.% of the mixed particles have a particle size less than 30μm.

[0018] Preferably, the grinding speed in step 2) is 350-450 rpm, and the grinding time is 10-30 min.

[0019] Optionally, the grinding is performed by wet ball milling, and the mass ratio of the total mass of the frit raw material and SnO2, the grinding balls and water is 1:(1.5-3):(0.6-0.8) in the wet ball milling.

[0020] Optionally, the grinding balls include alumina grinding balls with a particle size of 6-8 mm and alumina grinding balls with a particle size of 8-10 mm, and the mass of the alumina grinding balls with a particle size of 6-8 mm accounts for 50%-80% of the total mass of the grinding balls.

[0021] Preferably, after the grinding step in step 2), the method further includes the steps of spraying polyvinyl alcohol aqueous solution on the ground powder to perform granulation, then compression molding and drying, and then calcining the dried product to obtain the cordierite ceramic material.

[0022] Optionally, the mass ratio of the polyvinyl alcohol aqueous solution to the ground powder is (3-9):(91-97).

[0023] Optionally, the mass concentration of polyvinyl alcohol in the polyvinyl alcohol aqueous solution is 0.5-5 wt.%.

[0024] The compression molding pressure is 12-16 MPa, and the compression molding time is 20-60 s.

[0025] The drying temperature is 60-100℃, and the drying time is 1-4 h.

[0026] Optionally, the average polymerization degree of polyvinyl alcohol in the polyvinyl alcohol aqueous solution is 1600-2000, and further optionally, the average polymerization degree of polyvinyl alcohol in the polyvinyl alcohol aqueous solution is 1750. The polyvinyl alcohol used in the present application can be obtained commercially, for example, from Tianjin Damao Chemical Reagent Factory.

[0027] Preferably, the preheating in step 2) includes heating to 550-600℃ at a heating rate of 2-4℃ / min.

[0028] After the preheating, first calcination is performed at a first calcination temperature of 750-810℃, and the holding time of the first calcination is 1-8 h.

[0029] After the first calcination, second calcination is performed at a second calcination temperature of 950-1050℃, and the holding time of the second calcination is 1-4 h.

[0030] The heating rate from the first calcination to the second calcination is 1-3℃ / min.

[0031] Optionally, the calcination step is followed by a cooling step.

[0032] The invention provides a cordierite ceramic material prepared by the method described above.

[0033] Preferably, the cordierite phase in the cordierite ceramic material accounts for more than 95wt.% of the total mass of the crystalline phase in the cordierite ceramic material.

[0034] The magnesium aluminate spinel phase in the cordierite ceramic material accounts for less than 5wt.% of the total mass of the crystalline phase in the cordierite ceramic material.

[0035] Preferably, the average thermal expansion coefficient of the cordierite ceramic material is 1.5x10 -6 -2.5x10 -6 ℃ -1 , the bending strength is 55-70MPa, and the bulk density is 2.30-2.50g / cm 3 .

[0036] The invention also provides a cordierite ceramic material prepared by the method described above or the cordierite ceramic material described above for use in the fields of refractory materials, precise electronic packaging materials, biomedical coating materials, or chemical anticorrosion equipment materials.

[0037] The technical solution of the invention has the following advantages:

[0038] 1. The preparation method of the cordierite ceramic material provided by the present application comprises the following steps: 1) mixing chromium-iron waste residue and fly ash according to a mass ratio of (3-5):(5-7), heating to obtain a molten mixture, and then performing water quenching treatment to obtain a clinker raw material; 2) mixing the clinker raw material obtained in step 1) with SnO2 according to a mass ratio of (95-99):(1-5), grinding, and then performing calcination treatment to obtain the cordierite ceramic material; the calcination treatment comprises preheating, first calcination and second calcination, and the heating rate from preheating to first calcination is 8-12℃ / min. The present application uses specific proportions of chromium-iron waste residue and fly ash as raw materials to prepare MgO-Al2O3-SiO2 system cordierite ceramic materials, which can realize harmless and efficient resource utilization of chromium-iron waste residue and fly ash. The chromium-iron waste residue (yield 1.2-1.5 tons per ton of chromium-iron waste residue) is rich in MgO, SiO2, Al2O3 and Cr2O3, among which the SiO2-Al2O3-MgO three components account for 82.9wt.%, and these components of the chromium-iron waste residue are highly matched with the chemical composition of the cordierite ceramic material. The fly ash (annual output 4.9 billion tons) is rich in SiO2, Al2O3, Fe2O3 and CaO. The addition of fly ash supplements the SiO2 and Al2O3 components, which not only provides a source of silicon and aluminum for the synthesis of cordierite, but also provides kinetic conditions for reducing the melting temperature and melting-crystallization due to the abundant glass phase. The chromium-iron waste residue and fly ash cooperate with each other to provide a natural complementary advantage of components for preparing high-performance cordierite ceramic materials under specific dosage ratios. In terms of process optimization, the specific calcination treatment process adjustment includes preheating, first calcination and second calcination, while the heating rate from preheating to first calcination is controlled to be 8-12℃ / min, the rapid heating from preheating to first calcination is maintained, the high-temperature zone residence time is shortened, the crystal nucleus growth kinetics conditions are limited, and the crystallization behavior is inhibited, thereby avoiding the premature formation of spinel phase, ensuring the controllable crystallization of the amorphous matrix in the subsequent heat treatment. The specific amount of SnO2 significantly improves the density, thermal stability and corrosion resistance of the material through mechanisms such as reducing the reaction temperature, regulating the crystal phase path and inhibiting decomposition in the synthesis of cordierite. The preparation method of the cordierite ceramic material provided by the present application has overall process cooperation, and the cordierite ceramic material obtained has low mass content of magnesium aluminum spinel phase, high mass content of cordierite phase, low thermal expansion coefficient, high bending strength, excellent thermal stability, good high-temperature performance and mechanical properties, and can meet the needs of special application scenarios such as high temperature, high strength and corrosion resistance.

[0039] 2. The method for preparing the cordierite ceramic material provided by the application, the heating temperature in step 1) for obtaining the molten mixture is 1500-1650 DEG C, and the heating time is 1-4 h; the calcination treatment in step 2) comprises preheating, first calcination and second calcination, the preheating comprises heating at a temperature increasing rate of 2-4 DEG C / min to 550-600 DEG C; the first calcination is carried out after the preheating, the first calcination temperature is 750-810 DEG C, and the holding time of the first calcination is 2-8 h; the second calcination is carried out after the first calcination, the second calcination temperature is 950-1050 DEG C, and the holding time of the second calcination is 1-4 h; the temperature increasing rate from the first calcination to the second calcination is 1-3 DEG C / min. The cordierite ceramic material is prepared by the method of high-temperature melting and low-temperature crystallization. Cr2O3 contained in the chromium-iron waste residue can be oxidized into the high-migration carcinogen Cr 6+ in the environment, and there is a risk of soil and groundwater pollution, and the high-temperature melting solidification at a specific temperature can also play a role in stabilizing Cr, fixing Cr in the glass phase and the crystal phase in the chromium-iron waste residue, so that Cr is not easy to be oxidized, and the dissolution of Cr in the material is inhibited. In dynamics, the selective inhibition of magnesium-aluminum spinel and the precipitation of homogeneous cordierite crystals are realized by using the dynamic control in the process of frit crystallization, the calcination treatment process can accurately control the thermodynamic and kinetic parameters, realize the optimization of crystal structure, size and distribution, significantly reduce the energy consumption in the preparation process, and improve the crystallization performance and mechanical properties of the material, thereby comprehensively improving the mechanical, optical and process properties of the cordierite ceramic material. The magnesium-aluminum spinel is in the crystallization stage at about 700 DEG C, and by accurately controlling the preheating temperature and the first calcination temperature, the crystallization behavior of the magnesium-aluminum spinel can be accurately inhibited by the rapid heating process (such as the temperature increasing rate in the interval of 600-750 DEG C is greater than 8 DEG C / min) from preheating to the first calcination stage, and the amorphous matrix of the material is further ensured to be controllable crystallization in the subsequent heat treatment. At the same time, the ratio of fly ash to chromium-iron waste residue and the addition of crystallization agent further control the synthesis amount and crystal size of cordierite, and through the synergistic effect of reconstructing the thermodynamic driving force and dynamic mass transfer conditions, the high-performance cordierite ceramic material is prepared.

[0040] 3. The method for preparing the cordierite ceramic material provided by the application, the process optimization not only improves the production efficiency, but also significantly reduces the production cost, and provides technical support for the high-value utilization of industrial solid waste. At the same time, through component adjustment and process optimization, the microstructure and performance of the cordierite ceramic material can be further regulated, and the customized design of the material is realized. The obtained cordierite ceramic material has good electrical insulation performance, wide market prospect and extremely high economic value. The technical blank of preparing the cordierite ceramic material from the chromium-iron waste residue and fly ash is filled.

[0041] 4、The preparation method of the cordierite ceramic material provided by the application provides a new technical path for the resource utilization of industrial solid waste, and promotes green manufacturing and sustainable development through technical innovation. Fly ash and chromium-iron waste residue are the main sources of industrial solid waste, and their large-scale storage not only occupies land resources, but also causes serious threats to the environment. By converting them into cordierite ceramic materials, not only is the resource utilization of waste achieved, but also the dependence on natural raw materials is significantly reduced, and the negative impact on the environment is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed in the specific embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0043] Figure 1 XRD pattern of the chromium-iron waste residue used in the examples and comparative examples of the present application;

[0044] Figure 2 XRD pattern of the fly ash used in the examples and comparative examples of the present application;

[0045] Figure 3 XRD pattern of the clinker raw material prepared in Example 5 of the present application;

[0046] Figure 4 XRD pattern of the cordierite ceramic material prepared in Examples 2-5 of the present application.

[0047] Figure 5 XRD pattern of the cordierite ceramic material prepared in Example 5 and Comparative Example 3 of the present application.

[0048] Figure 6 SEM image of the cordierite ceramic material prepared in Example 5 of the present application.

[0049] Figure 7 SEM image of the cordierite ceramic material prepared in Comparative Example 3 of the present application. DETAILED DESCRIPTION

[0050] The following examples are provided to better further understand the present application and are not limited to the best mode, and do not limit the content and protection scope of the present application. Any person who obtains any product the same as or similar to the present application under the inspiration of the present application or by combining the present application with other prior art features falls within the protection scope of the present application.

[0051] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0052] The average degree of polymerization of polyvinyl alcohol in the aqueous solution of polyvinyl alcohol used in the embodiments or comparative examples of the present invention is 1750. Polyvinyl alcohol is commercially available and was purchased from Tianjin Damao Chemical Reagent Factory.

[0053] The XRD patterns of the ferrochrome waste slag raw materials used in the embodiments or comparative examples of this invention are as follows: Figure 1 As shown, the XRD pattern of fly ash raw material is as follows: Figure 2 As shown, the glassy phase (amorphous phase) content in ferrochrome waste slag is 46 wt.%, and the crystalline phase content is 54 wt.%, of which magnesium aluminum spinel phase accounts for 23.82 wt.% and forsterite phase accounts for 30.18 wt.%; the glassy phase content in fly ash is 66.09 wt.%, and the crystalline phase content is 33.91 wt.%, of which mullite phase accounts for 25.22 wt.% and quartz phase accounts for 8.69 wt.%. The specific composition of ferrochrome waste slag and fly ash by mass fraction is shown in Table 1.

[0054] Table 1

[0055]

[0056]

[0057] Example 1

[0058] This embodiment provides a method for preparing cordierite ceramic material, including the following steps:

[0059] 1) 30 wt.% ferrochrome slag and 70 wt.% fly ash were ball-milled and mixed evenly to obtain mixed particles of raw materials. The particles with a size less than 30 μm accounted for more than 90 wt.% of the total mixed particles. Then, the above mixed particles were placed in a silicon molybdenum rod high-temperature furnace and heated to 1500℃ in air atmosphere to melt the mixed particles for 4 hours and clarify them to obtain a molten mixture. The molten mixture was then poured into water for water quenching to obtain frit raw material. The composition of the frit raw material, by mass fraction, included: 48.89% SiO2, 29.02% Al2O3, 3.33% Fe2O3, 2.93% CaO, 9.23% MgO, 2.77% Cr2O3, 1.49% KNaO, 0.98% TiO2, 0.15% SO3, and 1.21% loss on ignition.

[0060] 2) The frit raw material is placed in a planetary ball mill after adding Sn02, and the frit raw material and Sn02 are mixed at a mass ratio of 95:5, then wet ball milling is carried out at a constant speed of 350 rpm for 30 min at room temperature; the total mass of the frit raw material and Sn02, the mass ratio of the grinding balls and water during wet ball milling is 1:1.5:0.8, the grinding balls include alumina grinding balls with a particle size of 6-8 mm and alumina grinding balls with a particle size of 8-10 mm, the mass of the alumina grinding balls with a particle size of 6-8 mm accounts for 80% of the total mass of the grinding balls, and the wet ball-milled powder is granulated by spraying a polyvinyl alcohol aqueous solution with a mass concentration of 1% polyvinyl alcohol, and the mass ratio of the polyvinyl alcohol aqueous solution to the ground powder is 3:97; then, 11 g of the granulated powder is weighed and placed in a single-shaft powder tablet press to be pressed into a cuboid sample with a size of 60 mm x 10 mm x 10 mm (the pressing forming pressure is 12 MPa, and the pressing forming time is 60 s); the pressed sample is placed in a constant-temperature drying oven at 60°C for drying for 4 h to remove free water in the sample, and a sample to be fired is obtained. Calcination is carried out in an air atmosphere, and the calcination schedule is as follows: heating from room temperature to 560°C at a heating rate of 2°C / min, then rapidly heating from 560°C to 750°C at a heating rate of 8°C / min for first calcination, the first calcination holding time is 8 h; then heating from 750°C to 950°C at a heating rate of 1°C / min for second calcination, the second calcination holding time is 4 h; finally, the furnace is cooled to obtain the cordierite ceramic material.

[0061] Example 2

[0062] The present embodiment provides a preparation method of a cordierite ceramic material, comprising the following steps:

[0063] 1) 40 wt.% of chromium-iron waste residue and 60 wt.% of fly ash are uniformly ball-mixed to obtain mixed particles of raw materials, and the particles with a particle size of less than 30 μm in the mixed particles account for more than 90 wt.% of the total mass of the mixed particles; then the mixed particles are placed in a silicon-molybdenum rod high-temperature furnace, heated to 1600°C, and the mixed particles are heated and melted in an air atmosphere for 2 h and clarified to obtain a molten mixture; then the molten mixture is poured into water to obtain a frit raw material; the components of the frit raw material, in terms of mass fraction, include: 45.77% Si02, 28.69% Al203, 3.35% Fe203, 2.97% CaO, 12.05% MgO, 3.69% Cr203, 1.33% KNaO, 0.90% Ti02, 0.16% SO3, and 1.09% loss on ignition;

[0064] 2) the frit raw material is placed in a planetary ball mill after adding Sn02, the frit raw material and Sn02 are mixed at a mass ratio of 97:3, then wet ball milling is performed at a constant speed of 400 rpm for 20 min at room temperature; the total mass of the frit raw material and Sn02, the mass ratio of the grinding balls and water during wet ball milling is 1:2.0:0.7, the grinding balls include alumina grinding balls with a particle size of 6-8 mm and alumina grinding balls with a particle size of 8-10 mm, the mass of the alumina grinding balls with a particle size of 6-8 mm accounts for 65% of the total mass of the grinding balls, the milled powder is granulated by spraying a polyvinyl alcohol aqueous solution with a mass concentration of 1% polyvinyl alcohol, and the mass ratio of the polyvinyl alcohol aqueous solution to the milled powder is 6:94; then, 11 g of the granulated powder is weighed and placed in a single-shaft powder tablet press to be pressed into a cuboid sample with a size of 60 mm x 10 mm x 10 mm (the pressing forming pressure is 14 MPa, and the pressing forming time is 45 s); the pressed sample is placed in a constant-temperature drying oven at 80°C for drying for 2 h to remove free water in the sample, to obtain a sample to be fired; calcination is performed in an air atmosphere, and the calcination schedule is as follows: heating from room temperature to 580°C at a heating rate of 3°C / min, then rapidly heating from 580°C to 780°C at a heating rate of 10°C / min for first calcination, the first calcination holding time is 1 h; then heating from 780°C to 1000°C at a heating rate of 2°C / min for second calcination, the second calcination holding time is 2 h; finally, the furnace is cooled to obtain the cordierite ceramic material.

[0065] Example 3

[0066] The embodiment provides a preparation method of a cordierite ceramic material, including the following steps.

[0067] 1) 50 wt.% of chromium-iron waste residue and 50 wt.% of fly ash are uniformly ball-mixed to obtain mixed particles of raw materials, wherein the particles with a particle size of less than 30 μm account for more than 90 wt.% of the total mass of the mixed particles; then the mixed particles are placed in a silicon-molybdenum rod high-temperature furnace, heated to 1650°C, and the mixed particles are heated to melt for 1 h and clarified in an air atmosphere to obtain a molten mixture; then the molten mixture is poured into water to obtain a frit raw material; the components of the frit raw material include, in terms of mass fraction: 42.66% SiO2, 28.37% Al2O3, 3.38% Fe2O3, 3.02% CaO, 14.88% MgO, 4.62% Cr2O3, 1.17% KNaO, 0.83% TiO2, 0.18% SO3, and 0.89% loss on ignition;

[0068] 2) The frit raw material is placed in a planetary ball mill after adding Sn02, and the frit raw material and Sn02 are mixed at a mass ratio of 99:1, and then dry ball milling is performed at a constant speed of 450 rpm for 10 min at room temperature; for wet ball milling, the total mass of the frit raw material and Sn02, the mass of the grinding balls, and the mass of water are in a ratio of 1:2.5:0.6, the grinding balls include alumina grinding balls with a particle size of 6-8 mm and alumina grinding balls with a particle size of 8-10 mm, the mass of the alumina grinding balls with a particle size of 6-8 mm accounts for 80% of the total mass of the grinding balls, and the wet ball-milled powder is granulated by spraying a polyvinyl alcohol aqueous solution with a mass concentration of 1% polyvinyl alcohol, and the mass ratio of the polyvinyl alcohol aqueous solution to the wet ball-milled powder is 9:91; then, 11 g of the granulated powder is weighed and placed in a single-shaft powder tablet press to be pressed into a cuboid sample with a size of 60 mm x 10 mm x 10 mm (the pressing forming pressure is 16 MPa, and the pressing forming time is 30 s); the pressed sample is placed in a constant-temperature drying oven at 100°C for drying for 1 h to remove free water in the sample, and a sample to be fired is obtained; calcination is performed in an air atmosphere, and the calcination schedule is as follows: heating from room temperature to 600°C at a heating rate of 4°C / min, then rapidly heating from 600°C to 810°C at a heating rate of 12°C / min for first calcination, the first calcination holding time is 4 h; then heating from 810°C to 1050°C at a heating rate of 3°C / min for second calcination, the second calcination holding time is 1 h; finally, the furnace is cooled to obtain the cordierite ceramic material.

[0069] Example 4

[0070] The present embodiment provides a method for preparing a cordierite ceramic material, comprising the following steps:

[0071] 1) 50 wt.% of chromium-iron waste residue and 50 wt.% of fly ash are uniformly ball-mixed to obtain mixed particles of raw materials, and the mass fraction of particles with a particle size of less than 30 μm in the total mixed particles is more than 90 wt.%; then the mixed particles are placed in a silicon-molybdenum rod high-temperature furnace, heated to 1650°C, and the mixed particles are melted and clarified in an air atmosphere for 2 h to obtain a molten mixture; then the molten mixture is poured into water to obtain a frit raw material; the components of the frit raw material, in terms of mass fraction, include: 42.66% Si02, 28.37% Al203, 3.38% Fe203, 3.02 CaO, 14.88% MgO, 4.62% Cr203, 1.17% KNaO, 0.83% Ti02, 0.18% SO3, and 0.89% loss on ignition;

[0072] 2) After adding SnO2 to the fused raw material, it is placed in a planetary ball mill at a mass ratio of 99:1. Dry ball milling is then performed at a constant speed of 400 rpm for 20 minutes at room temperature. For wet ball milling, the mass ratio of the total mass of the fused raw material and SnO2, the grinding balls, and the water is 1:2:0.7. The grinding balls include alumina grinding balls with a particle size of 6-8 mm and alumina grinding balls with a particle size of 8-10 mm. The mass of the 6-8 mm alumina grinding balls accounts for 65% of the total mass of the grinding balls. A 1% polyvinyl alcohol aqueous solution is sprayed onto the ball-milled powder for granulation. The mass ratio of the polyvinyl alcohol aqueous solution to the ground powder is 6:94. Subsequently, 11 g of the granulated powder is weighed and placed in a single-axis powder press. The sample was pressed into a rectangular block with dimensions of 60mm × 10mm × 10mm using a sheet forming machine (pressing pressure: 14MPa, pressing time: 45s). The pressed sample was then placed in an 80℃ constant temperature drying oven for 2 hours to remove free water, yielding a sample to be calcined. Calcination was then performed in air under the following conditions: heating from room temperature to 600℃ at a heating rate of 3℃ / min, followed by a rapid heating from 600℃ to 750℃ at a heating rate of 8℃ / min for a first calcination, with a holding time of 4 hours; then heating from 750℃ to 1050℃ at a heating rate of 1℃ / min for a second calcination, with a holding time of 4 hours; finally, the sample was cooled in the furnace to obtain the cordierite ceramic material.

[0073] Example 5

[0074] This embodiment provides a method for preparing cordierite ceramic material, including the following steps:

[0075] 1) 40 wt.% ferrochrome slag and 60 wt.% fly ash were ball-milled and mixed evenly to obtain mixed particles of raw materials. The particles with a size less than 30 μm accounted for more than 90 wt.% of the total mixed particles. Then, the above mixed particles were placed in a silicon molybdenum rod high-temperature furnace and heated to 1600℃ in air atmosphere to melt the mixed particles for 2 hours and clarify them to obtain a molten mixture. The molten mixture was then poured into water and quenched to obtain frit raw material. The composition of the frit raw material, by mass fraction, included: 45.77% SiO2, 28.69% Al2O3, 3.35% Fe2O3, 2.97% CaO, 12.05% MgO, 3.69% Cr2O3, 1.33% KNaO, 0.90% TiO2, 0.16% SO3, and 1.09% loss on ignition.

[0076] 2) The raw material mixture pellets obtained in step 1) are placed in a planetary ball mill, and Sn02 is added to the raw material mixture pellets in a mass ratio of 97:3, and then dry ball milling is performed at a constant speed of 400 rpm for 20 min at room temperature; in wet ball milling, the mass ratio of the total mass of the raw material mixture pellets and Sn02, the grinding balls, and water is 1:2:0.7, the grinding balls include alumina grinding balls with a particle size of 6-8 mm and alumina grinding balls with a particle size of 8-10 mm, the mass of the alumina grinding balls with a particle size of 6-8 mm accounts for 65% of the total mass of the grinding balls, and the ground powder is granulated by spraying a polyvinyl alcohol aqueous solution with a mass concentration of 1% of polyvinyl alcohol on the powder after ball milling, and the mass ratio of the polyvinyl alcohol aqueous solution to the ground powder is 6:94; then, 11 g of the granulated powder is weighed and placed in a single-shaft powder tablet press to be pressed and formed, and a cuboid sample with a size of 60 mm x 10 mm x 10 mm is obtained (the pressing and forming pressure is 16 MPa, and the pressing and forming time is 30 s); the pressed sample is placed in a constant-temperature drying oven at 80°C for drying for 2 h to remove free water in the sample, and a sample to be fired is obtained; calcination is performed in an air atmosphere, and the calcination schedule is as follows: heating from room temperature to 600°C at a heating rate of 3°C / min, then rapidly heating from 600°C to 780°C at a heating rate of 10°C / min for first calcination, the first calcination holding time is 8 h; then heating from 780°C to 1000°C at a heating rate of 2°C / min for second calcination, the second calcination holding time is 2 h; finally, the furnace is cooled to obtain the cordierite ceramic material.

[0077] Comparative Example 1

[0078] This comparative example provides a preparation method of a cordierite ceramic material, which is different from Example 5 only in that the raw material mixture pellets obtained by uniformly ball-milling 40 wt.% of chromium-iron waste residue and 60 wt.% of fly ash are replaced by raw material mixture pellets obtained by uniformly ball-milling 60 wt.% of chromium-iron waste residue and 40 wt.% of fly ash in step 1).

[0079] Comparative Example 2

[0080] This comparative example provides a preparation method of a cordierite ceramic material, which is different from Example 5 only in that the mass ratio of the raw material mixture pellets to Sn02 is replaced by 90:10 in step 2).

[0081] Comparative Example 3

[0082] This comparative example provides a preparation method of a cordierite ceramic material, which is different from Example 5 only in that the first calcination at a heating rate of 10°C / min from 600°C to 780°C is replaced by first calcination at a heating rate of 3°C / min from 600°C to 780°C in step 2).

[0083] Comparative Example 4

[0084] This comparative example provides a method for preparing a cordierite ceramic material, which is only different from Example 5 in that the same mass of fly ash is used to replace the chromium-iron waste residue in step 1).

[0085] Comparative Example 5

[0086] This comparative example provides a method for preparing a cordierite ceramic material, which is only different from Example 5 in that the same mass of chromium-iron waste residue is used to replace the fly ash in step 1).

[0087] Comparative Example 6

[0088] This comparative example provides a method for preparing a cordierite ceramic material, which is only different from Example 5 in that the same mass of kaolin (kaolin component and mass content are shown in Table 2) is used to replace the fly ash in step 1).

[0089] Table 2

[0090]

[0091] Comparative Example 7

[0092] This comparative example provides a method for preparing a cordierite ceramic material, which is only different from Example 5 in that the same mass of TiO2 is used to replace SnO2 in step 2).

[0093] Test Example

[0094] The frit raw material prepared in Example 5 was subjected to XRD scanning test, and the obtained XRD pattern is shown in FIG. 1; the cordierite ceramic materials prepared in Examples 2-5 and Comparative Example 3 were subjected to XRD scanning test, and the XRD patterns obtained in Examples 2-5 are shown in FIG. 2, and the XRD patterns of the cordierite ceramic materials prepared in Example 5 and Comparative Example 3 are shown in FIG. 3; the cordierite ceramic materials prepared in Example 5 and Comparative Example 3 were subjected to SEM scanning test, and the SEM pattern obtained in Example 5 is shown in FIG. 4, and the SEM pattern obtained in Comparative Example 3 is shown in FIG. 5. Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

[0095] The cordierite ceramic materials prepared in Examples 1-5 and Comparative Examples 1-7 were used as test samples, and the mass content of each crystal phase was determined by K value internal standard method (also known as reference intensity method), and the specific steps were as follows: (1) corundum (α-Al2O3, JCPDS-43-1484) was selected as the standard substance; (2) the test sample was mixed with corundum at a mass ratio of 4:1 (20wt.%) and was ground to prepare a mixed sample; (3) the reference intensity of each phase was determined according to the relative intensity ratio (RIR) provided in the JCPDS card​​​​​ (4) The diffraction data were processed by Jade 6.5 software, and the content of each crystal phase was calculated by combining formula (1-1), (1-2), (1-3).

[0096]

[0097] In formula (1-1), (1-2), (1-3): I j : the strongest diffraction peak intensity of phase j (phase j is the crystal phase to be measured) in the mixed sample, I s : the strongest diffraction peak intensity of the standard substance (corundum), K s J : the reference intensity (RIR value) of phase j relative to the standard substance, w j : the mass fraction of phase j in the mixed sample, w s : the mass fraction of the standard substance in the mixed sample (fixed at 20%), w j : the mass fraction of phase j in the original sample, ∑w t : the total mass fraction of each crystal phase in the original sample, w t : the mass fraction of phase j in the crystal phase in the original sample. The mass content of each crystal phase in the crystal phase is shown in Table 3.

[0098] The PCY2 thermal dilatometer produced by Hunan Xiangyi Instrument Co., Ltd. was used to determine the average thermal expansion coefficient (α) of the cordierite ceramic materials prepared in Examples 1-5 and Comparative Examples 1-7 at 25-800°C by using the top rod method. The determination results are shown in Table 3.

[0099] The WDW-20 microcomputer-controlled universal testing machine was used to determine the bending strength value of the cordierite ceramic materials prepared in Examples 1-5 and Comparative Examples 1-7 by using the three-point bending method, the span was 30 mm, and the test method referred to the GB / T 4741-1999 test standard. The determination results are shown in Table 3.

[0100] According to the QB / T 1642-2012 standard, the boiling method in the standard was used to determine the bulk density of the cordierite ceramic materials prepared in Examples 1-5 and Comparative Examples 1-7. The determination results are shown in Table 3.

[0101] Table 3

[0102]

[0103]

[0104] The mass content of the crystal phase in the quality determination result of the crystal phase is 75.60% mullite phase and 24.40% quartz phase in the crystal phase of the comparative example 4; the remaining crystal phase in the crystal phase of the comparative example 5 is quartz phase; the remaining crystal phase in the comparative example 6 is quartz phase; and the remaining crystal phase in the comparative example 7 is original enstatite.

[0105] Obviously, the above embodiments are only examples for clearly illustrating the present application, and are not intended to limit the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. All the embodiments do not need to be exhausted, and the obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A method for producing a cordierite ceramic material, characterized by, The method comprises the following steps: 1) mixing ferrochrome waste residue and fly ash according to a mass ratio of (3-5):(5-7), heating to obtain a molten mixture, and then performing water quenching to obtain a clinker raw material; 2) mixing the clinker raw material obtained in step 1) with SnO2 according to a mass ratio of (95-99):(1-5), grinding, and then performing calcination to obtain the cordierite ceramic material. The calcination process comprises preheating, first calcination and second calcination, and the temperature rising rate from preheating to first calcination is 8-12 ℃ / min.

2. The method of claim 1, wherein the cordierite ceramic material is prepared by the steps of: In step 1), the mass of the ferrochrome waste residue accounts for 30%-50% of the total mass of the ferrochrome waste residue and fly ash. And / or, the mass of the fly ash accounts for 50%-70% of the total mass of the ferrochrome waste residue and fly ash. And / or, the heating temperature in step 1) is 1500-1650 ℃, and the heating time is 1-4 h.

3. The method for producing the cordierite ceramic material according to claim 1 or 2, characterized in that, The heating in step 1) is performed in an oxidizing atmosphere.

4. Process for the production of cordierite ceramic materials according to any one of claims 1 to 3, characterized in that In step 1), the components of the clinker raw material include, in percentage by mass: 40-50% SiO2, 28-30% Al2O3, 3-5% Fe2O3, 2-4% CaO, 8-15% MgO, 3-6% Cr2O3, <2% KNaO, <2% TiO2, <1% SO3, and the balance is loss on ignition.

5. The method for the preparation of cordierite ceramic materials according to any one of claims 1 to 4, characterized in that, The components of the ferrochrome waste residue include, in percentage by mass: 25-30% SiO2, 25-30% Al2O3, 3-5% Fe2O3, 3-5% CaO, 28-32% MgO, 8-10% Cr2O3, <1% KNaO, <1% TiO2, <0.5% SO3, and the balance is loss on ignition.

6. The method for the production of cordierite ceramic materials according to any one of claims 1 to 5, characterized in that The components of the fly ash include, in percentage by mass: 55-60% SiO2, 28-32% Al2O3, 3-5% Fe2O3, 2-4% CaO, <1% MgO, <2.5% KNaO, <2% TiO2, <0.5% SO3, and the balance is loss on ignition.

7. The method for the production of cordierite ceramic materials according to any one of claims 1 to 6, characterized in that In step 1), the particle size of 90 wt.% or more of the mixed particles formed by mixing the ferrochrome waste residue and the fly ash is less than 30 μm.

8. The method for the production of the cordierite ceramic material according to any one of claims 1 to 7, characterized in that In step 2), the grinding speed is 350-450 rpm, and the grinding time is 10-30 min.

9. Process for the production of the cordierite ceramic material according to any one of claims 1 to 8, characterized in that The wet ball milling is adopted, and the mass ratio of the total mass of the clinker raw material and SnO2, the grinding balls and water is 1:(1.5-3):(0.6-0.8) during the wet ball milling.

10. The method for preparing cordierite ceramic material according to claim 9, characterized in that, The grinding balls include alumina grinding balls with a particle size of 6-8 mm and alumina grinding balls with a particle size of 8-10 mm, and the mass of the alumina grinding balls with a particle size of 6-8 mm accounts for 50%-80% of the total mass of the grinding balls.

11. Process for the production of the cordierite ceramic material according to any one of claims 1 to 10, characterized in that After the grinding step in step 2), the following steps are further included: spraying polyvinyl alcohol aqueous solution on the ground powder to perform granulation, then performing compression molding and drying, and then performing calcination to obtain the cordierite ceramic material. The compression molding pressure is 12-16 MPa, and the compression molding time is 20-60 s. The drying temperature is 60-100 ℃, and the drying time is 1-4 h.

12. The method of claim 11, wherein the cordierite ceramic material is prepared by the steps of: The mass ratio of the polyvinyl alcohol aqueous solution to the ground powder is (3-9):(91-97).

13. The method for preparing cordierite ceramic material according to claim 11, characterized in that, The mass concentration of the polyvinyl alcohol in the polyvinyl alcohol aqueous solution is 0.5-5 wt.%.

14. The method for the production of the cordierite ceramic material according to any one of claims 1 to 13, characterized in that The preheating in step 2) comprises heating to 550-600℃ at a temperature increasing rate of 2-4℃ / min; The first calcination is performed after the preheating, the first calcination temperature is 750-810℃, and the holding time of the first calcination is 1-8 h; The second calcination is performed after the first calcination, the second calcination temperature is 950-1050℃, and the holding time of the second calcination is 1-4 h; The temperature increasing rate from the first calcination to the second calcination is 1-3℃ / min.

15. A cordierite ceramic material, characterized by, The cordierite ceramic material is prepared by the preparation method of any one of claims 1-14.

16. The cordierite ceramic material of claim 15, wherein The cordierite phase in the cordierite ceramic material accounts for 95 wt.% or more of the total mass of the crystal phases in the cordierite ceramic material. The magnesium-aluminum spinel phase in the cordierite ceramic material accounts for 5 wt.% or less of the total mass of the crystal phases in the cordierite ceramic material.

17. The cordierite ceramic material of claim 15 or 16, wherein, The average coefficient of thermal expansion α of the cordierite ceramic material is 1.5 × 10⁻⁶ at 25-800 °C. -6 -2.5×10 -6 ℃ -1 Its flexural strength is 55-70 MPa, and its bulk density is 2.30-2.50 g / cm³. 3 .

18. The cordierite ceramic material prepared by the preparation method of any one of claims 1-14 or the cordierite ceramic material of any one of claims 15-17 is applied in the field of refractory materials, precise electronic packaging materials, biomedical coating materials, or chemical anticorrosion equipment materials.

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