A thermal shock-resistant and corrosion-resistant honeycomb ceramic and its preparation method

Abstract

The present invention discloses a thermal shock-resistant and corrosion-resistant honeycomb ceramic and a preparation method thereof. The honeycomb ceramic comprises a base powder and a composite additive; the composite additive comprises samarium oxide added in an amount of 1% to 9% by weight of the base powder and zirconium oxide added in an amount of 1% to 9% by weight of the base powder. The present invention improves the acid and alkali corrosion resistance of the honeycomb ceramic by adding samarium oxide, while simultaneously improving the thermal shock resistance of the ceramic by adding zirconium oxide, thereby buffering the deformation of the ceramic during the sintering process. Thus, a thermal shock-resistant and corrosion-resistant honeycomb ceramic is obtained, and the synergistic effect simultaneously improves the corrosion resistance of the ceramic.

Description

Technical Field

[0001] The invention relates to the field of honeycomb ceramics, in particular to a honeycomb ceramic that is resistant to thermal shock and corrosion and a preparation method thereof. Background Art

[0002] Honeycomb ceramics are widely used in automotive exhaust purification and industrial waste gas treatment. They serve as carriers for three-way catalytic converters to reduce harmful substances in automobile exhaust and are also used in industrial waste gas treatment equipment to reduce harmful gas emissions. However, in actual applications, exhaust / tail gas often contains acidic / alkaline gases such as sulfur dioxide, nitrogen oxides, and ammonia. Under high temperature conditions, the corrosive substances generated by these gases can gradually corrode honeycomb ceramics, causing material aging, strength loss, and structural damage, significantly shortening their service life. In addition, honeycomb ceramics with poor thermal shock resistance may suffer thermal shock damage or high-temperature creep when operated in high-temperature environments, which can also affect their performance and service life.

[0003] Research has shown that improving the raw material formula of honeycomb ceramics can effectively enhance the thermal shock resistance and corrosion resistance of ceramic materials. Chinese patent application publication number CN117362070A discloses a honeycomb ceramic thermal accumulator and its preparation method. The honeycomb ceramic thermal accumulator comprises a base powder and a rare earth additive. The rare earth additive is added in an amount of 1-17 wt% of the base powder and includes at least one of cerium oxide, lanthanum oxide, yttrium oxide, and niobium oxide. By weight, the base powder comprises 45-55 parts bauxite powder, 3-5 parts cordierite powder, 1.5-3.5 parts kaolin powder, 0.75-1.25 parts pyroxene powder, 28-32 parts mullite powder, 2.5-3.5 parts potassium feldspar powder, and 5-8 parts raw talc powder.

[0004] The Chinese invention patent application with publication number CN115057691A discloses a high-aluminum honeycomb ceramic material resistant to low-concentration hydrofluoric acid corrosion and its preparation method. By introducing raw materials such as barite, zircon sand, and chromium oxide into the formula, the product has good corrosion resistance when the hydrofluoric acid concentration is below 5%. However, it does not explore the corrosion resistance of ceramic materials in alkaline environments. At the same time, the material has a large shrinkage rate and a high degree of deformation, and parameters such as compressive strength and thermal shock resistance are not characterized. The Chinese invention patent application with publication number CN107892581A discloses a high-strength and corrosion-resistant zirconium corundum honeycomb ceramic body and its preparation method. The high-strength and corrosion-resistant zirconium corundum honeycomb ceramic body prepared by this preparation method can ensure that it has a high operating temperature and high heat capacity, improve its thermal, mechanical properties and corrosion resistance, and significantly extend its service life. However, it only provides the approximate service life of the ceramic, and does not provide specific experimental content and relevant parameters for the corrosion resistance of the ceramic. Chinese invention patent application publication number CN101148355A discloses a method for preparing partially stabilized zirconia (PSZ) ceramics with improved thermal shock resistance. In Example 1, 3 mol% Y2O3 and ZrO2 powders are added, and in Example 2, 7 mol% Y2O3 and ZrO2 powders are added. This method can improve the thermal shock resistance of the material. Chinese invention patent application publication number CN109706452B discloses a method for preparing a ceramic coating on a high-carbon steel surface. A coating raw material containing silica powder and alumina ceramic powder is ball-milled, 1.6-1.7% rare earth samarium oxide is added, and a binder is added and mixed uniformly to obtain a rare earth ceramic coating raw material. The resulting rare earth ceramic coating raw material is applied to the treated high-carbon steel surface and sintered to obtain a finished product, thereby improving the surface strength and corrosion resistance of the high-carbon steel. This ceramic coating preparation process involves complex steps and does not provide relevant data on its corrosion resistance. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a thermal shock and corrosion resistant honeycomb ceramic and a preparation method thereof, in view of the deficiencies in the existing technology, so as to improve the thermal shock resistance and corrosion resistance of the ceramic.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] A thermal shock and corrosion resistant honeycomb ceramic comprises a basic powder and a composite additive; the composite additive comprises samarium oxide added in an amount of 1wt%-9wt% of the basic powder and zirconium oxide added in an amount of 1wt%-9wt% of the basic powder.

[0008] Currently, no research has been conducted to demonstrate the synergistic effect of adding samarium oxide and zirconium oxide to ceramic raw materials as composite additives to simultaneously improve both thermal shock resistance and corrosion resistance. However, with the addition of zirconium oxide at concentrations ranging from 1% to 9% samarium oxide, the acid and alkali corrosion resistance and thermal shock resistance of the samples gradually improved.

[0009] In a preferred embodiment of the present invention, the composite additive comprises samarium oxide in an amount of 1 wt% to 9 wt% of the base powder and zirconium oxide in an amount of 7 wt% to 9 wt% of the base powder.

[0010] When 1w%-9wt% of samarium oxide is added and the amount of zirconium oxide added is 7wt%-9wt%, the acid and alkali corrosion resistance and thermal shock resistance of the sample can achieve the best results.

[0011] In a preferred embodiment of the present invention, the composite additive comprises samarium oxide in an amount of 7 wt% to 9 wt% of the base powder and zirconium oxide in an amount of 7 wt% to 9 wt% of the base powder.

[0012] When 7%-9wt% of samarium oxide and 7%-9wt% of zirconium oxide are added at the same time, the ceramic has both good corrosion resistance and thermal shock resistance. Compared with single addition, the combination of the two can play a synergistic role in corrosion resistance, and the thermal shock resistance is also significantly improved compared to the original sample without additives.

[0013] In a preferred embodiment of the present invention, the base powder comprises the following raw materials in parts by weight: 40-60 parts of bauxite powder, 2-6 parts of cordierite powder, 1-4 parts of kaolin, 0.5-1.5 parts of pyroxene powder, 20-35 parts of mullite powder, 2-4 parts of potassium feldspar, 4-9 parts of raw talc, 2-5‰ of the total mass of the powder as a dispersant, and 0.5-2‰ of the total mass of the powder as a grinding aid.

[0014] In a preferred embodiment of the present invention, the aluminum oxide content of the bauxite powder is greater than 80%;

[0015] The kaolin powder is Suzhou kaolin.

[0016] The present invention also discloses a thermal shock and corrosion-resistant honeycomb ceramic, wherein the thermal shock resistance / compressive strength of the thermal shock and corrosion-resistant honeycomb ceramic is 129-140 MPa, the weight loss rate after 96 hours of treatment with 98% concentrated sulfuric acid is 0.15-0.21%, the weight loss rate after 96 hours of treatment with 98% concentrated sulfuric acid + 96 hours of treatment with 50% dilute sulfuric acid is 0.96-1.01%, the weight loss rate after 96 hours of treatment with 20% NaOH is 0.08-0.10%, and the weight loss rate after 96 hours of treatment with 20% NaOH + 96 hours of treatment with 28% NaOH is 0.28-0.32%. Preferably, the true density of the thermal shock and corrosion-resistant honeycomb ceramic is 3.43-3.47 g / cm 3 , the linear shrinkage rate is 2.79-3.29%.

[0017] The present invention also discloses a method for preparing thermal shock-resistant and corrosion-resistant honeycomb ceramics, comprising the following steps:

[0018] S1. Weigh the raw materials by weight and grind them into a ball mill to prepare a mixture;

[0019] S2, adding 1-4% of cellulose by weight of the mixture, 1-3% of palm oil by weight of the mixture, 3-10‰ of polyethylene oxide by weight of the mixture, and 10-20% of deionized water by weight of the mixture to the mixture, and kneading to obtain a kneaded mud segment;

[0020] S3, refining the kneaded mud segment to obtain a refined mud segment;

[0021] S4, pressing the refined mud segment into the desired product using a mold to obtain a wet blank;

[0022] S5, drying the wet blank to obtain a dry blank;

[0023] S6, sintering the dry blank to obtain a finished ceramic product.

[0024] In a preferred embodiment of the present invention, the viscosity of the cellulose in S2 is 80,000-100,000, the palm oil is 28-degree palm oil, and the molecular weight of the polyethylene oxide is 1 million-8 million.

[0025] In a preferred embodiment of the present invention, the ball milling speed in S1 is 10-40 rpm, and the ball milling time is 6-10 hours;

[0026] The kneading speed in S2 is 20-40 rpm, and the kneading time is 10-30 minutes;

[0027] The vacuum degree of refining in S3 is 0.06-0.09;

[0028] The sintering temperature in S6 is 1150°C-1600°C, and the sintering time is 8-9h.

[0029] In a preferred embodiment of the present invention, before S6, the process further includes cutting both ends of the dry blank, wherein the cutting size is 1-1.20 times the length of the finished ceramic product.

[0030] Compared with existing technologies, the present invention offers the following advantages: The present invention develops a thermal shock-resistant and corrosion-resistant honeycomb ceramic and its preparation method. By adding a composite additive consisting of samarium oxide and zirconium oxide to the ceramic raw materials, the corrosion resistance of the honeycomb ceramic is synergistically enhanced, ensuring its thermal shock resistance and significantly extending its service life. The present invention also utilizes simple raw material components and offers low production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Schematic diagram of the true density of ceramics with 1%-9% samarium oxide added in the screening experiment of the present invention.

[0032] Figure 2 This is a schematic diagram of the linear shrinkage of ceramics with 1%-9% samarium oxide added in the screening experiment of the present invention.

[0033] Figure 3 Schematic diagram of the acid corrosion resistance of ceramics with 1%-9% samarium oxide added in the screening experiment of the present invention.

[0034] Figure 4 This is a schematic diagram of the alkali corrosion resistance of ceramics with 1%-9% samarium oxide added in the screening experiment of the present invention.

[0035] Figure 5 Schematic diagram of the compressive strength of ceramics with 1%-9% samarium oxide added in the screening experiment of the present invention.

[0036] Figure 6 This is a schematic diagram of the true density of ceramics with 1%-9% zirconium oxide added in the screening experiment of the present invention.

[0037] Figure 7 This is a schematic diagram of the linear shrinkage of zirconia ceramics with 1%-9% added in the screening experiment of the present invention.

[0038] Figure 8 This is a schematic diagram of the acid corrosion resistance of ceramics with 1%-9% zirconium oxide added in the screening experiment of the present invention.

[0039] Figure 9 This is a schematic diagram of the alkali corrosion resistance of ceramics with 1%-9% zirconium oxide added in the screening experiment of the present invention.

[0040] Figure 10 This is a schematic diagram of the compressive strength of ceramics with 1%-9% zirconia added in the screening experiment of the present invention. DETAILED DESCRIPTION

[0041] In order to verify the effect of different formulations of the above-mentioned composite additives on improving the performance of thin-walled honeycomb ceramics, the applicant conducted a series of experimental studies, as follows:

[0042] 1. Effect of samarium oxide addition on ceramic properties

[0043] According to the above method, raw materials are weighed by weight, 1%-9% samarium oxide is added to the raw materials, and the raw materials are then placed in a ball mill and ball-milled at 40 revolutions per minute for 10 hours to produce a mixture. The mixture is then added to a kneader, and 4% by weight of HPMC (100,000 viscosity cellulose), 2% 28-degree palm oil, 5‰ of 1-8 million molecular weight polyethylene oxide, and 15% deionized water are added. The kneader is set to 30 revolutions per minute and kneaded for 20 minutes to produce a kneaded clay segment. The kneaded clay segment is then placed in a vacuum kneader and refined at a vacuum of 0.09 to produce a refined clay segment. The refined clay segment is pressed into a sample, dried, and fired at 1600°C for 3 hours to produce a thin-walled honeycomb ceramic sample. The true density, linear shrinkage, acid and alkali corrosion resistance, and thermal shock resistance of the sample are measured using the following testing methods.

[0044] (1) True density test: Use a true density measuring instrument to measure the true density of samples with different additive contents;

[0045] (2) Linear shrinkage test: record the dimensions of the sample before and after sintering, compare the dimensional changes before and after sintering, and calculate the linear shrinkage of the ceramic;

[0046] (3) Acid corrosion resistance test: One group of samples was placed in a 98% dilute sulfuric acid solution and stirred at room temperature (25°C) for 96 hours using a magnetic stirrer with a speed set to 450 rpm. The mass loss rate of the samples was measured after the samples were taken out and dried. Another group of samples was placed in a 50% dilute sulfuric acid solution and stirred for 96 hours. The samples were then placed in a 50% dilute sulfuric acid solution and stirred for 96 hours. The mass loss rate of the samples was measured after the samples were taken out and dried. The acid corrosion resistance of the samples was characterized by the mass loss rate.

[0047] (4) Alkali corrosion resistance test: One group of samples was placed in a 20% sodium hydroxide solution and stirred at room temperature (25°C) for 96 hours using a magnetic stirrer with a speed set to 450 rpm. After being taken out and dried, the mass loss rate of the samples was measured. Another group of samples was placed in a 20% sodium hydroxide solution and stirred for 96 hours. Then, they were placed in a 28% sodium hydroxide solution and stirred for 96 hours. After being taken out and dried, the mass loss rate of the samples was measured. The alkali corrosion resistance of the samples was characterized by the mass loss rate.

[0048] (5) Thermal shock resistance test: The ceramic samples were heated to 800°C in a high-temperature furnace and then quickly transferred to cold water at 25°C for cooling. After repeated thermal cycling for 5 times, the compressive strength of the samples was tested and compared with the compressive strength of the samples at room temperature without thermal cycling to evaluate their thermal shock resistance.

[0049] Figure 1 is the true density of ceramics with different samarium oxide addition amounts. Figure 2 is the linear shrinkage of ceramics with different samarium oxide addition amounts. Figure 3 Acid corrosion resistance of ceramics with different samarium oxide addition amounts. Figure 3 (a) Acid corrosion resistance condition is 98% concentrated sulfuric acid treatment for 96 hours, Figure 3 (b) Acid corrosion resistance conditions are 98% concentrated sulfuric acid treatment for 96 hours + 50% dilute sulfuric acid treatment for 96 hours.

[0050] Figure 4 Alkali corrosion resistance of ceramics with different samarium oxide addition amounts. Figure 4 (a) Alkali corrosion resistance condition is 20% NaOH treatment for 96 hours, Figure 4 (b) Alkali corrosion resistance conditions are 20% NaOH treatment for 96 hours + 28% NaOH treatment for 96 hours. Figure 5 Thermal shock resistance of ceramics with different samarium oxide addition amounts.

[0051] Depend on Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 As the amount of samarium oxide added increases, the sample's true density and linear shrinkage gradually increase, while its mass loss after immersion in acidic and alkaline solutions decreases, indicating improved acid and alkali corrosion resistance. The best effect is achieved when the samarium oxide addition is 7%-9%. However, the corresponding sample exhibits high shrinkage and deformation, and its thermal shock resistance is average. Further optimization of ceramic properties requires consideration of other additives.

[0052] 2. Effect of zirconia addition on ceramic properties

[0053] According to the above method, raw materials are weighed by weight, 1%-9% zirconium oxide is added to the raw materials, and the raw materials are then placed in a ball mill and ball-milled at 40 revolutions per minute for 10 hours to produce a mixture. The mixture is then added to a kneader, and 4% by weight of HPMC 100,000 viscosity cellulose, 2% 28-degree palm oil, 5‰ of 1-8 million molecular weight polyethylene oxide, and 15% deionized water are added. The kneader is set to 30 revolutions per minute and kneaded for 20 minutes to produce a kneaded clay segment. The kneaded clay segment is placed in a vacuum kneader and refined at a vacuum of 0.09 to produce a refined clay segment. The refined clay segment is pressed into a sample, dried, and fired at 1600°C for 3 hours to produce a thin-walled honeycomb ceramic sample. The true density, linear shrinkage, acid and alkali corrosion resistance, and thermal shock resistance of the sample are measured using the following testing methods.

[0054] (1) True density test: Use a true density measuring instrument to measure the true density of samples with different additive contents;

[0055] (2) Linear shrinkage test: record the dimensions of the sample before and after sintering, compare the dimensional changes before and after sintering, and calculate the linear shrinkage of the ceramic;

[0056] (3) Acid corrosion resistance test: One group of samples was placed in a 98% dilute sulfuric acid solution and stirred at room temperature (25°C) for 96 hours using a magnetic stirrer with a speed set to 450 rpm. The mass loss rate of the samples was measured after the samples were taken out and dried. Another group of samples was placed in a 50% dilute sulfuric acid solution and stirred for 96 hours. The samples were then placed in a 50% dilute sulfuric acid solution and stirred for 96 hours. The mass loss rate of the samples was measured after the samples were taken out and dried. The acid corrosion resistance of the samples was characterized by the mass loss rate.

[0057] (4) Alkali corrosion resistance test: One group of samples was placed in a 20% sodium hydroxide solution and stirred at room temperature (25°C) for 96 hours using a magnetic stirrer with a speed set to 450 rpm. After being taken out and dried, the mass loss rate of the samples was measured. Another group of samples was placed in a 20% sodium hydroxide solution and stirred for 96 hours. Then, they were placed in a 28% sodium hydroxide solution and stirred for 96 hours. After being taken out and dried, the mass loss rate of the samples was measured. The alkali corrosion resistance of the samples was characterized by the mass loss rate.

[0058] (5) Thermal shock resistance test: The ceramic samples were heated to 800°C in a high-temperature furnace and then quickly transferred to cold water at 25°C for cooling. After repeated thermal cycling for 5 times, the compressive strength of the samples was tested and compared with the compressive strength of the samples at room temperature without thermal cycling to evaluate their thermal shock resistance.

[0059] Figure 6 The true density of ceramics with different zirconia addition amounts. Figure 7 Linear shrinkage of ceramics with different zirconia addition amounts. Figure 8 Acid corrosion resistance of ceramics with different zirconium oxide addition amounts. Figure 8 (a) Acid corrosion resistance condition is 98% concentrated sulfuric acid treatment for 96 hours, Figure 8 (b) Acid corrosion resistance conditions are 98% concentrated sulfuric acid treatment for 96 hours + 50% dilute sulfuric acid treatment for 96 hours. Figure 9 Alkali corrosion resistance of ceramics with different zirconium oxide addition amounts. Figure 9 (a) Alkali corrosion resistance condition is 20% NaOH treatment for 96 hours, Figure 9 (b) Alkali corrosion resistance conditions are 20% NaOH treatment for 96 hours + 28% NaOH treatment for 96 hours.

[0060] Figure 10 Thermal shock resistance of ceramics with different zirconia addition amounts.

[0061] Depend on Figure 6 、 Figure 7 、 Figure 8 、 Figure 9 、 Figure 10 It can be seen that with the increase in the addition of zirconium oxide, the true density of the sample gradually increases, the linear shrinkage gradually decreases, and the overall sample shows a trend of change from inward contraction to outward expansion. Although the mass loss rate after immersion in acidic and alkaline solutions shows a downward trend, its effect on the corrosion resistance of the ceramic is smaller than that of samarium oxide. With the increase in the addition of zirconium oxide, the compressive strength of the corresponding sample gradually increases after undergoing 5 thermal cycles, indicating that the addition of zirconium oxide can significantly enhance the thermal shock resistance of the ceramic. This is because zirconium oxide transforms from tetragonal to monoclinic phase during the cooling process, causing volume expansion, compensating for some of the firing shrinkage. At the same time, diffusely distributed microcracks are generated in the matrix. These tiny cracks cause the propagation direction of the main crack to bifurcate or change, effectively hindering the propagation and extension of the crack, thereby improving the toughness and indirectly enhancing the thermal shock resistance.

[0062] Therefore, based on the above comparative experiments, it is considered to add an appropriate amount of zirconium oxide on the basis of adding 7%-9% of samarium oxide, so as to obtain honeycomb ceramics with good thermal shock resistance and corrosion resistance.

[0063] 3. Effect of adding 7%-9% samarium oxide and 1%-9% zirconium oxide on ceramic properties

[0064] According to the above method, samples were prepared, and the true density, linear shrinkage, acid and alkali corrosion resistance and thermal shock resistance of the samples were tested. Table 1 shows the performance parameters of the samples prepared with different amounts of samarium oxide and zirconium oxide added.

[0065] Table 1 Performance parameters of samples prepared with different samarium oxide and zirconium oxide addition amounts

[0066]

[0067] As shown in Table 1, when the samarium oxide addition level is constant, the true density of the sample gradually increases and the linear shrinkage gradually decreases as the zirconium oxide addition level increases. When the zirconium oxide addition level is within the range of 7%-9%, the sintering deformation of the sample is minimized. Furthermore, with the addition of zirconium oxide, the sample's acid and alkali corrosion resistance and thermal shock resistance gradually improve, with the optimal effect achieved when the zirconium oxide addition level is between 7% and 9%.

[0068] Combined with the experimental results of single additives, it can be seen that compared with the single addition of 7%-9% samarium oxide or 7%-9% zirconium oxide, when 7%-9% samarium oxide and 7%-9% zirconium oxide are added at the same time, the ceramic has both good corrosion resistance and thermal shock resistance. Compared with the single addition, the combination of the two can play a synergistic role in corrosion resistance, and the thermal shock resistance is also significantly improved compared to the original sample without additives.

[0069] Example 1

[0070] A thermal shock and corrosion-resistant honeycomb ceramic is made from the following raw materials in parts by weight (kg): 50 parts of bauxite powder with an aluminum oxide content greater than 80%, 3 parts of cordierite powder, 2 parts of Suzhou kaolin, 0.5 parts of pyrope powder, 25 parts of mullite powder, 3.5 parts of potassium feldspar, 4 parts of raw talc, 5‰ of the total weight of the powder in the amount of a dispersant, 2‰ of the total weight of the powder in the amount of a grinding aid, 8% of the total weight of the powder in the amount of samarium oxide, and 7% of the total weight of the powder in the amount of zirconium oxide.

[0071] A method for preparing thermal shock-resistant and corrosion-resistant honeycomb ceramics comprises the following steps:

[0072] (1) Weighing each raw material by weight, placing the raw material into a ball mill, and ball milling at a speed of 20 revolutions per minute for 9 hours to prepare a mixture;

[0073] (2) adding the mixture to a kneader, adding 2% of the mass of the mixture of HPMC 100,000 viscosity cellulose, 2% of 28 degree palm oil, 8‰ of 5 million molecular weight polyethylene oxide, and 15% of deionized water, setting the kneader speed to 30 revolutions per minute, and kneading for 20 minutes to obtain a kneaded mud segment;

[0074] (3) putting the kneaded mud segment into a vacuum mud kneading machine and refining it at a vacuum degree of 0.08 to obtain a refined mud segment;

[0075] (4) using a mold to press into the desired product to obtain a wet blank;

[0076] (5) drying the wet blank to obtain a dry blank;

[0077] (6) cutting the two ends of the dry blank to a size of 1-1.20 times the length of the finished product to obtain a cut dry blank;

[0078] (7) The cut dry blank is placed in a kiln and fired at 1150°C to obtain a finished product.

[0079] The performance indicators of the finished ceramic products, such as true density, linear shrinkage, acid and alkali corrosion resistance, and thermal shock resistance, are tested, as shown in Table 2.

[0080] Table 2 Properties of the finished ceramic product obtained in Example 1

[0081]

[0082] Example 2

[0083] A thermal shock and corrosion-resistant honeycomb ceramic is made from the following raw materials in parts by weight (kg): 50 parts of bauxite powder with an aluminum oxide content greater than 80%, 3 parts of cordierite powder, 2 parts of Suzhou kaolin, 0.5 parts of pyrope powder, 25 parts of mullite powder, 3.5 parts of potassium feldspar, 4 parts of raw talc, 5‰ of the total weight of the powder in the amount of a dispersant, 2‰ of the total weight of the powder in the amount of a grinding aid, 8% of the total weight of the powder in the amount of samarium oxide, and 9% of the total weight of the powder in the amount of zirconium oxide.

[0084] A method for preparing thermal shock-resistant and corrosion-resistant honeycomb ceramics comprises the following steps:

[0085] (1) Weighing each raw material by weight, placing the raw material into a ball mill, and ball milling at a speed of 20 revolutions per minute for 9 hours to prepare a mixture;

[0086] (2) adding the mixture to a kneader, adding 2% of the mass of the mixture of HPMC 100,000 viscosity cellulose, 2% of 28 degree palm oil, 8‰ of 5 million molecular weight polyethylene oxide, and 15% of deionized water, setting the kneader speed to 30 revolutions per minute, and kneading for 20 minutes to obtain a kneaded mud segment;

[0087] (3) putting the kneaded mud segment into a vacuum mud kneading machine and refining it at a vacuum degree of 0.08 to obtain a refined mud segment;

[0088] (4) using a mold to press into the desired product to obtain a wet blank;

[0089] (5) drying the wet blank to obtain a dry blank;

[0090] (6) cutting the two ends of the dry blank to a size of 1-1.20 times the length of the finished product to obtain a cut dry blank;

[0091] (7) The cut dry blank is placed in a kiln and fired at 1150°C to obtain a finished product.

[0092] The performance indicators of the finished ceramic products, such as true density, linear shrinkage, acid and alkali corrosion resistance, and thermal shock resistance, are tested, as shown in Table 3.

[0093] Table 3 Performance of ceramic finished product obtained in Example 2

[0094]

[0095] Example 3

[0096] A thermal shock and corrosion-resistant honeycomb ceramic is made from the following raw materials in parts by weight (kg): 50 parts of bauxite powder with an aluminum oxide content greater than 80%, 3 parts of cordierite powder, 2 parts of Suzhou kaolin, 0.5 parts of pyrope powder, 25 parts of mullite powder, 3.5 parts of potassium feldspar, 4 parts of raw talc, 5‰ of the total weight of the powder as a dispersant, 2‰ of the total weight of the powder as a grinding aid, 8% of the total weight of the powder as samarium oxide, and 8% of the total weight of the powder as zirconium oxide.

[0097] A method for preparing thermal shock-resistant and corrosion-resistant honeycomb ceramics comprises the following steps:

[0098] (1) Weighing each raw material by weight, placing the raw material into a ball mill, and ball milling at a speed of 20 revolutions per minute for 9 hours to prepare a mixture;

[0099] (2) adding the mixture to a kneader, adding 2% of the mass of the mixture of HPMC 100,000 viscosity cellulose, 2% of 28 degree palm oil, 8‰ of 5 million molecular weight polyethylene oxide, and 15% of deionized water, setting the kneader speed to 30 revolutions per minute, and kneading for 20 minutes to obtain a kneaded mud segment;

[0100] (3) putting the kneaded mud segment into a vacuum mud kneading machine and refining it at a vacuum degree of 0.08 to obtain a refined mud segment;

[0101] (4) using a mold to press into the desired product to obtain a wet blank;

[0102] (5) drying the wet blank to obtain a dry blank;

[0103] (6) cutting the two ends of the dry blank to a size of 1-1.20 times the length of the finished product to obtain a cut dry blank;

[0104] (7) The cut dry blank is placed in a kiln and fired at 1150°C to obtain a finished product.

[0105] The performance indicators of the finished ceramic products, such as true density, linear shrinkage, acid and alkali corrosion resistance, and thermal shock resistance, are tested, as shown in Table 4.

[0106] Table 4 Performance of ceramic finished product obtained in Example 3

[0107]

[0108] The above embodiments are intended to illustrate the present invention, not to limit the invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions only illustrate the specific working principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A thermal shock and corrosion resistant honeycomb ceramic, characterized in that: The invention comprises a base powder and a composite additive; the composite additive comprises samarium oxide added in an amount of 1 wt % to 9 wt % of the base powder and zirconium oxide added in an amount of 3 wt % to 9 wt % of the base powder; The base powder comprises the following raw materials in parts by weight: 40-60 parts of bauxite powder, 2-6 parts of cordierite powder, 1-4 parts of kaolin, 0.5-1.5 parts of pyroxene powder, 20-35 parts of mullite powder, 2-4 parts of potassium feldspar, 4-9 parts of raw talc, 2-5‰ of the total mass of the powder as a dispersant, and 0.5-2‰ of the total mass of the powder as a grinding aid.

2. The thermal shock and corrosion resistant honeycomb ceramic according to claim 1, characterized in that: The composite additive includes samarium oxide added in an amount of 1 wt % to 9 wt % of the base powder and zirconium oxide added in an amount of 7 wt % to 9 wt % of the base powder.

3. The thermal shock and corrosion resistant honeycomb ceramic according to claim 2, characterized in that: The composite additive includes samarium oxide added in an amount of 7wt%-9wt% of the base powder and zirconium oxide added in an amount of 7wt%-9wt% of the base powder.

4. The thermal shock and corrosion resistant honeycomb ceramic according to claim 1, characterized in that: The aluminum oxide content of the bauxite powder is greater than 80%; The kaolin powder is Suzhou kaolin.

5. A thermal shock and corrosion resistant honeycomb ceramic according to any one of claims 1 to 4, characterized in that: The compressive strength of the thermal shock and corrosion resistant honeycomb ceramic is 129-140 MPa. The weight loss rate after treatment with 98% concentrated sulfuric acid for 96 hours is 0.15-0.21%, the weight loss rate after treatment with 98% concentrated sulfuric acid for 96 hours plus 50% dilute sulfuric acid for 96 hours is 0.96-1.01%, the weight loss rate after treatment with 20% NaOH for 96 hours is 0.08-0.10%, and the weight loss rate after treatment with 20% NaOH for 96 hours plus 28% NaOH for 96 hours is 0.28-0.32%. The true density of the thermal shock and corrosion resistant honeycomb ceramic is 3.43-3.47 g / cm 3 The linear shrinkage of the thermal shock and corrosion resistant honeycomb ceramic is 2.79-3.29%.

6. A method for preparing the thermal shock and corrosion resistant honeycomb ceramic according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Weigh the raw materials by weight and grind them into a ball mill to prepare a mixture; S2, adding 1-4% of cellulose by weight of the mixture, 1-3% of palm oil by weight of the mixture, 3-10‰ of polyethylene oxide by weight of the mixture, and 10-20% of deionized water by weight of the mixture to the mixture, and kneading to obtain a kneaded mud segment; S3, refining the kneaded mud segment to obtain a refined mud segment; S4, pressing the refined mud segment into the desired product using a mold to obtain a wet blank; S5, drying the wet blank to obtain a dry blank; S6, sintering the dry blank to obtain a finished ceramic product.

7. The preparation method according to claim 6, characterized in that The viscosity of the cellulose in S2 is 80,000-100,000, the palm oil is 28-degree palm oil, and the molecular weight of the polyethylene oxide is 1,000,000-8,000,000.

8. The preparation method according to claim 6, characterized in that: The ball milling speed in S1 was 10-40 rpm, and the ball milling time was 6-10 h; The kneading speed in S2 is 20-40 rpm, and the kneading time is 10-30 minutes; The vacuum degree of refining in S3 is 0.06-0.09; The sintering temperature in S6 is 1150°C-1600°C, and the sintering time is 8-9h.

9. The preparation method according to claim 6, characterized in that Before S6, the process also includes cutting both ends of the dry blank, wherein the cutting size is 1-1.20 times the length of the finished ceramic product.

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