A high-porous thin-wall cordierite carrier with good protectiveness and preparation method thereof

Abstract

The invention discloses a high-porous thin-wall cordierite carrier with good protectiveness and a preparation method thereof. The carrier comprises a carrier raw material and ingredients. The carrier raw material comprises, by weight, 28% to 35% of spherical and flaky mixed talc, 13% to 16% of spherical silicon oxide, 16% to 19% of flaky aluminum oxide, 8% of fibrous boehmite, 8% of fibrous kaolin, and 15% to 30% of inorganic filler. By selecting the morphology and stacking arrangement of the raw materials, the internal resistance of the mud material under force sliding is improved and the deformation is reduced. At the same time, by introducing high-temperature resistant inorganic powder with coarser particle size and consistent or similar expansion coefficient, the extrusion performance is improved.

Description

Technical Field

[0001] The invention relates to the technical field of honeycomb ceramics, and in particular to a high-porous thin-wall cordierite carrier with good protectiveness and a preparation method thereof. Background Art

[0002] The development of the industrialization of the automobile industry has brought about increasingly serious exhaust pollution. As the control standards for automobile exhaust emissions become increasingly stringent, countries around the world, including China, are also increasingly strict with diesel vehicle exhaust emissions. In order to meet ultra-low emissions and reduce exhaust pollution, the after-treatment system will become more complicated, so it is necessary to further improve the performance of the honeycomb ceramic carrier. In terms of improving performance, reducing the wall thickness of the carrier can reduce the ignition temperature and optimize cold start emissions; increase the cross-sectional opening rate, increase the specific surface area, and improve the catalytic conversion rate; reduce back pressure and improve engine efficiency, which is beneficial to improve fuel economy. At the same time, it can meet the National VI automobile exhaust emission requirements, so the control of the wall thickness of the honeycomb ceramic carrier is particularly important.

[0003] At present, the wall thickness of the ternary catalytic agent carrier 400 holes / square inch honeycomb ceramic carrier is generally about 4 mils, and the wall thickness of the 600 holes / square inch honeycomb ceramic carrier can reach 3 mils. However, due to the reduction in wall thickness, it often produces new problems: since the pore wall is very thin, the wall of the product is stressed or slides under gravity during the extrusion process, causing the product to twist and deform. At the same time, in order to meet the thermal shock performance of the sintered product, the raw material is required to be finer, and D50 is often 3 to 18μm. There is a strong force between particles, so the extrusion performance is also higher. In order to improve the extrusion performance, the amount of water added to the mud will also be increased, resulting in a high water loss rate during the drying process of the mud, which leads to product deformation. Summary of the invention

[0004] Purpose of the invention:

[0005] In order to overcome the problems existing in the prior art, the present invention provides a high-porous thin-wall cordierite carrier with good protectiveness and a preparation method thereof. By selecting the raw material morphology and stacking arrangement, the internal resistance of the mud material under force sliding is improved and the deformation is reduced.

[0006] To solve the above problems, the present invention adopts the following technical solutions:

[0007] A highly porous thin-walled cordierite carrier with good protectiveness comprises carrier raw materials and ingredients. The carrier raw materials comprise, by weight, 28% to 35% of spherical and flaky mixed talc, 13% to 16% of spherical silicon oxide, 16% to 19% of flaky aluminum oxide, 8% of fibrous boehmite, 8% of fibrous kaolin, and 15% to 30% of inorganic filler.

[0008] Preferably, the average particle size of the talc is 10 to 15 μm, the average particle size of the silicon oxide is 3 to 8 μm, the average particle size of the aluminum oxide is 3 to 8 μm, the average particle size of the boehmite is 3 to 8 μm, the average particle size of the kaolin is 3 to 8 μm, and the average particle size of the inorganic filler is 3 to 8 μm.

[0009] Preferably, the weight proportions of the spherical talc and the flaky talc are equal.

[0010] Preferably, the inorganic filler is one or both of irregular spherical β-spodumene and cordierite.

[0011] Preferably, the ingredients include an organic binder, an inorganic binder and a surfactant.

[0012] Preferably, the organic binder is 4-5% methyl cellulose and 1-3% polyvinyl alcohol based on the weight of the carrier raw material.

[0013] Preferably, the inorganic binder is aluminum dihydrogen phosphate accounting for 1 to 2% of the weight of the carrier raw material.

[0014] Preferably, the surfactant accounts for 2.5-5% of the weight of the carrier raw material and is one or more of glycerol, potassium laurate, and oleic acid.

[0015] The present invention also discloses a method for preparing a high-porous thin-wall cordierite carrier with good protectiveness, comprising the following steps:

[0016] S1. Weigh the carrier raw materials according to weight, and stir them in a mixer at a speed of 15 to 100 r / min for 10 to 40 min to obtain a mixture;

[0017] S2. Add the mixed material, organic binder, inorganic binder, surfactant and water into a mixer, and stir them together at a speed of 10 to 90 r / min for 10 to 40 minutes to obtain a slurry;

[0018] S3, putting the mixture into a vacuum clay kneading machine for kneading, and then putting the mixture into an extrusion molding machine to form an embryo;

[0019] S4, the embryo body after extrusion molding is treated with microwaves, and dried, cut and sintered at the same time to obtain a honeycomb ceramic carrier.

[0020] Preferably, the drying temperature is 50-150° C., the sintering temperature is 1200-1500° C., and the sintering time is 4-20 hours.

[0021] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0022] 1. By selecting the raw material morphology and stacking arrangement, the internal resistance of the clay under force sliding is increased and the deformation is reduced.

[0023] 2. The extrusion performance is improved by introducing high temperature resistant inorganic powder with coarser particle size and consistent or similar expansion coefficient. DETAILED DESCRIPTION

[0024] All features disclosed in this specification, or steps in all methods or processes disclosed, except mutually exclusive features and / or steps, can be combined in any manner.

[0025] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below.

[0026] A highly porous thin-walled cordierite carrier with good protectiveness comprises carrier raw materials and ingredients. The carrier raw materials comprise, by weight, 28% to 35% of spherical and flaky mixed talc, 13% to 16% of spherical silicon oxide, 16% to 19% of flaky aluminum oxide, 8% of fibrous boehmite, 8% of fibrous kaolin, and 15% to 30% of inorganic filler.

[0027] Preferably, the average particle size of the talc is 10 to 15 μm, the average particle size of the silicon oxide is 3 to 8 μm, the average particle size of the aluminum oxide is 3 to 8 μm, the average particle size of the boehmite is 3 to 8 μm, the average particle size of the kaolin is 3 to 8 μm, and the average particle size of the inorganic filler is 3 to 8 μm.

[0028] Preferably, the weight proportions of the spherical talc and the flaky talc are equal.

[0029] Preferably, the inorganic filler is one or both of irregular spherical β-spodumene and cordierite.

[0030] Preferably, the ingredients include an organic binder, an inorganic binder and a surfactant.

[0031] Preferably, the organic binder is 4-5% methyl cellulose and 1-3% polyvinyl alcohol based on the weight of the carrier raw material.

[0032] Preferably, the inorganic binder is aluminum dihydrogen phosphate accounting for 1 to 2% of the weight of the carrier raw material.

[0033] Preferably, the surfactant accounts for 2.5-5% of the weight of the carrier raw material and is one or more of glycerol, potassium laurate, and oleic acid.

[0034] The present invention also discloses a method for preparing a high-porous thin-wall cordierite carrier with good protectiveness, comprising the following steps:

[0035] S1. Weigh the carrier raw materials according to weight, and stir them in a mixer at a speed of 15 to 100 r / min for 10 to 40 min to obtain a mixture;

[0036] S2. Add the mixed material, organic binder, inorganic binder, surfactant and water into a mixer, and stir them together at a speed of 10 to 90 r / min for 10 to 40 minutes to obtain a slurry;

[0037] S3, putting the mixture into a vacuum clay kneading machine for kneading, and then putting the mixture into an extrusion molding machine to form an embryo;

[0038] S4, the embryo body after extrusion molding is treated with microwaves, and dried, cut and sintered at the same time to obtain a honeycomb ceramic carrier.

[0039] Preferably, the drying temperature is 50-150° C., the sintering temperature is 1200-1500° C., and the sintering time is 4-20 hours.

[0040] Embodiment 1:

[0041] The high-porous thin-walled cordierite carrier includes a carrier raw material and ingredients. The carrier raw material includes 28.5% of spherical and flaky mixed talc in weight, with an average particle size of 10 to 15 μm, and the weight portions of spherical talc and flaky talc are equal, 13% of spherical silicon oxide, with an average particle size of 3 to 8 μm, 18% of flaky aluminum oxide, with an average particle size of 3 to 8 μm, 8% of fibrous boehmite, with an average particle size of 3 to 8 μm, 8% of fibrous kaolin, with an average particle size of 3 to 8 μm, and 24.5% of β-spodumene, with an average particle size of 3 to 8 μm.

[0042] The ingredients include an organic binder, an inorganic binder and a surfactant. The organic binder is 4.5% of methyl cellulose and 1% of polyvinyl alcohol, which account for 1% of the weight of the carrier raw material; the inorganic binder is aluminum dihydrogen phosphate, which accounts for 1% of the weight of the carrier raw material; and the surfactant is 1% of glycerol and 2% of potassium laurate, which account for 1% of the weight of the carrier raw material.

[0043] Embodiment 2:

[0044] The high-porous thin-wall cordierite carrier includes a carrier raw material and ingredients. The carrier raw material includes 30% of spherical and flaky mixed talc in weight, with an average particle size of 10 to 15 μm, and the weight portions of spherical talc and flaky talc are equal, 15% of spherical silicon oxide, with an average particle size of 3 to 8 μm, 16% of flaky aluminum oxide, with an average particle size of 3 to 8 μm, 8% of fibrous boehmite, with an average particle size of 3 to 8 μm, 8% of fibrous kaolin, with an average particle size of 3 to 8 μm, 12.5% ​​of β-spodumene, with an average particle size of 3 to 8 μm, and 10.5% of cordierite, with an average particle size of 3 to 8 μm.

[0045] The ingredients include an organic binder, an inorganic binder and a surfactant. The organic binder is 4.5% of methyl cellulose and 3% of polyvinyl alcohol, which account for 1% of the weight of the carrier raw material; the inorganic binder is aluminum dihydrogen phosphate, which accounts for 1% of the weight of the carrier raw material; and the surfactant is 3% of glycerol and 1% of potassium laurate, which account for 3% of the weight of the carrier raw material.

[0046] Embodiment 3:

[0047] The high-porous thin-wall cordierite carrier includes a carrier raw material and ingredients. The carrier raw material includes 34.5% of spherical and flaky mixed talc in weight, with an average particle size of 10 to 15 μm, and the weight portions of spherical talc and flaky talc are equal, 15% of spherical silicon oxide, with an average particle size of 3 to 8 μm, 18% of flaky aluminum oxide, with an average particle size of 3 to 8 μm, 8% of fibrous boehmite, with an average particle size of 3 to 8 μm, 8% of fibrous kaolin, with an average particle size of 3 to 8 μm, and 16.5% of cordierite, with an average particle size of 3 to 8 μm.

[0048] The ingredients include an organic binder, an inorganic binder and a surfactant. The organic binder is 4% methyl cellulose and 2% polyvinyl alcohol, which account for 2% of the weight of the carrier raw material; the inorganic binder is aluminum dihydrogen phosphate, which accounts for 2% of the weight of the carrier raw material; and the surfactant is glycerol, which accounts for 2.5% of the weight of the carrier raw material.

[0049] Embodiment 4:

[0050] The high-porous thin-wall cordierite carrier includes a carrier raw material and ingredients. The carrier raw material includes 32% of spherical and flaky mixed talc in weight, with an average particle size of 10 to 15 μm, the weight portions of spherical talc and flaky talc are equal, 15.5% of spherical silicon oxide, with an average particle size of 3 to 8 μm, 18.5% of flaky aluminum oxide, with an average particle size of 3 to 8 μm, 8% of fibrous boehmite, with an average particle size of 3 to 8 μm, 8% of fibrous kaolin, with an average particle size of 3 to 8 μm, 10.5% of β-spodumene, with an average particle size of 3 to 8 μm, and 7.5% of cordierite, with an average particle size of 3 to 8 μm.

[0051] The ingredients include an organic binder, an inorganic binder and a surfactant. The organic binder is methyl cellulose accounting for 4% of the weight of the carrier raw material and 1% of polyvinyl alcohol; the inorganic binder is aluminum dihydrogen phosphate accounting for 1% of the weight of the carrier raw material; and the surfactant is potassium laurate accounting for 4% of the weight of the carrier raw material.

[0052] Embodiment 5:

[0053] The high-porous thin-wall cordierite carrier includes a carrier raw material and ingredients. The carrier raw material includes 30% of spherical and flaky mixed talc in weight, with an average particle size of 10 to 15 μm, and the weight portions of spherical talc and flaky talc are equal, 14% of spherical silicon oxide, with an average particle size of 3 to 8 μm, 18.6% of flaky aluminum oxide, with an average particle size of 3 to 8 μm, 8% of fibrous boehmite, with an average particle size of 3 to 8 μm, 8% of fibrous kaolin, with an average particle size of 3 to 8 μm, and 21.4% of cordierite, with an average particle size of 3 to 8 μm.

[0054] The ingredients include an organic binder, an inorganic binder and a surfactant. The organic binder is 5% methyl cellulose and 1% polyvinyl alcohol, which account for 5% of the weight of the carrier raw material; the inorganic binder is aluminum dihydrogen phosphate, which accounts for 1% of the weight of the carrier raw material; and the surfactant is 3% glycerol, which accounts for 3% of the weight of the carrier raw material.

[0055] Embodiment 6:

[0056] The high-porous thin-walled cordierite carrier includes a carrier raw material and ingredients. The carrier raw material includes 30.5% of spherical and flaky mixed talc in weight, with an average particle size of 10 to 15 μm, and the weight portions of spherical talc and flaky talc are equal, 13.5% of spherical silicon oxide, with an average particle size of 3 to 8 μm, 19% of flaky aluminum oxide, with an average particle size of 3 to 8 μm, 8% of fibrous boehmite, with an average particle size of 3 to 8 μm, 8% of fibrous kaolin, with an average particle size of 3 to 8 μm, and 21% of β-spodumene, with an average particle size of 3 to 8 μm.

[0057] The ingredients include an organic binder, an inorganic binder and a surfactant. The organic binder is 4.5% of methyl cellulose and 2% of polyvinyl alcohol, which account for 4.5% of the weight of the carrier raw material; the inorganic binder is aluminum dihydrogen phosphate, which accounts for 2% of the weight of the carrier raw material; and the surfactant is potassium laurate, which accounts for 5% of the weight of the carrier raw material.

[0058] Embodiment 7:

[0059] The high-porous thin-walled cordierite carrier includes a carrier raw material and ingredients. The carrier raw material includes 29.5% of spherical and flaky mixed talc in weight, with an average particle size of 10 to 15 μm, and the weight portions of spherical talc and flaky talc are equal, 14% of spherical silicon oxide, with an average particle size of 3 to 8 μm, 18% of flaky aluminum oxide, with an average particle size of 3 to 8 μm, 8% of fibrous boehmite, with an average particle size of 3 to 8 μm, 8% of fibrous kaolin, with an average particle size of 3 to 8 μm, and 22.5% of β-spodumene, with an average particle size of 3 to 8 μm.

[0060] The ingredients include an organic binder, an inorganic binder and a surfactant. The organic binder is 4% of methyl cellulose and 3% of polyvinyl alcohol, which account for 1% of the weight of the carrier raw material; the inorganic binder is aluminum dihydrogen phosphate, which accounts for 1% of the weight of the carrier raw material; and the surfactant is 1% of glycerol and 2% of potassium laurate, which account for 1% of the weight of the carrier raw material.

[0061] Comparative Example 1:

[0062] The high-porous thin-wall cordierite carrier includes carrier raw materials and ingredients. The carrier raw materials include, by weight, 30% of flaky talc with an average particle size of 10 to 15 μm, 15% of spherical silica with an average particle size of 3 to 8 μm, 16% of flaky alumina with an average particle size of 3 to 8 μm, 8% of flaky boehmite with an average particle size of 3 to 8 μm, 8% of flaky kaolin with an average particle size of 3 to 8 μm, 12.5% ​​of β-spodumene with an average particle size of 3 to 8 μm, and 10.5% of cordierite with an average particle size of 3 to 8 μm.

[0063] The ingredients include an organic binder, an inorganic binder and a surfactant. The organic binder is 4.5% of methyl cellulose and 3% of polyvinyl alcohol, which account for 1% of the weight of the carrier raw material; the inorganic binder is aluminum dihydrogen phosphate, which accounts for 1% of the weight of the carrier raw material; and the surfactant is 3% of glycerol and 1% of potassium laurate, which account for 3% of the weight of the carrier raw material.

[0064] The difference from Example 2 is that the talc is in the form of flakes, and the boehmite and kaolin are also in the form of flakes.

[0065] Comparative Example 2:

[0066] The high-porous thin-wall cordierite carrier includes carrier raw materials and ingredients. The carrier raw materials include, by weight, 30% of flaky talc with an average particle size of 10 to 15 μm, 15% of spherical silica with an average particle size of 3 to 8 μm, 16% of flaky alumina with an average particle size of 3 to 8 μm, 8% of fibrous boehmite with an average particle size of 3 to 8 μm, 8% of fibrous kaolin with an average particle size of 3 to 8 μm, 12.5% ​​of β-spodumene with an average particle size of 3 to 8 μm, and 10.5% of cordierite with an average particle size of 3 to 8 μm.

[0067] The ingredients include an organic binder, an inorganic binder and a surfactant. The organic binder is 4.5% of methyl cellulose and 3% of polyvinyl alcohol, which account for 1% of the weight of the carrier raw material; the inorganic binder is aluminum dihydrogen phosphate, which accounts for 1% of the weight of the carrier raw material; and the surfactant is 3% of glycerol and 1% of potassium laurate, which account for 3% of the weight of the carrier raw material.

[0068] The difference from Example 2 is that the talc is all in the form of flakes.

[0069] Comparative Example 3:

[0070] The high-porous thin-walled cordierite carrier includes carrier raw materials and ingredients. The carrier raw materials include 35% of spherical and flaky mixed talc in weight, with an average particle size of 10 to 15 μm, the weight portions of spherical talc and flaky talc are equal, 20.5% of spherical silicon oxide, with an average particle size of 3 to 8 μm, 24.5% of flaky aluminum oxide, with an average particle size of 3 to 8 μm, 10% of fibrous boehmite, with an average particle size of 3 to 8 μm, and 10% of fibrous kaolin, with an average particle size of 3 to 8 μm.

[0071] The ingredients include an organic binder, an inorganic binder and a surfactant. The organic binder is 4.5% of methyl cellulose and 1% of polyvinyl alcohol, which account for 1% of the weight of the carrier raw material; the inorganic binder is aluminum dihydrogen phosphate, which accounts for 1% of the weight of the carrier raw material; and the surfactant is 1% of glycerol and 2% of potassium laurate, which account for 1% of the weight of the carrier raw material.

[0072] No inorganic fillers are used in the raw materials.

[0073] Comparative Example 4:

[0074] The high-porous thin-walled cordierite carrier includes carrier raw materials and ingredients. The carrier raw materials include 40% of spherical and flaky mixed talc in weight, with an average particle size of 10 to 15 μm, the weight portions of spherical talc and flaky talc are equal, 15% of spherical silicon oxide, with an average particle size of 3 to 8 μm, 20% of flaky aluminum oxide, with an average particle size of 3 to 8 μm, 12.5% ​​of fibrous boehmite, with an average particle size of 3 to 8 μm, and 12.5% ​​of fibrous kaolin, with an average particle size of 3 to 8 μm.

[0075] The ingredients include an organic binder, an inorganic binder and a surfactant. The organic binder is 4.5% of methyl cellulose and 3% of polyvinyl alcohol, which account for 1% of the weight of the carrier raw material; the inorganic binder is aluminum dihydrogen phosphate, which accounts for 1% of the weight of the carrier raw material; and the surfactant is 3% of glycerol and 1% of potassium laurate, which account for 3% of the weight of the carrier raw material.

[0076] No inorganic fillers are used in the raw materials.

[0077] The extrusion speed, verticality, and shrinkage rate of the above-mentioned embodiments and comparative examples were measured. The extrusion speed used the same screw extruder, and the extrusion motor frequency was set to 20 Hz. The extrusion speed was measured at this frequency. The shrinkage rate and verticality of the mud were measured for the mud embryo with a height of 400 mm after microwave drying. The specific results are shown in the following table:

[0078]

[0079]

[0080] It can be seen from the test results that the carrier raw materials include 28% to 35% of spherical and flaky mixed talc, 13% to 16% of spherical silica, 16% to 19% of flaky alumina, 8% of fibrous boehmite, 8% of fibrous kaolin, and 15% to 30% of inorganic fillers in terms of weight. By selecting the morphology and stacking arrangement of the raw materials, the internal resistance of the mud under force sliding is improved and the deformation is reduced. At the same time, the extrusion performance is improved by introducing high-temperature resistant inorganic powder with coarser particle size and consistent or similar expansion coefficient.

[0081] The purpose of the above embodiments is to exemplarily reproduce and deduce the technical solution of the present invention, and to fully describe the technical solution, purpose and effect of the present invention. Its purpose is to make the public understand the disclosed content of the present invention more thoroughly and comprehensively, and it does not limit the scope of protection of the present invention.

[0082] The above embodiments are not exhaustive enumerations of the present invention, and there may be multiple other implementations not listed. Any replacement and improvement made without violating the concept of the present invention shall fall within the protection scope of the present invention.

Claims

1. A highly porous thin-walled cordierite carrier with good protective properties, characterized in that: The invention comprises carrier raw materials and ingredients, wherein the carrier raw materials include 28% to 35% of spherical and flake mixed talc, 13% to 16% of spherical silicon oxide, 16% to 19% of flake aluminum oxide, 8% of fibrous boehmite, 8% of fibrous kaolin, and 15% to 24.5% of inorganic filler in proportion to weight; The average particle size of the talc is 10-15 μm, the average particle size of the silicon oxide is 3-8 μm, the average particle size of the aluminum oxide is 3-8 μm, the average particle size of the boehmite is 3-8 μm, the average particle size of the kaolin is 3-8 μm, and the average particle size of the inorganic filler is 3-8 μm; The inorganic filler is one or both of irregular spherical β-spodumene and cordierite.

2. A highly porous thin-walled cordierite carrier with good protectiveness according to claim 1, characterized in that: The weight proportions of spherical talc and plate-shaped talc are equal.

3. A highly porous thin-walled cordierite carrier with good protectiveness according to claim 1, characterized in that: The ingredients include an organic binder, an inorganic binder and a surfactant.

4. A highly porous thin-walled cordierite carrier with good protective properties according to claim 3, characterized in that: The organic binder is 4-5% of methyl cellulose and 1-3% of polyvinyl alcohol, accounting for 4-5% of the weight of the carrier raw material.

5. The highly porous thin-walled cordierite carrier with good protectiveness according to claim 3, characterized in that: The inorganic binder is aluminum dihydrogen phosphate accounting for 1-2% of the weight of the carrier raw material.

6. A highly porous thin-walled cordierite carrier with good protective properties according to claim 3, characterized in that: The surfactant accounts for 2.5-5% of the weight of the carrier raw material and is one or more of glycerol, potassium laurate and oleic acid.

7. A method for preparing a highly porous thin-walled cordierite carrier with good protectiveness as claimed in any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Weigh the carrier raw materials according to weight, and stir them in a mixer at a speed of 15 to 100 r / min for 10 to 40 min to obtain a mixture; S2. Add the mixed material, organic binder, inorganic binder, surfactant and water into a mixer, and stir them together at a speed of 10 to 90 r / min for 10 to 40 minutes to obtain a slurry; S3, putting the mixture into a vacuum clay kneading machine for kneading, and then putting the mixture into an extrusion molding machine to form an embryo; S4, the embryo body after extrusion molding is treated with microwaves, and dried, cut and sintered at the same time to obtain a honeycomb ceramic carrier.

8. The method for preparing a highly porous thin-walled cordierite carrier with good protectiveness according to claim 7, characterized in that: The drying temperature is 50-150°C, the sintering temperature is 1200-1500°C, and the sintering time is 4-20h.

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