A method for preparing a high-strength, high-sphericity spherical molecular sieve

Abstract

The invention discloses a method for preparing a high-strength and high-sphericity spherical molecular sieve, which belongs to the technical field of molecular sieve preparation. The method comprises the following steps: adding molecular sieve raw powder, clay and water / colloid solution into an inclined strong mixer, adjusting the speed and time of the inclined strong mixer, and preparing a block mixture; adding molecular sieve raw powder and clay into the block mixture, adjusting the weight ratio of the water / colloid solution to the sum of the molecular sieve raw powder and clay, and adjusting the speed and time of the inclined strong mixer to obtain a fine wet material or a wet material with a certain particle size distribution; adding the fine wet material into the wet material with a certain particle size distribution, and rolling and shaping the material with a disc to obtain the high-strength and high-sphericity spherical molecular sieve, which solves the problems of uneven strength distribution, low strength, low granulation efficiency, low sphericity, large amount of dust in dry powder granulation, etc. when granulating by a high-speed granulator combining wet and dry methods.

Description

Technical Field

[0001] The invention belongs to the technical field of molecular sieve preparation, and in particular relates to a method for preparing a high-strength and high-sphericity spherical molecular sieve. Background Art

[0002] At present, the industry mainly uses disc granulators to produce spherical molecular sieve particles, and uses dry mixed powder to add water, organic / inorganic binders and other binders to produce molecular sieve products with high sphericity; however, there are problems such as low compressive strength and low production efficiency.

[0003] Chinese patent CN110237771A discloses that a stirring granulator is first used to quickly granulate to form a small particle core, and then a mixed dry material is added and water is sprayed, and a disc granulator is used to coat the small particle core so that the small particle core gradually grows to form the desired molecular sieve particle size. The particle core formed by stirring in the first step of this method has a low sphericity, and the prepared molecular sieve particles are often not round; the second step requires subsequent addition of dry mixed powder to adjust the sphericity of the molecular sieve. The dry method has a large amount of dust during coating, low granulation efficiency, and low compressive strength.

[0004] Chinese patent CN 116493042 A discloses a method of using titanium silicon molecular sieve, binder and surfactant as raw materials, first supporting a mixed solution with surfactant and siliceous binder, adopting a rapid mixing granulation method, adjusting the water content by adding dry powder and rotating at a low speed, and finally preparing molecular sieve particles with a small particle size of 1 to 1.5 mm by a sieving method; the invention first stirs the surfactant and the binder into a mixed solution, and the use of surfactant increases the cost of raw material preparation, and does not explain how to adjust materials with an inappropriate particle size (less than 1 mm and greater than 1.5 mm) to high-strength molecular sieve particles with a suitable particle size; in addition, the preparation of molecular sieve particles containing clay and the sphericity of the molecular sieve are not elaborated in detail. Summary of the invention

[0005] Aiming at the problems of uneven strength distribution, low strength, low granulation efficiency, low sphericity, large amount of dust in dry powder granulation, etc., which occur when granulating by disc granulator or high-speed granulator combined wet and dry method in industry, the present invention proposes a method for preparing spherical molecular sieve with high strength and high sphericity. The present invention firstly uses an inclined strong mixer to fully wet the material so that the block material obtains a certain strength, and then supplements the molecular sieve and clay mixture. By adjusting the liquid solution content in the molecular sieve and clay mixture and the speed and time of the inclined strong mixer, fine wet material or wet material with a certain particle size distribution is prepared. The prepared wet material is directly rolled by disc for a certain time to prepare a molecular sieve with high strength and high sphericity, thereby solving the above problems.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A method for preparing a high-strength, high-sphericity spherical molecular sieve comprises the following steps:

[0008] Adding molecular sieve raw powder, clay and water / colloid solution (water or colloidal solution) into an inclined strong mixer, adjusting the speed and time of the inclined strong mixer to prepare a block mixture;

[0009] Adding molecular sieve powder and clay to the block mixture, adjusting the weight ratio of the water / colloid solution to the sum of the molecular sieve powder and clay, and adjusting the speed and time of the inclined strong mixer to obtain fine wet materials or wet materials with a certain particle size distribution;

[0010] The fine wet material is added into the wet material with a certain particle size distribution, and the disc is rolled to shape the spherical molecular sieve with high strength and high sphericity.

[0011] The particle size of the fine wet material is ≤0.1 mm; the wet material with a certain particle size distribution is a wet material with a particle size ≥0.4 mm.

[0012] In the present invention, the order of preparing fine wet material or wet material with a certain particle size distribution is not limited. Fine wet material can be prepared first and then wet material with a certain particle size distribution, or wet material with a certain particle size distribution can be prepared first and then fine wet material.

[0013] Preferably, the weight ratio of the molecular sieve raw powder, clay and water / colloid solution is (0.70-0.9):(0.1-0.3):(0.3-0.45). In the present invention, the molecular sieve raw powder can be added in the form of dry powder directly purchased, or it can be first mixed with water to obtain a wet material, and then the wet material, clay and water / colloid solution are mixed, as long as the weight ratio of the molecular sieve raw powder, clay and water / colloid solution is within the above range. That is, the molecular sieve raw powder can be a dried powder or a wet material. When the wet material is added, it is converted into a dried powder and water / colloid solution is added; similarly, the clay can be a dried clay or a wet material. When the wet material is added, it is converted into a dry material and water / colloid solution is added according to the ratio.

[0014] Preferably, the clay comprises kaolin, halloysite or attapulgite.

[0015] Preferably, the water / colloid solution comprises water, silica sol, carboxymethyl cellulose aqueous solution or aluminum sol.

[0016] Preferably, after the molecular sieve raw powder, clay and water / colloid solution are added into the inclined strong mixer, the speed of the inclined strong mixer is 700 to 3000 rpm for 1 to 10 min.

[0017] Preferably, after adding the molecular sieve powder and clay, the weight ratio of the water / colloid solution to the sum of the molecular sieve powder and clay is adjusted to (0.20-0.35):1.

[0018] Preferably, when preparing fine wet materials, the speed of the inclined intensive mixer is 1500 to 3000 rpm, and the time is 1 to 10 min.

[0019] Preferably, when preparing a wet material with a certain particle size distribution, high-speed mixing is first performed and then low-speed mixing. During high-speed mixing, the speed of the inclined intensive mixer is 1500 to 3000 rpm, and the time is 1 to 5 min; during low-speed mixing, the speed of the inclined intensive mixer is 700 to 1500 rpm, and the time is 1 to 15 min.

[0020] Preferably, the time for the disc rolling shaping is 30 minutes to 2 hours.

[0021] In the present invention, the particle size of the spherical molecular sieve can be adjusted according to the weight of the added fine wet material.

[0022] Compared with the prior art, the present invention has the following advantages and technical effects:

[0023] (1) The present invention adds molecular sieve raw powder, clay, and water / colloid solution into an inclined strong mixer, and mixes them uniformly by high-speed rotation. The mixing and granulation are integrated, and the materials do not need to be mixed in advance. After the molecular sieve raw powder and clay are added later, the high-speed rotation can be used again to squeeze out the water in the previously added materials, and the molecular sieve raw powder and clay added later can also be mixed uniformly. The molecular sieve raw powder and clay added twice can be added in an integrated manner, and do not need to be mixed in advance, thereby reducing the mixing and granulation time. The molecular sieve raw powder and clay can contain a certain liquid solution (i.e., water / colloid solution), and the molecular sieve raw powder and clay do not need to be dried before mixing, thereby saving the drying heat of the starting raw materials. Moreover, the closed wet mixing is performed during mixing, and no dust is generated.

[0024] (2) The present invention adopts high-speed rotation mixing, and the moisture content of the wet mixed material is uniform. After the material is fully moistened, the particles gradually grow and agglomerate during high-speed rotation. The high-speed extrusion force is large, and the internal solution gradually seeps out to form molecular sieve particles. The present invention first adds an excess liquid solution (i.e., water / colloid solution), and the molecular sieve raw powder and clay are fully wet mixed to form a block material. Then, the molecular sieve raw powder and clay are supplemented and the liquid solution content is adjusted. This can ensure that the liquid solution content inside the material is uniform, and can generate high-strength, high-spherical molecular sieve particles, avoid the generation of irregular flat particles, and avoid adjusting the sphericity of the flat particles.

[0025] (3) Compared with the conventional disc granulation and high-speed granulation followed by dry coating preparation, the high-speed wet granulation of the present invention can avoid mixing of materials and has the characteristics of fast spheroidization time, high sphericity, high granulation efficiency and high compressive strength. Through two high-speed rotations, more liquid solution is squeezed out from the inside of the molecular sieve particles, and the content of the internal liquid solution after wet granulation is small, the granulation strength is high, and high-strength, high-sphericity spherical molecular sieve particles are formed. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0027] Figure 1 This is a flow chart of the method for preparing a high-strength, high-sphericity spherical molecular sieve according to the present invention;

[0028] Figure 2 This is a physical picture of the molecular sieve prepared in Example 1;

[0029] Figure 3 This is a physical picture of the molecular sieve prepared by only using the disk dry granulation method in Comparative Example 1. DETAILED DESCRIPTION

[0030] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0031] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0032] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0033] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0034] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0035] All raw materials used in the embodiments of the present invention are purchased from the market. As an example, the molecular sieve powder for preparing 4A type spherical molecular sieve is purchased from Zhengzhou Aluminum City New Material Technology Co., Ltd., or it can be a wet material with high water content ("wet material with high water content" means adding water to the molecular sieve powder first, and then mixing it with clay, water / colloid solution, ensuring that the weight ratio of molecular sieve powder, clay and water / colloid solution is (0.70-0.9): (0.1-0.3): (0.3-0.45)); the molecular sieve powder for preparing X type spherical molecular sieve is purchased from Zhengzhou Aluminum City New Material Technology Co., Ltd., or it can be a wet material with high water content; the silica sol model is LS-30, purchased from Shaoyang Yudu Chemical Co., Ltd.; the aluminum sol solid content is 20wt%, purchased from Yangzhou Zhongtianli New Materials Co., Ltd.

[0036] In the embodiments of the present invention, the compressive strength of the spherical molecular sieve is tested according to HGT 2783-2020.

[0037] The flow chart of the method for preparing the high-strength and high-sphericity spherical molecular sieve of the present invention is shown in Figure 1 .

[0038] The technical solution of the present invention is further illustrated by the following embodiments.

[0039] Example 1 Preparation of high-strength, high-sphericity spherical 4A molecular sieve

[0040] (1) Preparation of block 4A type mixed material: add molecular sieve raw powder (4A type spherical molecular sieve raw powder), kaolin and water in a weight ratio of 0.9:0.1:0.4 into an inclined intensive mixer, adjust the speed of the inclined intensive mixer to 2500 rpm, rotate for 2 minutes, and prepare a block mixed material;

[0041] (2) Preparation of fine wet materials: Add molecular sieve powder and kaolin to a portion of the block mixture of (1), adjust the weight ratio of water to the sum of the molecular sieve powder and the clay mixture to 0.34:1 (i.e., water: (molecular sieve powder + clay mixture) = 0.34:1, weight ratio), adjust the speed of the inclined intensive mixer to 2000 / min, rotate for 3 minutes, and obtain high-speed mixing to prepare uniform fine wet materials;

[0042] (3) Preparation of wet material with a certain particle size distribution: Add molecular sieve powder and kaolin to the block mixture of another part (1), adjust the weight ratio of water to the sum of the molecular sieve powder and clay mixture to 0.34:1, first mix at high speed and then mix at low speed, as follows: in the first step of high-speed mixing, the speed of the inclined intensive mixer is 2500 rpm and the time is 4 minutes; in the second step of low-speed mixing, the speed of the inclined intensive mixer is 1500 rpm and the time is 5 minutes, to obtain a wet material with a certain particle size distribution;

[0043] (4) Preparation of high-strength, high-sphericity spherical molecular sieves with suitable particle size: The fine wet material prepared in (2) was added to the wet material with a certain particle size distribution prepared in (3), and the disc was rolled for 1 hour to prepare a high-strength, high-sphericity spherical 4A type molecular sieve. The molecular sieve with a particle size of 2 to 2.5 mm had a compressive strength of 40 N and a sphericity of 1. The actual picture of the molecular sieve prepared in Example 1 is shown in Figure 2 It can be seen that the molecular sieve prepared in this embodiment has a high sphericity and no irregular particles. The sphericity of the molecular sieve prepared in this embodiment is consistent with the sphericity of the molecular sieve prepared by only disc granulation.

[0044] Example 2 Preparation of high-strength, high-sphericity spherical X-type molecular sieve

[0045] (1) Preparation of blocky X-type mixed material: molecular sieve raw powder (X-type spherical molecular sieve raw powder), kaolin and water were added into an inclined intensive mixer at a weight ratio of 0.85:0.15:0.45, and the speed of the inclined intensive mixer was adjusted to 3000 rpm for 3 min to prepare a blocky mixed material;

[0046] (2) Preparation of fine wet materials: Add molecular sieve powder and kaolin to the block mixture of (1), adjust the weight ratio of water to the sum of the molecular sieve powder and clay mixture to 0.32:1, adjust the speed of the inclined intensive mixer to 3000 rpm and the time to 3 min, and obtain high-speed mixing to prepare uniform fine wet materials;

[0047] (3) Preparation of wet material with a certain particle size distribution: Add molecular sieve powder and kaolin to the block mixture of (1), adjust the weight ratio of water to the sum of the molecular sieve powder and clay mixture to 0.32:1, first mix at high speed and then mix at low speed, specifically as follows: in the first step of high-speed mixing, the speed of the inclined strong mixer is 2000 rpm and the time is 4 minutes; in the second step of low-speed mixing, the speed of the inclined strong mixer is 1000 rpm and the time is 5 minutes, to obtain a wet material with a certain particle size distribution;

[0048] (4) Preparation of high-strength, high-sphericity spherical molecular sieves with suitable particle size: The fine wet material prepared in (2) is added to the wet material with a certain particle size distribution prepared in (3), and the disc is rolled for 1 hour to prepare a high-strength, high-sphericity spherical X-type molecular sieve. The compressive strength of the molecular sieve with a particle size of 2 to 2.5 mm is 30N, and the sphericity is 1. The sphericity of the molecular sieve prepared in this example is consistent with the sphericity of the molecular sieve prepared by disc granulation alone.

[0049] Example 3 Preparation of high-strength, high-sphericity spherical 4A molecular sieve

[0050] (1) Preparation of block 4A type mixture: add molecular sieve raw powder (4A type spherical molecular sieve raw powder), attapulgite and 0.1wt% carboxymethyl cellulose aqueous solution in a weight ratio of 0.9:0.1:0.45 into an inclined intensive mixer, adjust the speed of the inclined intensive mixer to 3000 rpm and the mixing time to 1 min to prepare a block mixture;

[0051] (2) Preparation of fine wet materials: Adding molecular sieve powder and attapulgite to the block mixture of (1), adjusting the weight ratio of carboxymethyl cellulose to the sum of the molecular sieve powder and the mixture of halloysite to 0.35:1, adjusting the speed of the inclined strong mixer to 3000 rpm for 1 min, and obtaining high-speed mixing to prepare uniform fine wet materials;

[0052] (3) Preparation of wet material with a certain particle size distribution: Add molecular sieve powder and attapulgite to the block mixture of (1), adjust the weight ratio of carboxymethyl cellulose to the sum of the molecular sieve powder and clay mixture to 0.35:1, first mix at high speed and then mix at low speed, specifically as follows: in the first step of high-speed mixing, the speed of the inclined strong mixer is 3000 rpm and the time is 1 hour; in the second step of low-speed mixing, the speed of the inclined strong mixer is 1500 rpm and the time is 1 minute, to obtain a wet material with a certain particle size distribution;

[0053] (4) Preparation of high-strength, high-sphericity spherical molecular sieves with suitable particle size: The fine wet material prepared in (2) is added to the wet material with a certain particle size distribution prepared in (3), and the disc is rolled for 1.5 hours to prepare a high-strength, high-sphericity spherical 4A molecular sieve. The compressive strength of the molecular sieve with a particle size of 2 to 2.5 mm is 45N, and the sphericity is 1. The sphericity of the molecular sieve prepared in this example is consistent with the sphericity of the molecular sieve prepared by disc granulation alone.

[0054] Example 4 Preparation of high-strength, high-sphericity spherical X-type molecular sieve

[0055] (1) Preparation of block X-type mixture: add molecular sieve raw powder (X-type spherical molecular sieve raw powder), halloysite and silica sol in a weight ratio of 0.8:0.2:0.3 into an inclined intensive mixer, adjust the speed of the inclined intensive mixer to 700 rpm and the time to 10 min to prepare a block mixture;

[0056] (2) Preparation of fine wet materials: Add molecular sieve powder and halloysite to the block mixture of (1), adjust the ratio of silica sol in the molecular sieve powder and halloysite mixture to 0.23:1, and rotate the inclined intensive mixer at a speed of 1200 rpm for 10 min to obtain high-speed mixing to prepare uniform fine wet materials;

[0057] (3) Preparation of wet material with a certain particle size distribution: add molecular sieve powder and halloysite to the block mixture of (1), adjust the ratio of silica sol in the molecular sieve powder and clay mixture to 0.23:1, mix at high speed first and then at low speed, as follows: in the first step of high-speed mixing, the speed of the inclined strong mixer is 1500 rpm and the time is 5 min; in the second step of low-speed mixing, the speed of the inclined strong mixer is 700 rpm and the time is 15 min, to obtain a wet material with a certain particle size distribution;

[0058] (4) Preparation of high-strength, high-sphericity spherical molecular sieves with suitable particle size: The fine wet material prepared in (2) is added to the wet material with a certain particle size distribution prepared in (3), and the disc is rolled and shaped for 30 minutes to prepare a high-strength, high-sphericity spherical X-type molecular sieve. The compressive strength of the molecular sieve with a particle size of 2 to 2.5 mm is 45N, and the sphericity is 1. The sphericity of the molecular sieve prepared in this example is consistent with the sphericity of the molecular sieve prepared by disc granulation alone.

[0059] Example 5 Preparation of high-strength, high-sphericity spherical 4A molecular sieve

[0060] (1) Preparation of block 4A type mixture: add molecular sieve raw powder, kaolin and aluminum sol in a weight ratio of 0.9:0.1:0.37 into an inclined intensive mixer, adjust the speed of the inclined intensive mixer to 1000 rpm and the time to 5 min to prepare a block mixture;

[0061] (2) Preparation of fine wet materials: Add molecular sieve powder and kaolin to the block mixture of (1), adjust the ratio of aluminum sol in the molecular sieve powder and halloysite mixture to 0.3:1, and rotate the inclined intensive mixer at a speed of 1500 rpm for 5 min to obtain high-speed mixing to prepare uniform fine wet materials;

[0062] (3) Preparation of wet material with a certain particle size distribution: Add molecular sieve powder and kaolin to the block mixture of (1), adjust the ratio of aluminum sol in the molecular sieve powder and clay mixture to 0.3:1, first mix at high speed and then mix at low speed, specifically as follows: in the first step of high-speed mixing, the speed of the inclined strong mixer is 2000 rpm and the time is 3 minutes; in the second step of low-speed mixing, the speed of the inclined strong mixer is 800 rpm and the time is 7 minutes, to obtain a wet material with a certain particle size distribution;

[0063] (4) Preparation of high-strength, high-sphericity spherical molecular sieves with suitable particle size: The fine wet material prepared in (2) is added to the wet material with a certain particle size distribution prepared in (3), and the disc is rolled and shaped for 3 hours to prepare a high-strength, high-sphericity spherical 4A type molecular sieve. The compressive strength of the molecular sieve with a particle size of 2 to 2.5 mm is 50N, and the sphericity is 1. The sphericity of the molecular sieve prepared in this example is consistent with the sphericity of the molecular sieve prepared by disc granulation alone.

[0064] Comparative Example 1 Preparation of 4A type spherical molecular sieve using only disk dry granulation

[0065] The 4A molecular sieve raw powder and kaolin were accurately weighed in a weight ratio of 0.9:0.1, and granulated only by a disc granulator. Water was added while adding a dry mixture of the molecular sieve raw powder and kaolin. The granulation time in the disc granulator was 12 hours, and 4A spherical molecular sieves were prepared. The molecular sieves with a particle size of 2 to 2.5 mm had a compressive strength of 30 N and a sphericity of 1.

[0066] Comparative Example 1 The actual picture of the molecular sieve prepared by using only a disc granulator is shown in Figure 3 ,Depend on Figure 2 and Figure 3 It can be seen that the sphericity of the molecular sieve prepared by the method of the present invention is consistent with the sphericity of the molecular sieve prepared only by disc granulation.

[0067] Comparative Example 2 Preparation of X-type spherical molecular sieve using only disk dry granulation

[0068] The X-type molecular sieve raw powder and kaolin were accurately weighed in a weight ratio of 0.85:0.15, and granulated only by a disc granulator. Water was added while adding a dry mixture of the molecular sieve raw powder and kaolin. The granulation time in the disc granulator was 12 hours, and an X-type spherical molecular sieve was prepared. The molecular sieve with a particle size of 2 to 2.5 mm had a compressive strength of 22N and a sphericity of 1.

[0069] By comparing and analyzing Examples 1 and 2 with Comparative Examples 1 and 2, it can be seen that the molecular sieve prepared by the high-speed granulator of the present invention has high compressive strength and high sphericity, and the sphericity is consistent with that of the disc dry granulation.

[0070] Comparative Example 3

[0071] The same as Example 1, except that in step (1), the weight ratio of molecular sieve powder, kaolin and water is 0.9:0.1:0.2.

[0072] Since the amount of water added in the early stage in this comparative example is relatively small, the molecular sieve has more flat irregular particles, and molecular sieve particles with high sphericity cannot be obtained.

[0073] Comparative Example 4

[0074] The same as Example 1, except that the molecular sieve powder and kaolin were not added in step (2) and step (3), that is, the content of the liquid solution was not adjusted in the later stage.

[0075] Since the content of the liquid solution was not adjusted in the later stage of this comparative example, the molecular sieve was a block-like wet material and high-spherical molecular sieve particles could not be obtained.

[0076] Comparative Example 5

[0077] The same as Example 1, except that step (1) is not performed, and the weight ratio of water to the sum of the molecular sieve powder and kaolin is directly adjusted to 0.34:1 according to the weight ratio of the molecular sieve raw powder to kaolin (that is, after adding the raw materials, the weight ratio of water to the sum of the molecular sieve raw powder and kaolin is directly adjusted to 0.34), to prepare type A spherical molecular sieve, the molecular sieve with a particle size of 2 to 2.5 mm has a compressive strength of 25N, the molecular sieve particles are flat, low in strength, and have a sphericity of 0.8.

[0078] It can be seen from Example 1 and Comparative Example 5 that directly adjusting the ratio of water / colloid solution to molecular sieve raw powder and clay to the final weight ratio cannot avoid the formation of irregular flat particles even after disc rolling shaping, and high-strength, high-spherical molecular sieve particles cannot be obtained.

[0079] Comparative Example 6

[0080] (1) 0.5 kg of silica sol as a binder and 0.3 kg of an organic silicon surfactant were dissolved in 6 L of water at 40° C. and stirred evenly to prepare a blended liquid, 15 kg of titanium silicon molecular sieve was used as the first raw material powder and added to a mixing granulator. After the mixing granulator was started, the blended liquid was added at one time through the pipeline, and then the first mixing granulation was carried out under the conditions of a stirring tool speed of 1200 rpm and a rotating mixing barrel speed of 30 rpm. When the powder particles aggregated and nucleated to form a molecular sieve wet ball with a particle size of about 1.2 mm;

[0081] (2) The mixing granulator was adjusted to a stirring tool speed of 400 rpm and a rotating mixing barrel speed of 45 rpm, 2.5 kg of titanium silicon molecular sieve was added as the second raw material powder, and the second mixing granulation was performed. The stirring and mixing was stopped when the wet balls of the molecular sieve did not stick together (the first mixing granulation and the second mixing granulation took a total of 35 min), and then the mixture was dried at 70°C for 2.5 h to obtain microspheres. The microspheres were sieved using standard sieves of 12 mesh and 18 mesh, and microspheres with a particle size of 12-18 mesh were taken. The microspheres were then calcined at 580°C for 4 h to obtain spherical titanium silicon molecular sieve catalysts with a ball diameter of 1.1 to 1.5 mm. The molecular sieve obtained in this comparative example was relatively flat, with a sphericity of 0.7.

[0082] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for preparing a high-strength, high-sphericity spherical molecular sieve, characterized in that: The following steps are involved: Adding molecular sieve raw powder, clay and water / colloid solution into an inclined strong mixer, adjusting the speed and time of the inclined strong mixer to prepare a block mixture, wherein the weight ratio of the molecular sieve raw powder, clay and water / colloid solution is (0.70-0.9): (0.1-0.3): (0.3-0.45); Adding molecular sieve powder and clay to the block mixture, adjusting the weight ratio of the water / colloid solution to the sum of the molecular sieve powder and clay, adjusting the speed and time of the inclined strong mixer, and obtaining fine wet materials and wet materials with a certain particle size distribution, wherein the water / colloid solution refers to water or colloidal solution, and after adding the molecular sieve powder and clay, adjusting the weight ratio of the water / colloid solution to the sum of the molecular sieve powder and clay to (0.20-0.35):1; The fine wet material is added into the wet material with a certain particle size distribution, and the disc is rolled to shape the spherical molecular sieve with high strength and high sphericity; When preparing fine wet materials, the speed of the inclined intensive mixer is 1500-3000 rpm, and the time is 1-10 min; When preparing wet materials with a certain particle size distribution, first mix at high speed and then mix at low speed. When mixing at high speed, the speed of the inclined strong mixer is 1500-3000 rpm, and the time is 1-5 minutes; when mixing at low speed, the speed of the inclined strong mixer is 700-1500 rpm, and the time is 1-15 minutes.

2. The method for preparing a high-strength, high-sphericity spherical molecular sieve according to claim 1, characterized in that: The clay includes kaolin, halloysite or attapulgite.

3. The method for preparing a high-strength, high-sphericity spherical molecular sieve according to claim 1, characterized in that: The colloidal solution includes silica sol, carboxymethyl cellulose aqueous solution or aluminum sol.

4. The method for preparing a high-strength, high-sphericity spherical molecular sieve according to claim 1, characterized in that: After adding the molecular sieve raw powder, clay and water / colloid solution into the inclined strong mixer, the rotating speed of the inclined strong mixer is 700-3000 rpm and the mixing time is 1-10 min.

5. The method for preparing a high-strength, high-sphericity spherical molecular sieve according to claim 1, characterized in that: The time for the disc rolling shaping is 30min~2h.

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