阅读说明：本技术 一种4n高纯拟薄水铝石及其制备方法 (4N high-purity pseudo-boehmite and preparation method thereof ) 是由 杜善国 宋科鹏 杨丛林 樊慧芳 赵言培 周峰 孔杰 贾叶凯 于 2021-10-14 设计创作，主要内容包括：本发明特别涉及一种4N高纯拟薄水铝石及其制备方法,属于拟薄水铝石技术领域,方法包括：得到高纯氯化铝溶液；将高纯碳酸氢铵溶液和高纯氯化铝溶液连续加入第一溶剂进行前驱体反应,获得白色浆料；将白色浆料进行第一过滤洗涤,获得前驱体滤饼；将前驱体滤饼加入第二溶剂,获得前驱体浆料；将助剂和前驱体浆料混合进行水热处理,后进行第二过滤洗涤,得到拟薄水铝石滤饼；将拟薄水铝石滤饼进行烘干,得到高纯拟薄水铝石,通过控制原料纯度,达到提高产品纯度的目的；反应过程引入底液,可保证氯化铝与碳酸氢铵充分反应,确保前驱体有序析出且晶粒尺寸均匀；水热处理引入助剂调节体系pH,定型拟薄水铝石最终晶型晶貌,达到提高酸分散性的目的。(The invention particularly relates to 4N high-purity pseudoboehmite and a preparation method thereof, belonging to the technical field of pseudoboehmite, and the method comprises the following steps: obtaining high-purity aluminum chloride solution; continuously adding a high-purity ammonium bicarbonate solution and a high-purity aluminum chloride solution into a first solvent for precursor reaction to obtain white slurry; carrying out first filtration washing on the white slurry to obtain a precursor filter cake; adding the precursor filter cake into a second solvent to obtain precursor slurry; mixing the auxiliary agent and the precursor slurry, carrying out hydrothermal treatment, and then carrying out second filtration and washing to obtain a pseudo-boehmite filter cake; drying the pseudo-boehmite filter cake to obtain high-purity pseudo-boehmite, and achieving the purpose of improving the product purity by controlling the purity of raw materials; the base solution is introduced in the reaction process, so that the aluminum chloride and the ammonium bicarbonate can be ensured to fully react, the precursor is ensured to be orderly separated out, and the crystal grain size is uniform; the hydrothermal treatment introduces an auxiliary agent to adjust the pH of the system, and the final crystal morphology of the pseudo-boehmite is shaped, so that the aim of improving the acid dispersibility is fulfilled.)

1. A preparation method of 4N high-purity pseudoboehmite is characterized by comprising the following steps:

obtaining an aluminum chloride solution;

continuously adding an ammonium bicarbonate solution and the aluminum chloride solution into a first solvent to perform precursor reaction to obtain white slurry;

carrying out first filtration washing on the white slurry to obtain a precursor filter cake;

adding the precursor filter cake into a second solvent to obtain precursor slurry;

mixing an auxiliary agent and the precursor slurry, carrying out hydrothermal treatment, and then carrying out second filtration and washing to obtain a pseudo-boehmite filter cake;

and drying the pseudoboehmite filter cake to obtain the high-purity pseudoboehmite.

2. The method for preparing the 4N high-purity pseudoboehmite according to claim 1, characterized in that the obtaining of the high-purity aluminum chloride solution specifically comprises:

preparing high-purity hydrochloric acid into a hydrochloric acid solution;

mixing the hydrochloric acid solution with aluminum hydroxide to obtain a mixture;

heating, condensing and refluxing the mixture, and then filtering to obtain an aluminum chloride solution;

wherein the purity of the aluminum hydroxide, the purity of the high-purity hydrochloric acid and the purity of the ammonium bicarbonate solution are all more than 4N.

3. The method for preparing 4N high-purity pseudoboehmite according to claim 1, characterized in that the volume of the first solvent is 10-20% of the total volume of the white slurry, and the volume ratio of the high-purity aluminum chloride solution to the high-purity ammonium bicarbonate solution is 0.3-0.7.

4. The method for preparing 4N high-purity pseudoboehmite according to claim 1, characterized in that the reaction temperature of the precursor reaction is 20-40 ℃.

5. The method for preparing the 4N high-purity pseudo-boehmite according to claim 1, characterized in that the solid content of the mixed system of the auxiliary agent and the precursor slurry in the hydrothermal treatment is 5-15%, and the addition volume of the auxiliary agent is 3-10% of the total volume of the mixed system of the auxiliary agent and the precursor slurry.

6. The method of claim 1, wherein the auxiliary agent comprises one of ammonium bicarbonate, ammonium carbonate, ammonia water and choline.

7. The method for preparing 4N high-purity pseudoboehmite according to claim 1, characterized in that the temperature of the hydrothermal treatment is 85-135 ℃, and the time of the hydrothermal treatment is 1.5-4 h.

8. The method for preparing 4N high-purity pseudoboehmite according to claim 1, characterized in that the drying temperature for drying is less than 140 ℃.

9. The method of preparing 4N highly pure pseudoboehmite according to claim 1, characterized in that the volume of the washing liquid of the first filtration washing is 15% or more of the volume of the white slurry, and the volume of the washing liquid of the second filtration washing is 20% or more of the total volume of the system in which the assistant and the precursor slurry are mixed.

10. A 4N high purity pseudoboehmite prepared by the method for preparing a 4N high purity pseudoboehmite according to any one of claims 1 to 9.

Technical Field

The invention belongs to the technical field of pseudo-boehmite, and particularly relates to 4N high-purity pseudo-boehmite and a preparation method thereof.

Background

The pseudo-boehmite is a nano material with a lamellar microstructure, has better pore channel distribution and is commonly used as a catalyst carrier. Meanwhile, the pseudo-boehmite product also has better acid dispersibility and is commonly used for microcrystalline abrasive precursors, paper coating materials and the like.

The production process of pseudo-boehmite mainly comprises a carbonization method, a neutralization method and an alchol-aluminium method. The three methods have advantages and disadvantages respectively, wherein the aluminum alkoxide method product has high purity, uniform grain size and good dispersibility, but the industrialization is not easy to realize due to high equipment requirement and large risk coefficient; the carbonization method has simple flow and mature process, but can not meet the requirements of higher purity and dispersibility of the pseudo-boehmite due to the defects of the process principle; the principle and the synthesis process of the neutralization method are close to those of the aluminum alkoxide method, the product performance is obviously improved compared with that of the carbonization method, the substitution of the aluminum alkoxide method can be realized, but waste liquid containing sulfate or chlorate is generated in the synthesis process and is not easy to treat.

Disclosure of Invention

The invention aims to provide 4N high-purity pseudo-boehmite and a preparation method thereof, and solves the problem of low purity of the existing neutralization pseudo-boehmite product.

The embodiment of the invention provides a preparation method of 4N high-purity pseudoboehmite, which comprises the following steps:

obtaining an aluminum chloride solution;

continuously adding an ammonium bicarbonate solution and the aluminum chloride solution into a first solvent to perform precursor reaction to obtain white slurry;

carrying out first filtration washing on the white slurry to obtain a precursor filter cake;

adding the precursor filter cake into a second solvent to obtain precursor slurry;

mixing an auxiliary agent and the precursor slurry, carrying out hydrothermal treatment, and then carrying out second filtration and washing to obtain a pseudo-boehmite filter cake;

and drying the pseudoboehmite filter cake to obtain the high-purity pseudoboehmite.

Optionally, the obtaining of the high-purity aluminum chloride solution specifically comprises:

preparing high-purity hydrochloric acid into a hydrochloric acid solution;

mixing the hydrochloric acid solution with high-purity aluminum hydroxide to obtain a mixture;

heating, condensing and refluxing the mixture, and then filtering to obtain a high-purity aluminum chloride solution;

wherein the purity of the high-purity aluminum hydroxide, the purity of the high-purity hydrochloric acid and the purity of the high-purity ammonium bicarbonate solution are all more than 4N.

Optionally, the volume of the first solvent is 10% to 20% of the total volume of the white slurry, and the volume ratio of the high-purity aluminum chloride solution to the high-purity ammonium bicarbonate solution is 0.3 to 0.7.

Optionally, the reaction temperature of the precursor reaction is 20-40 ℃.

Optionally, in the hydrothermal treatment, the solid content of the auxiliary agent and the precursor slurry mixed system is 5% -15%, and the adding volume of the auxiliary agent is 3% -10% of the total volume of the auxiliary agent and the precursor slurry mixed system.

Optionally, the auxiliary agent includes one of ammonium bicarbonate, ammonium carbonate, ammonia water and choline.

Optionally, the temperature of the hydrothermal treatment is 85-135 ℃, and the time of the hydrothermal treatment is 1.5-4 h.

Optionally, the drying temperature of the drying is less than 140 ℃.

Optionally, the volume of the washing liquid of the first filtration washing is more than 15% of the volume of the white slurry, and the volume of the washing liquid of the second filtration washing is more than 20% of the total volume of the auxiliary agent and the precursor slurry mixed system.

Based on the same inventive concept, the embodiment of the invention also provides 4N high-purity pseudoboehmite, and the pseudoboehmite is prepared by the preparation method of the 4N high-purity pseudoboehmite.

One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

the preparation method of the 4N high-purity pseudoboehmite provided by the embodiment of the invention comprises the following steps: obtaining an aluminum chloride solution; continuously adding an ammonium bicarbonate solution and the aluminum chloride solution into a first solvent to perform precursor reaction to obtain white slurry; carrying out first filtration washing on the white slurry to obtain a precursor filter cake; adding the precursor filter cake into a second solvent to obtain precursor slurry; mixing an auxiliary agent and the precursor slurry, carrying out hydrothermal treatment, and then carrying out second filtration and washing to obtain a pseudo-boehmite filter cake; drying the pseudoboehmite filter cake to obtain high-purity pseudoboehmite, and achieving the purpose of improving the product purity by controlling the purity of raw materials; the base solution is introduced in the reaction process, so that the full reaction of the aluminum chloride and the ammonium bicarbonate can be ensured, and the orderly precipitation of the precursor and the uniform grain size can be ensured; the hydrothermal treatment introduces an auxiliary agent to adjust the pH of the system, and the final crystal morphology of the pseudo-boehmite is shaped, so that the aim of improving the acid dispersibility is fulfilled.

The foregoing description is only an overview of the technical solutions of the present invention, and the embodiments of the present invention are described below in order to make the technical means of the present invention more clearly understood and to make the above and other objects, features, and advantages of the present invention more clearly understandable.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

FIG. 1 is a flow chart of a method provided by an embodiment of the present invention;

fig. 2 is a process diagram provided by an embodiment of the invention.

Detailed Description

The present invention will be described in detail below with reference to specific embodiments and examples, and the advantages and various effects of the present invention will be more clearly apparent therefrom. It will be understood by those skilled in the art that these specific embodiments and examples are for the purpose of illustrating the invention and are not to be construed as limiting the invention.

Throughout the specification, unless otherwise specifically noted, terms used herein should be understood as having meanings as commonly used in the art. Accordingly, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. If there is a conflict, the present specification will control.

Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment and the like used in the present invention are commercially available or can be prepared by existing methods.

In order to solve the technical problems, the general idea of the embodiment of the application is as follows:

according to an exemplary embodiment of the present invention, there is provided a method for preparing 4N high purity pseudoboehmite, the method including:

in the embodiment, the purity of the obtained high-purity aluminum hydroxide is more than 4N; obtaining high-purity hydrochloric acid with the purity of more than 4N and the concentration of 38 percent; obtaining high-purity ammonium bicarbonate with the purity of more than 4N;

s1, obtaining a high-purity aluminum chloride solution;

in this embodiment, obtaining a high-purity aluminum chloride solution specifically includes:

s1.1, preparing high-purity hydrochloric acid into a hydrochloric acid solution;

s1.2, mixing the hydrochloric acid solution with high-purity aluminum hydroxide to obtain a mixture;

s1.3, heating, condensing and refluxing the mixture, and then filtering to obtain a high-purity aluminum chloride solution;

in this embodiment, the 38% high-purity hydrochloric acid is prepared into a 23% hydrochloric acid solution; adding 10 wt% of high-purity aluminum hydroxide into 23% hydrochloric acid solution, heating to boil, condensing and refluxing steam, cooling, and filtering to obtain filtrate, thereby obtaining the high-purity aluminum chloride solution.

Preparing the high-purity ammonium bicarbonate into a solution of 200g/L, and filtering to obtain a filtrate to prepare the high-purity ammonium bicarbonate solution.

S2, continuously adding a high-purity ammonium bicarbonate solution and the high-purity aluminum chloride solution into a first solvent for precursor reaction to obtain white slurry;

specifically, deionized water is added into a reaction vessel, and a high-purity aluminum chloride solution and a high-purity ammonium bicarbonate solution are respectively added into the reaction vessel at a constant speed through a constant flow pump to synthesize white slurry; the whole process is continuously stirred until the slurry reaches a certain liquid amount, and the addition of the high-purity aluminum chloride solution and the high-purity ammonium bicarbonate solution is stopped.

As an alternative embodiment, the volume of the first solvent is 10% to 20% of the total volume of the white slurry, and the volume ratio of the high-purity aluminum chloride solution to the high-purity ammonium bicarbonate solution is 0.3 to 0.7.

The volume of the first solvent is controlled to be 10-20% of the total volume of the white slurry, if the liquid content is higher than 20%, the solid content of the slurry is too low, the water consumption is large, and if the liquid content is lower than 10%, the concentration of the system is too high, which is not beneficial to orderly precipitation of the precursor.

Controlling the volume ratio of the high-purity aluminum chloride solution to the high-purity ammonium bicarbonate solution to be 0.3-0.7, if the volume ratio is higher than 0.7, the pH value of the system is too high, the crystal phase of a precursor is transformed, and if the volume ratio is lower than 0.3, the pH value of the system is too low, the precursor cannot be separated out

As an alternative embodiment, the reaction temperature of the precursor reaction is 20-40 ℃.

The reaction temperature of the precursor reaction is controlled to be 20-40 ℃, if the temperature is higher than 40 ℃, the crystal phase of the precursor can be transformed, and if the temperature of the system is lower than 20 ℃, the solubility of aluminum chloride and ammonium bicarbonate can be influenced.

S3, carrying out first filtering and washing on the white slurry to obtain a precursor filter cake;

specifically, the stirring was stopped, and then, filtration and washing were performed to obtain a precursor cake.

As an alternative embodiment, the volume of the washing liquid of the first filtration washing is more than 15% of the volume of the white slurry.

The volume of the washing liquid of the first filtering washing is controlled to be more than 15% of the volume of the white slurry, and if the volume of the washing liquid is less than 15%, the precursor chloride ion residue is too high, so that the purity is not easy to ensure.

S4, adding the precursor filter cake into a second solvent to obtain precursor slurry;

specifically, water is added to the filter cake to make a precursor slurry.

S5, mixing the auxiliary agent and the precursor slurry, performing hydrothermal treatment, and performing second filtration and washing to obtain a pseudo-boehmite filter cake;

specifically, the precursor slurry is added with an auxiliary agent for hydrothermal treatment, and then filtered and washed again to obtain the pseudo-boehmite filter cake.

As an optional embodiment, in the hydrothermal treatment, the solid content of the auxiliary agent and the precursor slurry mixed system is 5% to 15%, and the addition volume of the auxiliary agent is 3% to 10% of the total volume of the auxiliary agent and the precursor slurry mixed system.

Controlling the solid content of the auxiliary agent and the precursor slurry mixed system in the hydrothermal treatment to be 5% -15%, if the solid content is higher than 15%, the grain size distribution of the final product is not uniform, and if the solid content is lower than 5%, the water consumption is too large.

The volume of the addition of the auxiliary agent is controlled to be 3% -10% of the total volume of the mixed system of the auxiliary agent and the precursor slurry, if the volume is higher than 10%, the pH value of the system is too high, the final product is subjected to phase inversion, and if the volume is lower than 3%, the hydroxyl power of the system is insufficient, and the crystalline phase of the final product cannot be perfected.

As an alternative embodiment, the auxiliary agent comprises one of ammonium bicarbonate, ammonium carbonate, ammonia, and choline.

As an alternative embodiment, the temperature of the hydrothermal treatment is 85-135 ℃, and the time of the hydrothermal treatment is 1.5-4 h.

Controlling the temperature of the hydrothermal treatment to be 85-135 ℃, if the temperature is higher than 135 ℃, the final product is in phase inversion, and if the temperature is lower than 85 ℃, the product is in imperfect crystalline phase development. Controlling the hydrothermal treatment time to be 1.5h-4h, if the time is higher than 4h, the system is not changed any more, and if the time is lower than 1.5h, the crystal phase development of the product is incomplete.

As an alternative embodiment, the volume of the washing liquid of the second filtration washing is more than 20% of the total volume of the auxiliary agent and the precursor slurry mixing system.

And controlling the volume of the washing liquid of the second filtering and washing to be more than 20% of the total volume of the auxiliary agent and the precursor slurry mixed system, and if the volume is less than 20%, the impurity residue of the product is too high, so that the purity is not easy to ensure.

S6, drying the pseudo-boehmite filter cake to obtain the high-purity pseudo-boehmite.

As an alternative embodiment, the drying temperature of the drying is less than 140 ℃.

Controlling the drying temperature of drying to be less than 140 ℃, and if the drying temperature exceeds 140 ℃, converting the crystal phase of the filter cake

According to another exemplary embodiment of the present invention, there is provided a 4N high purity pseudoboehmite prepared by the method for preparing a 4N high purity pseudoboehmite as provided above.

The 4N high purity pseudoboehmite of the present application and the preparation method thereof will be described in detail with reference to examples, comparative examples and experimental data.

Example 1

A preparation method of 4N high-purity pseudoboehmite comprises the following steps: adding 700mL of deionized water into a 5L reaction container, taking a high-purity aluminum chloride solution and a high-purity ammonium bicarbonate solution, respectively adding the high-purity aluminum chloride solution and the high-purity ammonium bicarbonate solution into the reaction container through a constant flow pump, controlling the stirring speed to be 400r/min, controlling the volume ratio of the aluminum chloride solution to the ammonium bicarbonate solution to be 0.3, stopping feeding when the reaction is carried out at 25 ℃ to 5L, stopping stirring, and adding 1L of deionized water into a filter cake after filtering for washing. Adding deionized water into the filter cake to prepare 3L slurry, adding 100mL ammonia water, carrying out hydrothermal treatment at 98 ℃ for 3h, filtering the slurry, adding 1L deionized water into the filter cake to wash, and drying the filter cake at 100 ℃ to obtain the high-purity high-dispersion pseudoboehmite, wherein the purity of the product is more than 4N.

Example 2

A preparation method of 4N high-purity pseudoboehmite comprises the following steps: adding 700mL of deionized water into a 5L reaction container, taking a high-purity aluminum chloride solution and a high-purity ammonium bicarbonate solution, respectively adding the high-purity aluminum chloride solution and the high-purity ammonium bicarbonate solution into the reaction container through a constant flow pump, controlling the stirring speed to be 400r/min, controlling the volume ratio of the aluminum chloride solution to the ammonium bicarbonate solution to be 0.7, stopping feeding when the reaction is carried out at 25 ℃ to 5L, stopping stirring, and adding 1L of deionized water into a filter cake after filtering for washing. Adding deionized water into the filter cake to prepare 3L slurry, adding 100mL ammonia water, carrying out hydrothermal treatment at 98 ℃ for 3h, filtering the slurry, adding 1L deionized water into the filter cake to wash, and drying the filter cake at 100 ℃ to obtain the high-purity high-dispersion pseudoboehmite, wherein the purity of the product is more than 4N.

Example 3

A preparation method of 4N high-purity pseudoboehmite comprises the following steps: adding 700mL of deionized water into a 5L reaction container, taking a high-purity aluminum chloride solution and a high-purity ammonium bicarbonate solution, respectively adding the high-purity aluminum chloride solution and the high-purity ammonium bicarbonate solution into the reaction container through a constant flow pump, controlling the stirring speed to be 400r/min, controlling the volume ratio of the aluminum chloride solution to the ammonium bicarbonate solution to be 0.55, stopping feeding when the reaction is carried out at the temperature of 20 ℃ to 5L, stopping stirring, filtering, and adding 1L of deionized water into a filter cake for washing. Adding deionized water into the filter cake to prepare 3L slurry, adding 100mL ammonia water, carrying out hydrothermal treatment at 98 ℃ for 3h, filtering the slurry, adding 1L deionized water into the filter cake to wash, and drying the filter cake at 100 ℃ to obtain the high-purity high-dispersion pseudoboehmite, wherein the purity of the product is more than 4N.

Example 4

A preparation method of 4N high-purity pseudoboehmite comprises the following steps: adding 700mL of deionized water into a 5L reaction container, taking a high-purity aluminum chloride solution and a high-purity ammonium bicarbonate solution, respectively adding the high-purity aluminum chloride solution and the high-purity ammonium bicarbonate solution into the reaction container through a constant flow pump, controlling the stirring speed to be 400r/min, controlling the volume ratio of the aluminum chloride solution to the ammonium bicarbonate solution to be 0.55, stopping feeding when the reaction is carried out at 40 ℃ to 5L, stopping stirring, and adding 1L of deionized water into a filter cake after filtering for washing. Adding deionized water into the filter cake to prepare 3L slurry, adding 100mL ammonia water, carrying out hydrothermal treatment at 98 ℃ for 3h, filtering the slurry, adding 1L deionized water into the filter cake to wash, and drying the filter cake at 100 ℃ to obtain the high-purity high-dispersion pseudoboehmite, wherein the purity of the product is more than 4N.

Example 5

A preparation method of 4N high-purity pseudoboehmite comprises the following steps: adding 700mL of deionized water into a 5L reaction container, taking a high-purity aluminum chloride solution and a high-purity ammonium bicarbonate solution, respectively adding the high-purity aluminum chloride solution and the high-purity ammonium bicarbonate solution into the reaction container through a constant flow pump, controlling the stirring speed to be 400r/min, controlling the volume ratio of the aluminum chloride solution to the ammonium bicarbonate solution to be 0.55, stopping feeding when the reaction is carried out at 25 ℃ to 5L, stopping stirring, and adding 1L of deionized water into a filter cake after filtering for washing. Adding deionized water into the filter cake to prepare 3L slurry, adding 100mL ammonia water, carrying out hydrothermal treatment at 85 ℃ for 3h, filtering the slurry, adding 1L deionized water into the filter cake to wash, and drying the filter cake at 100 ℃ to obtain the high-purity high-dispersion pseudoboehmite, wherein the purity of the product is more than 4N.

Example 6

A preparation method of 4N high-purity pseudoboehmite comprises the following steps: adding 700mL of deionized water into a 5L reaction container, taking a high-purity aluminum chloride solution and a high-purity ammonium bicarbonate solution, respectively adding the high-purity aluminum chloride solution and the high-purity ammonium bicarbonate solution into the reaction container through a constant flow pump, controlling the stirring speed to be 400r/min, controlling the volume ratio of the aluminum chloride solution to the ammonium bicarbonate solution to be 0.55, stopping feeding when the reaction is carried out at 25 ℃ to 5L, stopping stirring, and adding 1L of deionized water into a filter cake after filtering for washing. Adding deionized water into the filter cake to prepare 3L slurry, adding 100mL ammonia water, carrying out hydrothermal treatment at 135 ℃ for 3h, filtering the slurry, adding 1L deionized water into the filter cake to wash, and drying the filter cake at 100 ℃ to obtain the high-purity high-dispersion pseudoboehmite, wherein the purity of the product is more than 4N.

Example 7

A preparation method of 4N high-purity pseudoboehmite comprises the following steps: adding 700mL of deionized water into a 5L reaction container, taking a high-purity aluminum chloride solution and a high-purity ammonium bicarbonate solution, respectively adding the high-purity aluminum chloride solution and the high-purity ammonium bicarbonate solution into the reaction container through a constant flow pump, controlling the stirring speed to be 400r/min, controlling the volume ratio of the aluminum chloride solution to the ammonium bicarbonate solution to be 0.55, stopping feeding when the reaction is carried out at 25 ℃ to 5L, stopping stirring, and adding 1L of deionized water into a filter cake after filtering for washing. Adding deionized water into the filter cake to prepare 3L slurry, adding 100mL ammonia water, carrying out hydrothermal treatment at 98 ℃ for 1.5h, filtering the slurry, adding 1L deionized water into the filter cake to wash, and drying the filter cake at 100 ℃ to obtain the high-purity high-dispersion pseudoboehmite, wherein the purity of the product is more than 4N.

Example 8

A preparation method of 4N high-purity pseudoboehmite comprises the following steps: adding 700mL of deionized water into a 5L reaction container, taking a high-purity aluminum chloride solution and a high-purity ammonium bicarbonate solution, respectively adding the high-purity aluminum chloride solution and the high-purity ammonium bicarbonate solution into the reaction container through a constant flow pump, controlling the stirring speed to be 400r/min, controlling the volume ratio of the aluminum chloride solution to the ammonium bicarbonate solution to be 0.55, stopping feeding when the reaction is carried out at 25 ℃ to 5L, stopping stirring, and adding 1L of deionized water into a filter cake after filtering for washing. Adding deionized water into the filter cake to prepare 3L slurry, adding 100mL ammonia water, carrying out hydrothermal treatment at 98 ℃ for 4h, filtering the slurry, adding 1L deionized water into the filter cake to wash, and drying the filter cake at 100 ℃ to obtain the high-purity high-dispersion pseudoboehmite, wherein the purity of the product is more than 4N.

Example 9

A preparation method of 4N high-purity pseudoboehmite comprises the following steps: adding 700mL of deionized water into a 5L reaction container, taking a high-purity aluminum chloride solution and a high-purity ammonium bicarbonate solution, respectively adding the high-purity aluminum chloride solution and the high-purity ammonium bicarbonate solution into the reaction container through a constant flow pump, controlling the stirring speed to be 400r/min, controlling the volume ratio of the aluminum chloride solution to the ammonium bicarbonate solution to be 0.55, stopping feeding when the reaction is carried out at 25 ℃ to 5L, stopping stirring, and adding 1L of deionized water into a filter cake after filtering for washing. Adding deionized water into the filter cake to prepare 3L slurry, adding 90mL ammonia water, carrying out hydrothermal treatment at 98 ℃ for 4h, filtering the slurry, adding 1L deionized water into the filter cake to wash, and drying the filter cake at 100 ℃ to obtain the high-purity high-dispersion pseudoboehmite, wherein the purity of the product is more than 4N.

Example 10

A preparation method of 4N high-purity pseudoboehmite comprises the following steps: adding 700mL of deionized water into a 5L reaction container, taking a high-purity aluminum chloride solution and a high-purity ammonium bicarbonate solution, respectively adding the high-purity aluminum chloride solution and the high-purity ammonium bicarbonate solution into the reaction container through a constant flow pump, controlling the stirring speed to be 400r/min, controlling the volume ratio of the aluminum chloride solution to the ammonium bicarbonate solution to be 0.55, stopping feeding when the reaction is carried out at 25 ℃ to 5L, stopping stirring, and adding 1L of deionized water into a filter cake after filtering for washing. Adding deionized water into the filter cake to prepare 3L slurry, adding 300mL of ammonia water, carrying out hydrothermal treatment at 98 ℃ for 4h, filtering the slurry, adding 1L of deionized water into the filter cake to wash, and drying the filter cake at 100 ℃ to obtain the high-purity high-dispersion pseudoboehmite, wherein the purity of the product is more than 4N.

Example 11

A preparation method of 4N high-purity pseudoboehmite comprises the following steps: adding 700mL of deionized water into a 5L reaction container, taking a high-purity aluminum chloride solution and a high-purity ammonium bicarbonate solution, respectively adding the high-purity aluminum chloride solution and the high-purity ammonium bicarbonate solution into the reaction container through a constant flow pump, controlling the stirring speed to be 400r/min, controlling the volume ratio of the aluminum chloride solution to the ammonium bicarbonate solution to be 0.55, stopping feeding when the reaction is carried out at 25 ℃ to 5L, stopping stirring, and adding 1L of deionized water into a filter cake after filtering for washing. Adding deionized water into the filter cake to prepare 3L of slurry, adding 100mL of saturated ammonium bicarbonate solution (25 ℃), carrying out hydrothermal treatment at 98 ℃ for 4h, filtering the slurry, adding 1L of deionized water into the filter cake to wash, and drying the filter cake at 100 ℃ to obtain the high-purity high-dispersion pseudoboehmite, wherein the product purity is more than 4N.

Example 12

A preparation method of 4N high-purity pseudoboehmite comprises the following steps: adding 700mL of deionized water into a 5L reaction container, taking a high-purity aluminum chloride solution and a high-purity ammonium bicarbonate solution, respectively adding the high-purity aluminum chloride solution and the high-purity ammonium bicarbonate solution into the reaction container through a constant flow pump, controlling the stirring speed to be 400r/min, controlling the volume ratio of the aluminum chloride solution to the ammonium bicarbonate solution to be 0.55, stopping feeding when the reaction is carried out at 25 ℃ to 5L, stopping stirring, and adding 1L of deionized water into a filter cake after filtering for washing. Adding deionized water into the filter cake to prepare 3L slurry, adding 100mL saturated ammonium carbonate solution (25 ℃), carrying out hydrothermal treatment at 98 ℃ for 4h, filtering the slurry, adding 1L deionized water into the filter cake to wash, and drying the filter cake at 100 ℃ to obtain the high-purity high-dispersion pseudoboehmite, wherein the purity of the product is more than 4N.

Example 13

A preparation method of 4N high-purity pseudoboehmite comprises the following steps: adding 700mL of deionized water into a 5L reaction container, taking a high-purity aluminum chloride solution and a high-purity ammonium bicarbonate solution, respectively adding the high-purity aluminum chloride solution and the high-purity ammonium bicarbonate solution into the reaction container through a constant flow pump, controlling the stirring speed to be 400r/min, controlling the volume ratio of the aluminum chloride solution to the ammonium bicarbonate solution to be 0.55, stopping feeding when the reaction is carried out at 25 ℃ to 5L, stopping stirring, and adding 1L of deionized water into a filter cake after filtering for washing. Adding deionized water into the filter cake to prepare 3L of slurry, adding 100mL of saturated choline solution (25 ℃), carrying out hydrothermal treatment at 98 ℃ for 4h, filtering the slurry, adding 1L of deionized water into the filter cake to wash, and drying the filter cake at 100 ℃ to obtain the high-purity high-dispersion pseudoboehmite, wherein the purity of the product is more than 4N.

Comparative example 1

The pseudo-boehmite product of a certain company in China is purchased in the market.

Comparative example 2

Pseudo-boehmite products of a certain foreign company are purchased in the market.

Examples of the experiments

The pseudo-boehmite provided in examples 1 to 13 and comparative examples 1 to 2 were subjected to the purity and acid dispersibility index tests, and the test results are shown in the following table.

From the above table, the pseudoboehmite prepared by the method has high purity and good acid dispersibility, and the method can effectively reduce the apparent viscosity of colloid after the pseudoboehmite is dispersed.

One or more technical solutions in the embodiments of the present invention at least have the following technical effects or advantages:

(1) according to the method provided by the embodiment of the invention, the aim of improving the product purity is fulfilled by controlling the purity of the raw materials; the base solution is introduced in the reaction process, so that the full reaction of the aluminum chloride and the ammonium bicarbonate can be ensured, and the orderly precipitation of the precursor and the uniform grain size can be ensured; the hydrothermal treatment introduces an auxiliary agent to adjust the pH of the system, and the final crystal morphology of the pseudo-boehmite is shaped, so that the aim of improving the acid dispersibility is fulfilled;

(2) the pseudo-boehmite obtained by the method provided by the embodiment of the invention has high purity, good acid dispersibility, uniform grain size distribution and concentrated pore size distribution, and is more suitable for the fields of coating, grinding materials, ceramic binders, high-end catalysts and the like;

(3) the method provided by the embodiment of the invention can effectively reduce the apparent viscosity of the colloid after the pseudoboehmite is dispersed.

Finally, it should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.