CN-121990599-A - Dealcoholization method of alcohol-containing aluminum hydroxide slurry and preparation method of aluminum hydroxide

CN121990599ACN 121990599 ACN121990599 ACN 121990599ACN-121990599-A

Abstract

The invention relates to the field of aluminum hydroxide preparation, and discloses a dealcoholization method of alcohol-containing aluminum hydroxide slurry and a preparation method of aluminum hydroxide. The method comprises contacting an alcohol-containing aluminum hydroxide slurry with a C6 alkane and extracting to obtain an extraction product containing an oil phase and an aqueous phase, and separating the dealcoholized aluminum hydroxide slurry from the aqueous phase of the extraction product. The invention can reduce the alcohol content in the alcohol-containing aluminum hydroxide slurry to below 0.15 weight percent through simple extraction by selecting an extracting agent, and simultaneously ensures that the carbon residue value in the finally obtained aluminum hydroxide product is not higher than 0.3 weight percent, thereby being very suitable for large-scale industrial preparation of high-purity aluminum hydroxide.

Inventors

CUI KAI
LU WEI
LI KEZHI
LI BIN
LUO HE
LU HUI
LV FANGFANG

Assignees

中国石油化工股份有限公司
中国石化催化剂有限公司

Dates

Publication Date: 20260508
Application Date: 20241101

Claims (10)

1. A process for dealcoholizing an aluminum hydroxide slurry containing alcohol, characterized in that the process comprises contacting an aluminum hydroxide slurry containing alcohol with a C6 alkane and extracting to obtain an extraction product containing an oil phase and an aqueous phase, and separating the dealcoholized aluminum hydroxide slurry from the aqueous phase of the extraction product.
2. The dealcoholization process of claim 1, wherein the dealcoholization process further comprises separating an alcohol alkane mixture from the oil phase of the extraction product; Preferably, the dealcoholization method further comprises rectifying the alcohol-alkane mixture, and separating to obtain alcohol and C6 alkane; preferably, the dealcoholization method further comprises the steps of recycling alcohol separated by rectification treatment to aluminum hydroxide preparation, and/or recycling C6 alkane separated by rectification treatment to dealcoholization of alcohol-containing aluminum hydroxide slurry.
3. The dealcoholization process of claim 1, wherein the dealcoholized aluminum hydroxide slurry is the aqueous phase at a distance of not less than 0.5cm from the interface of the oil phase and aqueous phase; Preferably, the dealcoholized aluminum hydroxide slurry is the aqueous phase at a distance of not less than 1cm from the interface of the oil phase and the aqueous phase.
4. The dealcoholization process of claim 2, wherein the alkoxide mixture is the oil phase at a distance of not less than 0.5cm from the interface of the oil phase and aqueous phase; preferably, the alcohol alkane mixture is the oil phase having a distance from the interface of the oil phase and the water phase of not less than 1 cm; Preferably, the dealcoholization process further comprises the step of combining an interfacial extraction product between the dealcoholized aluminum hydroxide slurry and the alkoxide mixture in the extraction product with an alcohol-containing aluminum hydroxide slurry to be dealcoholized; preferably, the interfacial extraction product is an extraction product having a distance of less than 0.5cm from the interface between the oil phase and the aqueous phase; More preferably, the interfacial extraction product is an extraction product that is less than 1cm from the distance between the interfaces of the oil and water phases.
5. The dealcoholization process of any of claims 1-4, wherein the C6 alkane is selected from one or more of n-hexane, 2-methylpentane, 3-methylpentane, 2, 3-dimethylbutane, and 2, 2-dimethylbutane; Preferably, the C6 alkane is n-hexane; preferably, the alcohol is a C1-C10 alkanol, more preferably a C4-C8 alkanol; Further preferably, the alcohol is one or more of n-butanol, n-pentanol, iso-pentanol, n-hexanol and iso-hexanol.
6. The dealcoholization process of any one of claims 1-4, wherein the weight ratio of the alcohol-containing aluminum hydroxide slurry to the C6 alkane is from 1:0.1 to 10, preferably from 1:0.2 to 1, more preferably from 1:0.2 to 0.8; Preferably, the contacting is performed with stirring; preferably, the extraction conditions include a temperature of 10-40 ℃ for 1-20 hours; More preferably, the conditions of the extraction include a temperature of 15-30 ℃ for a period of 8-12 hours.
7. The method of any of claims 1-4, wherein the aluminum hydroxide slurry containing alcohol is derived from a hydrolysis reaction product of a hydrolysis reaction of aluminum alkoxide with water; Preferably, the aluminum alkoxide is obtained by reacting an alcohol with aluminum metal; Preferably, in the alcohol-containing aluminum hydroxide slurry, the alcohol content is 10 wt% or less, and the aluminum hydroxide content as aluminum oxide is 20 wt% or less; more preferably, the alcohol-containing aluminum hydroxide slurry has an alcohol content of 0.5 to 8% by weight and an aluminum hydroxide content of 6 to 15% by weight in terms of aluminum oxide.
8. A process for the preparation of aluminum hydroxide, comprising: 1) Reacting an alcohol with aluminum metal to obtain a mixture containing aluminum alkoxide; 2) Carrying out hydrolysis reaction on the mixture and water to obtain a hydrolysis reaction product; 3) Separating the hydrolysis reaction product to obtain alcohol-containing aluminum hydroxide slurry; 4) Dealcoholizing the alcohol-containing aluminum hydroxide slurry to obtain dealcoholized aluminum hydroxide slurry; 5) Drying the dealcoholized aluminum hydroxide slurry, Wherein the dealcoholization treatment of step 4) is performed according to the dealcoholization method of any one of claims 1 to 7.
9. The production method according to claim 8, wherein in step 1), the molar ratio of the metallic aluminum to the alcohol is 1:3.2-5; Preferably, in step 1), the reaction conditions of the alcohol and the aluminum include a temperature of 80-200 ℃ for 0.5-3 hours; preferably, in step 2), the weight ratio of the mixture to water is 1:0.5-10; Preferably, in the step 2), the conditions of the hydrolysis reaction comprise a temperature of 20-90 ℃ and a time of 0.1-2h; preferably, in the step 5), the conditions of the drying treatment include a temperature of 100-150 ℃ and a time of 4-48 hours.
10. Use of the dealcoholization process of the alcohol-containing aluminum hydroxide slurry as set forth in any one of claims 1 to 7 for producing aluminum hydroxide.

Description

Dealcoholization method of alcohol-containing aluminum hydroxide slurry and preparation method of aluminum hydroxide Technical Field The invention relates to the field of aluminum hydroxide preparation, in particular to a dealcoholization method of alcohol-containing aluminum hydroxide slurry and a preparation method of aluminum hydroxide. Background The aluminum hydroxide is widely applied to industries such as oil refining, medicine, building, electronics and the like, and along with the high-speed development of economy in China and the increase of the demand of each industry for the aluminum hydroxide, the market scale of the aluminum hydroxide is continuously expanding. The preparation method of aluminum hydroxide is more, for example, the preparation of aluminum hydroxide can be realized by adopting various processes such as the reaction of soluble aluminum salt and ammonia water, the reaction of tetrahydroxy sodium aluminate and excessive carbon dioxide, the reaction of Al 3+ and alkaline substances, the reaction of AlO 2- and acidic substances, and the like. However, the aluminum hydroxide prepared by the method has lower purity, and the fields of partial oil refining catalysts, automobile exhaust gas treatment catalysts, fine chemical engineering and the like generally require the use of high-purity aluminum hydroxide with purity of more than 99.9 percent. Aluminum alkoxide hydrolysis is the main method for preparing high-purity aluminum hydroxide at present, and the production process generally comprises the steps of reacting alcohol with aluminum to generate aluminum alkoxide, hydrolyzing the aluminum alkoxide with water to obtain aluminum hydroxide slurry, and finally drying the aluminum hydroxide slurry to obtain aluminum hydroxide. Wherein, after the hydrolysis reaction of aluminum alkoxide, a certain amount of alcohol is entrained in the obtained aluminum hydroxide slurry, and the alcohol is difficult to remove by a conventional separation method due to the specificity of the aluminum hydroxide slurry. If alcohol entrained in the aluminum hydroxide slurry is not removed, carbon residue in the finally prepared aluminum hydroxide is excessively high, purity and quality of the finally prepared aluminum hydroxide are affected, and the entrained alcohol also increases raw material consumption in the preparation process of the aluminum hydroxide, so that production cost of a product is increased. Thus, when preparing high purity aluminum hydroxide by existing aluminum alkoxide hydrolysis methods, how to remove alcohol from the alcohol-containing aluminum hydroxide slurry is a key issue in improving the quality of aluminum hydroxide. In the current industrial production, the most common way to remove the alcohol entrained in the aluminium hydroxide slurry is filtration and repeated washing, for example, CN107640780a discloses a process for preparing aluminium hydroxide, wherein to obtain high purity aluminium hydroxide, three stages of filtration washing are performed on aluminium hydroxide slurry after aluminium alkoxide hydrolysis, and the washing liquid is distilled and extracted to separate out alcohol. However, the method has low treatment efficiency and complex flow, and needs to repeatedly wash at a higher temperature, so that the water consumption and the energy consumption are huge. In addition, CN113735152a provides a method for removing alcohol entrained in aluminum hydroxide slurry, which comprises the steps of introducing water vapor into preheated alcohol-containing aluminum hydroxide slurry for steam stripping, taking alcohol entrained in aluminum hydroxide slurry out by water vapor after steam stripping to obtain alcohol-containing water vapor, and then separating alcohol and water by condensation. However, this method requires preheating the whole of the alcoholic aluminum hydroxide slurry to 80-96 ℃ and then stripping with steam at 100-200 ℃ and is also energy intensive. Meanwhile, in the preheating process, the aging reaction of the aluminum hydroxide is continuously carried out when the aluminum hydroxide stays at a higher temperature, so that the quality of the product is adversely affected. Aiming at the current situation of the process for preparing high-purity aluminum hydroxide by an aluminum alkoxide hydrolysis method, the development of an alcohol-containing aluminum hydroxide slurry dealcoholization method which is simple, convenient and easy to implement and has low energy consumption is an important task which needs to be completed currently. Disclosure of Invention The invention aims to solve the problems of complex alcohol removal, high energy consumption and the like in alcohol-containing aluminum hydroxide slurry, and provides a novel alcohol removal method for alcohol-containing aluminum hydroxide slurry. According to the method provided by the invention, the alcohol content in the alcohol-containing aluminum hydroxide slurry can be reduced to below 0.15 wt% throug