Preparation method of high-purity nano-alumina powder

Abstract

The invention relates to a preparation method of high-purity nano-alumina powder, comprising the following steps: (1) metallic aluminium pretreatment; (2) decomposition; (3) concentration; (4) crystallization; (5) fractional crystallization. The preparation method of the high-purity nano-alumina powder (99.999%) provided by the invention adopts high-purity metallic aluminum sheet and 30%-35% high-purity hydrochloric acid for a reflux heating reaction to form the high-purity alumina powder. During the reaction process, no mercury or mercury compound catalyst is added, thus avoiding mercury pollution and directly preparing the high-purity alumina powder. The repeated recrystallization and purification process of the alumina powder is saved.

Description

technical field [0001] The invention belongs to the field of chemical reagents, in particular to a preparation method of high-purity nano-alumina powder. Background technique [0002] High-purity alumina powder has a wide range of uses, high prices, and a relatively large market volume. Different countries use different production processes to compete for production. At present, the main production methods of high-purity alumina powder classified by raw materials are: [0003] (1) Use high-purity aluminum (aluminum powder) as raw material, react with water, or add organic matter (such as choline) to form organic matter, then hydrolyze, and the precipitated aluminum hydroxide is calcined to obtain high-purity alumina powder. The purity of the alumina powder prepared by this method depends on the purity of aluminum or aluminum powder, and the reaction with water is also a factor affecting the purity. Although this type of method has a simple process, it has disadvantages suc...

AI Technical Summary

Problems solved by technology

This type of method is the main method of industrial production, and the purity of the product is controllable, but there are many waste residues, waste water and waste gas in the process, and the environmental pollution is serious

[0006] (4) Using aluminum alcohol as raw material, through multi-step purification, pure aluminum alcohol is obtained, then hydrolyzed to obtain aluminum hydroxide, and calcined to obtain high-purity alumina powder. This method has high product purity and controllable quality, but the process is long and the cost is high

Adding additives during calcination can easily introduce new impurities; when the calcined product is re-ground and re-concentrated acid treatment, it is difficult to remove the impurities entering the crystal lattice, so the product purity is low, and it is difficult to treat the waste concentrated acid; on the other hand, the powder It is difficult to control the shape during the grinding process, and the product application fields are limited