Method for preparing micron-sized ultra-high-purity aluminum oxide powder by virtue of full-process regulation control

Abstract

The invention relates to high-purity aluminum oxide powder and in particular relates to a method for preparing micron-sized ultra-high-purity aluminum oxide powder by virtue of full-process regulation control. The method comprises the following steps: melting a high-purity aluminum ingot, repeatedly vacuumizing at a high temperature, filling nitrogen gas for protection, performing ultrasonic pneumatic nebulization, centrifuging, quenching and dispersing of a high-speed pure aluminum turntable and quick cooling of high-purity de-ionized water on molten aluminum by virtue of a ceramic liquid guide pipe to obtain high-activity aluminum slurry, producing an active hydrolysis reaction to generate aluminum hydroxide, repeatedly diluting and filtering through the high-purity de-ionized water to further remove impurities, drying and grinding products, and calcining at 1000-1300 DEG C to obtain the micron-sized (less than 2 microns) aluminum oxide powder with the purity of 99.999%. According to the method, the processes in different stages are optimized, so that the purity of active aluminum powder, the aluminum hydroxide and the final aluminum oxide are well controlled and the cost is reduced; the pollution is avoided, the operation is convenient, and the industrial production is facilitated.

Description

technical field [0001] The invention relates to high-purity alumina powder, in particular to a method for preparing micron-sized ultra-high-purity alumina powder through whole-process control. Background technique [0002] High-purity alumina powder is an ultra-fine powder material with a purity above 99.999% (5N). It has a wide range of uses and is used in the electronics industry, biochemical ceramics, structural ceramics, and functional ceramics. One of the basic materials in high-tech fields such as chemical industry; with the research and development of new materials, there are higher requirements for the performance of alumina, in order to improve the strength, toughness, compactness, transparency, photoelectric performance or To reduce the sintering temperature, etc., it is required to use ultra-fine alumina powder raw materials with high purity, particle size from micron to nano-scale, narrow particle size distribution range, and good sintering activity. High-perform...

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Problems solved by technology

[0004] Chinese patent document CN102863000A discloses a method of pyrolysis of ammonium aluminum sulfate to prepare high-purity alumina. The high-purity ammonium aluminum sulfate is ground to obtain ammonium aluminum sulfate precursor powder with uniform particle size, which is then sintered to obtain high-purity alumina powder. Although the process is relatively simple and the cost is relatively low in this method, its production cycle is long, there is thermal dissolution phenomenon, and the SO produced during the decomposition process 3 , NH 3 will cause serious pollution to the environment

[0006] Chinese patent document CN102531009A discloses a method of hydrolysis of aluminum isopropoxide, in which organic aluminum alcohol is dissolved in alcohol solvent to obtain aluminum alcohol phase, catalyst, water and alcohol solvent are added to aluminum alcohol phase for hydrolysis reaction, and sol is obtained and dried Obtain hydrated alumina powder and heat it at 700-920°C to obtain high-purity alumina. This method has complex procedures, many process links, difficult control of purity, high production cost, and serious environmental pollution.

[0007] The above-mentioned processes all have shortcomings such as high cost, polluting the environment, and complicated procedures. Therefore, it is very necessary to overcome the defects in the prior art in view of the problems in the prior art.

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