Preparation method of aluminum oxide powder

A technology of alumina powder and aluminum hydroxide, which is applied in the direction of alumina/aluminum hydroxide, can solve the problems of reduced purity, high water attached to filter cake, difficult filtration, etc., and achieves simple process, low production cost and high purity Effect

Inactive Publication Date: 2013-10-16
GUIZHOU BRANCH CHINA ALUMINUM IND
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  • Abstract
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Problems solved by technology

This method has two disadvantages: (1) The temperature of the sublimation process is controlled at about 150°C, which is higher than that of SiCl 4 Sublimation temperature, so Si impurities cannot be removed; (2) Anhydrous aluminum chlori

Method used

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Examples

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preparation example Construction

[0016] A method for preparing alumina powder. The preparation process uses anhydrous aluminum chloride and ammonia water as raw materials. First, the anhydrous aluminum chloride is subjected to sublimation and desublimation purification, and then it is made into a solution, which is mixed with ammonia water under stirring. And, aluminum hydroxide powder is obtained, dried and calcined at high temperature to obtain alumina powder.

[0017] During operation, the aluminum chloride used is industrial anhydrous aluminum chloride, the content of aluminum chloride is ≥99%, and the specification of ammonia water is analytical pure or superior pure, preferably superior pure.

[0018] The specific implementation plan is as follows:

[0019] (1) Put anhydrous aluminum chloride into the sublimation device. The lower part of the device is the discharge area, and the top is the collection area. A heater with precise temperature control is installed outside the two areas. The inner tank of ...

Embodiment 1

[0030] This example is a method for preparing anhydrous aluminum chloride by sublimation and desublimation, which is applicable to examples 2-5.

[0031] Take 200g of anhydrous aluminum chloride and put it into the discharge area of ​​the sublimation device. Set the temperature of the heater in the discharge area to 200°C and the temperature of the heater in the collection area to 160°C. After 2 hours, turn off the heater and take out the collection area , to obtain 190 g of anhydrous aluminum chloride purified once by sublimation. The sublimation purification process was repeated twice to obtain 171 g of pure anhydrous aluminum chloride for use.

Embodiment 2

[0033] Add 300ml pure water in the beaker, pour into embodiment 1 gained pure anhydrous aluminum chloride 60g, stir to make it dissolve. Add 500ml of analytically pure ammonia water with a concentration of 8% into another beaker, and put it in a water bath at 55°C. After the temperature of the ammonia water in the beaker reaches 55°C, drop the aluminum chloride solution into the ammonia water with a peristaltic pump at a speed of 5ml / min, and at the same time start stirring at a speed of 350rpm. After the aluminum chloride solution is added dropwise, age for 1.5 hours, filter with suction, and wash to obtain an aluminum hydroxide filter cake. The filter cake was dried in a vacuum drying oven, crushed, and calcined in a muffle furnace at 1200°C for 4 hours to obtain high-purity alumina powder.

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Abstract

The invention relates to a preparation method of aluminum oxide powder and particularly relates to a preparation method of high-purity aluminum oxide powder. The preparation method is characterized in that according to the preparation process, anhydrous aluminum chloride and ammonia water are taken as raw materials, sublimation, desublimation and purification are firstly performed on the anhydrous aluminum chloride, then a solution is prepared, the solution is neutralized with the ammonia water under stirring to obtain aluminum hydroxide powder, and drying and high-temperature calcination are further performed to obtain the aluminum oxide powder. According to the preparation method of the aluminum oxide powder, the anhydrous aluminum chloride is taken as the raw material, a two-temperature region is used for sublimation, desublimation and purification, chemical neutralization reaction is further performed with the ammonia water, reaction temperature, stirring speed and feeding speed are further controlled to obtain the aluminum hydroxide powder with high purity and good filtering property, and drying and high-temperature calcination are performed to obtain the high-purity aluminum oxide powder with the purity being not lower than 99.95%. The preparation method has the advantages of simple process, low production cost, two-step purification, high purity of the obtained aluminum oxide and no production of colloids during neutralization reaction.

Description

technical field [0001] A method for preparing alumina powder, in particular to a method for preparing high-purity alumina powder. Background technique [0002] As one of the cutting-edge materials, high-purity alumina has been widely used in many fields such as optics, chemical industry and special ceramics to manufacture light-transmitting alumina sintered bodies, high-density particle sintered bodies, gem single crystals, electronic components, Abrasive materials, luminescent materials, etc. With the rise of the LED green lighting industry, the demand for sapphire substrates has grown rapidly in recent years, and it has also greatly stimulated the demand for high-purity alumina powder materials. [0003] Anhydrous aluminum chloride is an important inorganic salt of aluminum, usually prepared by chemical processing of bauxite or metal aluminum chlorination. Industrial products are often light yellow, gray or orange because they contain free chlorine, iron and traces of ot...

Claims

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Application Information

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IPC IPC(8): C01F7/02
Inventor 王俊王毅杨双凤杨洪山胡文豪
Owner GUIZHOU BRANCH CHINA ALUMINUM IND
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