Preparation method of high-purity aluminum oxide

A high-purity alumina and aluminum hydroxide technology, applied in the preparation of alumina/hydroxide, etc., can solve the problems of easy fire and explosion, large equipment investment, complex production process, etc., to prevent the entry of impurities and pollution-free The effect of strong controllability of waste emissions and process

Active Publication Date: 2014-01-22
何礼君 +2
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Problems solved by technology

This process must be carried out in two steps, and the isopropanol involved in the reaction needs to be distilled and purified. The equipment investment is large, and it is easy to catch fire and explode during operation, and the production cost is high.
[0009] The above methods (1) to (4) due to technical reasons, the obtained alumina product has high Na and K plasma content, and the product purity can only reach 4N5 level, and the above method has complicated production process, long process and high production cost
In addition, the above process will produce some by-products, which will easily cause environmental pollution.
[0010] The aluminum alcohol method of method (5) is currently the most commonly used production process for high-purity alumina in the world, but the aluminum alcohol method has a long process flow and poor product quality stability. The isopropanol used in the reaction needs to be recovered by distillation, and energy consumption High, high requirements for production control and equipment design, large equipment investment, low production efficiency, high production cost

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  • Preparation method of high-purity aluminum oxide

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[0027] The invention provides a method for preparing high-purity alumina, comprising: reacting high-purity aluminum with a purity greater than 99.99% and an electronic-grade hydrocarbyl ammonium hydroxide solution to form an aluminum organic double salt, and hydrolyzing the formed aluminum organic double salt to form hydroxide Aluminum; the generated aluminum hydroxide is filtered, such as vacuum filtered, washed with pure water and dried at a temperature of 100-200°C to obtain high-purity aluminum hydroxide with a purity of 99.999% or more; the dried high-purity aluminum hydroxide is passed through Calcined at high temperature to obtain high-purity alumina with a purity above 99.999%.

[0028] The high-purity aluminum in the present invention refers to aluminum with a purity of more than 99.99%. In order to obtain high-purity aluminum raw materials with high activity, no pollution and favorable reaction, high-purity aluminum ingots (5N grade) can be rolled to obtain high-puri...

Embodiment 1

[0044] In the polytetrafluoroethylene reaction container of 500L, add the high-purity aluminum foil (Nantong Taide, purity 5N) that 5kg thickness is 5um, 300L concentration is the electronic grade tetramethylammonium hydroxide solution of 5wt% (Runjing chemical industry, electronic Grade TMAH) reacted at a temperature of 20°C. After 5 hours of reaction, almost no gas was released, and the reaction ended. The aluminum hydroxide precipitate is discharged from the reaction vessel, and after vacuum filtration, the mother liquor is returned to the reaction vessel to continue to participate in the reaction. The filtered aluminum hydroxide solid is washed with pure water and then dried in vacuum at a temperature of 100°C. The dried aluminum hydroxide powder was calcined at a temperature of 750° C. to finally obtain 3.5 kg of alumina powder. Its purity was tested to be greater than 99.999%, and the test results are shown in Table 1.

Embodiment 2

[0046] In a 500L polytetrafluoroethylene reaction vessel, add 5kg of high-purity aluminum foil with a thickness of 20um, and 240L of the mother liquor returned from Example 1, and react at a temperature of 60°C. After 3.5 hours of reaction, almost no gas was released, and the reaction ended. The precipitated aluminum hydroxide was drained from the reaction vessel. The mother liquor after aluminum hydroxide precipitation and filtration can be returned to the reaction vessel to continue to participate in the reaction, and the filtered aluminum hydroxide solid is washed with pure water and then dried in vacuum at a temperature of 200°C. The dried aluminum hydroxide powder was calcined at a temperature of 1300° C. to finally obtain 8.75 kg of alumina powder. Its purity is greater than 99.999% after inspection.

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Abstract

The invention provides a preparation method of high-purity aluminum oxide, which is mainly characterized by comprising the following steps: reacting high-purity aluminum and an electronic grade alkyl ammonium hydroxide solution to generate organic aluminum complex salt; further hydrolyzing the organic aluminum complex salt to obtain aluminum hydroxide and the alkyl ammonium hydroxide; and filtering the generated aluminum hydroxide, washing, performing vacuum drying, and performing high-temperature calcination to obtain high-purity aluminum oxide powder. The preparation method has the advantages of short production flow, high process controllability, no environmental pollution, high product purity, low cost and the like. The high-purity aluminum oxide powder prepared by the method is applicable to the fields of LED (light-emitting diode) sapphires, laser crystals, electronic ceramics, special ceramics, luminescent materials and the like.

Description

technical field [0001] The invention relates to a method for preparing high-purity aluminum oxide, in particular to a method for preparing high-purity aluminum hydroxide and aluminum oxide by reacting high-purity aluminum with electronic grade hydrocarbyl ammonium hydroxide solution. Background technique [0002] High-purity alumina generally refers to alumina with a purity greater than 99.99%. Due to its excellent optical, electrical, magnetic and thermal properties, high-purity alumina can be used as rare earth fluorescent materials, ceramic materials, LED substrate materials, etc. In recent years, with the continuous expansion of the LED market, the demand for high-purity alumina is also increasing. However, the LED market has very high requirements on the purity of high-purity alumina, and the higher the purity, the better the quality of the product. Therefore, the preparation of high-purity alumina has always been one of the problems to be studied and solved urgently i...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01F7/42
Inventor 何礼君陈慧峰栗华矗
Owner 何礼君
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