Dilute nitric acid solution dipping and calcination process for regenerating waste active alumina

A technology of activated alumina and dilute nitric acid, applied in alumina/aluminum hydroxide and other directions, can solve the problems of a large amount of waste activated alumina, affecting the normal production of manufacturers, and non-recycling, etc., and achieves novel process, important environmental protection and Economical, good effect of promotion and application value

Inactive Publication Date: 2007-12-26
FUZHOU UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The amount of waste alumina accounts for about 5% of the production of hydrogen peroxide. A 50,000-ton hydrogen peroxide plant consumes 2,000-3,000 tons per year. The amount of waste is large, and it is shelved for a long time. It occupies a large area and is piled up like a mountain, causing great pollution to the environment and seriously affecting Manufacturer's normal production
There are dozens of hydrogen peroxide production plants in the country, and the amount of waste activated alumina is very large, which has not yet been recycled

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0011] The waste activated alumina is washed with water and dried. Put the dried waste activated alumina in the pool, soak it with 8% dilute nitric acid solution for 5 minutes, discharge the impregnated dilute nitric acid solution, wash with water, dehydrate and dry, and place the dried material in a kiln for calcination at 550°C , keep warm for 2 hours, and cool down to room temperature naturally. The specific surface area of ​​the regenerated activated alumina was measured to be 234.71m 2 / g, the pore volume is 0.421cm 3 / g, the average pore diameter is 7.12nm.

Embodiment 2

[0013] The waste activated alumina is washed with water and dried. Put the dried waste activated alumina in the pool, soak it with 8% dilute nitric acid solution for 10 minutes, discharge the impregnated dilute nitric acid solution, wash with water, dehydrate and dry, and place the dried material in a kiln for calcination at 550°C , keep warm for 2 hours, and cool down to room temperature naturally. The specific surface area of ​​the regenerated activated alumina was measured to be 351.97m 2 / g, the pore volume is 0.436cm 3 / g, the average pore diameter is 6.85nm.

Embodiment 3

[0015] The waste activated alumina is washed with water and dried. Put the dried waste activated alumina in the pool, soak it with 8% dilute nitric acid solution for 25 minutes, discharge the impregnated dilute nitric acid solution, wash with water, dehydrate and dry, and place the dried material in a kiln for calcination at 550°C , keep warm for 2 hours, and cool down to room temperature naturally. The specific surface area of ​​the regenerated activated alumina was measured to be 226.28m 2 / g, the pore volume is 0.429cm 3 / g, the average pore diameter is 7.72nm.

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PUM

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Abstract

The process of regenerating waste active alumina includes the following steps: washing waste active alumina in water and stoving; dipping waste active alumina inside 8-20 % dilute nitric acid solution in a pond for 5-25 min; washing dipped waste active alumina in water and stoving; calcining in a kiln the 500-800 deg.c for 2-6 hr, and naturally cooling to room temperature to obtain regenerated active alumina. The process can improve the inner pore structure of active alumina and raise activity to reach the aim of regeneration, and the regenerated active alumina has high activity, low processing cost and environment friendship.

Description

Technical field: [0001] The invention relates to a regeneration technology of waste activated alumina. Background technique: [0002] In the process of producing hydrogen peroxide by anthraquinone method, activated alumina is used to purify and regenerate the working fluid. After several months of use, it loses its activity and regeneration ability and is discarded. The discarded alumina is called waste activated alumina. The amount of waste alumina accounts for about 5% of the production of hydrogen peroxide. A 50,000-ton hydrogen peroxide plant consumes 2,000-3,000 tons per year. The amount of waste is large, and it is shelved for a long time. It occupies a large area and is piled up like a mountain, causing great pollution to the environment and seriously affecting Manufacturer's normal production. There are dozens of hydrogen peroxide production plants in the country, and the amount of waste activated alumina is very large, which has not been recycled so far. From the ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01F7/02
Inventor 于岩阮玉忠吴任平陈小娟
Owner FUZHOU UNIV
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