Method for reducing content of sodium in aluminum hydroxide

A technology of aluminum hydroxide and sodium content, applied in the direction of aluminate/alumina/aluminum hydroxide purification, etc., can solve the problems of environmental pollution, crystal growth, easy to grow, etc., to achieve easy industrialization, improve performance, and speed up transmission. effects of qualitative processes

Inactive Publication Date: 2011-04-20
GUIZHOU BRANCH CHINA ALUMINUM IND
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to address the deficiencies in the above-mentioned prior art, to provide a reduced aluminum hydroxide that can effectively reduce the sodium content, av

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] Alkali-produced aluminum hydroxide (average particle size: 66 μm) and pure water are mixed into a slurry with a solid content of 400g / L, and the slurry is moved into a hydrothermal reaction kettle with a stirring device. An appropriate amount of aluminum nitrate is added to the base slurry to adjust the pH value of the slurry, and the pH value of the slurry is adjusted to 3-5. The mechanical stirring speed was 100 RPM. Electric heating is used to raise the temperature of the hydrothermal reaction kettle, so that the aluminum hydroxide water-based slurry is subjected to hydrothermal treatment at a temperature of 140° C., and the hydrothermal treatment time is 8 hours. After the hydrothermal treatment, the reaction kettle was naturally cooled to below 90°C, and the treated aluminum hydroxide slurry was filtered using a plate and frame filter, and the filter cake was washed with hot pure water three times, and then treated at a temperature of 180°C. The filter cake is dri...

Embodiment 2

[0019] Alkali-produced aluminum hydroxide (average particle size 8μm) and pure water are mixed into a slurry with a solid content of 200g / L, and the slurry is moved into a hydrothermal reaction kettle with a stirring device. An appropriate amount of glacial acetic acid is added to the base slurry to adjust the pH value of the slurry, and the pH value of the slurry is adjusted to be about 3. The mechanical stirring speed was 50 RPM. Electric heating is used to raise the temperature of the hydrothermal reaction kettle, and the aluminum hydroxide water-based slurry is subjected to hydrothermal treatment at a temperature of 180° C., and the hydrothermal treatment time is 2 hours. After the hydrothermal treatment, let the reactor cool down naturally to below 90°C, filter the treated aluminum hydroxide slurry with a plate and frame filter, wash the filter cake with hot pure water three times, and then dry it at a temperature of 160°C After being dispersed, qualified aluminum hydrox...

Embodiment 3

[0021] Alkali-produced aluminum hydroxide (average particle size 1.5μm) and pure water are mixed into a slurry with a solid content of 150g / L, and the slurry is moved into a hydrothermal reaction kettle with a stirring device. A certain amount of nitric acid is added to the water-based slurry to adjust the pH value of the slurry, and the pH value of the slurry is adjusted to 4. The mechanical stirring speed was 150 RPM. Electric heating is used to raise the temperature of the hydrothermal reaction kettle, so that the aluminum hydroxide water-based slurry is subjected to hydrothermal treatment at a temperature of 120° C., and the hydrothermal treatment time is 10 hours. After the hydrothermal treatment, let the reactor cool down naturally to below 90°C, filter the treated aluminum hydroxide slurry with a plate and frame filter, wash the filter cake with hot pure water three times, and then dry it at a temperature of 100°C , get qualified aluminum hydroxide powder after breakin...

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Abstract

The invention relates to a method for reducing the content of sodium in aluminum hydroxide, in particular to a method for preparing low-sodium aluminum hydroxide (Na2O is less than 0.1 percent) serving as a fire retardant or a raw material for calcining low-sodium aluminum oxide. The method is characterized by comprising the following steps of: after homogenizing the aluminum hydroxide by using pure water, performing hydro-thermal treatment, and filtering, washing and drying to obtain low-sodium aluminum hydroxide powder. In the method, the aluminum hydroxide prepared by a Bayer process or a sintering process is subjected to the hydro-thermal treatment, so that adherent alkali and lattice alkali in the aluminum hydroxide are dissolved in the water, and the low-sodium aluminum hydroxide powder is obtained by processes of solid-liquid separation, washing, drying and the like, wherein the powder can be used as the fire retardant or the raw material for calcining the low-sodium aluminum oxide. The method has the advantages that a process is simple, industrialization is easy to realize and the like, so the using performance of the aluminum hydroxide fire retardant can be improved effectively, and the low-sodium aluminum hydroxide can be used as the raw material for calcining low-sodium alpha-aluminum oxide.

Description

technical field [0001] A method for reducing sodium content in aluminum hydroxide, relating to a low-sodium aluminum hydroxide (Na 2 O<0.1%) preparation method. Background technique [0002] At present, aluminum hydroxide used as a flame retardant and a raw material for the production of alumina is mainly produced by the alkaline process, Na 2 O is one of the most harmful impurities in aluminum hydroxide. Na in aluminum hydroxide 2 O impurities not only affect the color tone of artificial marble products, but also have an adverse effect on the electrical insulation properties of the products. Na 2 O content also affects the thermal stability of aluminum hydroxide, such as Na 2 When the O content is 0.3%, the dehydration temperature of aluminum hydroxide is 210 ° C, while Na 2 The dehydration temperature is 255℃ when the O content is 0.1%. In addition, Na in aluminum hydroxide during calcination 2 O can react to form β-Al 2 o 3 and other impurities to reduce α-Al...

Claims

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Application Information

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IPC IPC(8): C01F7/46
Inventor 王建立姚长江韩冬战兰文兰耿红娟马艳红
Owner GUIZHOU BRANCH CHINA ALUMINUM IND
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