Production process of high-purity superfine alpha-aluminium oxide powder

A micro-powder, high-purity technology, applied in the preparation of alumina/aluminum hydroxide, alumina/hydroxide, etc., can solve the problems of environmental pollution, high energy consumption of α-type alumina, and low output.

Inactive Publication Date: 2003-07-30
XINXIANG HI TECH CERAMIC MATERIAL
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The α-alumina produced by this method consumes a lot of energy, has a low output, and has a large particle size.
Another method is to use ammonium aluminum sulfate for direct thermal d

Method used

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  • Production process of high-purity superfine alpha-aluminium oxide powder
  • Production process of high-purity superfine alpha-aluminium oxide powder

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0011] Embodiment 1: first tap water is produced high-purity water according to the conventional method, gets refined ammonium bicarbonate and puts into container and adds high-purity water, produces the aqueous solution of ammonium bicarbonate, makes this solution concentration be 4mel / L, then adds refined ammoniacal liquor to make above-mentioned The pH of the solution is 10.

[0012] Put the refined ammonium aluminum sulfate into the container, add high-purity water to prepare the ammonium aluminum sulfate aqueous solution, make the concentration 0.2mel / L, control the temperature of the prepared ammonium bicarbonate aqueous solution with a pH of 9 to 10 at 60°C, and then Add the above-mentioned aluminum ammonium sulfate aqueous solution of same volume in this solution, and this solution temperature should be 50 ℃, make the two mix together and carry out microscopic reaction. It is 200 rpm, and the reaction temperature is controlled at 60° C., so that the reaction rate is 40...

Embodiment 2

[0017] Embodiment 2: produce high-purity water according to the method for embodiment 1, ammonium bicarbonate aqueous solution and aluminum ammonium sulfate aqueous solution, the concentration of ammonium bicarbonate aqueous solution is 2mel / L, then add refined ammonia water and make the pH value of its solution 9, temperature control 58°C, and then add the same volume of ammonium aluminum sulfate aqueous solution with a concentration of 0.2mel / L and a temperature of 60°C to the solution to mix the two for microscopic reaction. The stirring speed is 180 rpm, and the reaction temperature is controlled at 50°C. ℃, the reaction rate is 30L / min, and then generates α-Al according to the operating steps and process conditions of Example 1 2 o 3 .

Embodiment 3

[0018] Embodiment 3: produce high-purity water according to the method for embodiment 1, ammonium bicarbonate aqueous solution and aluminum ammonium sulfate aqueous solution, the concentration of ammonium bicarbonate aqueous solution is 3mel / L, then adds refined ammoniacal liquor and makes the pH value of its solution 10, temperature is 50°C, and then add the same volume of aluminum ammonium sulfate aqueous solution with a concentration of 0.5 mel / L and a temperature of 60°C to the solution to mix the two for microscopic reaction, the stirring speed is 180 rpm, and the reaction temperature is controlled at 55°C , the reaction rate is 35L / min, then generate α-Al according to the operation steps and process conditions of Example 1 2 o 3 .

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Abstract

The present invention discloses a production process of high-purity superfine alpha-aluminum oxide powder. Refined ammonium bicarbonate and aluminum ammonium sulfate is first mixed with pure water toprepare solution, refined ammonia water is added into the solution of ammonium bicarbonate to produce micro reaction, and the product is filtered, washed and sintered in tunnel kiln. The said production process can result in alpha-Al2O3 content up to 99.99, D50 granularity of 0.1-5 microns, BET specific surface area of 2-20 sq m/g, true density of 3.80-3.97 g/cu cm bulk density of 0.3-0.5 g/cu cm, densified density of 0.6-1.3 g/cu cm, sintered density of 3.92-3.96 g/cu cm and alpha-Al2O3 phase converting rate greater than 95%.

Description

technical field [0001] The invention belongs to the production of α-Al 2 o 3 method, especially related to the production of high-purity α-Al 2 o 3 micronized method. Background technique [0002] At present, there are many ways to produce high-purity ultra-fine aluminum hydroxide in the world, but there are different problems such as difficulty in high-purity, poor sinterability of products, high cost, and residual unreacted aluminum particles. Patent 86102252 is titled "Method for Producing α-Alumina Using a Steam Fluidized Reactor", which is a process for converting an alumina compound into an anhydrous product with an α-alumina content of at least 10% by weight. The aluminum compound is sent to the reactor after being dehydrated and heated, and is fluidized with steam in the reactor, and the reaction temperature is kept at 900-1350°C to produce a product with good uniformity and excellent abrasiveness. The α-alumina produced by this method consumes a lot of energy, ...

Claims

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Application Information

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IPC IPC(8): C01F7/02C01F7/30
Inventor 张庆军许仁新许寿记张洪运
Owner XINXIANG HI TECH CERAMIC MATERIAL
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