Method for synthesizing aluminium oxide powder by using combustion method

Abstract

The invention relates to a method for synthesizing aluminium oxide powder by using a combustion method, and belongs to the technical field of chemical synthesis of powder materials. The method comprises the following steps: (1) ignition: continuously or intermittently igniting in a reaction device; (2) oxygen delivery: feeding oxygen into the reaction device; (3) aluminum powder conveying: conveying aluminum powder with the grain size less than or equal to 100 mu m into the reaction device through gas; (4) combustion: igniting the aluminum powder so that the aluminum powder is combusted in oxygen; and (5) cooling: cooling combustion products and collecting the combustion products to obtain the aluminium oxide powder. The problem that preparation of aluminium oxide powder by an existing aqueous solution method has lots of procedures, and is long in production period and large in water consumption is solved. Water is not used in the method, and the aluminium oxide powder which has the size of nanoscale or above and has the various purities of 2N-6N is obtained at one step by using aluminum as a raw material; and the product is high in purity, low in sodium content, uniform in particle size, good in dispersibility and good in spheroidization. A synthetic process is short in technological process, the equipment is simple, the cost is low, energy consumption is low, synthesis efficiency is high, pollution does not exist, and waste gas, waste water and solid wastes do not exist.

Description

technical field [0001] The invention belongs to the technical field of chemical synthesis of powder materials, in particular to a method for synthesizing alumina powder by a combustion method. Background technique [0002] As a fine chemical product, alumina powder has developed rapidly at home and abroad, and is widely used in aerospace, weapons, electrical insulation materials, integrated circuit substrates, high-speed cutting tools, high-strength wear-resistant and corrosion-resistant materials, high-intensity gas discharge lamps Tubes, carriers for phosphors, single crystal materials, catalyst carriers, laser materials and many other high-tech cutting-edge industries. It is an important basic material for sodium lamp tubes, precision instruments and aviation optical devices. [0003] Alumina powder is required to be ultra-fine, high-purity, with narrow particle size distribution, stable phase state, and no serious agglomeration. At present, the preparation methods of u...

AI Technical Summary

Problems solved by technology

The product sodium potassium content that this method obtains is high, and product purity is low

[0005] The disadvantages of ammonium aluminum sulfate pyrolysis are: complex process, high energy consumption, high cost, and environmental pollution problems, high sodium and potassium content of the obtained product, and low product purity

The content of sodium per gram of alumina powder produced by this method is more than tens of milligrams, and the content of other trace elements is also relatively high. The purity of the product can only reach the level of 4N, which cannot meet the requirements of artificial sapphire production.

[0007] The disadvantages of the improved Bayer method are: the production process is relatively complicated, the dissolution of raw materials is difficult to control during the production process, γ-diaspore is prone to appear, the sintering temperature is high, the product yield is low, the solubility of raw materials in the production process is difficult to control, and the sintering temperature High, low product yield, high cost, and product purity does not meet the needs of intraocular lenses

[0009] Disadvantages of the alcohol-salt hydrolysis method: complex process, many equipment involved, high price of organic alcohol, difficult recovery, large amount of waste liquid, high price, high production cost, high performance requirements for raw materials, reagents, processes, equipment, etc., even using The pure water and indoor air will have an important impact on the purity. At the same time, the addition of alkali during the hydrolysis process will lead to the introduction of sodium and potassium elements, which will eventually lead to high sodium and potassium content in the product, thus affecting the purity.

[0011] Disadvantages of the direct activation hydrolysis method of high-purity aluminum: the hydrolysis process is carried out in a fully enclosed organic lining environment, which cannot be purified again, the process is long, the cost is high, and the process conditions are harsh. There are production safety hazards

The shape of the product is irregular, the bulk density is low, and it is difficult to produce high-density products

Images