Preparation method for spherical aluminum oxide powder

Abstract

The invention discloses a preparation method for nano-scale and micro-scale spherical aluminum oxide powder. According to the invention, the manner of combining a sol-gel technology with an emulsion method is utilized to prepare the spherical aluminum oxide; a water-based aluminum sol is used as a main raw material; an organic reagent is used as a dispersion medium; the spherical aluminum oxide is compounded in the manner of water-in-oil emulsion polymerization; the interfacial tension between an oil phase and a water phase is utilized to manufacture a tiny spherical droplet; and the formation of a water-phase sol particle and the gel is limited in the tiny droplet. The raw material components of the spherical aluminum oxide according to the technology are convenient for design; the particle size of the powder is within the scope of 0.5-100mu m and is adjustable; the spheroidization rate is high; the liquidity is excellent; and the dispersion is easy.

Description

technical field [0001] The invention relates to the field of chemical technology, in particular to the field of material technology, in particular to a method for preparing spherical alumina powder. Background technique [0002] Alumina powder has excellent physical and chemical properties, and is widely used in the fields of electronics, petrochemical, refractory materials, ceramics, grinding, pharmaceuticals, catalysis, and aerospace. The characteristics and application fields of alumina powder are closely related to its particle morphology. Common alumina powders are mostly worm-like, square-shaped and hollow flocculent, which makes alumina powder prone to uneven particle size and dispersion. Poor performance, easy reunion, poor fluidity and other defects. Among the different shapes of alumina powder, spherical alumina powder has regular shape, reasonable particle size distribution, large bulk density, small specific surface area and good fluidity, which can greatly impr...

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Problems solved by technology

Chinese patent CN1278458A discloses a method for preparing spherical alumina by spray drying and granulation. In this invention, aluminum sol and alumina powder are used as raw materials to configure slurry, which is formed into balls by spray drying, and then calcined at high temperature to obtain spherical alumina. The spherical alumina prepared by this process contains a large number of nearly spherical or quasi-spherical particles, the spheroidization rate is low, the surface smoothness is poor, and the particle size distribution is wide. Spray drying is easy to produce hollow balls and cue balls, and spray drying requires a lot of heat energy. high consumption

Both Chinese patents CN102249276A and CN106315647A adopt a spray melting method to prepare spherical alumina, using alumina or aluminum hydroxide as raw material, injecting powder into the flame to melt at high temperature, and spheroidizing under the action of surface tension to form spherical alumina Powder, this method requires a complex and expensive flame spheroidization furnace, as well as powder separation, filtration, and collection equipment. Moreover, when this process prepares nano-scale spherical alumina powder, the fusion between particles is easy to agglomerate or fuse.

Chinese patent CN106241845A discloses a method for preparing spherical alumina by high-temperature spray pyrolysis using anhydrous gas-phase aluminum chloride as an aluminum source. The spherical alumina synthesized by this invention has high purity and uniform particle size distribution, but the synthesis of the precursor Need to use chlorine gas, and pyrolysis to generate hydrogen chloride by-product, both are corrosive and harmful gases, easily corrode equipment, pollute the environment, and the process operation is dangerous

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