MANUFACTURE METHOD OF FLAKE ALUMINUM OXIDE USING MICROWAVE

摘要

A method for manufacturing flake-like aluminum oxide using microwaves is provided to produce flake-like aluminum oxide powder of a macro-crystal structure having a good aspect ratio and suppress the formation of multi crystals and twin crystals. A method for manufacturing flake-like aluminum oxide using microwaves includes the steps of: (1) grinding an alumina hydrate or aluminum salt as a starting material, sorting out the particles having a particle size of 5-50 micron, and pre-treating the starting material; (2) heating the pre-treated starting material to prepare a transitional alumina; (3) selecting one or two or more, as a molten salt, selected from calcium carbonate, sodium chloride, potassium carbonate, potassium sulfate, and sodium sulfate, selecting one or two or more, as an additive, selected from LiF2, AlF3, NaF, P2(SO4)3, NaPF6, and K2TiF6, mixing the molten salt with the additive, and dispersing and grinding the mixture in the transitional alumina; (4) melt-synthesizing a flake-like aluminum oxide from the dispersed and ground mixture using microwave as a heating source; (5) precipitating the molten salt and additive from the synthesized aluminum oxide; (6) removing foreign substances such as the remaining additive adhered to the surfaces of the recovered flake-like aluminum oxide crystal particles. Further, the alumina hydrate is Al(OH)3, and the aluminum salt is one selected from Al2(SO4)3.4-18H2O, Al(NO3)3.9H2O or Al(CHOO)3OH.