Fabrication and Characterization of High Purity of Fine Alumina from Korean Alunite and Sulfate Salts

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J. Korean Ceram. Soc. > Volume 16(1); 1979 > Article

Journal of the Korean Ceramic Society 1979;16(1): 13.

국산 명반석과 황산염으로부터 고순도의 미세한 알루미나의 제조 및 특성에 관한 연구

변수일, 이수영, 김종희

한국과학원 재료공학과

Fabrication and Characterization of High Purity of Fine Alumina from Korean Alunite and Sulfate Salts

ABSTRACT

High purity alumina has been extracted form low grade Korean alunite. Alunite ore was treated by 15% $NH_4OH$ solution, followed by 10% $H_2SO_4$ leaching and metallic impurities such as Fe and Ti were removed by solvent extraction method. Alumina prepared by the extraction process was 99.9% in purity. Hot Petroleum Drying Method has been employed for the preparation of uniformly fine alumina powder, using chemical reagent aluminum sulfate and ammonium aluminum sulfate extrated from Korea alunite. The sinterability of alumina powder prepared by Hot Petroleum Drying Method was shown to be improved in comparison with the one treated by other methods such as ball milling method, but dry pressing was difficult due to the agglomeration of calcined powder. The best slip of alumina powder prepared by Hot Petroleum Drying Method contained a lower soild content than the one treated by other methods. The alumina body formed by soild and drain casting with the former alumina powder showed a higher sintered density.