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      Permanent link:
      https://www.ias.ac.in/article/fulltext/boms/023/04/0301-0304

    • Keywords

       

      Aluminium hydroxide; corundum; thermal transformation

    • Abstract

       

      Aluminium hydroxides have been precipitated from various aluminium salts and the differences in their thermal behaviour have been investigated. Pseudoboehmite derived from the nitrate, sulfate and chloride all form γ-Al2O3 at ∼ 400°C but the formation of α-A12O3 at 1200°C occurs more readily in the material derived from the sulfate. This contains a higher concentration of anionic impurities related to differences in the solubility of the original aluminium salts. The sulfate is retained in the gel to higher temperatures at which its eventual decomposition may lead to the formation of a reactive pore structure which facilitates the nucleation of α-A12O3.

    • Author Affiliations

       

      J Temuujin1 Ts Jadambaa2 K J D Mackenzie3 P Angerer4 F Porte5 F Riley5

      1. Institute of Chemistry and Chemical Technology, Mongolian Academy of Sciences, Ulaanbaatar 51, Mongolia
      2. Department of Chemical Technology, Mongolian Technical University, Ulaanbaatar 46, Mongolia
      3. Department of Materials, University of Oxford, Oxford - OX1 3PH, UK
      4. Institute of Materials, German Aerospace Centre, Köln, Germany
      5. Department of Materials, University of Leeds, Leeds - LS2 9JT, UK
    • Dates

       

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