Study of alumina prepared from Iraqi kaolin

  • Dhuha M. Oudah Al-Sumaidaie
Keywords: Alumina, Iraqi kaolin, sulfuric acid, X – Ray diffraction.


The current research was conducted to report the synthesis of alumina powder from Iraqi kaolin. The kaolin was transformed to metakaolin by calcinations at temperature 800 °C for three hours. Then the calcined kaolin was treated with (1.5 M) from H2SO4 for 6 hours to form Al2(SO4)3.12H2O solution. The precipitate was dried at 80oC for 10 hours and calcinations at different temperatures for two hours. The samples which result was characterized by X–Ray diffraction (XRD) and X–Ray fluorescence (XRF). The results indicate to the crystalline hydrate aluminum sulfate for the sample that be as – synthesis and when calcinations at 600 oC transformed into aluminum sulfate phase. The phases of alumina which we obtain consisted of a gamma alumina phase which getting at calcinations 1000 oC and an alpha alumina phase at calcinations 1300 oC.
The optimum conditions for preparation alumina from Iraqi kaolin is at reaction time 6 hours, particle size 75μm and concentration acid is (1.5 M) where was the highest percentage of extraction alumina is 98.8%. The effect of calcinations temperature on the rate of extracted alumina was studying in this research and found that the alumina ratio was extracted increasing with increase the calcinations temperature.