MAS NMR Evidence for the Presence of Silicon in the Alumina Spinel from Thermally Transformed Kaolinite
- 1 November 1996
- journal article
- Published by Wiley in Journal of the American Ceramic Society
- Vol. 79 (11) , 2980-2982
Abstract
Georgia kaolinite dehydroxylated at 950°C for 24 h, then leached with KOH at 90°C for 1 h, shows a well‐resolved 29 Si MAS NMR resonance at −77.5 ppm, within 2 ppm of the calculated position for Si incorporated in γ‐alumina spinel. From a knowledge of the total SiO 2 in the leached sample and its partitioning between the spinel and residual grain boundary phases, a maximum of 3.9 wt% is estimated to be present in the spinel.Keywords
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