| 摘要 |
The invention relates to a hyperstoichiometric MgAl2O4 spinel, a process for the synthesis thereof and to the use of said spinel. For the synthesis of the spinel, which can be used, in particular, for a high-temperature crucible, a precursor mixture is prepared from intimately mixed oxides of the respective metals of the spinel, with the magnesium being added to the precursor mixture hyperstoichiometrically. Prior to the spinel formation, one to five percent by mass, relative to the metal oxides of the spinel, of a reactive salt which comprises fluorine and/or boron is/are added to said precursor mixture, and the thus doped precursor mixture is mixed for 0,5 to 3 hours. Finally, for the synthsis of the Mg(1+x)Al2O4 spinel, which is hyperstoichiometric with regard to the magnesium, the mixed precursor mixture is heated at a temperature of between 1150.degree.C and 1400.degree.C for between 0,5 and 4 hours.
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