| China clay-alumina mixtures were sintered at 1400°-
16000C for 2-12 hrs. Four different sources of alumina and
a variety of mineralisers were evaluated. Mullitization
from 40 to 100 per cent takes place, depending upon the
fineness of alumina, clay/alumina ratio, sintering temperature,
and time and mineralisers. Finer alumina and
a clay/alumina ratio of 57/43 are preferable. Transition
metal oxides were generally more effective and the optimum
amount was about 1 per cent. Porosity of the sintered
products varied between 4 and 40 per cent. |
