Z. Jaworskagalas et al., MORPHOLOGICAL AND PHASE-CHANGES OF TRANSITION ALUMINAS DURING THEIR REHYDRATION, Journal of Materials Science, 28(8), 1993, pp. 2075-2078
Transition aluminas (TA), obtained by fast (0.5-1 s) calcination of gi
bbsite in the temperature range 375-600-degrees-C, were rehydrated at
20, 70 and 90-degrees-C. The rehydration process was investigated usin
g transmission electron microscopy, X-ray, and thermogravimetric-diffe
rential thermal analysis. During rehydration, the TAs react yielding a
luminium hydroxides: pseudoboehmite, boehmite, and bayerite. The phase
-composition changes are accompanied by changes in particle morphology
. Using transmission electron microscopy, six stages of rehydration we
re found, with characteristic morphological changes occurring. The cha
nges are responsible for connecting the particles into stable grains d
uring the process of obtaining catalyst carriers or adsorbents from TA
.