The rehydration of dehydrated products of boehmite with different textural morphology calcined at the temperature below 1000℃ is investigated by XRD and SEM.It is found that every dehydrated alumina is capable of being rehydratied and the rehydration product is boehmite. Rehydrates with different textural morphology have been produced from aluminas with different textural morphology, and the textural morphology of a rehydrate depends both on the starting alumina and on the hydrothermal conditions.The rehydration ability of aluminas is determined by their textural morphology and calcined temperature. Aluminas are directly rehydrated to rehydrate and the rehydration process is not the reverse. Process of the dehydration of the initial boehmite.
The rehydration of several α-Al2O3 has been investigated by means of XRD,DTA, TG and nitrogen adsorption methods. It is found that all α-Al2O3 samples arecapable of rehydration at 250℃ and under saturated pressure. The rehydrated products depend on starting α-Al2O3. α-Al2O3 dehydrated at above 1000℃ rehydrates toboehmite, α-Al2O3 derived from diaspore at low temperatures rehydrates to diaspore.The quantitative analysis of the rehydration of α-Al2O3 has been studied.
