NEW INVESTIGATIONS ON THE THERMAL REACTIONS OF GIBBSITE

Ⅰ.INTRODUCTIONConsiderable investigations on the phase transitions of gibbsite underhydrothermal conditions have established that gibbsite dehydrates to boehmiteand the latter,in turn,to γ-alumina.Nevertheless,a complete agreement hasnot yet been reached on the various changes that take place on heating gibbsitein air.The present work started from an intention to search for the cause ofthe disagreement.Both natural and artificial specimens of hydrous alumina were used inthe experiment.Hydrous alumina gels were prepared in connection with anintention to investigate the effect of the degree of crystallinity on the positionof endotherms on the thermograms of the hydrates.