TG/XRD/Sem Study of the Conversion of Gibbsite to (Pseudo) Boehmite

Abstract The conversion of gibbsite to (pseudo) boehmite has been studied by thermogravimetry, X‐ray diffractometry and scanning electron microscopy, supplemented by density and surface area measurements. As a reference for desired product properties, commercial pseudoboehmite, laboratory synthesized pseudoboehmite and autoclaved boehmite have also been studied. Three kinds of heating processes have been applied: in an oven, in a steam flow and under vacuum. All experiments were carried out at 220°C. Prolonged heating under vacuum resulted in a complete conversion of gibbsite to (pseudo) boehmite. The product still differs too much from commercial pseudoboehmite to be a valuable alternative. Also taking into account the manufacturing implications of vacuum heating, this process seems hardly feasible on a large scale.