Preparation of nanosized γ-Al2O3 from coal gangue

This paper reports the preparation of nanosized γ-Al₂O₃ from coal gangue. The process consist of five stages: calcined coal gangue to prepare metakaolin, alkaline-leaching and alkaline-fusion the metakaolin, preparation of γ-AO(OH), and γ-AO(OH) transferred to γ-Al₂O₃ with high temperature heat treatment. The samples were characterized by different scanning calorimetries and thermogravimetry (DSC-TGA), X-ray diffractometer (XRD), X-ray fluorescence spectrometer (XRF) Scanning electron microscopy (SEM) and BET surface area measurements. The results indicated that the prepared γ-Al₂O₃ were lightweight, non-crystallinne structure, white porous solids. The particle size is about 20-50 nm, γ-Al₂O₃ particles and particles form a three-dimensional network structure, the diameters of the pores inside the particles are between 2 and 10 nm.