Thermally Activated Al(OH)3: Part I—Morphology and Porosity Evaluation

Aluminum hydroxide is an essential material for the industrial production of ceramics (especially insulators and refractories), desiccants, absorbents, flame retardants, filers plastics rubbers, catalysts, various construction materials. The calcination process Al(OH)3 first induces dehydration and, finally, results in α-Al2O3 formation. Nevertheless, this contains intermediary steps has been proven to be complicated due development numerous transitional alumina. Each step investigation vital entire because final properties materials based on aluminum trihydroxide are determined by their phase composition, morphology, porosity, etc. In paper, five dried, milled, size-classified specimens were thermally treated at 260, 300, 400 °C; then, they studied order identify effects temperature properties, such as particle specific surface area, pore size, distribution. major oxide compounds identified all samples characteristic bauxite—namely, Al2O3 * 3H2O, SiO2, Fe2O3, Na2O, CaO. Particles with smaller sizes (<10 µm = 76.28%) presented highest humidity content (~5 wt.%), while registered a mass loss ~25 wt.% ignition °C. particles had shapes hexagonal or quasi-hexagonal platelets resulted large spherulitic concretions. obtained suggest that ceramic powders calcined °C should used applications adsorbents catalysts high area about 200–240 m2/g small width (3–3.5 nm).