Preparation of a nanodispersed aluminum hydroxide-based binder used for the production of refractory corundum ceramics

The preparation of the rehydrated metastable ρ phase of alumina with a large specific surface based on domestic aluminum hydroxide is studied in order to develop a method for producing a calcium-free binder (analog of the α-Bond binder produced abroad by the Almatis company for the preparation of corundum refractories with a high thermal stability). Three types of aluminum hydroxide specimens from three enterprises, i.e., obtained from different raw materials and by different methods, are studied. The specimens with a specific surface smaller than ~240 m2/g represented by the η-, χ-, ν-, θ-, ρ,and δ-Al2O3 structural modifications are isolated due to “impact” dehydration. The dehydration of Al(OH)3 under reduced pressures is studied. The product with a phase composition closest to that of the α-Bond binder is obtained under an impact thermal load at 600°C and a rarefaction of 0.01 MPa.