METHOD OF PRODUCING REFRACTORY PRODUCTS FROM CORUNDUM CERAMICS Russian patent published in 2017 - IPC C04B35/101 C04B35/626 

FIELD: chemistry.

SUBSTANCE: moulding mixture is prepared comprising electrocorundum at a fraction ratio of 0.5÷3 mm to 0.01÷0.5 mm, equal to 4:3, finely dispersed reactive alumina, nanodispersed technological binder based on aluminium oxide and water used in place of the gate fluid, in a ratio, wt %: electrocorundum 68÷72; finely dispersed reactive alumina (FDRA) - 25÷29; the said binder 1÷6; water in the mass excess of 6÷10. Nanodisperse technological binder based on aluminium oxide, produced from the alloy D16 by chemical dispersion, is a white powder of the following composition: AlO(OH) - γ-Boehmite (98%) and an admixture of Ca(CO₃) - Calcite (2%). Dry mixing of the moulding mixture begins with fractions of electrocorundum, a mixture of reactive alumina is separately prepared with an alumina-based nanodispersed process binder, which is then added to fractionated electrocorundum, the resulting mixture is wetted with water and homogenized with continuous stirring. Moulding is carried out by vibratory casting method with the application of vibro-oscillation along the vertical and horizontal axes of the mould, the resulting preform is air-hardened, dried and calcined at temperatures of 1500-1550°C.

EFFECT: increasing thermal and mechanical characteristics with decreasing open porosity.

3 ex