RAW MIX AND METHOD OF MANUFACTURING HEAT- INSULATING GRANULAR MATERIAL Russian patent published in 2001 - IPC

FIELD: manufacture of heat-insulating materials. SUBSTANCE: raw components includes waste which results from processing black shales. Raw mix comprises, wt %: 59.06; SiO₂, 0.95; TiO₂, 16.55; Al₂O₃, 2.75; Fe₂O₃, 1.83; MgO, 3.15; K₂O, 2.57; Na₂O, 1.45; P₂O₅, 0.21; CO₂, 2.57; FeO, 4.61; MnO, 0.09; p.p.p., 5.20; C_org, 1.26 (55.2-56.2 wt %); microsilica resulting from crystalline silicon production (6.7-7.7 wt %) and liquid glass bond (37.1 wt %). Granules are molded from mix by plastic method and are fired using two-step mode, namely temperature rises up to 400 C at rate of 133 C/min, granules are kept at given temperature for 30 minutes, temperature rises up to 1175 C at rate of 5 C/min, and granules are kept at given temperature for 10 minutes. The resulting temperature has bulk density of 143-151 kg/cubic m. EFFECT: reduced average temperature and reduced firing temperature. 3 cl, 1 ex, 1 tbl