METHOD FOR PRODUCING WHITE MICRODISPERSED SILICA Russian patent published in 1997 - IPC

FIELD: metallurgy. SUBSTANCE: proposed process is carried out in conventional melting furnace used for production of ferrosilicon or silicon from feedstock containing SiO₂ source and solid carbon-containing reducing agent. Resulting microdispersed silica is recovered from off-gases leaving melting furnace. Solid reducing agent charged into furnace contains volatile substances in amount less than 1.25 kg per 1 kg of microdispersed silica to be produced, temperature in gaseous atmosphere of furnace above charge being maintained at above 500 C. Resulting microdispersed silica has whiteness up to 90 and reflecting capacity 65 to 90%. EFFECT: 1) good-quality product is obtained; 2) process is conducted in conventional-type furnace and uses cheap, readily available starting materials. 4 cl