METHOD OF PRODUCTION OF SILICA FROM FERROALLOY PRODUCTION WASTE Russian patent published in 2004 - IPC

FIELD: inorganic materials technology.

SUBSTANCE: invention aims to produce silica by chemically processing ferroalloy production waste. Waste fraction 0.002-0.02 mm is treated for 1.5-2 h with alkali solution having concentration 50-150 g Na₂O/l at temperature 100-120^оС and liquid-to-solids ratio 3:1. Thus obtained mixture is cooled to temperature below 100^оС and filtered. Liquid phase is depurated to remove impurities by passage over magnetic field with intensity 500-1500 kA/m and velocity 2-3 m/s. Depurated liquid phase is heated to 50-60^оС, mineral acid is added to pH 5-6, filtered, and resulting precipitate is washed and dried.

EFFECT: increased yield of valuable produce, simplified process, reduced expenses, reduced process time, and improved purity of finished product.

2 cl, 2 tbl