Patent ID: 8110166
Filing Date: 2012-02-07
Classification: C01B,C01P

Abstract:
1. A process for producing silica from olivine, the silica in powder form with controlled specific surface area, the process comprising: (a) providing olivine particles of grain size less than or equal to about 1 mm; (b) mixing the olivine particles and a mineral acid solution in a leaching reaction at greater than or equal to about 50° C. and less than or equal to about 110° C., and reacting for greater than or equal to about 10 minutes and less than or equal to about 600 minutes in order to obtain silica with a controlled Brunauer, Emmett, and Teller (“BET”) specific surface area greater than or equal to about 50 m (c) optionally separating at least part of undissolved olivine particles and other minerals from a resulting silica slurry; (d) filtering the resulting silica slurry to separate dissolved metal salts from the silica and washing a resulting silica filter cake; (e) slurrying the resulting silica filter cake in an aqueous solution at a pH greater than or equal to about 1 and less than or equal to about 5 and subjecting the slurried silica filter cake to dispersion in order to obtain a low viscosity slurry having a viscosity greater than or equal to about 1 mPa-sec and less than or equal to about 200 mPa-sec, with a solid content greater than or equal to about 10% and less than or equal to about 30%; (f) separating mineral impurities from the low viscosity silica slurry; (g) optionally adjusting a pH value of the low viscosity silica slurry; and (h) drying the low viscosity silica slurry.