Prosess for fremstilling av utfelt silika fra olivin

Process for the production of precipitated silica from olivine including the following steps: providing olivine particles with a particle size preferably below 1 mm in diameter, preferably mixing olivine and water to form an olivine/water slurry, mixing the olivine/water slurry with hydrochloric acid (HCl), preferably at a Concentration at 18 wt % or above, and at a temperature preferably between 50 -130° C., and reacting for a period of time, preferably between 20-360 minutes, removal of coarse mineral impurities (sand product), separation of precipitated silica from mother solution, mechanical treatment of the separated precipitated silica and optionally some water to obtain a slurry, preparation of a low viscosity slurry by adding sodium aluminate or another suitable aluminate, preferably to 100-6000 p.p.m., and adjusting the pH, preferably to values between 4-9 ageing at a temperature between 50-150° C. according to product requirements dispersion of silica slurry removal of fine mineral impurities (sand product) drying of the silica.