Patent ID: 8114371
Filing Date: 2012-02-14
Classification: C01B,C01P,C09C,Y10T

Abstract:
1. A process for the production of precipitated silica from olivine, comprising the following steps: providing olivine particles with a particle size below 1 mm in diameter, mixing the olivine particles and water to form an olivine/water slurry, mixing the olivine/water slurry with hydrochloric acid (HCI), at a concentration at 18 wt % or above, and at a temperature between 50-130°C, to form an olivine/acid slurry, and reacting the olivine/acid slurry for a period of time between 20-360 minutes to form a reacted mixture, wherein the reacted mixture contains coarse mineral impurities, removing the coarse mineral impurities (sand product) from the reacted mixture to obtain a mother solution comprisingprecipitated silica, separating the precipitated silica from the mother solution, mechanically treating the separated precipitated silica and optionally some water to obtain a slurry, preparing a low viscosity slurry by adding sodium aluminate or another aluminate, to 100-6000 p.p.m., and adjusting the pH to a value between 4-9, ageing the low viscosity slurry at a temperature between 50-150°C. according to product requirements, dispersing the aged silica slurry, wherein the slurry contains fine mineral impurities, removing the fine mineral impurities (sand product) from the slurry to obtain a substantially purified slurry, and drying the silica.