Patent ID: 7270794
Filing Date: 2007-09-18
Classification: C01B,C04B,C08B,C08H,Y02E,Y02W

Abstract:
1. A process for production of amorphous silica from siliceous plant matter containing water insoluble metallic compounds comprising the steps of: soaking said siliceous plant matter in an aqueous solution comprising citric acid wherein said citric acid is present in an amount which solubilizes at least some of said water insoluble metallic compounds; after said step of soaking said siliceous plant matter, separating the aqueous solution from said siliceous plant matter; and, after said step of separating the aqueous solution from the siliceous plant matter, thermally pyrolyzing said siliceous plant matter in the presence of oxygen at a temperature wherein the resulting silica is comprised of silica of amorphous form.