The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 14, 1984
Filed:
May. 11, 1983
Ruud Spijker, Heemskerk, NL;
Unie van Kunstmestfabrieken B.V., Utrecht, NL;
Abstract
Process for preparing pure silicon dioxide from a hexafluorosilicic acid solution by controllably and vigorously admixing, stirring or blending a hexafluorosilicic acid solution with a quantity of ammonium hydroxide solution amounting to about 40 to about 75 percent by weight of the quantity stoichiometrically required for the converting hexafluorosilicic acid to ammonium fluoride and silicon dioxide to thereby form a reaction mixture and a precipitate therein; separating out this precipitate; treating the precipitate-free liquid with ammonium hydroxide and then recovering the pure silicon dioxide. The silicon dioxide is pure enough to be useful as a catalyst support or as a substitute for quartz.