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:
May. 18, 1982
Filed:
Mar. 27, 1981
Dennis H Michalski, Lakeland, FL (US);
International Minerals & Chemical Corp., Terre Haute, IN (US);
Abstract
An improved method of defluorinating wet process phosphoric acid using silica-containing dust which is obtained as a waste product collected from the fumes of a submerged arc furnace process of making silicon metal alloys. The silica-containing dust has a very small particle size, and contains at least about 60% by weight silica (SiO.sub.2), and has a very high surface/mass ratio which increases the efficiency of the defluorination reaction. The defluorination reaction using this silica-containing fume takes less time than required using prior methods employing diatomaceous earth as the silica source. The presence of silicon metal alloy particles in the dust are thought to have a catalytic effect on the defluorination reaction.