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:
Jul. 22, 1980
Filed:
Oct. 23, 1978
Subhas K Sikdar, San Juan Capistrano, CA (US);
James H Moore, La Verne, CA (US);
Occidental Research Corporation, Irvine, CA (US);
Abstract
Hydrofluoric acid is recovered from fluosilicic acid by reacting fluosilicic acid with sodium hydroxide to form a first slurry having a pH of from about 11 to about 14, the first slurry containing sodium metasilicate and precipitated sodium fluoride. Sodium fluoride is recovered from the first slurry leaving a first solution which is reacted with sodium fluosilicate or fluosilicic acid or both to form a second slurry comprising silica and dissolved sodium fluoride. The reaction occurs under such conditions that the second slurry contains precipitated amorphous silica. The precipitated amorphous silica is separated from the second slurry leaving a second solution of sodium fluoride. Sodium fluoride is recovered from the second solution. Recovered sodium fluoride is reacted with sulfuric acid to produce hydrogen fluoride.