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:
Jun. 01, 1993
Filed:
Apr. 30, 1990
Applicant:
Inventors:
Sharon D Fritts, Youngstown, NY (US);
Tilak V Bommaraju, Grand Island, NY (US);
Walter W Ruthel, Grand Island, NY (US);
Assignee:
Occidental Chemical Corporation, Niagara Falls, NY (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C25B / ; C25B / ; C25B / ;
U.S. Cl.
CPC ...
204 95 ; 204 86 ; 204128 ; 204242 ; 210726 ; 210 95 ; 423305 ; 423490 ; 423555 ;
Abstract
Disclosed is a method of removing fluoride and sulfate ions from an aqueous stream by adding calcium chloride and a source of phosphate ion to the stream to form a first precipitate of calcium sulfate and a compound of calcium, fluoride, and phosphate. The precipitate is separated from the aqueous stream and a source of carbonate ion is added to the stream to form a second precipitate which contains fluoride and calcium. The second precipitate is then separated from the aqueous stream.