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:
Apr. 05, 1983
Filed:
Aug. 05, 1982
Applicant:
Inventors:
Dennis C Annarelli, Newtown, PA (US);
Richard E Hall, Trenton, NJ (US);
Assignee:
FMC Corporation, Philadelphia, PA (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C01B / ; C01B / ;
U.S. Cl.
CPC ...
423305 ; 423158 ; 423181 ; 423D / ; 210665 ; 210667 ; 210669 ; 210687 ;
Abstract
Either commercial yellow phosphorus or a phosphorus sludge is reacted with a slurry of calcium hydroxide in aqueous sodium hydroxide to form a sodium hypophosphite solution containing calcium and hydroxide ions. The solution is neutralized with phosphoric acid or an acid phosphate salt with the co-production of an insoluble calcium phosphate. The neutral solution is contacted with an ion exchange resin charged with sodium ions to remove any remaining calcium ions.