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. 18, 2000
Filed:
Feb. 09, 1999
Applicant:
Inventors:
Assignee:
Osram Sylvania Inc., Danvers, MA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C01G / ; C01F / ; C22B / ; C01B / ;
U.S. Cl.
CPC ...
423 53 ; 423155 ; 4231573 ; 4231575 ;
Abstract
A method for purifying a phosphorus containing scheelite ore is described wherein the calcite phase is selectively dissolved prior to dissolution of the apatite phase. Selective dissolution of the calcite produces several benefits: (1) a usable calcium solution, (2) enhanced apatite dissolution, and (3) lower volumes of toxic acid solution for disposal.