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. 07, 1983
Filed:
Dec. 14, 1981
Applicant:
Inventors:
Assignee:
Stamicarbon, B.V., Geleen, NL;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C01F / ; C01F / ; C22B / ; C01B / ;
U.S. Cl.
CPC ...
423 211 ; 423 215 ; 423167 ; 423319 ; 423320 ;
Abstract
Recovery of yttrium, lanthanides and radium free calcium sulphate in a phosphoric acid process by digesting phosphate rock with an excess of phosphoric acid in the presence of more than about 5 wt.% of SO.sub.4 -ions calculated to the amount of phosphate rock, separating out the insoluble residue and recovering yttrium and lanthanides therefrom, precipitating calcium sulphate from the remaining solution with sulphuric acid and separating this calcium sulphate from the resulting phosphoric acid solution.