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:
May. 15, 2007
Filed:
Sep. 07, 2004
Viktor Stoller, Bad Harzburg, DE;
Juliane Meese-marktscheffel, Goslar, DE;
Armin Olbrich, Seesen, DE;
Michael Erb, Salzgitter, DE;
Gerhard Gille, Goslar, DE;
Viktor Stoller, Bad Harzburg, DE;
Juliane Meese-Marktscheffel, Goslar, DE;
Armin Olbrich, Seesen, DE;
Michael Erb, Salzgitter, DE;
Gerhard Gille, Goslar, DE;
H. C. Starck GmbH & Co. KG, , DE;
Abstract
A process for reducing the content of alkali metal impurities (e.g., potassium) in ammonium metallate solutions is described. The process involves subjecting a feed solution containing ammonium metallate and alkali metal impurities to membrane filtration. The membrane filtration results in the formation of a retentate having a reduced level alkali metal relative to the feed solution, and a permeate containing substantially the balance of alkali metal. The permeate may also be further treated, to remove alkali metal there from, by passage through a cation exchange column, thereby forming a cation exchange treated permeate that may be combined with the retentate of the membrane filtration step.