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:
Nov. 04, 2003
Filed:
May. 07, 2002
Mitsui Mining & Smelting Co., Ltd., Tokyo, JP;
Abstract
An object of the present invention is to provide a method for preventing concentration of a radioactive substance in a generated extraction residue in a method of producing tantalum, niobium, or a similar substance including collecting and refining a raw material containing the substances through a fluoridation process by use of a hydrofluoric acid-containing solution. The object can be attained by employing an ingredient-regulated raw material prepared from an ore or a concentrate and, as an additive, a substance insoluble to hydrofluoric acid or a mixed acid containing hydrofluoric acid as an essential component; or by increasing the amount of the extraction residue through addition of the insoluble substance to a solvent during the fluoridation process, to thereby reduce the relative radioactive substance content to an arbitrary value.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile