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:
Jan. 10, 2012
Filed:
Jul. 11, 2008
Mitsuo Abumiya, Tokyo, JP;
Yusuke Sato, Akita, JP;
Hironobu Mikami, Akita, JP;
Masami Oouchi, Tokyo, JP;
Tetsuo Fujita, Tokyo, JP;
Masayoshi Matsumoto, Tokyo, JP;
Mitsuo Abumiya, Tokyo, JP;
Yusuke Sato, Akita, JP;
Hironobu Mikami, Akita, JP;
Masami Oouchi, Tokyo, JP;
Tetsuo Fujita, Tokyo, JP;
Masayoshi Matsumoto, Tokyo, JP;
Dowa Metals and Mining Co., Ltd., Tokyo, JP;
Abstract
Provided is a method of easily producing easily-filterable and stable scorodite that meets the leaching standard (conformance to Japanese Environmental Agency Notice 13) with excellent reproducibility and without using complex operations, when processing arsenic that is included in non-ferrous smelting intermediates, and particularly when processing arsenic in the form of a sulfide. Scorodite is produced by a leaching step of leaching arsenic from a non-ferrous melting intermediate containing arsenic in the weakly acid region, a solution adjusting step of oxidizing trivalent arsenic to pentavalent arsenic by adding an oxidizing agent to the leaching solution, and a crystallizing step of converting the arsenic in the adjusted solution to scorodite crystals.