Title:
METHOD FOR RECOVERING USEFUL ELEMENT FROM RARE EARTH - TRANSITION METAL ALLOY SCRAP
Document Type and Number:
WIPO Patent Application WO/2003/078671
Kind Code:
A1
Abstract:
A method for recovering useful elements from a rare earth - transition metal alloy scrap, which comprises a step (A) of immersing the rare earth - transition metal alloy scrap in an aqueous solution of an ammonium salt of a mineral acid, a step (B) of passing a gas containing oxygen through said solution, to thereby oxidize the scrap and produce a precipitate comprising a powder containing oxides, hydroxides and the like as main components, a step (C) of separating said precipitate, and a step (D) of recovering rare earth elements from the separated precipitate. The method allows the economical and safe recovery of useful elements such as rare earth elements without the consumption of a large amount of acid and the need for the advance selection with respect to the form of a scrap or a preliminary crushing step.
Inventors:
OHRAI HIROSHI (JP)
YOKOI HIDEO (JP)
YOKOI HIDEO (JP)
Application Number:
PCT/JP2003/003238
Publication Date:
September 25, 2003
Filing Date:
March 18, 2003
Export Citation:
Assignee:
SANTOKU CORP (JP)
OHRAI HIROSHI (JP)
YOKOI HIDEO (JP)
OHRAI HIROSHI (JP)
YOKOI HIDEO (JP)
International Classes:
C01F17/206; C22B7/00; C22B59/00; (IPC1-7): C22B59/00; C22B3/00; C22B3/04; C22B3/44; C22B7/00; C01F17/00; C01G51/00
Foreign References:
| JPS62187112A | 1987-08-15 | |||
| JPS634028A | 1988-01-09 | |||
| JPH0514777B2 | 1993-02-25 | |||
| JP7072312B2 | ||||
| EP0790321A1 | 1997-08-20 | |||
| JPH0790394A | 1995-04-04 |
Attorney, Agent or Firm:
Sakai, Hajime (7 CKojimachi 5-chome Chiyoda-ku, Tokyo, JP)
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