Invention Grant
- Patent Title: Method of recovering rare-earth elements
- Patent Title (中): 回收稀土元素的方法
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Application No.: US14389304Application Date: 2012-12-07
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Publication No.: US09228248B2Publication Date: 2016-01-05
- Inventor: Kaoru Sugita , Yasushi Kobayashi , Yoshihiro Taguchi , Satoshi Takeda , Yuji Ota , Masashi Ojiri , Kazuhiro Oda , Hiroshi Sano
- Applicant: NIPPON LIGHT METAL COMPANY, LTD.
- Applicant Address: JP Tokyo
- Assignee: NIPPON LIGHT METAL COMPANY, LTD.
- Current Assignee: NIPPON LIGHT METAL COMPANY, LTD.
- Current Assignee Address: JP Tokyo
- Agency: Birch, Stewart, Kolasch & Birch, LLP
- Priority: JP2012-081228 20120330
- International Application: PCT/JP2012/081855 WO 20121207
- International Announcement: WO2013/145455 WO 20131003
- Main IPC: C22B59/00
- IPC: C22B59/00 ; B09B3/00 ; C01F17/00 ; C22B3/26 ; C22B3/04 ; C22B3/20 ; C22B3/44 ; C22B7/00

Abstract:
Provided is a method of recovering rare-earth elements by which rare-earth elements can be recovered efficiently from a bauxite residue serving as a raw material and containing the rare-earth elements. Specifically provided is a method of recovering rare-earth elements from a raw material, the raw material being a bauxite residue produced as a by-product in a Bayer process, the method including: using a bauxite residue having a specific surface area of 35 m2/g or more; adding, to the raw material bauxite residue, a liquid leaching agent formed of an aqueous solution of at least one kind of mineral acid selected from sulfuric acid, hydrochloric acid, nitric acid, and sulfurous acid, thereby preparing a slurry having a liquid-solid ratio of 2 to 30 and a pH of 0.5 to 2.2; subjecting the slurry to leaching treatment of the rare-earth elements under a temperature condition of room temperature to 160° C.; subjecting the slurry after the leaching treatment to solid-liquid separation, yielding a leachate; and separating and recovering the rare-earth elements from the leachate.
Public/Granted literature
- US20150086449A1 METHOD OF RECOVERING RARE-EARTH ELEMENTS Public/Granted day:2015-03-26
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