Method of recovering rare-earth elements
US9228248B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 7, 2012 |
| Grant date | Jan 5, 2016 |
| Priority date | — |
| Expiry date | Dec 7, 2032 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W30/50
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.