Title:
EXTRACTION OF METALS FROM METALLIC COMPOUNDS
Document Type and Number:
WIPO Patent Application WO/2014/113742
Kind Code:
A3
Abstract:
Methods for the extraction of metals such as rare earth metals and thorium from metal compounds and solutions. The methods may include the selective precipitation of rare earth elements from pregnant liquor solutions as rare earth oxalates. The rare earth oxalates are converted to rare earth carbonates in a metathesis reaction before being digested in an acid and treated for the extraction of thorium. A two-step extraction method may be applied to precipitate thorium as thorium hydroxide under controlled pH conditions such that pure thorium precipitate is recovered from a first step and a thorium-free rare earth solution is recovered at the subsequent step. The resulting rare earth solutions are of extremely high purity and may be processed directly in a solvent extraction circuit for the separation of rare earth elements, or may be processed for the direct production of a 99.9% bulk rare earth hydroxide/oxide concentrate.
Inventors:
KASAINI HENRY (US)
Application Number:
PCT/US2014/012153
Publication Date:
November 12, 2015
Filing Date:
January 18, 2014
Export Citation:
Assignee:
RARE ELEMENT RESOURCES LTD (US)
International Classes:
C22B3/06
Domestic Patent References:
| WO2012149642A1 | 2012-11-08 |
Foreign References:
| US3740199A | 1973-06-19 | |||
| US3378352A | 1968-04-16 | |||
| US2849286A | 1958-08-26 | |||
| US2988421A | 1961-06-13 | |||
| US4461748A | 1984-07-24 | |||
| US3087948A | 1963-04-30 |
Other References:
See also references of EP 2946024A4
Attorney, Agent or Firm:
DOCKERY, David, F. (8055 East Tufts AvenueSuite 45, Denver CO, US)
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