Abstract
The rare earth elements (REE) are composed of 17 elements that are 15 elements of lanthanide added scandium and yttrium. REE are divided into light rare earth elements (LREE) and heavy rare earth elements (HREE). Although the supply source of LREE is distributed around the world, the supply sources are unevenly distributed. Thus, the development of a new HREE supply source is required. In this study, we focused on the weathered residual rare earth ore as a new HREE supply source. Since so far this weathered residual rare earth ore could not be treated neither by flotation nor by wet high intensity magnetic separation, it was not considered as HREE resource before. In this study, we investigated the leaching of HREE from the weathered residual rare earth ore and elucidated the effectiveness of planetary milling with sodium hydroxide as a method to enhance their recovery. For this purpose, the weathered residual rare earth ore was first grinded by planetary mill in the presence of sodium hydroxide and then leached by sulfuric acid. The influence of planetary milling on HREE recovery was investigated by assisting the leaching experiments with X-ray absorption fine structure (XAFS) in cerium and yttrium K-edge. Since yttrium was the most contained HREE in the weathered residual rare earth ore used in this study, we focused on yttrium in XAFS analysis. Results clearly showed that the recovery of HREE increased by planetary milling with sodium hydroxide. XAFS analysis revealed that a part of the yttrium in the weathered residual rare earth ore was changed to yttrium hydroxide by planetary milling with sodium hydroxide. It is supposed that all HREE were affected like yttrium due to a similar behavior observed in leaching.
Original language | English |
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Title of host publication | IMPC 2018 - 29th International Mineral Processing Congress |
Publisher | Canadian Institute of Mining, Metallurgy and Petroleum |
Pages | 2681-2689 |
Number of pages | 9 |
ISBN (Electronic) | 9787030227119 |
Publication status | Published - 2019 Jan 1 |
Event | 29th International Mineral Processing Congress, IMPC 2018 - Moscow, Russian Federation Duration: 2018 Sep 17 → 2018 Sep 21 |
Other
Other | 29th International Mineral Processing Congress, IMPC 2018 |
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Country | Russian Federation |
City | Moscow |
Period | 18/9/17 → 18/9/21 |
Keywords
- Heavy rare earth elements
- Leaching
- Planetary milling
- Weathered residual rare earth ore
- X-ray absorption fine structure analysis
ASJC Scopus subject areas
- Mechanical Engineering
- Earth-Surface Processes
- Geochemistry and Petrology
- Geotechnical Engineering and Engineering Geology