|
| Recovery of Rare Earth Elements from Molten Salt Electrolytic Slag via Magnetic Separation, Roasting and Acid Leaching |
|
Received:January 31, 2023
Revised:February 06, 2023
Accepted:February 13, 2023
Published Online:April 20, 2023
|
| View Full Text View/Add Comment Download reader |
| DOI：doi：10.3969/j.issn.1007-7545.2023.05.008 |
| KeyWord:rare earth recovery; molten salt electrolysis slag; roasting; magnetic separation; mineral phase conversion |
| Author | Institution |
| YAN Rong-wei |
中国科学技术大学稀土学院;中国科学院赣江创新研究院资源与生态环境研究所 |
| LI Hui-quan |
中国科学技术大学稀土学院;中国科学院赣江创新研究院资源与生态环境研究所;中科院绿色过程与工程重点实验室，战略金属资源绿色循环利用国家工程研究中心，中国科学院过程工程研究所;中国科学院大学化学工程学院 |
| XING Peng |
中科院绿色过程与工程重点实验室，战略金属资源绿色循环利用国家工程研究中心，中国科学院过程工程研究所 |
| YE Chun-lin |
中国南方稀土集团有限公司 |
| WANG Chen-ye |
中科院绿色过程与工程重点实验室，战略金属资源绿色循环利用国家工程研究中心，中国科学院过程工程研究所 |
| ZHU Gan-yu |
中科院绿色过程与工程重点实验室，战略金属资源绿色循环利用国家工程研究中心，中国科学院过程工程研究所 |
| ZHONG Li-qin |
中国南方稀土集团有限公司 |
|
| Hits: 1566 |
| Download times: 1808 |
| Abstract: |
| A process of magnetic separation, roasting, and leaching was proposed to extract rare earth elements from molten salt electrolytic slag. The results of the full process examination show that iron removal efficiency of the raw material is 45.59% under the optimal magnetic separation strength of 100 mT. The optimal process conditions of the non-magnetic phase in the roasting and leaching process include roasting temperature of 750 ℃, CaO dosage of 30%, leaching temperature of 25 ℃, and HCl concentration of 3 mol/L. The total recoveries of Nd and Pr reach 95.98% and 96.15% respectively in the whole process. The in-situ XRD combined with thermodynamic analysis was used to clarify the mineral phase transformation law during roasting. It is found that during the roasting process, REF3 reacts with CaO to form REO, while CaCl2 reacts with CaO and REF3 to form REOCl, which further transforms into REO. Increasing roasting temperature can reduce the formation of insoluble phase REOCl and promote transformation of REF3 to soluble phase REO, thus increasing the leaching efficiency of rare earth. This study can provide theoretical guidance for the recovery of rare earth. |
| Close |