Jinqiu Huang, Lizhi Zhang
The rare earth calcium thermal reduction slag (RCS) generated during the production of heavy rare earth metal contains large amounts of rare earth and fluoride compounds. In this study, rare earth elements (REEs) and fluorine in the RCS were recovered by the CaO roasting–hydrochloric acid leaching method. Firstly, the thermodynamic feasibility of converting rare earth fluoride to rare earth oxides through CaO roasting was demonstrated. The influence of roasting conditions and leaching conditions on the leaching rate of the REEs was investigated. Optimal results, a 95.48% leaching rate of the REEs, were obtained under the following conditions: a CaO dosage of 15%, a roasting temperature of 1000 ◦C, and a roasting duration of 90 min. XRD, SEM, and EDS results revealed that during the calcination process, the REEs present in fluorite (CaF2) in isomorphic form were transformed into acid-soluble rare earth oxides; furthermore, the rare earth metallic in the RCS remained unchanged even after roasting. In the leaching process, rare earth metals and rare earth oxides are efficiently extracted, while CaF2 rarely dissolves. The leaching slag contained 97.31% CaF2 with a F recovery of 96.92%.
@article{b77c4ed3-03a5-4ddc-9394-f7f78210ffc9,
title={2024 Huang Rare earth recovery from calcium reduction slag},
author={Jinqiu Huang and Lizhi Zhang},
year={2026},
language={en}
}TY - JOUR TI - 2024 Huang Rare earth recovery from calcium reduction slag AU - Jinqiu Huang AU - Lizhi Zhang PY - 2026 LA - en ER -
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