A new finding and technology for selective separation of different REEs from CaO-SiO2-CaF2-P2O5-Fe3O4-RE2O3 system

Lan, Xi; Gao, Jintao; Xue, Kairong; Xu, Huanhuan; Zhang, Guo

doi:10.1016/j.seppur.2022.121121

Cited by 7 publications

(2 citation statements)

References 30 publications

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“…Currently, the utilization of Bayan Obo tailings is still in the laboratory research stage. The main treatment options include physical separation, as well as hydrometallurgical and pyrometallurgical treatments [6,15,20,[22][23][24][25][26][27]. In a typical Bayan Obo tailing treatment process, physical operations such as grinding, screening, magnetic force, flotation, gravity separation, and density-based separation are used as pretreatments to release and concentrate metallic parts (MFs) and non-metallic fractions (NMFs) [28].…”

Section: Introductionmentioning

confidence: 99%

The Process Mineralogical Characterization of Bayan Obo Rare-Earth Tailings and Density Functional Theory Study of the Occurrence State of Sc

Shao,

Du,

Deng

et al. 2023

Minerals

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As Bayan Obo rare-earth tailings, which are generated after the production of mineral products with the raw ore from different mining areas, are considered secondary resources rich in valuable elements such as F, Fe, REE, and Nb, an effective method is urgently needed to recover such valuable elements for resource recycling and environmental conservation. A mineralogical analysis can enable process diagnosis, design, and optimization and is the key to comprehensively utilizing valuable elements. Hence, detailed mineralogical characterization is necessary as a starting point to develop a feasible processing flowsheet. In this study, various detection methods, namely inductively coupled plasma-optical emission spectrometry (ICP), X-ray Fluorescence Spectrometer (XRF), X-ray powder diffractometer (XRD), scanning electron microscopy system with an energy dispersive spectrometer (SEM-EDS), mineral liberation analysis (MLA), and electron probe microanalysis (EPMA), were applied to conduct detailed mineralogical characterization of Bayan Obo rare-earth tailings, and the occurrence state of Sc in the main Sc-bearing minerals was studied using density functional theory (DFT). The results showed that Fe mainly occurs in hematite, riebeckite, ankerite, siderite, and pyrite, with contents of 50.15 wt%, 27.94 wt%, 8.34 wt%, 4.92 wt%, and 5.59 wt%, respectively. Nearly all F occurs in 26.8 wt% fluorite. The main rare-earth minerals are bastnasite, apatite, and monazite (La), with contents of 5.0%, 5.0%, and 1.6% in Bayan Obo rare-earth tailings, respectively. Notably, 48.47%, 21.70%, 10.34%, and 10.28% of niobium element occurs in nioboaeschynite, pyrochlore, dingdaohengite, and ilmenorutile, respectively. Scandium was detected in five minerals, namely aegirine, riebeckite, monazite, ilmenorutile, and niobite, with average contents of 0.04 wt%, 0.22 wt%, 0.06 wt%, 0.06 wt%, and 1.58 wt%, respectively. According to the DFT analysis, the state of Sc in aegirine is different from that in riebeckite. Scandium in aegirine mainly substitutes Fe or enters the interstitial lattice site, while Sc in riebeckite tends to replace Fe. Based on these results, a process for recovering valuable elements from tailings is proposed.

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Section: Introductionmentioning

confidence: 99%

The Process Mineralogical Characterization of Bayan Obo Rare-Earth Tailings and Density Functional Theory Study of the Occurrence State of Sc

Shao,

Du,

Deng

et al. 2023

Minerals

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“…), interest in silicon doped with rare-earth elements has recently increased due to their essential role in the formation of silicon properties [10][11][12]. The world practice shows that during the technological processing of semiconductor wafers in the production of various structures and devices, various interactions of defects with each other occur, which are determined primarily by uncontrolled and specially introduced point defects characterized by maximum mobility in the lattice [13][14][15][16]. Therefore, the processes of defect structure formation of the crystal must be related to them.…”

Section: Introductionmentioning

confidence: 99%

Capacitive Spectroscopy of Deep Levels in Silicon with Samarium Impurity

Utamuradova,

Daliev,

Daliev

et al. 2023

East Eur. J. Phys.

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The effect of thermal treatment on the behavior of samarium atoms introduced into silicon during the growth process was studied using the method of transient capacitive deep-level spectroscopy (DLTS). It has been shown that various high-temperature treatments lead to the activation of samarium atoms in the bulk of n-Si and the formation of deep levels. The energy spectrum of deep levels arising during heat treatments has been determined. The dependence of the efficiency of formation of these levels in n‑Si<Sm> on the processing temperature has been studied. It was found that the higher the content of samarium atoms in the bulk of silicon at the same high-temperature treatment temperature, the higher the concentration of the deep level EC–0.39 eV. From this, we can conclude that the EC–0.39 eV level is associated with the activation of samarium atoms in the n-Si<Sm> volume.

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