Leaching Behaviors of Calcium and Aluminum from an Ionic Type Rare Earth Ore Using MgSO4 as Leaching Agent

He, Qiang; Qiu, Jiang; Rao, Minglu; Xiao, Yanfei

doi:10.3390/min11070716

Cited by 9 publications

(3 citation statements)

References 30 publications

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“…However, according to EPMA analysis (Figure 2), the Sc association with Mg in RMF is low. He Q. et al [45] and Xiao Y. et al [46,47] showed that the ion-exchangeable phase of REEs could be easily extracted by MgSO4 solutions. Furthermore, it was revealed that Sc leaching could be performed even at pH 4 and higher using MgSO4 solution with the concentration 12-36 g L −1 that will be shown in our future article.…”

Section: Study Of the Kinetics And Mechanism Of Sc Leaching From Rmfmentioning

confidence: 99%

Selective Scandium (Sc) Extraction from Bauxite Residue (Red Mud) Obtained by Alkali Fusion-Leaching Method

et al. 2022

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Bauxite residue, known as “red mud,” is a potential raw material for extracting rare-earth elements (REEs). The main REEs (Sc, Y, La, Ce, Nd, Nb, and Sm) from the raw bauxite are concentrated in RM after the Bayer leaching process. The earlier worldwide studies were focused on the scandium (Sc) extraction from RM by concentrated acids to enhance the extraction degree. This leads to the dissolution of major oxides (Fe2O3 and Al2O3) from RM. This article studies the possibility of selective Sc extraction from alkali fusion red mud (RMF) by diluted nitric acid (HNO3) leaching at pH ≥ 2 to prevent co-dissolution of Fe2O3. RMF samples were analyzed by X-ray fluorescence spectrometry (XRF), X-ray diffraction (XRD), electron probe microanalysis (EPMA), and inductively coupled plasma mass spectrometry (ICP-MS). It was revealed that Sc concentration in RMF can reach up to 140–150 mg kg−1. Sc extraction was 71.2% at RMF leaching by HNO3 at pH 2 and 80 °C during 90 min. The leaching solution contained 8 mg L−1 Sc and a high amount of other REEs in the presence of relatively low concentrations of impurity elements such as Fe, Al, Ti, Ca, etc. The kinetic analysis of experimental data by the shrinking core model showed that Sc leaching process is limited by the interfacial diffusion and the diffusion through the product layer. The apparent activation energy (Ea) was 19.5 kJ/mol. The linear dependence of Sc extraction on magnesium (Mg) extraction was revealed. According to EPMA of RMF, Sc is associated with iron minerals rather than Mg. This allows us to conclude that Mg acts as a leaching agent for the extraction of Sc presented in the RMF in an ion-exchangeable phase.

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Section: Study Of the Kinetics And Mechanism Of Sc Leaching From Rmfmentioning

confidence: 99%

Selective Scandium (Sc) Extraction from Bauxite Residue (Red Mud) Obtained by Alkali Fusion-Leaching Method

et al. 2022

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“…However, in a reverse drop process, due to the large amount of urea and the high pH, the free OH À may promote the formation of the precipitate. [12] Therefore, the reaction and formation of yttrium carbonate in a positive drop reaction is less and slower than that in the reverse drop process, as a result, the particle size and size distribution of yttrium carbonate obtained from a positive drop reaction is larger and more uniform than that from a reverse drop route. Therefore, positive mixing approach is adopted for the following investigations.…”

Section: Effects Of Synthetic Conditions On Yttrium Carbonatementioning

confidence: 99%

Size‐Controllable Synthesis of Submicro Spherical Yttrium Carbonate and In Situ Doping of Europium to Prepare Y₂O₃: Eu³⁺ Phosphor

Zhou

Zhang

Murali

et al. 2023

Physica Status Solidi (a)

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Herein, size‐controllable spherical yttrium carbonate powders with D50 in range from 225 to 743 nm are synthesized from Y(NO3)3·6H2O and urea. With the rise of the concentration ratio of urea/Y3+, temperature, and extension of aging time, diameter of yttrium carbonate spheres increases. When the urea/Y3+ is 40: 1 and ages for 4 h at 90 °C, the D50 of synthesized powder, which has been determined as Y(OH)CO3·1.3H2O, has the largest D50 of 743 nm with (D90–D10)/2D50 of 0.22. After decomposition, the D50 of formed Y2O3 decreases to 632 nm, the (D90–D10)/2D50 is 0.24, and the D50 of Y2O3 is in the range of 126–632 nm. Then, 6 mol. % Eu3+ is homogeneously doped into Y(OH)CO3·1.3H2O and Y2O3: Eu3+ spherical powder is obtained after roasting, which exhibits a strong emission peak at 613 nm. The developed synthetic method and the obtained size‐controllable spherical Y(OH)CO3·1.3H2O, Y2O3, and Y2O3: Eu3+ with a uniform size distribution own various potential applications.

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“…Therefore, the use of chloride or nitrate medium and preliminary Ca leaching should increase the REE extraction. However, the high amount of Ca and Al in the solution complicates the subsequent enrichment process of REEs [41].…”

Section: Solid Residue Characterizationmentioning

confidence: 99%

High-Selective Extraction of Scandium (Sc) from Bauxite Residue (Red Mud) by Acid Leaching with MgSO4

et al. 2022

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Bauxite residue, also known as red mud (RM), from alumina production is the most promising technogenic material for the production of scandium (Sc) and other rare earth elements (REEs). Conveniently, RM is processed by using a strong acid (pH < 2.5), which lead to co-dissolution of iron and other undesirable major components. In this work, for the first time, the possibility of selective extraction of scandium from red mud by using highly diluted acid (pH > 4) in the presence of MgSO4 was shown. The effect of temperature (40–80 °C), time (0–60 min), pH (2–5), and the MgSO4 concentration (12–36 g L−1) on Sc extraction efficiency was evaluated. It was shown that Sc extraction was higher than 63% even at a pH of 4, at 80 °C, after 1 h, while more than 80% could be extracted at a pH of 2. Iron extraction reduced from 7.7 to 0.03% by increasing the pH from 2 to 4. The kinetics study using the shrinking core model (SCM) has shown that diffusion through a product layer is a rate-limiting stage of the process at high temperatures (>60 °C) and low pH (<3), whereas, at lower temperatures and higher pH values, the leaching rate is limited by diffusion through the liquid film.

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Leaching Behaviors of Calcium and Aluminum from an Ionic Type Rare Earth Ore Using MgSO4 as Leaching Agent

Cited by 9 publications

References 30 publications

Selective Scandium (Sc) Extraction from Bauxite Residue (Red Mud) Obtained by Alkali Fusion-Leaching Method

Selective Scandium (Sc) Extraction from Bauxite Residue (Red Mud) Obtained by Alkali Fusion-Leaching Method

Size‐Controllable Synthesis of Submicro Spherical Yttrium Carbonate and In Situ Doping of Europium to Prepare Y₂O₃: Eu³⁺ Phosphor

High-Selective Extraction of Scandium (Sc) from Bauxite Residue (Red Mud) by Acid Leaching with MgSO4

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Leaching Behaviors of Calcium and Aluminum from an Ionic Type Rare Earth Ore Using MgSO4 as Leaching Agent

Cited by 9 publications

References 30 publications

Selective Scandium (Sc) Extraction from Bauxite Residue (Red Mud) Obtained by Alkali Fusion-Leaching Method

Selective Scandium (Sc) Extraction from Bauxite Residue (Red Mud) Obtained by Alkali Fusion-Leaching Method

Size‐Controllable Synthesis of Submicro Spherical Yttrium Carbonate and In Situ Doping of Europium to Prepare Y2O3: Eu3+ Phosphor

High-Selective Extraction of Scandium (Sc) from Bauxite Residue (Red Mud) by Acid Leaching with MgSO4

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Size‐Controllable Synthesis of Submicro Spherical Yttrium Carbonate and In Situ Doping of Europium to Prepare Y₂O₃: Eu³⁺ Phosphor