An Interdisciplinary Perspective from the Earth Scientist’s Periodic Table: Similarity and Connection between Geochemistry and Metallurgy

Sun, Fenglong; Zhao, Zhongwei

doi:10.1016/j.eng.2020.04.002

Cited by 10 publications

(5 citation statements)

References 50 publications

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“…Accordingly, it indicated that Ce(III) has a high affinity to SO 4 2– , while transition metals (Me(II)) are inclined to be bound with O 2– . Elemental affinity in geochemistry is associated with element migration in metallurgy . In geochemistry, ionic potential ( z / r ) discriminates the ability of ions to attract valence electrons, and electronegativity (χ) indicates the degree of electron transfer between two reactants .…”

Section: Resultsmentioning

confidence: 99%

“…Elemental affinity in geochemistry is associated with element migration in metallurgy. 69 In geochemistry, ionic potential (z/r) discriminates the ability of ions to attract valence electrons, and electronegativity (χ) indicates the degree of electron transfer between two reactants. 70 In HSAB theory, the cation with the higher ionic potential and lower electronegativity could be classified as the hard acid, while the reverse is true for soft acid.…”

Section: Theoretical Perspective Of the Sulfationmentioning

confidence: 99%

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Insights into the Selective Transformation of Ceria Sulfation and Iron/Manganese Mineralization for Enhancing the Selective Recovery of Rare Earth Elements

Zhou

Xiao

Guo

et al. 2023

Environ. Sci. Technol.

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To cope with the urgent and unprecedented demands for rare earth elements (REEs) in sophisticated industries, increased attention has been paid to REE recovery from recycled streams. However, the similar geochemical behaviors of REEs and transition metals often result in poor separation performance due to nonselectivity. Here, a unique approach based on the selective transformation between ceria sulfation and iron/ manganese mineralization was proposed, leading to the enhancement of the selective separation of REEs. The mechanism of the selective transformation of minerals could be ascribed to the distinct geochemical and metallurgical properties of ions, resulting in different combinations of cations and anions. According to hardsoft acid-base (HSAB) theory, the strong Lewis acid of Ce(III) was inclined to combine with the hard base of sulfates (SO 4 2− ), while the borderline acid of Fe(II)/Mn(II) prefers to interact with oxygen ions (O 2-). Both in situ characterization and density functional theory (DFT) calculation further revealed that such selective transformation might trigger by the generation of an oxygen vacancy on the surface of CeO 2 , leading to the formation of Ce 2 (SO 4 ) 3 and Fe/Mn spinel. Although the electron density difference of the configurations (CeO 2−x -SO 4 , Fe 2 O 3−x -SO 4 , and MnO 2−x -SO 4 ) shared a similar direction of the electron transfer from the metals to the sulfate-based oxygen, the higher electron depletion of Ce (Q Ce = −1.91 e) than Fe (Q Fe = −1.66 e) and Mn (Q Mn = −1.64 e) indicated the higher stability in the Ce−O−S complex, resulting in the larger adsorption energy of CeO 2−x -SO 4 (−6.88 eV) compared with Fe 2 O 3−x -SO 4 (−3.10 eV) and MnO 2−x -SO 4 (−2.49 eV). This research provided new insights into the selective transformation of REEs and transition metals in pyrometallurgy and thus offered a new approach for the selective recovery of REEs from secondary resources.

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Section: Resultsmentioning

confidence: 99%

Section: Theoretical Perspective Of the Sulfationmentioning

confidence: 99%

Insights into the Selective Transformation of Ceria Sulfation and Iron/Manganese Mineralization for Enhancing the Selective Recovery of Rare Earth Elements

Zhou

Xiao

Guo

et al. 2023

Environ. Sci. Technol.

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“…This tendency is in accordance with the orthogonal experimental results that calcinating temperature plays the primary role in mineral transformation, and higher temperature is beneficial to the Ce recovery with low Fe and Mn leaching concentration. According to the geochemical and metallurgical principle, both Mn and Fe are classified as the chalcophile elements that have a strong affinity with S. In general, the higher ionic potential of Mn(IV) ( z / r = 8) results in a priority to the reduction of MnO 2 by S than that of Fe 2 O 3 (Fe(III), z / r = 5) and CeO 2 (Ce(IV), z / r = 5), as well as other components (Al(III), z / r = 6; Ca(II), z / r = 2). Similar transformation processes were also reported in the recovery of Ni over Fe 2 O 3 from iron-rich nickeliferous lateritic ores, in which Fe 2 O 3 was first reduced over NiO (Ni(II) z / r = 3) to form FeS 2 and then facilitated the reduction of NiO as metallic Ni for further recovery .…”

Section: Resultsmentioning

confidence: 99%

“…This tendency is in accordance with the orthogonal experimental results that calcinating temperature plays the primary role in mineral transformation, and higher temperature is beneficial to the Ce recovery with low Fe and Mn leaching concentration. According to the geochemical and metallurgical principle, 35 both Mn and Fe are classified as the chalcophile elements that have a strong affinity with S. In general, the higher ionic potential of Mn(IV) (z/r = 8) results in a priority to the reduction of MnO 2 by S than that of first reduced over NiO (Ni(II) z/r = 3) to form FeS 2 and then facilitated the reduction of NiO as metallic Ni for further recovery. 36 Such an order of prioritizing reduction process may benefit to MnO 2 reduction despite the much lower content of MnO 2 (0.14 wt %) than Fe 2 O 3 (5.28 wt %) in the tailings.…”

Section: Effects On Ceomentioning

confidence: 99%

Selective Leaching of Rare Earth Elements from Ion-Adsorption Rare Earth Tailings: A Synergy between CeO₂ Reduction and Fe/Mn Stabilization

Zhou

Xiao

Guo

et al. 2021

Environ. Sci. Technol.

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The increasing demand for rare earth elements (REEs) motivates the development of novel strategies for cost-effective REE recovery from secondary sources, especially rare earth tailings. The biggest challenges in recovering REEs from ion-adsorption rare earth tailings are incomplete extraction of cerium (Ce) and the coleaching of iron (Fe) and manganese (Mn). Here, a synergistic process between reduction and stabilization was proposed by innovatively using elemental sulfur (S) as reductant for converting insoluble CeO 2 into soluble Ce 2 (SO 4 ) 3 and transforming Fe and Mn oxides into inert FeFe 2 O 4 and MnFe 2 O 4 spinel minerals. After the calcination at 400 °C, 97.0% of Ce can be dissolved using a diluted sulfuric acid, along with only 3.67% of Fe and 23.3% of Mn leached out. Thermodynamic analysis reveals that CeO 2 was indirectly reduced by the intermediates MnSO 4 and FeS in the system. Density functional theory calculations indicated that Fe(II) and Mn(II) shared similar outer electron arrangements and coordination environments, favoring Mn(II) over Ce(III) as a replacement for Fe(II) in the FeO 6 octahedral structure of FeFe 2 O 4 . Further investigation on the leaching process suggested that 0.5 mol L −1 H 2 SO 4 is sufficient for the recovery of REEs (97.0%). This research provides a promising strategy to selectively recover REEs from mining tailings or secondary sources via controlling the mineral phase transformation.

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“…As +3 /As +5 are both large, polarisable ions. They are soft cations and should bind well to soft donors like S −2 explaining the different sulfide minerals species that are formed in the leaching with Na 2 S – NaOH, Sun and Zhao (2020).…”

Section: Introductionmentioning

confidence: 99%

Alkaline sulphide leaching of tennantite in copper flotation concentrates to selectively dissolve arsenic

Cuevas

Bruckard

Pownceby

et al. 2021

Mineral Processing and Extractive Metallurgy

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High-arsenic copper flotation concentrates, in which the major arsenic-bearing mineral was tennantite, were leached with an alkaline sulphide system. At a pulp density of 5 wt% solids with 100-150 g/L Na 2 S and 50 g/L NaOH, over 91 wt% As was dissolved within 2 h at 100°C. From concentrates containing 3.4-4.9 wt% As, leach residues containing <0.5 wt% As were obtained making them suitable as a smelter feed without a penalty for arsenic. Copper dissolution ranged from 16 to 22 wt% Cu, with significant amounts of calcium, iron and sulphur also dissolved. In a leach at 34.0 wt% solids, excellent arsenic extraction was obtained (97.9 wt% As), but the levels of copper, calcium, and iron dissolution were 0.5, 1.1, and 0.2 wt%, respectively, meaning excellent selectivity for arsenic was achieved. X-ray diffraction and electron probe microanalyses indicated the mechanism for arsenic dissolution from tennantite, and bornite abundance in the residue.

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An Interdisciplinary Perspective from the Earth Scientist’s Periodic Table: Similarity and Connection between Geochemistry and Metallurgy

Cited by 10 publications

References 50 publications

Insights into the Selective Transformation of Ceria Sulfation and Iron/Manganese Mineralization for Enhancing the Selective Recovery of Rare Earth Elements

Insights into the Selective Transformation of Ceria Sulfation and Iron/Manganese Mineralization for Enhancing the Selective Recovery of Rare Earth Elements

Selective Leaching of Rare Earth Elements from Ion-Adsorption Rare Earth Tailings: A Synergy between CeO₂ Reduction and Fe/Mn Stabilization

Alkaline sulphide leaching of tennantite in copper flotation concentrates to selectively dissolve arsenic

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An Interdisciplinary Perspective from the Earth Scientist’s Periodic Table: Similarity and Connection between Geochemistry and Metallurgy

Cited by 10 publications

References 50 publications

Insights into the Selective Transformation of Ceria Sulfation and Iron/Manganese Mineralization for Enhancing the Selective Recovery of Rare Earth Elements

Insights into the Selective Transformation of Ceria Sulfation and Iron/Manganese Mineralization for Enhancing the Selective Recovery of Rare Earth Elements

Selective Leaching of Rare Earth Elements from Ion-Adsorption Rare Earth Tailings: A Synergy between CeO2 Reduction and Fe/Mn Stabilization

Alkaline sulphide leaching of tennantite in copper flotation concentrates to selectively dissolve arsenic

Contact Info

Product

Resources

About

Selective Leaching of Rare Earth Elements from Ion-Adsorption Rare Earth Tailings: A Synergy between CeO₂ Reduction and Fe/Mn Stabilization