| 1. |
- Sun, Tianming, et al.
(author)
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Pyrometallurgical Treatment of Apatite Concentrate with the Objective of Rare Earth Element Extraction : Part I
- 2017
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In: Journal of Sustainable Metallurgy. - : Springer. - 2199-3823 .- 2199-3831. ; 3:4, s. 829-845
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Journal article (peer-reviewed)abstract
- Apatite, Ca 5 (PO 4 ) 3 F, concentrate from LKAB in Kiruna, Sweden, has been characterized and pyrometallurgically treated using (i) silicon metal and fluxes to extract phosphorus and transition metals at 1600 °C (Part I publication), and (ii) carbon to extract phosphorus without fluxing at temperatures exceeding 1800 °C (Part II publication), with the ultimate objective to recover rare earth elements from the resulting slag/residue phases. A variety of methods (SEM/EDS, EPMA, DTA-TGA, Sessile drop, ICP-MS/OES, and XRD) have been used for the characterization and analysis of both the concentrate and reaction products. Elemental deportment, except for the rare earth metals, is broadly in line with the equilibrium thermodynamic predictions performed using HSC Chemistry ® . Phase diagrams were predicted using FactSage ® and a custom phosphate database to explain the observed melting/fluxing behaviors.
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| 2. |
- Kennedy, M. W., et al.
(author)
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Pyrometallurgical Treatment of Apatite Concentrate with the Objective of Rare Earth Element Recovery : Part II
- 2017
-
In: Journal of Sustainable Metallurgy. - : Springer. - 2199-3823 .- 2199-3831. ; 3:4, s. 846-857
-
Journal article (peer-reviewed)abstract
- Apatite, Ca 5 (PO 4 ) 3 F, is a useful raw material for the production of both elemental phosphorus and phosphoric acid, and the mine tailings present at Luossavaara-Kiirunavaara AB (LKAB) in Kiruna, Sweden, represent a significant potential European source of apatite if upgraded to a concentrate. In the present study, pilot apatite concentrate made from the LKAB tailings has been pyrometallurgically treated using carbon to extract phosphorus without fluxing at temperatures exceeding 1800 °C, with the ultimate objective of recovery of rare earth elements (REEs) from the resulting slag/residue phases. Experimental behavior has been modeled using equilibrium thermodynamic predictions performed using HSC ® . A process is proposed, and mass–energy balance presented, for the simultaneous production of P 4 and CaC 2 (ultimately for acetylene, C 2 H 2 , and PVC production) from apatite, producing a lime residue significantly enriched in REEs. Possible implications to kiln-based processing of apatite are also discussed.
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