Pyrometallurgical Treatment of Apatite Concentrate with the Objective of Rare Earth Element Recovery: Part II

• Published in: Journal of sustainable metallurgy 2017, Vol.3 (4), p.846-857
• Main Authors: Kennedy, Mark William, Sun, Tianming, Yurramendi, Lourdes, Arnout, Sander, Aune, Ragnhild E., Tranell, Gabriella
• Format: Article
• Language: English
• Subjects: Acetylene; Apatite; Chemical industry; Earth and Environmental Science; Environment; Fluxing; Metallic Materials; Phosphoric acid; Phosphorus; Polyvinyl chloride; Rare earth elements; Recovery; Research Article; Sustainable Development
• ISSN: 2199-3823; 2199-3831
• DOI: 10.1007/s40831-017-0148-y

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.