US 12,371,337 B2
Use of calcium fluoride in the bayer process
Lisa Côté, Canton-Tremblay (CA); Sébastien Fortin, Chicoutimi (CA); and Élizabeth Gingras-Lafleur, Chicoutimi (CA)
Assigned to Rio Tinto Alcan International Limited, Montreal (CA)
Appl. No. 17/433,450
Filed by Rio Tinto Alcan International Limited, Montreal (CA)
PCT Filed Feb. 24, 2020, PCT No. PCT/IB2020/051564
§ 371(c)(1), (2) Date Aug. 24, 2021,
PCT Pub. No. WO2020/174372, PCT Pub. Date Sep. 3, 2020.
Claims priority of application No. 2019900590 (AU), filed on Feb. 25, 2019.
Prior Publication US 2022/0135417 A1, May 5, 2022
Int. Cl. C01F 7/0633 (2022.01); C01F 7/0613 (2022.01); C01F 7/0646 (2022.01); C01F 7/47 (2022.01)
CPC C01F 7/0633 (2013.01) [C01F 7/0613 (2013.01); C01F 7/0646 (2013.01); C01F 7/47 (2013.01)] 21 Claims
OG exemplary drawing
 
1. A Bayer process that includes:
contacting bauxite and calcium fluoride with sodium hydroxide and forming a slurry, with the calcium fluoride providing at least 1 wt. % of the calcium added to the process to precipitate phosphorus-containing compounds from the slurry, and
precipitating alumina from a pregnant liquor of the slurry.