Abstract: Processes are provided for the selective recovery of lithium from brines using aqueous redox reactions, involving lithium extraction into a particulate ferric phosphate solid in the form of an iron (III) heterosite, in the presence of a reducing agent capable of reducing ionic lithium, at a controlled lithium extraction pH. Lithium elution involves exposing the loaded lithium ferrous phosphate solids, in the form of lithium iron (II) triphylite, to an oxidizing agent capable of mediating the oxidation of the sequestered atomic lithium. This is carried out at a controlled acidic lithium elution pH. Conditions in the lithium extraction and elution steps are provided so that a concentrated liquid lithium eluate is provided to subsequent steps of impurity removal and lithium carbonate precipitation.
Type:
Grant
Filed:
September 15, 2020
Date of Patent:
April 25, 2023
Assignee:
InCoR Lithium
Inventors:
Ken Baxter, David Dreisinger, Hiroki Fukuda