US 12,215,408 B2
Processes for the separation of rare earth elements and non-rare earth elements into individual high purity elements
William Rusty Sutterlin, Tuscaloosa, AL (US)
Assigned to INVENTURE RENEWABLES INC., Tuscaloosa, AL (US)
Filed by Inventure Renewables, Inc., Tuscaloosa, AL (US)
Filed on Dec. 10, 2020, as Appl. No. 17/118,386.
Claims priority of provisional application 62/946,078, filed on Dec. 10, 2019.
Prior Publication US 2021/0172042 A1, Jun. 10, 2021
Int. Cl. C22B 59/00 (2006.01); C22B 3/42 (2006.01)
CPC C22B 59/00 (2013.01) [C22B 3/42 (2013.01)] 24 Claims
OG exemplary drawing
 
1. A continuous ion exchange/continuous ion chromatography (CIX/CIC) process for the separation of rare earth elements (REEs) and non-rare earth elements from a feedstock starting material comprising at least one rare earth element (REE) and at least one non-rare earth element and having iron as a contaminant, comprising sequential use of a CIX/CIC anion exchange resin column to first remove ferric tetrachloride anion FeCl4− followed by a CIX/CIC cationic exchange resin column to isolate REEs,
the method comprising the steps of:
(a) providing the feedstock starting material comprising at least one rare earth element (REE) and at least one non-rare earth element and having iron as a contaminant;
(b) making a modified feedstock by a process comprising mixing the feedstock starting material in a hydrochloric acid (HCl) solution, or adding the feedstock starting material to the hydrochloric acid solution, wherein the hydrochloric acid solution has a concentration of between about 0.01 molarity and 10 molarity, wherein the iron reacts with the HCl in the presence of chlorides to generate a plurality of FeCl4− anion complexes,
thereby generating a modified feedstock starting material comprising the hydrochloric acid
(c) adding or loading the modified feedstock starting material of step (b) into or onto a CIX/CIC anion exchange resin column, whereby the ferric tetrachloride anion FeCl4− in the modified feedstock starting material is retained on the CIX/CIC anion exchange resin, and generating a first eluate;
(d) adding or loading the first eluate of (c) into or onto a CIX/CIC cationic exchange resin column, whereby REEs are retained on the CIX/CIC cationic exchange resin; and
(e) passing low to high gradient acid eluting solutions over or through the CIX/CIC cationic exchange resin column to generate a second eluate comprising REE,
wherein the passing comprises:
(i) first passing a first HCl acid-comprising eluting solution having a low HCl acid concentration of about 0.1 to 1 molarity thereby generating a second eluate wherein greater than about 50% of monovalent and/or divalent cations are eluted off the CIX/CIC cationic exchange resin column in the second eluate, followed by a second HCl acid-comprising eluting solution of about 1 to 2 HCl acid molarity thereby generating a third eluate wherein greater than about 50% of trivalent cations are eluted off the CIX/CIC cationic exchange resin column in the third eluate, followed by a third HCl acid-comprising eluting solution of about 3 to 10 or more HCl acid molarity thereby generating a fourth eluate wherein greater than about 50% of the REEs elute off the CIX/CIC cationic exchange resin column in the fourth eluate, or
(ii) passing an HCl acid-comprising eluting solution over or through the cationic exchange resin column, wherein the HCl acid-comprising eluting solution changes over time from: a first HCl acid-comprising eluting solution comprising about 0.1 to 1 HCl acid molarity thereby generating a second eluate wherein greater than about 50% of monovalent and/or divalent cations are eluted off the CIX/CIC cationic exchange resin column in the second eluate, to a second HCl acid-comprising eluting solution comprising about 1 to 2 molarity thereby generating a third eluate wherein greater than about 50% of trivalent cations are eluted off the CIX/CIC cationic exchange resin column in the third eluate, to a third HCl acid-comprising eluting solution comprising about 3 to 10 or more HCl acid molarity thereby generating a fourth eluate wherein greater than about 50% of the REEs elute off the CIX/CIC cationic exchange resin column in the fourth eluate;
thereby separating rare earth elements (REEs) and non-rare earth elements from the feedstock.