Processes for the separation of rare earth elements and non-rare earth elements into individual high purity elements

Abstract

In alternative embodiments, provided are processes and continuous ion exchange/continuous ion chromatography (CIX/CIC) systems for the separation of rare earth elements and non-rare earth elements, including metals, into individual high purity elements.

What is claimed is: 
     
         1 . A process for the separation of rare earth elements and non-rare earth elements, including metals, into individual high purity elements, comprising a process as set forth in  FIG.  1    and/or  FIG.  2   . 
     
     
         2 . A continuous ion exchange/continuous ion chromatography (CIX/CIC) system for the separation of rare earth elements and non-rare earth elements, including metals, into individual high purity elements, comprising a process as set forth in  FIG.  1    and/or  FIG.  2   . 
     
     
         3 . A process for the separation of rare earth elements (REE) and non-rare earth elements into individual high purity elements, comprising:
 (a) providing a starting material comprising at least one rare earth element (REE) and at least one non-rare earth elements;   (b) mixing the starting material in an acid or acid chloride solution, or adding the starting material to an acid or acid chloride solution, wherein the acid or acid chloride solution has greater than about 1 molarity chloride concentration, or between about 0.01 molarity and 10 molarity chloride concentration;   (c) adding or loading the starting material-comprising acid or acid chloride solution of step (b) into or onto an anion exchange resin column, whereby any ferric tetrachloride anion (optionally a FeCl 4   −1  complex binds to the anion exchange resin) in the starting material-comprising acid chloride solution is retained on the anion exchange resin, and generating a ferric tetrachloride (FeCl 4   −1  complex) anion-free, cationic metal-comprising eluate,   and optionally any zinc, thorium and/or uranium in the starting material-comprising acid chloride solution is also retained on the anion exchange resin;   (d) adding or loading the ferric tetrachloride anion-free, cationic metal-comprising eluate of (c) into or onto a cationic exchange resin column, whereby REEs are retained on the cationic exchange resin;   (e) passing low to high gradient acid eluting solutions over or through the cationic exchange resin column, wherein the passing comprises:   (i) first passing an eluting solution having a low acid concentration of about 0.1 to 1 molarity, followed by an eluting solution of about 1 to 2 molarity, followed by an eluting solution of about 3 to 10 or more molarity, or   (ii) passing an eluting solution over or through the cationic exchange resin column that changes over time from about 0.1 to 1 molarity, to about 1 to 2 molarity, to about 3 to 10 or more molarity, and   at low acid concentration of about 1 molarity or less, a majority of or greater than 50%, or at least about 50%, 60%, 70%, 80%, 85%, 90% or 95%, of monovalent and/or divalent cations are eluted off the cationic exchange resin column, and   at acid concentrations of between about 1 to 2 molarity, a majority of or greater than 50%, or at least about 50%, 60%, 70%, 80%, 85%, 90% or 95%, of trivalent cations (optionally aluminum cations) elute off the cationic exchange resin column, and   at acid concentrations greater than about 3 or more molarity, a majority of or greater than 50%, or at least about 50%, 60%, 70%, 80%, 85%, 90% or 95%, of the REEs elute off the cationic exchange resin column; and   (f) collecting the eluted REEs.   
     
     
         4 . The process of  claim 3 , wherein the at least one REE comprises lanthanum (La); cerium (Ce); praseodymium (Pr); neodymium (Nd); samarium (Sm); europium (Eu); gadolinium (Gd); terbium (Tb); dysprosium (Dy); holmium (Ho); erbium (Er); thulium (Tm); ytterbium (Yb); lutetium (Lu); yttrium (Y), scandium (Sc) or any combination thereof. 
     
     
         5 . The process of  claim 3 , wherein the non-rare earth elements comprise metals or metal oxides, and optionally the metals comprise iron or iron oxides, or aluminum or aluminum oxides. 
     
     
         6 . The process of  claim 3 , wherein the starting material comprises a mining waste, an acid mine drainage (AMD), an acid rock drainage (ARD), an acid or metalliferous drainage, AMD sludge, a coal overburden, a fire clay, a fly ash, an ore or any combination thereof. 
     
     
         7 . The process of  claim 3 , wherein the acid chloride solution comprises: hydrochloric acid or sulfuric acid combined with a chloride salt, and optionally the chloride salt comprises sodium chloride. 
     
     
         8 . The process of  claim 3 , wherein the anion exchange resin comprises a polymeric matrix to which functional groups are attached,
 and optionally the functional groups comprise: tertiary amino groups; primary amines; secondary amines; quaternary ammonium groups or a combination thereof;   and optionally the polymeric matrix comprises: N +(CH   3 ) 3  groups (type 1 resins); —N + (CH 3 ) 2 C 2 H 4 OH groups (type 2 resins); or, a combination thereof;   and optionally the polymeric matrix comprises styrene-divinylbenzene.   
     
     
         9 . The process of  claim 3 , wherein the anion exchange resin is regenerated by eluting off the ferric tetrachloride anion, and any zinc, thorium and/or uranium if present, by passing a water solution over or through the anion exchange resin, and the water dilutes the FeCl 4   −1  to form FeCl 3  which is not anionic and therefore not attracted to the anion exchange resin,
 and optionally collecting and recycling the elution solution, wherein optionally the elution solution comprises an FeCl 3  solution, and if present, the zinc, thorium and/or uranium.   
     
     
         10 . The process of  claim 3 , wherein the low to high gradient acid eluting solutions comprise hydrochloric acid or sulfuric acid. 
     
     
         11 . The process of  claim 3 , wherein the cationic exchange resin comprises crosslinked polystyrene, divinylbenzene or a combination thereof, or comprises sulfonic acid groups, carboxylic acid groups or a combination thereof. 
     
     
         12 . A continuous ion chromatography (CIC) process for the separation of rare earth elements (REE) and non-rare earth elements into individual high purity elements, comprising:
 (a) providing a starting material comprising at least one rare earth element (REE) and at least one non-rare earth elements;   (b) mixing the starting material in an acid or acid chloride solution, or adding the starting material to an acid or acid chloride solution, wherein the acid or acid chloride solution has greater than about 1 molarity chloride concentration, or between about 0.1 molarity and 10 molarity chloride concentration;   (c) adding or loading the starting material-comprising acid or acid chloride solution of step (b) into or onto a continuous ion chromatography (CIC) column comprising a strong cation (optionally Dowex 650C™ or Purolite SSTC60™ or equivalents) or strong anion (optionally Dowex 1™, Amberlite HPR550 OH™) resin, whereby the REEs are retained on the CIC column;   (d) adding to or passing through the CIC column of (c) an eluting solution comprising a chelating material, thereby eluting the REEs off the CIC column; and   (f) collecting the eluted REEs.   
     
     
         13 . The CIC process of  claim 12 , wherein the chelating material comprises: ethylenediamine, ethylenediaminetetraacetic acid (EDTA), lactic acid, glycolic acid, citric acid, acetic acid, ascorbic acid, and/or a sodium, a potassium or an ammonium salt thereof. 
     
     
         14 . The CIC process of  claim 12 , wherein the at least one REE comprises lanthanum (La); cerium (Ce); praseodymium (Pr); neodymium (Nd); samarium (Sm); europium (Eu); gadolinium (Gd); terbium (Tb); dysprosium (Dy); holmium (Ho); erbium (Er); thulium (Tm); ytterbium (Yb); lutetium (Lu); yttrium (Y), scandium (Sc) or any combination thereof. 
     
     
         15 . The CIC process of  claim 12 , wherein the starting material comprises a mining waste, an acid mine drainage (AMD), an acid rock drainage (ARD), an acid or metalliferous drainage, AMD sludge, a coal overburden, a fire clay, a fly ash, an ore or any combination thereof. 
     
     
         16 . The CIC process of  claim 12 , wherein the eluted solution comprising the at least one REE comprises a minimum of 300 ppm REE and less than three times the REE concentration of non-REEs into multiple fractions of similar molecular mass REEs, or light, mid and heavy REE fractions. 
     
     
         17 . A continuous ion exchange/continuous ion chromatography (CIX/CIC) system configured to practice the method of  claim 3 . 
     
     
         18 . A continuous ion exchange/continuous ion chromatography (CIX/CIC) system conured to practice the method of  claim 12 .