A system and method for separation and purification of dissolved rare earth/precious metals elements/compounds

Abstract

A method for purification and separation of mixed elements, comprising at least a first free flow electrophoresis separation chamber, wherein a solution of the mixed elements is passed through the first separation chamber, an electric field submitted perpendicular to the solution flow and separating mobile ions of the solution based on electrophoretic mobility. A continuous method comprises selecting a complexing ligand, and controlling the temperature and pH of the solution. Also, a system or method for separating components of a multi-component concentrate comprising directing solution to at least a first and second channel each receiving part of the solution; each channel comprising a concentration section comprising a first transverse electric field across the channel, a fractionation section comprising a second electric field in a direction opposite the first electric field thereby distributing ions of the solution across the channel, and a flow splitter at an output of the fractionation section that divides the flow of each channel into subflows concentrated in heavier elements and concentrated in lighter elements.

1 . A method of purification and separation of mixed elements, using differences between electrophoresis mobility of the elements or coordination complexes thereof in a continuous process, comprising:
 selecting a complexing ligand and forming a solution of the complexing ligand and the mixed elements;   controlling the temperature and pH of the solution; and   submitting a flow of the solution to an electric field submitted perpendicular to the solution.   
     
     
         2 . The method of  claim 1 , wherein said selecting the complexing ligand comprises selecting the complexing ligand with a concentration in a range between 1 μmol/L and 1 mol/L. 
     
     
         3 . The method of  claim 1 , comprising controlling a flow ratio between the mixed elements and the complexing ligand in a range between 1/100 and 1/3. 
     
     
         4 . The method of  claim 1 , comprising controlling a flow ratio between the mixed elements and the complexing ligand in a range between 1/10 and 1/3. 
     
     
         5 . The method of  claim 1 , comprising controlling the concentration of complexing ligand in a range between 1/1 and 10/1. 
     
     
         6 . The method of  claim 1 , comprising controlling the concentration of complexing ligand in a range between 2/1 and 5/1. 
     
     
         7 . The method of  claim 1 , wherein the complexing ligand comprises 10 mM 4-methyl benzyl amine and 4 mM HIBA. 
     
     
         8 . The method of  claim 1 , wherein said controlling the temperature comprises controlling the temperature in a range between 5 and 70° C. 
     
     
         9 . The method of  claim 1 , wherein said controlling the temperature comprises controlling the temperature in a range between 15 and 25° C. 
     
     
         10 . The method of  claim 1 , wherein said controlling the pH comprises controlling the pH in a range between 2 and 10. 
     
     
         11 . The method of  claim 1 , wherein said controlling the pH comprises controlling the pH in a range between 3 and 6. 
     
     
         12 . The method of  claim 1 , wherein the mixed elements are mixed rare earth elements or mixed precious metals. 
     
     
         13 . A system for purification and separation of mixed elements, comprising at least a first free flow electrophoresis separation chamber, wherein a solution of the mixed elements is passed through the first separation chamber, an electric field being submitted perpendicular to the solution flow and separating mobile ions of the solution based on electrophoretic mobility. 
     
     
         14 . The system of  claim 13 , comprising at least a second separation chamber, said second separation chamber being in series and/or in parallel with the first separation chamber for fractionation and refinery of metallic ions at the output of the first separation chamber. 
     
     
         15 . A multi-channel separation system for purification and separation of elements in a solution, comprising at least a first and a second channels each receiving part of the solution;
 each channel comprising a concentration section, a fractionation section, and a flow splitter at an output of the fractionation section;   said concentration section comprising electrodes that create a first transverse electric field across the channel, and said fractionation section comprising electrodes that create a second electric field in a direction opposite the first electric field across the channel, thereby distributing ions of the solution across the channel;   said flow splitter dividing the flow of each channel into a subflow concentrated in heavier elements and a subflow concentrated in lighter elements.   
     
     
         16 . The system of  claim 15 , further comprising a connection merging the subflows concentrated in heavier elements from the first and second channels, and a connection merging the subflows concentrated in lighter elements from the first and second channels. 
     
     
         17 . The system of  claim 15 , further comprising a connection merging the subflows concentrated in heavier elements from the first and second channels, and a connection merging the subflows concentrated in lighter elements from the first and second channels;
 further comprising a third and a fourth channels, the third channel receiving the merged subflows concentrated in lighter elements and said fourth channel receiving the merged subflows concentrated in heavier elements;   each one of the third and fourth channels comprising a concentration section, a fractionation section, and a flow splitter at an output of the fractionation section;   said concentration section comprising electrodes that create a first transverse electric field across the channel, and said fractionation section comprising electrodes that create a second electric field in a direction opposite the first electric field across the channel, thereby distributing ions of the solution across the channel;   said flow splitter dividing the flow of each channel into a subflow concentrated in heavier elements and a subflow concentrated in lighter elements.   
     
     
         18 . The system of  claim 15 , wherein the first electric field concentrates metallic ions or complexes to a first wall of the respective channel along the flow direction, and the second electric field forces the metallic ions or complexes to migrate across the respective channel to an opposite wall of the respective channel. 
     
     
         19 . The system of  claim 15 , wherein each channel comprises semi-permeable membranes preventing ions to reach the electrodes. 
     
     
         20 . A method for separating components of a multi-component concentrate, comprising:
 a) preparing a solution of the multi-component concentrate and a reagent;   b) directing the solution to at least a first and a second channel each receiving part of the solution; each channel comprising a concentration section comprising a first transverse electric field across the channel, a fractionation section comprising a second electric field in a direction opposite the first electric field across the channel thereby distributing ions of the solution across the channel, and a flow splitter at an output of the fractionation section that divides the flow of each channel into a subflow concentrated in heavier elements and a subflow concentrated in lighter elements;   c) repeating step b) until a target separation of isolated components is achieved; and   d) recovering the isolated components.   
     
     
         21 . The method of  claim 20 , further comprising diverting a stream of impurities and rejected components to a purification unit. 
     
     
         22 . The method of  claim 20 , further comprising processing a depleted solution from the recovery of the isolated components to a regeneration unit to yield a recycled reagent for use in step a). 
     
     
         23 . The method of  claim 20 , further comprising diverting of impurities and rejected components to a purification unit, and further comprising processing at least one of: i) a depleted solution from the recovery of the isolated components and ii) a depleted solution from the purification unit to a regeneration unit to yield a recycled reagent for use in step a).