Three-dimensional flow-through electrode and electrochemical cell

Abstract

A three-dimensional flow-through electrode includes an efficient current feeding mechanism including current feeders comprising rods of conductive material, such as graphite, which are inserted at predetermined spacing into a flow-through electrode, such as a block of graphite felt. The current feeders are appropriately spaced throughout the electrode to allow for efficient current distribution. The large surface area provided by the flow-through electrode makes it possible to expose solutions or gases to relatively large areas of electrical charges, instituting electrical chemical reactions. A number of electrolytic chemical processes using the electrolytic cells include water treatment, chemical processing and production, hydro-metallurgical applications, and environmental clean-up. A method to replace the use of cyanide in gold and silver processing operations is also provided.

What is claimed is:  
     
         1 . An electrochemical cell, comprising: 
 at least a first and a second three-dimensional flow-through electrode, wherein said first three-dimensional flow-through electrode is a positive electrode and said second three-dimensional flow-through electrode is a negative electrode; 
 a current feeder associated with each of said three-dimensional flow-through electrodes, wherein at least a substantial portion of each of said current feeders is located within said three-dimensional flow-through electrode associated with said current feeder;  
 a power supply coupled to each of said current feeders to create an electrical potential therebetween; and  
 wherein the electrochemical cell is operable to facilitate a chemical reaction on a feed solution which is flowing through said electrodes.  
   
     
     
         2 . An electrochemical cell, as claimed in  claim 1 , wherein at least one of said three dimensional flow-through electrodes includes a graphite felt material.  
     
     
         3 . An electrochemical cell, as claimed in  claim 2 , wherein said current feeder includes a plurality of graphite rods inserted at a predetermined spacing into said graphite felt three-dimensional flow-through electrode.  
     
     
         4 . An electrochemical cell, as claimed in  claim 3 , wherein said predetermined spacing is arranged according to the conductivity of said feed solution and said electrical potential.  
     
     
         5 . An electrochemical cell, as claimed in  claim 2 , wherein said graphite felt material includes at least about 17,000 square feet of graphite surface for each square foot of graphite felt.  
     
     
         6 . An electrochemical cell, as claimed in  claim 2 , wherein said current feeder is a conductive bar comprised on at least one of a graphite rod, a copper rod, a steel rod, and a noble metal rod.  
     
     
         7 . The electrochemical cell of  claim 1 , wherein said feed solution is water and sodium chloride.  
     
     
         8 . The electrochemical cell of  claim 1 , wherein said feed solution is water and sodium bromide.  
     
     
         9 . The electrochemical cell of  claim 1 , wherein said feed solution is sea water.  
     
     
         10 . The electrochemical cell of  claim 1 , wherein the feed solution is untreated water.  
     
     
         11 . A system for recovering a metal from an ore, comprising: 
 a reaction chamber containing ore;    a first manifold operatively associated with said reaction chamber operable to deliver a leaching solution to a lower portion of said reaction chamber;    a second manifold operatively associated with said reaction chamber operable to remove a pregnant solution from an upper portion of said reaction chamber; and    an electrochemical cell operatively associated with said second manifold and operable to facilitate a chemical reaction on said pregnant solution;    wherein said leaching solution is operable to leach a desired metal from said ore to become said pregnant solution and said chemical reaction is operable to remove at least a portion of said desired metal from said pregnant solution.    
     
     
         12 . The system for recovering a metal from an ore, as claimed in  claim 11 , further comprising an ore bin chamber operatively associated with said reaction chamber, and configured to deliver said ore to said reaction chamber.  
     
     
         13 . The system for recovering a metal from an ore, as claimed in  claim 12 , further comprising: 
 an ore delivery system operable to deliver ore to said ore bin chamber; and    an ore removal system operable to remove leached ore from said reaction chamber.    
     
     
         14 . The system for recovering a metal from an ore, as claimed in  claim 13 , further comprising: 
 a second ore bin chamber operatively associated with said ore removal system, and oriented to deliver said leached ore to a second reaction chamber;    a third manifold operatively associated with said second reaction chamber and operable to deliver a second leaching solution to a lower portion of said second reaction chamber;    a fourth manifold operatively associated with said second reaction chamber and operable to remove a second pregnant solution from an upper portion of said second reaction chamber; and    a second electrochemical cell operatively associated with said fourth manifold and operable to facilitate a chemical reaction on said second pregnant solution;    wherein said second leaching solution is operable to leach a second desired metal from said leached ore to become said second pregnant solution and said chemical reaction is operable to remove at least a portion of said second desired metal from said pregnant solution.    
     
     
         15 . The system for recovering a metal from an ore, as claimed in  claim 11 , wherein said electrochemical cell comprises: 
 at least a first and a second three-dimensional flow-through electrode, wherein said first three-dimensional flow-through electrode is a positive electrode and said second three-dimensional flow-through electrode is a negative electrode;    a current feeder associated with each of said three-dimensional flow-through electrodes, wherein at least a substantial portion of at least one of said current feeders is located within said three-dimensional flow-through electrode associated with said current feeder; and    a power supply coupled to each of said current feeders to create an electrical potential therebetween.    
     
     
         16 . The system for recovering a metal from an ore, as claimed in  claim 15 , wherein said power supply comprises a direct current supply operable to create about 9 volts of electrical potential between said current feeders.  
     
     
         17 . The system for recovering a metal from an ore, as claimed in  claim 15 , wherein said first and second three dimensional flow-through electrodes are about four inches by four inches, and about one inch thick, and a flow rate of said pregnant solution through said electrochemical cell is about 0.03 gallons per minute.  
     
     
         18 . A method for treating water, comprising: 
 providing an electrochemical cell having a first flow-through electrode and a second flow though electrode, said first and second flow-through electrodes spaced apart to provide an inter-electrode space;    applying a voltage between said first flow-through electrode and said second flow-through electrode to create a positively charged first flow-through electrode and a negatively charged second flow-through electrode;    feeding untreated water into said inter-electrode space; and    collecting treated water which has passed through said second flow-through electrode.    
     
     
         19 . The method for treating water, as claimed in  claim 18 , wherein said first and second flow-through electrodes are graphite felt electrodes and said applying a voltage step includes applying a voltage to a current feeder associated with each electrode.  
     
     
         20 . The method for treating water, as claimed in  claim 18 , wherein said second flow-through electrode is a copper wire screen electrode.  
     
     
         21 . The method for treating water, as claimed in  claim 18 , wherein said applying a voltage step includes: 
 providing a DC power supply having a positive terminal and a negative terminal; coupling said positive terminal to said first flow-through electrode; and coupling said negative terminal to said second flow-through electrode.    
     
     
         22 . The method for treating water, as claimed in  claim 21 , wherein said DC power supply has a voltage potential of about 9 Volts.