Method and apparatus for electrochemical recovery of mercury from solutions

Abstract

In embodiments there are disclosed a substantially flat, flow through electrode, electrochemical cells comprising substantially flat flow through cathodes, and methods for electrochemically recovering a metal substantially liquid at room temperature.

1 . A substantially flat, flow through electrode. 
     
     
         2 . The electrode according to  claim 1  wherein said electrode has a surface area of at least about 500 m 2  per 1 m 2  of geometric surface. 
     
     
         3 . A carbon felt electrode according to  claim 1 . 
     
     
         4 . An electrochemical cell comprising the electrode according to  claim 1 . 
     
     
         5 . A cathode according to  claim 1  for electrochemically depositing from solution a metal substantially liquid at room temperature. 
     
     
         6 . An electrochemical cell comprising a cathode according to  claim 5  and an anode, wherein said cathode and said anode each comprise substantially flat geometrical surfaces and said substantially flat cathode and anode geometrical surfaces are mutually opposed and are substantially uniformly distanced. 
     
     
         7 . The electrochemical cell according to  claim 6  wherein said distance between said electrode geometrical surfaces is less than about 2 cm and said cathode and said anode are in direct fluid contact. 
     
     
         8 . The electrochemical cell according to  claim 5  further comprising a solution inlet positioned to direct at least a portion of said solution to flow through said cathode. 
     
     
         9 . The electrochemical cell according to  claim 5  further comprising a collector for collecting said metal under gravity induced flow when said metal is electrochemically deposited at said cathode. 
     
     
         10 . An apparatus for treating a scrubber bleed solution, said apparatus comprising the electrode according to  claim 1 . 
     
     
         11 . A method for recovering mercury from solution, the method comprising collecting mercury electrochemically deposited at a cathode according to  claim 1 . 
     
     
         12 . A method for recovering from a solution a metal substantially liquid at room temperature, the method comprising the step of electrolytically depositing said metal at a substantially flat flow through cathode positioned in said solution and wherein said solution directly contacts both said cathode and a corresponding anode. 
     
     
         13 . The method according to  claim 12  wherein said cathode and said anode each have a substantially flat geometric surface and wherein said anode geometric surface and said cathode geometric surface are mutually opposed and substantially uniformly separated by a distance of less than about 2 cm. 
     
     
         14 . The method according to  claim 12  wherein said cathode has a surface area of at least about 500 m 2  per 1 m 2  of geometric surface. 
     
     
         15 . The method according to  claim 12  wherein the cathode is a carbon fibre cathode. 
     
     
         16 . The method according to  claim 12  wherein the current density between said anode and said cathode is less than about 10V per m 2  of geometrical cathode surface. 
     
     
         17 . The method according to  claim 12  wherein said solution is a scrubber bleed solution. 
     
     
         18 . The method according to  claim 12  wherein said metal is mercury. 
     
     
         19 . A continuous flow method according to  claim 12 . 
     
     
         20 . An electrochemical cell adapted to receive the electrode according to  claim 1  and comprising a solution inlet adapted to direct an electrolyte to flow through said electrode.