Process for separating metals

Abstract

An electrorefining apparatus is capable of operating in continuous mode, and includes a criticality control mechanism, preferably a geometric criticality control mechanism, for example, to control the dimensions of the apparatus. Electrochemical cells include a large surface area per unit volume, preferably in the form of thin, flat plates. Cells include a crusting liquid cathodes, a cast cathode, a fluidised cell or pulsed bed, a moving belt cathode, a consolidating cathode, or a liquid anode and a plate cathode. A continuous process for the isolation of metals, typically uranium, from spent nuclear fuels includes electrochemically treating the spent nuclear fuels in the apparatus.

1 . An electrorefining apparatus, the apparatus comprising an electrorefining cell having an anode and a cathode, wherein the apparatus is adapted for operation in continuous mode, and includes means for criticality control, the means for criticality control comprising electrochemical cells having a large surface area per unit volume.  
   
   
       2 . An apparatus as claimed in  claim 1  wherein the means for criticality control comprises a thin flat plate.  
   
   
       3 . An apparatus as claimed in  claim 2  wherein the thin flat plate is horizontally or vertically disposed.  
   
   
       4 . An apparatus as claimed in  claim 1  further comprising means for the removal of deposited material from the apparatus, following operation.  
   
   
       5 . An apparatus as claimed in  claim 4  wherein the means for removal of deposited material comprises sweeping means, conveyor means or means by which a section of the apparatus may be removed.  
   
   
       6 . An apparatus as claimed in  claim 1  further comprising a vessel, an anode and a crusting liquid cathode.  
   
   
       7 . An apparatus as claimed in  claim 6  wherein the crusting liquid cathode comprises a liquid metal cathode or liquid alloy cathode.  
   
   
       8 - 10 . (canceled)  
   
   
       11 . An apparatus as claimed in  claim 1  further comprising a vessel, an anode and a cast cathode.  
   
   
       12 . An apparatus as claimed in  claim 11  wherein the cast cathode comprises a metal or alloy cathode with a lower melting point than uranium metal.  
   
   
       13 . An apparatus as claimed in  claim 12  wherein the cast cathode is introduced to an electrorefiner cell as a melted liquid cathode which is then frozen to form a solid metal or alloy cathode as a horizontal thin slab.  
   
   
       14 - 15 . (canceled)  
   
   
       16 . An apparatus as claimed in of  claim 1  further comprising a fluidised cell or pulsed bed.  
   
   
       17 . An apparatus as claimed in  claim 16  wherein the fluidised cell or pulsed bed comprises a vessel including an anode and a cathode which comprises cathode beads or particulates.  
   
   
       18 . An apparatus as claimed in  claim 16  further comprising a ceramic divider.  
   
   
       19 . An apparatus as claimed in  claim 17  wherein the cathode beads or particulates are formed from graphite or uranium.  
   
   
       20 . (canceled)  
   
   
       21 . An apparatus as claimed in  claim 1  which comprises a vessel, an anode and a moving belt cathode.  
   
   
       22 . An apparatus as claimed in  claim 21  wherein the moving belt cathode is mounted on a pair of rollers.  
   
   
       23 . An apparatus as claimed in  claim 21  wherein the moving belt cathode comprises a refractory metal belt.  
   
   
       24 - 25 . (canceled)  
   
   
       26 . An apparatus as claimed in  claim 1  further comprising a vessel, an anode and a consolidating cathode.  
   
   
       27 . An apparatus as claimed in  claim 26  wherein the consolidating cathode comprises at least one pair of rotating cylinders, the cylinders being suspended vertically.  
   
   
       28 . (canceled)  
   
   
       29 . An apparatus as claimed in  claim 27  wherein the cylinders are formed from uranium metal.  
   
   
       30 . (canceled)  
   
   
       31 . An apparatus as claimed in  claim 1  further comprising a vessel, a liquid anode and a plate cathode.  
   
   
       32 . An apparatus as claimed in  claim 31  wherein the plate cathode is arranged in sections or modules.  
   
   
       33 . An apparatus as claimed in  claim 31  wherein the liquid anode comprises spent fuel pre-dissolved or slurried in liquid metal or alloy.  
   
   
       34 . An apparatus as claimed in  claim 31  wherein the plate cathode comprises a horizontal thin slab positioned above the anode in parallel plate arrangement.  
   
   
       35 . An apparatus as claimed in  claim 31  wherein the plate cathode is comprised of uranium.  
   
   
       36 . A continuous process for the isolation of metals from spent nuclear fuels, the process comprising electrochemically treating the spent nuclear fuels in an apparatus according to  claim 1 .  
   
   
       37 . A process as claimed in  claim 36  further comprising the electrochemical separation of uranium metal from spent nuclear fuel, the spent nuclear fuel comprising reduced metal oxides.  
   
   
       38 - 40 . (canceled)  
   
   
       41 . A process as claimed in  claim 36  wherein an electrolyte is introduced into the apparatus, the electrolyte comprising molten salt or an ionic liquid.  
   
   
       42 - 46 . (canceled)  
   
   
       47 . An apparatus as claimed in  claim 5 , wherein the sweeping means comprises a scraper.  
   
   
       48 . An apparatus as claimed in  claim 1 , wherein the anode is adapted for use in a continuous process.