Extraction of Liquid Elements by Electrolysis of Oxides

Abstract

An electrolytic extraction method wins a target element from an oxide feedstock compound thereof. The feedstock compound is dissolved in an oxide melt in contact with a cathode and an anode in an electrolytic cell. During electrolysis the target element is deposited at a liquid cathode and coalesces therewith. Oxygen is evolved on an anode bearing a solid oxide layer, in contact with the oxide melt, over a metallic anode substrate.

What is claimed is: 
     
         1 . A method of extracting a target element from an oxide feedstock incorporating the target element, the method comprising:
 providing a liquid electrolyte, at least 75% oxide by weight, in which the oxide feedstock is dissolved;   providing an anode, including a metallic anode substrate, in contact with the electrolyte;   providing a cathode, in contact with the electrolyte;   driving electrons from an oxygen precursor in the electrolyte into the metallic substrate across an oxide layer thereon to form gaseous oxygen;   reducing an oxide specie of the target element in the electrolyte to form the target element at the cathode.   
     
     
         2 . The method of  claim 1  wherein at least one element more reactive with respect to oxygen than the target element constitutes at least 50% by weight of the metallic anode substrate. 
     
     
         3 . The method of  claim 1  wherein the metallic anode substrate comprises at least one of scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, zirconium, niobium, molybdenum, hafnium, tungsten and tantalum. 
     
     
         4 . The method of  claim 1  wherein the metallic anode substrate is an alloy. 
     
     
         5 . The method of  claim 3  wherein one of scandium, titanium, vanadium, manganese, iron, cobalt, nickel, yttrium, zirconium, niobium, molybdenum, hafnium, tungsten and tantalum constitute at least 70% by weight of the metallic anode substrate. 
     
     
         6 . The method of  claim 3  wherein chromium constitutes at least 70% by weight of the metallic anode substrate. 
     
     
         7 . The method of  claim 3  wherein the target element constitutes at least 1% by weight of the metallic anode substrate. 
     
     
         8 . The method of  claim 3  further comprising at least 0.1% by weight of the metallic anode substrate one of thorium, hafnium, zirconium or yttrium. 
     
     
         9 . The method of  claim 1  wherein the target element is one of titanium, nickel, manganese, cobalt, zirconium, chromium and silicon. 
     
     
         10 . The method of  claim 1  wherein the target element is iron and the feedstock compound is an iron oxide. 
     
     
         11 . The method of  claim 10  wherein the iron is formed by reduction at the cathode at a temperature less than 1500° C. 
     
     
         12 . The method of  claim 1  wherein the target element constitutes at least 90% by weight of material formed by reduction at the cathode during electrolysis. 
     
     
         13 . The method of  claim 1  wherein the electrolyte comprises an oxide of thorium, uranium, beryllium, strontium, barium, hafnium, zirconium or a rare earth element. 
     
     
         14 . The method of  claim 1  wherein the target metal is iron and the anode substrate is at least 50% chromium by weight. 
     
     
         15 . The method of  claim 14  wherein the metallic anode substrate incorporates tantalum or vanadium. 
     
     
         16 . The method of  claim 10  wherein the cathode is liquid carbon steel. 
     
     
         17 . The method of  claim 1  wherein the target element is titanium. 
     
     
         18 . An apparatus comprising:
 a liquid electrolyte, at least 75% oxide by weight, including oxygen precursors and species bearing a target element from an oxide feedstock compound dissolved in the electrolyte;   a liquid cathode, in contact with the electrolyte;   an anode, including a metallic anode substrate and a solid oxide layer, meeting the electrolyte at a contact interface, opposite the cathode,   
       the apparatus being operable, upon connection of the anode and the cathode to a power source, to electrolyze the dissolved oxide feedstock compound, drive electrons from the oxygen precursors across the solid oxide layer to form gaseous oxygen and reduce the species bearing the target element to form the target element at the cathode 
     
     
         19 . The method of  claim 18  wherein the target element is iron, the feedstock compound is an iron oxide, and the cathode is liquid carbon steel. 
     
     
         20 . An apparatus comprising:
 a liquid electrolyte, at least 75% oxide by weight, including oxygen precursors and species bearing iron from an oxide feedstock compound dissolved in the electrolyte;   a liquid cathode, in contact with the electrolyte;   an anode, including a metallic anode substrate at least 50% by weight of which is chromium and at least 1% by weight of which is iron, meeting the electrolyte at a contact interface, opposite the cathode,   
       the apparatus being operable, upon connection of the anode and the cathode to a power source, to electrolyze the dissolved oxide feedstock compound, drive electrons from the oxygen precursors into the anode to form gaseous oxygen and reduce the species bearing iron to form iron at the cathode.