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US 8,764,962 B2Granted
Extraction of liquid elements by electrolysis of oxides
AssigneeMassachusetts Institute of Technology
InventorsAntoine Allanore, Donald R. Sadoway
Life of this patent
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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.
Claims43
A method of extracting a target element from an oxide feedstock of the target element, the method comprising:
- providing a liquid oxide electrolyte comprising at least 75% by weight of one or more oxide compounds, in which the oxide feedstock is dissolved forming ionic oxygen species and ionic target element species;
- providing an anode comprising a metallic anode substrate wherein one element constitutes at least 50% by weight of the metallic anode substrate, and wherein the one element is more reactive with respect to oxygen than the target element, the metallic anode substrate having a solid oxide layer comprising one or more oxides selected from the group consisting of the target element, the metallic anode substrate and the electrolyte, the anode in contact with the electrolyte;
- providing a cathode in contact with the electrolyte;
- driving electrons from the ionic oxygen species in the electrolyte into the metallic substrate across the solid oxide layer thereon so as to form gaseous oxygen;
- and
- reducing the ionic target element species in the electrolyte to form a liquid of the target element at the cathode, the target element having a melting temperature greater than 1200° C.
3 more elements
A method of extracting a target element from an oxide feedstock of the target element, the method comprising:
- providing a liquid oxide electrolyte in which the oxide feedstock is dissolved forming ionic oxygen species and ionic target element species, the oxide feedstock comprising an oxide of the target element selected from the group consisting of iron, titanium, nickel, manganese, cobalt, zirconium, chromium and silicon;
- providing an anode, in contact with the electrolyte at an interface, comprising a metallic anode substrate having at least 50% by weight of a metal selected from the group consisting of scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, zirconium, niobium, molybdenum, hafnium, tungsten and tantalum, the anode having a solid oxide outer layer comprising one or more oxides of a metal selected from the group consisting of chromium and iron;
- providing a liquid cathode in contact with the electrolyte;
- driving electrons from ionic oxygen species in the electrolyte into the metallic anode substrate across the oxide layer thereon to form gaseous oxygen;
- and
- reducing ionic species of the target element in the electrolyte to form the target element at the cathode.
3 more elements
A method of extracting iron from an oxide feedstock, the method comprising:
- providing a liquid oxide electrolyte comprising at least 75% by weight of one or more oxide compounds, in which the oxide feedstock is dissolved;
- providing 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, in contact with the electrolyte;
- providing a liquid cathode in contact with the electrolyte;
- driving electrons from oxygen precursors in the electrolyte into the metallic substrate to form gaseous oxygen;
- and
- reducing iron-bearing species in the electrolyte to form elemental iron at the cathode.
3 more elements
The method of 35 wherein a spinel phase develops on the anode during electrolysis.
An apparatus comprising:
- a liquid oxide electrolyte comprising at least 75% by weight of one or more oxide compounds selected from calcium oxide, magnesium oxide, aluminum oxide and silicon oxide, including ionic oxygen species and ionic target element species from an oxide feedstock compound dissolved in the electrolyte;
- a liquid cathode in contact with the electrolyte;
- and
- an anode, including a metallic anode substrate having at least 50% by weight of chromium and a metal selected from the group consisting of scandium, titanium, vanadium, manganese, iron, cobalt, nickel, zirconium, niobium, molybdenum, hafnium, tungsten and tantalum, the anode having a solid oxide layer comprising one or more oxides selected from the group consisting of the target element, the metallic anode substrate and the electrolyte, the anode in contact with the electrolyte at a contact interface,
- 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 ionic oxygen species across the solid oxide layer to form gaseous oxygen and reduce the ionic target element species to form the target element at the cathode.
2 more elements
An apparatus comprising:
- a liquid oxide electrolyte comprising at least 75% by weight of one or more oxide compounds and comprising an iron oxide feedstock dissolved therein thus forming ionic oxygen species and ionic iron species;
- a liquid cathode in contact with the electrolyte;
- and
- an anode, including a metallic anode substrate having at least 50% by weight of chromium and at least 1% by weight of iron, contacting the electrolyte at a contact interface,
- 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 ionic oxygen species into the anode to form gaseous oxygen and reduce the ionic iron species to form elemental iron at the cathode.
2 more elements
Dependencies are inferred from the claim text.