US20050139474A1 - Electrochemical cell for metal production - Google Patents
Electrochemical cell for metal production Download PDFInfo
- Publication number
- US20050139474A1 US20050139474A1 US10/505,262 US50526205A US2005139474A1 US 20050139474 A1 US20050139474 A1 US 20050139474A1 US 50526205 A US50526205 A US 50526205A US 2005139474 A1 US2005139474 A1 US 2005139474A1
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- US
- United States
- Prior art keywords
- cathode
- oxide
- cell
- housing
- metal oxides
- Prior art date
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- Abandoned
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- 229910052751 metal Inorganic materials 0.000 title claims abstract description 20
- 239000002184 metal Substances 0.000 title claims abstract description 20
- 238000004519 manufacturing process Methods 0.000 title description 8
- 238000000034 method Methods 0.000 claims abstract description 58
- 230000008569 process Effects 0.000 claims abstract description 54
- 150000003839 salts Chemical class 0.000 claims abstract description 30
- 229910044991 metal oxide Inorganic materials 0.000 claims abstract description 26
- 150000004706 metal oxides Chemical class 0.000 claims abstract description 26
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 14
- 239000003792 electrolyte Substances 0.000 claims abstract description 14
- 239000001301 oxygen Substances 0.000 claims abstract description 14
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 14
- 150000001768 cations Chemical class 0.000 claims abstract description 7
- 230000008021 deposition Effects 0.000 claims abstract description 7
- 239000000446 fuel Substances 0.000 claims description 16
- 239000002915 spent fuel radioactive waste Substances 0.000 claims description 11
- WZECUPJJEIXUKY-UHFFFAOYSA-N [O-2].[O-2].[O-2].[U+6] Chemical compound [O-2].[O-2].[O-2].[U+6] WZECUPJJEIXUKY-UHFFFAOYSA-N 0.000 claims description 10
- 229910000439 uranium oxide Inorganic materials 0.000 claims description 10
- 229910052770 Uranium Inorganic materials 0.000 claims description 8
- JFALSRSLKYAFGM-UHFFFAOYSA-N uranium(0) Chemical compound [U] JFALSRSLKYAFGM-UHFFFAOYSA-N 0.000 claims description 7
- FCTBKIHDJGHPPO-UHFFFAOYSA-N uranium dioxide Inorganic materials O=[U]=O FCTBKIHDJGHPPO-UHFFFAOYSA-N 0.000 claims description 6
- 150000003841 chloride salts Chemical class 0.000 claims description 5
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical group [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 claims description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 4
- 229910000310 actinide oxide Inorganic materials 0.000 claims description 4
- 229910052799 carbon Inorganic materials 0.000 claims description 4
- 238000005253 cladding Methods 0.000 claims description 4
- 239000008188 pellet Substances 0.000 claims description 4
- 229910001626 barium chloride Inorganic materials 0.000 claims description 3
- WDIHJSXYQDMJHN-UHFFFAOYSA-L barium chloride Chemical compound [Cl-].[Cl-].[Ba+2] WDIHJSXYQDMJHN-UHFFFAOYSA-L 0.000 claims description 3
- 239000001110 calcium chloride Substances 0.000 claims description 3
- 229910001628 calcium chloride Inorganic materials 0.000 claims description 3
- OOAWCECZEHPMBX-UHFFFAOYSA-N oxygen(2-);uranium(4+) Chemical compound [O-2].[O-2].[U+4] OOAWCECZEHPMBX-UHFFFAOYSA-N 0.000 claims description 3
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 claims description 2
- 229910052735 hafnium Inorganic materials 0.000 claims description 2
- VBJZVLUMGGDVMO-UHFFFAOYSA-N hafnium atom Chemical compound [Hf] VBJZVLUMGGDVMO-UHFFFAOYSA-N 0.000 claims description 2
- 238000003466 welding Methods 0.000 claims description 2
- 229910052726 zirconium Inorganic materials 0.000 claims description 2
- SHZGCJCMOBCMKK-KGJVWPDLSA-N beta-L-fucose Chemical compound C[C@@H]1O[C@H](O)[C@@H](O)[C@H](O)[C@@H]1O SHZGCJCMOBCMKK-KGJVWPDLSA-N 0.000 claims 1
- 210000004027 cell Anatomy 0.000 description 22
- 238000005868 electrolysis reaction Methods 0.000 description 6
- KWGKDLIKAYFUFQ-UHFFFAOYSA-M lithium chloride Chemical compound [Li+].[Cl-] KWGKDLIKAYFUFQ-UHFFFAOYSA-M 0.000 description 6
- 238000000151 deposition Methods 0.000 description 5
- 239000006227 byproduct Substances 0.000 description 4
- 229910052744 lithium Inorganic materials 0.000 description 4
- 239000007787 solid Substances 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 150000002739 metals Chemical class 0.000 description 3
- 239000003758 nuclear fuel Substances 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 description 2
- FUJCRWPEOMXPAD-UHFFFAOYSA-N Li2O Inorganic materials [Li+].[Li+].[O-2] FUJCRWPEOMXPAD-UHFFFAOYSA-N 0.000 description 2
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 2
- 229910052778 Plutonium Inorganic materials 0.000 description 2
- 229910052768 actinide Inorganic materials 0.000 description 2
- 150000001255 actinides Chemical class 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 229910001424 calcium ion Inorganic materials 0.000 description 2
- 239000000460 chlorine Substances 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- XUCJHNOBJLKZNU-UHFFFAOYSA-M dilithium;hydroxide Chemical compound [Li+].[Li+].[OH-] XUCJHNOBJLKZNU-UHFFFAOYSA-M 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- OYEHPCDNVJXUIW-UHFFFAOYSA-N plutonium atom Chemical compound [Pu] OYEHPCDNVJXUIW-UHFFFAOYSA-N 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 238000011946 reduction process Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229910000882 Ca alloy Inorganic materials 0.000 description 1
- 229910000925 Cd alloy Inorganic materials 0.000 description 1
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- 229910000733 Li alloy Inorganic materials 0.000 description 1
- 229910001093 Zr alloy Inorganic materials 0.000 description 1
- 239000004411 aluminium Substances 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 210000005056 cell body Anatomy 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000005363 electrowinning Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000004992 fission Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 239000002608 ionic liquid Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 238000001465 metallisation Methods 0.000 description 1
- 239000007800 oxidant agent Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 125000004430 oxygen atom Chemical group O* 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 150000003671 uranium compounds Chemical class 0.000 description 1
- -1 uranium ions Chemical class 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- G21C—NUCLEAR REACTORS
- G21C19/00—Arrangements for treating, for handling, or for facilitating the handling of, fuel or other materials which are used within the reactor, e.g. within its pressure vessel
- G21C19/42—Reprocessing of irradiated fuel
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
- C25C3/00—Electrolytic production, recovery or refining of metals by electrolysis of melts
- C25C3/34—Electrolytic production, recovery or refining of metals by electrolysis of melts of metals not provided for in groups C25C3/02 - C25C3/32
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
- C25C7/00—Constructional parts, or assemblies thereof, of cells; Servicing or operating of cells
- C25C7/005—Constructional parts, or assemblies thereof, of cells; Servicing or operating of cells of cells for the electrolysis of melts
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
- Y02E30/30—Nuclear fission reactors
Definitions
- This invention relates to methods for the production of metals from oxides present in spent nuclear fuels and is particularly applicable to the production of actinides, specifically uranium. Methods of the present invention can be used in the treatment of irradiated fuels for producing actinides in metallic form suitable for use as feeds in subsequent electrorefining processes.
- molten salts is intended to cover salts such as lithium chloride which melts at an elevated temperature and also ionic liquids which typically are liquid at room temperature or which melt at a temperature up to about: 100 ° C.
- the Dimitrovgrad SSC-RIAR process makes use of chemical oxidants (chlorine and oxygen gases) to react with powdered uranium dioxide fuel to form higher oxidation state compounds such as UO 2 Cl 2 which are soluble in the molten salt, In an electrochemical cell the uranium compounds are reduced to UO 2 at the cathode, forming a dendritic deposit.
- chemical oxidants chlorine and oxygen gases
- the second process developed by the Argonne National Laboratory (ANL) is fundamentally an electrorefining technology which uses direct current to anodically oxidise uranium to form uranium ions in the molten salt electrolyte. At the cathode the uranium is reduced and electrodeposited as dendritic uranium metal.
- the ANL process requires a metal feed. If oxide fuels are to be treated, it is necessary to reduce the uranium oxide (usually UO 2 pellets) to the metal. This reduction process is carried out chemically, using lithium metal in a LiCl or LiCl/KCl molten salt or a Li/Cd alloy, at 500 to 600° C. Alternatively, a salt transport process can be used involving a Cu—Mg—Ca alloy and molten CaCl 2 salt. However, in both reduction methods the by-products, Li 2 O and CaO respectively, need to be recovered from the molten salt phase by an electrolysis step. Effectively this means a two stage process.
- a disadvantage of the lithium reduction process for producing a metallic feed from an oxide is the production of Li 2 O by-product This requires recycle to make the process economic, and this is done by an electrolytic recovery of lithium metal. Hence this is a two stage process, comprising a reduction step followed by a lithium recovery stage.
- U.S. Pat. No. 5,378,325 discloses a low temper salt bath for the electrolysis of metal oxides to the corresponding metal, the bath comprising fluoride and chloride salts and including a low surface area carbonaceous anode.
- WO-A-00/40872 teaches a cell for the electrowinning of aluminium from alumina dissolved in a fluoride-containing molten electrolyte, the cell being provided with non-carbon metal-based anodes arranged to facilitate the circulation of electrolyte.
- much of the known prior art is merely concerned with metal oxides in general, and makes no mention of the metal oxides to be found in spent nuclear fuel.
- the process thereby involves the use of a single electrochemical process to reduce the metal oxide fuel to a metallic form, with oxygen, CO or CO 2 produced as the only by-products.
- the potential of the cathode is maintained and controlled so that only oxygen ionisation occurs and not the deposition of metal (eg Ca) from the cations (eg Ca ions) in the fused salt.
- the oxide comprises an actinide oxide, such as uranium oxide or irradiated uranium oxide.
- U.S. Pat. No. 6,540,902 describes a similar single step process for reducing to metallic form a metal oxide present in spent nuclear fuel, the process comprising cathodically electrolysing the oxide in the presence of a molten salt electrolyte, the potential of the cathode being controlled so as to prevent production of reductant metal from ions in the electrolyte, whilst the potential of the anode is controlled so as to prevent anode dissolution and gas evolution other than oxygen
- the present inventors have, however, now effected an improvement to the processes described in WO-A-01141152 and U.S. Pat. No. 6,540,902, thereby allowing a more practical efficient and financially viable process to be adopted in the production of metals from oxides.
- the new process is particularly beneficial in that it facilitates the removal of bolted and screwed fittings from the apparatus used for the production of the metal.
- au apparatus for performing a process for reducing to metallic form metal oxides, the said metal oxides comprising metal oxides present in spent nuclear fuel, wherein the apparatus comprises an electrochemical cell which comprises a body or housing, a cathode container, and a cathode connector, said body or housing being maintained as the cathode, and said electrochemical cell being free from bolted or screwed fittings.
- the body or housing of the cell which comprises the apparatus according to the first aspect of the invention is most conveniently maintained as the cathode by the provision of an electrical connection from a power supply, provided by means of a connector from the cathode terminal to the body or housing of the cell.
- said connector comprises a bolted connection, but this is positioned externally to the cell.
- No bolted or screwed connections are present within the cell, wherein a cathode connector is provided which is affixed to an internal surface of the cell, most preferably the base of the cell, generally by welding.
- said cathode connector comprises a cathode rail.
- the body or housing of the cell is maintained as the cathode, and said cathode is brought into contact with the cathode container by means of the cathode connector.
- contact is made between the cathode container and the cathode connector in order to facilitate the electrolytic process.
- Contact may be most conveniently achieved by means of a simple press connection between the two components.
- the cathode container preferably comprises a basket, such as a mesh basket, or vessel, typically a metal oxide retaining vessel, and—most preferably—comprises an assembly of such baskets or vessels.
- a basket such as a mesh basket, or vessel, typically a metal oxide retaining vessel, and—most preferably—comprises an assembly of such baskets or vessels.
- the oxide is in contact with the cathode coder and it is preferred that the cathode is in the form of a mesh basket or, most preferably, an assembly of mesh baskets, with the oxide being contained within the said baskets.
- contact between the assembly of cathode containers and the cathode connectors is most simply achieved when the cathode connectors are in the form of a multiplicity of cathode rails which are welded to the base of the cell, allowing press contact to be brought about by the weight of the oxide feedstock in the cathode basket.
- the anode may be any suitable inert anode, such as carbon.
- a process for reducing to metallic form metal oxides comprising metal oxides present in spent nuclear fuel, the process comprising cathodically electrolysing the oxide in the presence of a molten salt electrolyte in an apparatus according to the first aspect of the invention, the potential of the cathode being controlled so as to favor oxygen ionisation over deposition of metal from the cations present in the molten salt.
- the molten salt electrolyte may be any suitable molten salt or mixture of such salts, for instance chloride salts, preferably CaCl 2 and/or BaCl 2 .
- the oxide treated by the process according to the second aspect of the invention comprises an actinide oxide, such as uranium oxide or irradiated uranium oxide, or mixed uranium/plutonium oxides.
- the uranium oxide is commonly uranium dioxide.
- the oxide may comprise the oxide of a metal such as zirconium or hafnium.
- the fuel may be first treated mechanically to remove its zircaloy cladding before it is added to the electrolytic cell.
- the ziraloy cladding maybe treated with the fuel.
- the fuel may require to be sheared into sections of small length prior to treatment in order to expose the oxide fuel to the molten salt.
- Said oxide may be in any physical form, and this is generally dependent on the particular chemical nature of the spent nuclear fuel and the processing to which the material has previously been subjected.
- the fuel may comprise a powder, an amorphous mass, or a dense solid agglomerate.
- the material may be treated according to the method of the second aspect of the present invention by connection to an electrical circuit such that it serves as the cathode during electrolysis; as previously disclosed, connection to the circuit may be conveniently effected by the use of a cathode basket, into which the material is placed.
- the process provides a single electrochemical process to reduce the metal oxide fuel to a metallic form, with oxygen produced as the only by-product.
- the potential of the cathode is maintained and controlled so that only oxygen ionisation occurs and not the deposition of metal (eg Ca) from the cations (eg Ca ions) in the fused salt.
- the process according to the second aspect of the invention provides a more practical, efficient and financially viable means for the production of metal from oxides.
- the electrical continuity of the system which is provided is effective since all the components are held in the cathodic potential region and are, therefore, metallic in nature.
- an electrolytic cell which has a carbon anode, a mesh basket cathode and a cathode rail connector welded to the base of the cell.
- Irradiated oxide fuel is placed in the mesh basket.
- the electrolyte consists of a molten salt or a mixture of such salts comprising, for example, chloride salts such as CaCl 2 or BaCl 2 .
- a voltage is applied between the cathode and the anode.
- the reaction involves the diffusion of oxygen atoms to the surface of the solid, followed by ionisation according to the reaction: O 2 +4e ⁇ ⁇ 2O 2 ⁇ .
- the oxide ions which are produced dissolve in the electrolyte and are transferred to the anode where they are re-oxidised to produce oxygen, CO or CO 2 gases.
- the potential at the cathode may be controlled, via a third reference electrode, to ensure that the reaction occurring at the cathode is oxygen ionisation and not deposition of eg Ca metal from the cations in the fused salt. Electrolysis at elevated temperatures results in an increased rate of oxygen diffusion, thereby also encouraging ionisation rather than metal deposition.
- the irradiated fuel is left in the form of a metallic solid at the cathode.
- This metallic solid which contains fission products, can be removed or used directly as the feed for an electrorefinig process. The remaining components of the cell may be re-used immediately without the need for any cleaning.
- the electrolytic ionisation of oxygen and the electrorefining processes are carried out in the same cell and the same salt system.
- a second cathode, or cathode assembly may be required.
- the advantage of the apparatus and process of the present invention is that they facilitate the performance of an effectively single stage process which provides advantages over the prior art in terms of practicality, efficiency and cost.
- the process is advantageously used for the treatment of irradiated oxide nuclear fuel, possibly in the form of pellets and, most particularly, is applied to fuels such as uranium oxide, and mixed uranium and plutonium fuels.
- FIG. 1 shows an apparatus according to the first aspect of the invention which comprises a series of electrolytic cells, the bodies and housings of which are, in use, connected by means of cathode rails 1 to cathode baskets 2 .
- the cells also comprise anodes 4 , surrounded by anode protective sleeves 3 , and connected to an electrical supply by means of electrical connections 6 , these being protected by insulation shrouds 5 .
- the cathode baskets 2 which are equipped with basket handles 8 , cooled by means of cooling chambers 7 , are loaded with spent nuclear fuel pellets and lowered into the electrolyte 9 to a point at which contact is made with cathode rails 1 and, thereby, with the cell housing, which is maintained as the cathode, thereby allowing processing to commence.
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Physics & Mathematics (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Plasma & Fusion (AREA)
- General Engineering & Computer Science (AREA)
- High Energy & Nuclear Physics (AREA)
- Electrolytic Production Of Metals (AREA)
Abstract
A process for reducing to metallic form metal oxides includes cathodically electrolysing the oxide in the presence of a molten salt electrolyte whilst controlling the potential of the cathode so as to favour oxygen ionisation over deposition of metal from the cations present in the molten salt, and an apparatus for performing the said process. The apparatus is free from bolted or screwed fittings and includes an electrochemical cell that includes a body or housing, a cathode container, and a cathode connector, wherein the body or housing is maintained as the cathode.
Description
- This invention relates to methods for the production of metals from oxides present in spent nuclear fuels and is particularly applicable to the production of actinides, specifically uranium. Methods of the present invention can be used in the treatment of irradiated fuels for producing actinides in metallic form suitable for use as feeds in subsequent electrorefining processes.
- In the established art, two processes have been developed for the treatment of irradiated nuclear fuel making use of molten salts. As used herein, the term “molten salts” is intended to cover salts such as lithium chloride which melts at an elevated temperature and also ionic liquids which typically are liquid at room temperature or which melt at a temperature up to about: 100 ° C.
- The Dimitrovgrad SSC-RIAR process makes use of chemical oxidants (chlorine and oxygen gases) to react with powdered uranium dioxide fuel to form higher oxidation state compounds such as UO2Cl2 which are soluble in the molten salt, In an electrochemical cell the uranium compounds are reduced to UO2 at the cathode, forming a dendritic deposit. This process has both technical and environmental limitations.
- The second process, developed by the Argonne National Laboratory (ANL) is fundamentally an electrorefining technology which uses direct current to anodically oxidise uranium to form uranium ions in the molten salt electrolyte. At the cathode the uranium is reduced and electrodeposited as dendritic uranium metal.
- The ANL process requires a metal feed. If oxide fuels are to be treated, it is necessary to reduce the uranium oxide (usually UO2 pellets) to the metal. This reduction process is carried out chemically, using lithium metal in a LiCl or LiCl/KCl molten salt or a Li/Cd alloy, at 500 to 600° C. Alternatively, a salt transport process can be used involving a Cu—Mg—Ca alloy and molten CaCl2 salt. However, in both reduction methods the by-products, Li2O and CaO respectively, need to be recovered from the molten salt phase by an electrolysis step. Effectively this means a two stage process.
- A disadvantage of the lithium reduction process for producing a metallic feed from an oxide is the production of Li2O by-product This requires recycle to make the process economic, and this is done by an electrolytic recovery of lithium metal. Hence this is a two stage process, comprising a reduction step followed by a lithium recovery stage.
- The prior art discloses many processes and apparatuses for the reduction of metal oxides to metals by cathodic electrolysis of the oxide in a molten salt. Thus, for example U.S. Pat. No. 5,378,325 discloses a low temper salt bath for the electrolysis of metal oxides to the corresponding metal, the bath comprising fluoride and chloride salts and including a low surface area carbonaceous anode. Alternatively, WO-A-00/40872 teaches a cell for the electrowinning of aluminium from alumina dissolved in a fluoride-containing molten electrolyte, the cell being provided with non-carbon metal-based anodes arranged to facilitate the circulation of electrolyte. As with these disclosures, however, much of the known prior art is merely concerned with metal oxides in general, and makes no mention of the metal oxides to be found in spent nuclear fuel.
- In co-pending PCT patent application WO-A-01141152 there is disclosed a single step process for reducing to metallic form a metal oxide present in spent nuclear fuel, the process comprising cathodically electrolysing the oxide in the presence of a molten salt electrolyte, the potential of the cathode being controlled so as to favour oxygen ionisation over deposition of the metal from the cations present in the molten salt.
- The process thereby involves the use of a single electrochemical process to reduce the metal oxide fuel to a metallic form, with oxygen, CO or CO2 produced as the only by-products. The potential of the cathode is maintained and controlled so that only oxygen ionisation occurs and not the deposition of metal (eg Ca) from the cations (eg Ca ions) in the fused salt. Typically, the oxide comprises an actinide oxide, such as uranium oxide or irradiated uranium oxide.
- U.S. Pat. No. 6,540,902 describes a similar single step process for reducing to metallic form a metal oxide present in spent nuclear fuel, the process comprising cathodically electrolysing the oxide in the presence of a molten salt electrolyte, the potential of the cathode being controlled so as to prevent production of reductant metal from ions in the electrolyte, whilst the potential of the anode is controlled so as to prevent anode dissolution and gas evolution other than oxygen
- The present inventors have, however, now effected an improvement to the processes described in WO-A-01141152 and U.S. Pat. No. 6,540,902, thereby allowing a more practical efficient and financially viable process to be adopted in the production of metals from oxides. The new process is particularly beneficial in that it facilitates the removal of bolted and screwed fittings from the apparatus used for the production of the metal.
- Thus, according to a first aspect of the present invention there is provided au apparatus for performing a process for reducing to metallic form metal oxides, the said metal oxides comprising metal oxides present in spent nuclear fuel, wherein the apparatus comprises an electrochemical cell which comprises a body or housing, a cathode container, and a cathode connector, said body or housing being maintained as the cathode, and said electrochemical cell being free from bolted or screwed fittings.
- The body or housing of the cell which comprises the apparatus according to the first aspect of the invention is most conveniently maintained as the cathode by the provision of an electrical connection from a power supply, provided by means of a connector from the cathode terminal to the body or housing of the cell. Typically, said connector comprises a bolted connection, but this is positioned externally to the cell. No bolted or screwed connections are present within the cell, wherein a cathode connector is provided which is affixed to an internal surface of the cell, most preferably the base of the cell, generally by welding. Preferably said cathode connector comprises a cathode rail.
- In operation, the body or housing of the cell is maintained as the cathode, and said cathode is brought into contact with the cathode container by means of the cathode connector. Thus, contact is made between the cathode container and the cathode connector in order to facilitate the electrolytic process. Contact may be most conveniently achieved by means of a simple press connection between the two components.
- The cathode container preferably comprises a basket, such as a mesh basket, or vessel, typically a metal oxide retaining vessel, and—most preferably—comprises an assembly of such baskets or vessels. In order to effect electrical connection between such an assembly of cathode containers and the cell body during operation of the cell, it is necessary to provide a multiplicity of connectors and to effect contact between individual cathode baskets or vessels and individual connectors, preferably by means of a multiplicity of press connections.
- Preferably the oxide is in contact with the cathode coder and it is preferred that the cathode is in the form of a mesh basket or, most preferably, an assembly of mesh baskets, with the oxide being contained within the said baskets. In this case, contact between the assembly of cathode containers and the cathode connectors is most simply achieved when the cathode connectors are in the form of a multiplicity of cathode rails which are welded to the base of the cell, allowing press contact to be brought about by the weight of the oxide feedstock in the cathode basket. This represents the most preferred embodiment of the first aspect of the invention. The anode may be any suitable inert anode, such as carbon.
- According to a second aspect of the present invention, there is provided a process for reducing to metallic form metal oxides, the said metal oxides comprising metal oxides present in spent nuclear fuel, the process comprising cathodically electrolysing the oxide in the presence of a molten salt electrolyte in an apparatus according to the first aspect of the invention, the potential of the cathode being controlled so as to favor oxygen ionisation over deposition of metal from the cations present in the molten salt.
- The molten salt electrolyte, may be any suitable molten salt or mixture of such salts, for instance chloride salts, preferably CaCl2 and/or BaCl2.
- Preferably, the oxide treated by the process according to the second aspect of the invention comprises an actinide oxide, such as uranium oxide or irradiated uranium oxide, or mixed uranium/plutonium oxides. The uranium oxide is commonly uranium dioxide. Alternatively, the oxide may comprise the oxide of a metal such as zirconium or hafnium.
- In the said process, the fuel may be first treated mechanically to remove its zircaloy cladding before it is added to the electrolytic cell. Alternatively, the ziraloy cladding maybe treated with the fuel. The fuel may require to be sheared into sections of small length prior to treatment in order to expose the oxide fuel to the molten salt.
- Said oxide may be in any physical form, and this is generally dependent on the particular chemical nature of the spent nuclear fuel and the processing to which the material has previously been subjected. For example, the fuel may comprise a powder, an amorphous mass, or a dense solid agglomerate. In any event, the material may be treated according to the method of the second aspect of the present invention by connection to an electrical circuit such that it serves as the cathode during electrolysis; as previously disclosed, connection to the circuit may be conveniently effected by the use of a cathode basket, into which the material is placed.
- The process provides a single electrochemical process to reduce the metal oxide fuel to a metallic form, with oxygen produced as the only by-product. The potential of the cathode is maintained and controlled so that only oxygen ionisation occurs and not the deposition of metal (eg Ca) from the cations (eg Ca ions) in the fused salt.
- The process according to the second aspect of the invention provides a more practical, efficient and financially viable means for the production of metal from oxides. The electrical continuity of the system which is provided is effective since all the components are held in the cathodic potential region and are, therefore, metallic in nature.
- In order to carry out an embodiment of the process according to the second aspect of the present invention, using a metal oxide which comprises spent nuclear fuel, an electrolytic cell is assembled which has a carbon anode, a mesh basket cathode and a cathode rail connector welded to the base of the cell. Irradiated oxide fuel is placed in the mesh basket. The electrolyte consists of a molten salt or a mixture of such salts comprising, for example, chloride salts such as CaCl2 or BaCl2. A voltage is applied between the cathode and the anode. At the cathode the reaction involves the diffusion of oxygen atoms to the surface of the solid, followed by ionisation according to the reaction:
O2+4e−→2O2−. - The oxide ions which are produced dissolve in the electrolyte and are transferred to the anode where they are re-oxidised to produce oxygen, CO or CO2 gases. The potential at the cathode may be controlled, via a third reference electrode, to ensure that the reaction occurring at the cathode is oxygen ionisation and not deposition of eg Ca metal from the cations in the fused salt. Electrolysis at elevated temperatures results in an increased rate of oxygen diffusion, thereby also encouraging ionisation rather than metal deposition.
- After electrolysis the irradiated fuel is left in the form of a metallic solid at the cathode. This metallic solid, which contains fission products, can be removed or used directly as the feed for an electrorefinig process. The remaining components of the cell may be re-used immediately without the need for any cleaning.
- In an alternative embodiment in accordance with the present invention the electrolytic ionisation of oxygen and the electrorefining processes are carried out in the same cell and the same salt system. In such cases a second cathode, or cathode assembly, may be required.
- It is to be emphasised that the advantage of the apparatus and process of the present invention is that they facilitate the performance of an effectively single stage process which provides advantages over the prior art in terms of practicality, efficiency and cost. The process is advantageously used for the treatment of irradiated oxide nuclear fuel, possibly in the form of pellets and, most particularly, is applied to fuels such as uranium oxide, and mixed uranium and plutonium fuels.
- In order to fully illustrate the above and other features of the apparatus according to the first aspect of the invention, without in any way limiting the scope of the invention, a preferred embodiments will now be described with reference to the drawing.
-
FIG. 1 shows an apparatus according to the first aspect of the invention which comprises a series of electrolytic cells, the bodies and housings of which are, in use, connected by means ofcathode rails 1 tocathode baskets 2. The cells also compriseanodes 4, surrounded by anodeprotective sleeves 3, and connected to an electrical supply by means ofelectrical connections 6, these being protected byinsulation shrouds 5. - In operation, the
cathode baskets 2, which are equipped with basket handles 8, cooled by means of coolingchambers 7, are loaded with spent nuclear fuel pellets and lowered into theelectrolyte 9 to a point at which contact is made withcathode rails 1 and, thereby, with the cell housing, which is maintained as the cathode, thereby allowing processing to commence.
Claims (26)
1. An apparatus for performing a process for reducing to metallic form metal oxides, the metal oxides comprising metal oxides present in spent nuclear fuel, wherein the apparatus comprises:
an electrochemical cell which comprises:
a body or housing;
a cathode container; and
a cathode connector;
wherein said body or housing is maintained as the cathode, and said electrochemical cell is free from bolted or screwed fittings.
2. An apparatus as claimed in claim 1 wherein said cathode connector is affixed to an internal surface of the cell.
3. An apparatus as claimed in claim 2 wherein said cathode connector is affixed to an internal surface of the cell by means of welding.
4. An apparatus as claimed in claim 1 wherein an electrical connection from the cathode container to the body or housing of the cell is provided by means of a cathode connector.
5. An apparatus as claimed in claim 4 wherein said electrical connection is provided by means of a press connection.
6. An apparatus as claimed in claim 1 wherein said cathode connector comprises a cathode rail.
7. An apparatus as claimed in claim 6 wherein said rail is welded to the base of the cell.
8. An apparatus as claimed in claim 1 wherein the cathode container comprises a mesh basket or metal oxide retaining vessel.
9. An apparatus as claimed in claim 1 wherein the cathode container comprises an assembly of cathode containers.
10. An apparatus as claimed in claim 9 wherein said assembly comprises an assembly of mesh baskets or metal oxide retaining vessels.
11. An apparatus as claimed in claim 1 wherein the electromechanical cell further comprises a carbon anode.
12. An apparatus as claimed in claim 1 wherein the body or housing of the cell is maintained as the cathode by the provision of an electrical connection from a power supply to the body or housing of the cell.
13. A process for reducing to metallic form metal oxides, said metal oxides comprising metal oxides present in spent nuclear fuel, the process comprising:
cathodically electrolysing the oxide in the presence of a molten salt electrolyte in an apparatus, the apparatus comprising:
an electrochemical cell which comprises:
a body or housing;
a cathode container; and
a cathode connector;
wherein said body or housing is maintained as the cathode, and said electrochemical cell is free from bolted or screwed fittings;
controlling the potential of the cathode so as to favour oxygen ionisation over deposition of metal from the cations present in the molten salt.
14. A process as claimed in claim 13 wherein
maintaining the body or housing of the cell as the cathode while bringing the body or housing of the cell into contact with the cathode container by means of a press connection between said container and a cathode connector.
15. A process as claimed in claim 13 wherein the oxide comprises the oxide of zirconium or hafnium.
16. A process as claimed in claim 13 wherein the oxide comprises an actinide oxide.
17. A process as claimed in claim 16 wherein the actinide oxide comprises uranium oxide, irradiated uranium oxide and/or mixed uranium/plutonium oxide fuel pellets.
18. A process as claimed in claim 17 wherein the uranium oxide comprises uranium dioxide.
19. A process as claimed in claim 13 wherein the oxide is located in a mesh basket which forms the cathode.
20. A process as claimed in claim 13 wherein the molten salt electrolyte comprises at least one chloride salt.
21. A process as claimed in claim 20 wherein chloride salt is CaCl2 or BaCl2.
22. A process as claimed in claim 13 wherein the spent nuclear fuel comprises cladding.
23. A process as claimed in claim 13 , further comprising:
removing the cladding from the fuel prior to cathodically electrolysing the oxide and controlling the potential of the cathode.
24. A process as claimed in claim 13 further comprising:
using the metal oxides reduced to metallic form as the feed for an electrorefining process.
25. A process as claimed in claims 24 wherein the electrorefining process is carried out in a same electrolytic cell as cathodically electrolysing the oxide and controlling the potential of the cathode.
26. (canceled)
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
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GBGB0204671.2A GB0204671D0 (en) | 2002-02-28 | 2002-02-28 | Electrochemical cell for metal production |
GB0204671.2 | 2002-02-28 | ||
PCT/GB2003/000792 WO2003073436A1 (en) | 2002-02-28 | 2003-02-24 | Electrochemical cell for metal production |
Publications (1)
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US20050139474A1 true US20050139474A1 (en) | 2005-06-30 |
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Family Applications (1)
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US10/505,262 Abandoned US20050139474A1 (en) | 2002-02-28 | 2003-02-24 | Electrochemical cell for metal production |
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US (1) | US20050139474A1 (en) |
EP (1) | EP1481401B1 (en) |
JP (1) | JP2005519192A (en) |
KR (1) | KR20040093726A (en) |
CN (1) | CN1639803A (en) |
AU (1) | AU2003207344A1 (en) |
GB (1) | GB0204671D0 (en) |
RU (1) | RU2004127170A (en) |
WO (1) | WO2003073436A1 (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
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US20040244533A1 (en) * | 2001-06-06 | 2004-12-09 | Lewin Rober Glynn | Actinide production |
US20140021058A1 (en) * | 2011-02-04 | 2014-01-23 | Metalysis Limited | Electrolysis method and apparatus |
US9382632B2 (en) | 2013-06-21 | 2016-07-05 | Savannah River Nuclear Solutions, Llc | Electrochemical fluorination for processing of used nuclear fuel |
US9920443B2 (en) | 2010-12-23 | 2018-03-20 | Ge-Hitachi Nuclear Energy Americas Llc | Modular cathode assemblies and methods of using the same for electrochemical reduction |
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US20090272650A1 (en) * | 2005-12-27 | 2009-11-05 | Kawasaki Plant Systems Kabushiki Kaisha | Apparatus and Method for Recovering Valuable Substance From Lithium Secondary Battery |
RU2340021C1 (en) * | 2007-06-05 | 2008-11-27 | Николай Викторович СТЕПАНОВ | Method of spent nuclear fuel recycling |
KR100992716B1 (en) * | 2009-10-13 | 2010-11-05 | 석상엽 | Electrolyzer for withdrawing valuable metal which having more contact specific surface area |
CN101994133B (en) * | 2010-11-24 | 2012-10-17 | 中国原子能科学研究院 | Molten salt system for dry post-treatment of oxide spent fuel |
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JP5897397B2 (en) * | 2012-04-26 | 2016-03-30 | 株式会社東芝 | Electrolytic reduction device |
AU2013204396B2 (en) * | 2012-05-16 | 2015-01-29 | Lynas Services Pty Ltd | Electrolytic cell for production of rare earth metals |
GB2563792B8 (en) * | 2016-03-16 | 2022-04-27 | Richard Scott Ian | Conversion of spent uranium oxide fuel into molten salt reactor fuel |
CN107385484B (en) * | 2017-07-14 | 2020-03-31 | 南京信息工程大学 | Method for electrodepositing tungsten coating on single connecting wire |
RU2716137C1 (en) * | 2019-10-18 | 2020-03-06 | Федеральное государственное унитарное предприятие "Горно-химический комбинат" (ФГУП "ГХК") | Spent nuclear fuel voloxidation unit |
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Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3982928A (en) * | 1975-01-03 | 1976-09-28 | The United States Of America As Represented By The United States Energy Research And Development Administration | Separation of uranium from (Th,U)O2 solid solutions |
US5160367A (en) * | 1991-10-03 | 1992-11-03 | The United States Of America As Represented By The United States Department Of Energy | Salt transport extraction of transuranium elements from lwr fuel |
US5378325A (en) * | 1991-09-17 | 1995-01-03 | Aluminum Company Of America | Process for low temperature electrolysis of metals in a chloride salt bath |
US5640902A (en) * | 1995-03-23 | 1997-06-24 | Pitney Bowes Inc. | Single motor meter drum and shutter bar drive of a postage meter |
US5650053A (en) * | 1995-11-24 | 1997-07-22 | The United States Of America As Represented By The United States Department Of Energy | Electrorefining cell with parallel electrode/concentric cylinder cathode |
US6419813B1 (en) * | 2000-11-25 | 2002-07-16 | Northwest Aluminum Technologies | Cathode connector for aluminum low temperature smelting cell |
US6540902B1 (en) * | 2001-09-05 | 2003-04-01 | The United States Of America As Represented By The United States Department Of Energy | Direct electrochemical reduction of metal-oxides |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS4837319A (en) * | 1971-09-14 | 1973-06-01 | ||
JP2875819B2 (en) * | 1989-08-17 | 1999-03-31 | 財団法人電力中央研究所 | Molten salt electrorefining equipment |
DE60009455T2 (en) * | 1999-01-08 | 2005-01-20 | Moltech Invent S.A. | ALUMINUM ELECTRICITY CELL WITH OXYGEN DEVELOPING ANODES |
GB9928655D0 (en) * | 1999-12-03 | 2000-02-02 | British Nuclear Fuels Plc | Actinide production |
-
2002
- 2002-02-28 GB GBGB0204671.2A patent/GB0204671D0/en not_active Ceased
-
2003
- 2003-02-24 WO PCT/GB2003/000792 patent/WO2003073436A1/en active IP Right Grant
- 2003-02-24 KR KR10-2004-7013442A patent/KR20040093726A/en not_active Application Discontinuation
- 2003-02-24 US US10/505,262 patent/US20050139474A1/en not_active Abandoned
- 2003-02-24 RU RU2004127170/06A patent/RU2004127170A/en not_active Application Discontinuation
- 2003-02-24 AU AU2003207344A patent/AU2003207344A1/en not_active Abandoned
- 2003-02-24 EP EP03704816A patent/EP1481401B1/en not_active Expired - Lifetime
- 2003-02-24 CN CNA038048892A patent/CN1639803A/en active Pending
- 2003-02-24 JP JP2003572043A patent/JP2005519192A/en active Pending
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3982928A (en) * | 1975-01-03 | 1976-09-28 | The United States Of America As Represented By The United States Energy Research And Development Administration | Separation of uranium from (Th,U)O2 solid solutions |
US5378325A (en) * | 1991-09-17 | 1995-01-03 | Aluminum Company Of America | Process for low temperature electrolysis of metals in a chloride salt bath |
US5160367A (en) * | 1991-10-03 | 1992-11-03 | The United States Of America As Represented By The United States Department Of Energy | Salt transport extraction of transuranium elements from lwr fuel |
US5640902A (en) * | 1995-03-23 | 1997-06-24 | Pitney Bowes Inc. | Single motor meter drum and shutter bar drive of a postage meter |
US5650053A (en) * | 1995-11-24 | 1997-07-22 | The United States Of America As Represented By The United States Department Of Energy | Electrorefining cell with parallel electrode/concentric cylinder cathode |
US6419813B1 (en) * | 2000-11-25 | 2002-07-16 | Northwest Aluminum Technologies | Cathode connector for aluminum low temperature smelting cell |
US6540902B1 (en) * | 2001-09-05 | 2003-04-01 | The United States Of America As Represented By The United States Department Of Energy | Direct electrochemical reduction of metal-oxides |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20040244533A1 (en) * | 2001-06-06 | 2004-12-09 | Lewin Rober Glynn | Actinide production |
US9920443B2 (en) | 2010-12-23 | 2018-03-20 | Ge-Hitachi Nuclear Energy Americas Llc | Modular cathode assemblies and methods of using the same for electrochemical reduction |
US20140021058A1 (en) * | 2011-02-04 | 2014-01-23 | Metalysis Limited | Electrolysis method and apparatus |
US10066309B2 (en) * | 2011-02-04 | 2018-09-04 | Metalysis Limited | Method and apparatus for electrochemical reduction of a solid feedstock |
US9382632B2 (en) | 2013-06-21 | 2016-07-05 | Savannah River Nuclear Solutions, Llc | Electrochemical fluorination for processing of used nuclear fuel |
US9562297B2 (en) | 2013-06-21 | 2017-02-07 | Savannah River Nuclear Solutions, Llc | Galvanic cell for processing of used nuclear fuel |
Also Published As
Publication number | Publication date |
---|---|
JP2005519192A (en) | 2005-06-30 |
WO2003073436A1 (en) | 2003-09-04 |
RU2004127170A (en) | 2005-05-10 |
EP1481401B1 (en) | 2005-11-16 |
CN1639803A (en) | 2005-07-13 |
KR20040093726A (en) | 2004-11-08 |
AU2003207344A1 (en) | 2003-09-09 |
EP1481401A1 (en) | 2004-12-01 |
GB0204671D0 (en) | 2002-04-10 |
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