Process for separating metals

Inactive Publication Date: 2006-08-03
NUCLEAR DECOMMISSIONING AUTHORITY
View PDF11 Cites 12 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0029] Thus, according to a first aspect of the present invention, there is provided an electrorefining appara

Problems solved by technology

This limits the recovery, purification and electroplating of metals on to surfaces from aqueous solution to those metals whose electrode reduction potentials are more positive than the cathodic limit of the aqueous solution.
However, after a period of use the molten salt becomes loaded with fission products which not only begin to affect the quality of the product, but also result in too much heat generation within the salt.
The ANL process is, unfortunately, a batch process, since the uranium is collected in a receptacle at the bottom of the apparatus, requiring that the process is interrupted in order that the receptacle may be withdrawn and the product recovered.
In addition, the operation of the process is mechanically intense, involving the use of rotating anodes which are designed to scrape the product off the cathodes; difficulties are encountered on occasions due to the seizure of this mechanism.
A disadvantage of the lithium reduction process for producing a metallic feed from an oxide is the production of Li2O by-product.
However, these processes for the clean up of the ionic liquid are disadvantageous from an economic point of view.
However, when this method is applied to a composition which comprises a metal or metal compound comprising a uranium or a transuranic element, problems of criticality may arise, since ionic liquids serve as moderators in such systems.
In such circumstances, the difficulties may be obviated by placing a limit on the allowable dimensions of the electrochemical cell

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Process for separating metals
  • Process for separating metals
  • Process for separating metals

Examples

Experimental program
Comparison scheme
Effect test

first embodiment

[0039] the apparatus according to the first aspect of the present invention comprises a crusting liquid cathode. Generally, said crusting liquid cathode is comprised in a horizontal thin slab configuration. Preferably, said crusting liquid cathode comprises a liquid metal cathode or liquid alloy cathode. During the electrochemical separation process for the separation of uranium metal from spent nuclear fuel, uranium metal is deposited on the cathode surface, and this metal deposit and residual amounts of cathode metal and molten salt are then removed from said cathode surface, for example by intermittent scraping or scooping. Initially, a high potential and current density may be employed in order to promote crusting of the molten metal surface by solid uranium. The metal deposit recovered at the conclusion of the process generally requires purification in order to remove contaminants, such as residual cathodic material. Typically, the anode in said apparatus comprises a basket con...

second embodiment

[0040] the apparatus according to the first aspect of the present invention comprises a cast cathode. Preferably, said cast cathode comprises a metal or alloy cathode with a lower melting point than uranium metal, the melted cathode being introduced to an electrorefiner cell as a liquid which is then frozen to form a solid metal or alloy cathode as a horizontal thin slab. In operation during the separation of uranium metal from spent nuclear fuel, uranium metal is deposited on the cathode surface, and the cathode is then melted and transferred out of the cell, transporting with it the uranium metal deposit as a slurry. The anode in said apparatus is adapted for use in a continuous process, and preferably comprises a horizontal basket containing spent fuel, which may be continuously fed and discharged transversely.

third embodiment

[0041] the apparatus according to the first aspect of the present invention comprises a fluidised cell or pulsed bed. Preferably said fluidised cell or pulsed bed comprises cathode beads or particulates, preferably formed from graphite or uranium, and said electrorefiner cell is divided by a ceramic non-conducting membrane, forming a vertical thin slab. In operation during the separation of uranium metal from spent nuclear fuel, a charge is applied across the anode and cathode as though parallel plates and a molten salt containing dissolved uranium ions is pumped up through the cathode bed, resulting in the formation of uranium metal deposits on the bead or particulate surface. Typically, the anode in said apparatus comprises a basket containing spent fuel, which is adapted for use in a continuous process.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
Volumeaaaaaaaaaa
Dimensionaaaaaaaaaa
Melting pointaaaaaaaaaa
Login to view more

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.

Description

FIELD OF THE INVENTION [0001] This invention relates to processes for the separation of metals from compositions containing metals. The invention includes processes for the treatment of spent nuclear fuel forming part of a process for reprocessing, conditioning and / or partitioning nuclear fuels. Reference will be made hereinafter mainly to nuclear fuels but it should be understood that the invention is not restricted to any particular type of material and has application outside the nuclear industry. The processes involve the purification of a substance which is liquid at its operating temperature and at this temperature is comprised wholly or largely of ionic species. Such substances generally fall within one of two main classes, ionic liquids and molten salts. Ionic liquids typically have a relatively low melting point and usually contain an organic cation, whereas molten salts are generally totally inorganic and most commonly have a melting point of at least several hundred degre...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): C25C1/22C25C3/34B01DC25C3/00C25C7/00G21C19/48
CPCC25C3/34C25C7/005
Inventor HEBDITCH, DAVID JOHNBANFIELD, ZARA
Owner NUCLEAR DECOMMISSIONING AUTHORITY
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap