Classifications

• • 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
• • 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
  • C25C3/02—Electrolytic production, recovery or refining of metals by electrolysis of melts of alkali or alkaline earth metals
• • 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
  • C25C7/02—Electrodes; Connections thereof
• • 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
  • C25C7/02—Electrodes; Connections thereof
  • C25C7/025—Electrodes; Connections thereof used in cells for the electrolysis of melts

Definitions

• the process is also'useful forthe recovery of a highly pure sodium which, for example, is recently used as heat transfer medium for nuclear reactors.
• the invention relates to a development which provides the possibility to overcome the difliculties described above and by means of which it is generally possible to make metal surfaces readily and reliably wettable by molten alkali metals.
• the invention is particularly suitable for the preparation of sodium-coated electrodes which operate reliably from the beginning of the electrolysis.
• cathodes used for the deposition of molten sodium from the above-mentioned electrolytes can be treated such that they operate completely satisfactorily and free from troubles.
• a copper coating prior to cadmium-plating.
• the coating metals cadmium or gold remain by no means attached to the cathode during the electrolysis. They are rather dissolved very rapidly in the first portions of sodium deposited electrolytically. The metal surface beneath the cadmium plating will remain completely wettable even after the plating has been dissolved and the cathodes will perform fully satisfactorily as long as the coating of the metal surface with the alkali metal film will not be interrupted and the electrolytic cell dismantled, e.g. for repair work. After an interruption cathodes of this kind must again be provided with the cadmium or gold plating. The coating metal migrates out of the cells very rapidly.
• the cell will furnish a sodium which is completely free from cadmium or gold.
• the content of said metals is not high even during the first hours of operation because very thin coatings are absolutely suificient to bring about the effect of the invention, coatings of 1 to 5 microns thickness being fully adequate.
• thicker platings are not detrimental but unnecessary.
• the platings are easily applied in a manner known per se, e.g. by electrolytic deposition.
• the object of the invention i.e. reliable wettability of the electrode throughout the performance of the electrolysis and avoidance of troubles in the electrolysis by irregular flow of the liquid metal on the electrode and especially irregular deposition of metal at the electrode or outflow of the deposited metal in'an undesirable direction, is further developed in accordance with'the invention, additionally tothe embodiment described above, by another fundamental idea.
• This further development which is independently inventive besides the embodiment described above resides in the teaching to enlarge the inner surface area of the electrode material.
• the particularly efficient cathode of the invention consists of a plate provided with many holes and coated with cadmium or gold, if desired after copper plating, said coating being preferably applied to both sides.
• Such a cathode even when involved in the electrolysis on one side only, becomes completely covered by molten sodium which, by adhesion and enlargement of the area of contact between the base metal and sodium, is fixed very well to the plate. Adhesion to the base metal will still be improved by arranging a second identical or unperforated plate at a distance of a few'millimeters from the first plate and parallel with respect to the latter so that the intermediate space may also become filled with sodium.
• a net e.g. a glass cloth
• the electrodes of the invention have been developed primarily as cathodes, they may also be used as anodes (for raw sodium to be refined) if care is taken by constant supply of liquid sodium constantly filled.
• Process according metal is sodium.
• saidalkali wherein said metallic. surface inert to molten alkali is copper, iron, steel, alu-

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Electrolytic Production Of Metals (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=7620862

Family Applications (1)

Country Status (5)

Cited By (1)

Families Citing this family (1)

Citations (5)

Family Cites Families (1)

• 0
  • BE BE630049D patent/BE630049A/xx unknown
• 1962
  • 1962-03-30 DE DEZ9335A patent/DE1168651B/de active Pending
• 1963
  • 1963-03-12 CH CH313263A patent/CH459584A/de unknown
  • 1963-03-19 GB GB10861/63A patent/GB1042733A/en not_active Expired
  • 1963-03-29 US US269125A patent/US3409465A/en not_active Expired - Lifetime

Patent Citations (5)

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