Skip over navigation
PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
Definition statement
This subclass/group covers:

Electrolytic production or recovery (electrowinning) of metals and alloys from solutions or melts.

Electrorefining of metals and alloys in solutions or melts.

Constructional parts, cells or assemblies of cells for the electrolytic production, recovery or refining of metals or alloys.

Servicing or operating of cells for the electrolytic production, recovery or refining of metals or alloys.

Relationship between large subject matter areas

- Multi-step processes for surface treatment of metallic material involving at least one process provided for in class C23 and at least one process provided for in class C25 are classified in group C23F 17/00

- Compounds of particular interest are also classified in the relevant classes, C01 (inorganic chemistry), C07 (organic chemistry) and C08 (organic macromolecular compounds).

- The electrolytic or electrophoretic purification of materials is classified according to the nature of the liquid in the relevant places, e.g. A01K 63/00, C02F 1/46, C25B 15/08,C25D 21/16, C25F 7/02

- The electrolytic deposition of coatings (electroplating), the electrophoretic production of coatings and electroforming is classified in C25D.

-Production and refining of metals by non-electrolytic processes is classified in C22B, C21B, C21C. An electrothermal treatment (C22B 4/00) does not involve an electrolytic process.

-Alloys as such, prepared by electrolytic methods are classified in C22C.

References relevant to classification in this subgroup
This subclass/group does not cover:
Removing metallic impurities from waste water or sewage by electrolytic methods
Inhibiting corrosion of metals by anodic or cathodic protection
Single crystal growth
Informative references
Attention is drawn to the following places, which may be of interest for search:
Catalysts comprising metals,metal oxides or hydroxides
Processes for preparing catalysts
Refining molten metal during a continuous casting process
General processes of refining metals
Composition of alloys
Multistep processes for surface treatment of metallic material
Electrodes, membranes for fuel cells
Special rules of classification within this subclass

Classify each metal mentioned in the document, if too many are mentioned, then classify the examples and for the rest of the metals use C25C 1/00 or C25C 3/00, respectively.

Electrolytic production, recovery or refining of metals by electrolysis of solutions(C25C 5/00 takes precedence)
Special rules of classification within this group

Classify also in C25C 5/02, when applicable.

Electrolytic production, recovery or refining of metals by electrolysis of melts (C25C 5/00 takes precedence)
Special rules of classification within this subgroup

Classify also in C25C 5/04, when applicable.

Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:
Melt
molten salt or ionic liquid or fused bath
Cell construction, e.g. bottoms, walls, cathodes
References relevant to classification in this subgroup
This subclass/group does not cover:
Constructional parts, or assemblies thereof, of cells; servicing or operating of cells for the production of alloys or metals other than aluminium
Anodes
Informative references
Attention is drawn to the following places, which may be of interest for search:
Electrodes used in cells for the electrolysis of melts, other than aluminium production
[N: based on carbon]
Informative references
Attention is drawn to the following places, which may be of interest for search:
Carbon masses
Electrodes used in cells for the electrolysis of melts, other than aluminium production
Electrodes used for heating by electrical discharge, electrodes mainly consisting of carbon, self-baking type (e.g. Söderberg anodes)
H01B7/09
Heating by electrical discharge, electrodes mainly consisting of carbon
Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:
Söderberg anode
An electrode used in metallurgy, which continuously forms in an electrical furnace when a mixture of coke and coal-tar pitch is added to a heated steel casing and is baked as it passes through. It emerges into the furnace where it is continuously consumed.
Automatic control or regulation of cells (controlling or regulating in general G05)
Informative references
Attention is drawn to the following places, which may be of interest for search:
Controlling or regulating in general
G05
of titanium, zirconium, hafnium, tantalum or vanadium
Definition statement
This subclass/group covers:

Electrolytic production of the metal (titanium, hafnium, tantalum, vanadium) by the direct reduction of the metal ion at the electrode.

Reduction of the metal oxide by another metal (usually calcium) which is itself electrolytically reduced from the electrolyte (usually calcium chloride), although the reduction step of the metal ions is chemical rather than electrolytic.

Relationship between large subject matter areas

Documents involving the latter reaction should also be considered by a classifier in C22B 34/00.

Special rules of classification within this subgroup

Classification should also be made in C25C 5/04, when applicable.

of titanium
Definition statement
This subclass/group covers:

Electrolytic production of titanium by the direct reduction of the metal ion at the electrode.

Reduction of titanium oxide by another metal (usually calcium) which is itself electrolytically reduced from the electrolyte (usually calcium chloride), although the reduction step of the titanium ions is chemical rather than electrolytic.

Relationship between large subject matter areas

Documents involving the latter reaction should also be considered by a classifier in C22B 34/12.

Electrolytic production, recovery or refining of metal powders or porous metal masses
Constructional parts, or assemblies thereof, of cells; Servicing or operating of cells (for the production of aluminium C25C 3/06 to C25C 3/22 )
References relevant to classification in this group
This subclass/group does not cover:
Constructional parts, or assemblies thereof, of cells; servicing or operating of cells for the production of aluminium
of cells comprising at least a movable electrode (C25C 7/002, C25C 7/02 to C25C 7/06 take precedence)]
Definition statement
This subclass/group covers:

Movable electrodes, be it electrodes that move in space or electrodes that move around an axis, such as rotary electrodes.

Diaphragms; Spacing elements
Informative references
Attention is drawn to the following places, which may be of interest for search:
Diaphragms used in the electrolytic or electrophoretic production of compounds or non-metals
Membranes for fuel cells
Synonyms and Keywords

In patent documents the following expressions/words "diaphragm " and " membrane" are used as synonyms

Operating or servicing
Definition statement
This subclass/group covers:

Operating or servicing of cells, when generally applied to a cell or in a process of C25C.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Controlling or regulating in general
G05
This page is owned by Office of Patent Classification.
Last Modified: 10/11/2013