|  | C |
SECTION C — CHEMISTRY AND METALLURGY

|  | C |
Note(s) Definitions for Section C: Alkali metals: Li, Na, K, Rb, Cs, Fr Alkaline earth metals: Ca, Sr, Ba, Ra Lanthanides: elements with atomic numbers 57 to 71 inclusive Rare earths: Sc, Y, Lanthanides Actinides: elements with atomic numbers 89 to 103 inclusive Refractory metals: Ti, V, Cr, Zr, Nb, Mo, Hf, Ta, W Halogens: F, Cl, Br, I, At Noble gases: He, Ne, Ar, Kr, Xe, Rn Platinum group: Os, Ir, Pt, Ru, Rh, Pd Noble metals: Ag, Au, Platinum group Light metals: alkali metals, alkaline earth metals, Be, Al, Mg Heavy metals: metals other than light metals Iron group: Fe, Co, Ni Non-metals: H, B, C, Si, N, P, O, S, Se, Te, noble gases, halogens Metals: elements other than non-metals Transition elements: elements with atomic numbers 21 to 30 inclusive, 39 to 48 inclusive, 57 to 80 inclusive, 89 upwards

METALLURGY

|  | C25 |
ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR (electrodialysis, electro-osmosis, separation of liquids by electricity Fulltext... Hierarchy... Expanded...B01D; electrolytic machining Fulltext... Hierarchy... Expanded...B23P; electroless, i. e. chemical, plating Fulltext... Hierarchy... Expanded...C23C; anodic or cathodic protection Fulltext... Hierarchy... Expanded...C23F; electrolytic production of single crystals Fulltext... Hierarchy... Expanded...C30B; electrochemical methods of analysis Fulltext... Hierarchy... Expanded...G01N; electrochemical measuring, indicating or recording devices Fulltext... Hierarchy... Expanded...G01R; electrolytic circuit elements, e.g. capacitors, Fulltext... Hierarchy... Expanded...H01G; electrochemical current or voltage generators Fulltext... Hierarchy... Expanded...H01M) [2]

|  | C25 |
Note(s) Inventions dealing with electrolytic or electrophoretic processes and apparatus or operational features are classified (a) under the groups for the compounds or articles produced, and (b) under the groups provided for the apparatus or operational features. [2] The electrolytic or eletrophoretic purification of liquids is classified in the classes appropriate to the nature of the liquid, e.g. Fulltext... Hierarchy... Expanded...A01K 63/00, Fulltext... Hierarchy... Expanded...C02F 1/46, Fulltext... Hierarchy... Expanded...C25B 15/08, Fulltext... Hierarchy... Expanded...C25D 21/16, Fulltext... Hierarchy... Expanded...C25F 7/02. [2]

|  | C25B |
ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR [2]

|  | C25B |
Note(s) In this sub-class, in the absence of an indication to the contrary an invention is classified in the last appropriate place. [2] Compounds are secondarily classified in the appropriate classes, e.g. Fulltext... Hierarchy... Expanded...C01, Fulltext... Hierarchy... Expanded...C07, if of interest. [2]

|  | C25B 1/00 |
Electrolytic production of inorganic compounds or non-metals [2]

|  | C25B 1/02 |
· | of hydrogen or oxygen [2]

|  | C25B 1/04 |
· · | by electrolysis of water [2]

|  | C25B 1/06 |
· · · | in cells with flat or platelike electrodes [2]

|  | C25B 1/08 |
· · · · | of the filter-press type [2]

|  | C25B 1/10 |
· · · | in diaphragm cells [2]

|  | C25B 1/12 |
· · · | in pressure cells [2]

|  | C25B 1/14 |
· | of alkali metal compounds [2]

|  | C25B 1/16 |
· · | Hydroxides [2]

|  | C25B 1/18 |
· | of alkaline earth metal compounds or magnesium compounds [2]

|  | C25B 1/20 |
· · | Hydroxides [2]

|  | C25B 1/22 |
· | of inorganic acids [2]

|  | C25B 1/24 |
· | of halogens or compounds thereof [2]

|  | C25B 1/26 |
· · | Chlorine; Compounds thereof [2]

|  | C25B 1/28 |
· | of per-compounds [2]

|  | C25B 1/30 |
· · | Peroxides [2]

|  | C25B 1/32 |
· · | Perborates [2]

|  | C25B 1/34 |
· | Simultaneous production of alkali metal hydroxides and chlorine, its oxyacids or salts [2]

|  | C25B 1/36 |
· · | in mercury cathode cells [2]

|  | C25B 1/38 |
· · · | with vertical mercury cathode [2]

|  | C25B 1/40 |
· · · | with horizontal mercury cathode [2]

|  | C25B 1/42 |
· · · | Decomposition of amalgams [2]

|  | C25B 1/44 |
· · · · | with the aid of catalysts [2]

|  | C25B 1/46 |
· · | in diaphragm cells [2]

|  | C25B 3/00 |
Electrolytic production of organic compounds [2]

|  | C25B 3/02 |
· | by oxidation [2]

|  | C25B 3/04 |
· | by reduction [2]

|  | C25B 3/06 |
· | by halogenation [2]

|  | C25B 3/08 |
· · | by fluorination [2]

|  | C25B 3/10 |
· | by coupling reactions, e.g. dimerisation [2]

|  | C25B 3/12 |
· | of organometallic compounds [2]

|  | C25B 5/00 |
Electrogenerative processes, i.e. processes for producing compounds in which simultaneously electricity is generated [2]

|  | C25B 7/00 |
Electrophoretic production of compounds or non-metals [2]

|  | C25B 9/00 |
Constructional parts, or assemblies thereof, of cells (Fulltext... Hierarchy... Expanded...C25B 11/00, Fulltext... Hierarchy... Expanded...C25B 13/00 take precedence) [2]

|  | C25B 9/02 |
· | Holders for electrodes [2]

|  | C25B 9/04 |
· | Devices for current supply (electrical connections per se Fulltext... Hierarchy... Expanded...H01R); Electrode connections; Electric inter-cell connections [2]

|  | C25B 11/00 |
Electrodes; Manufacture thereof not otherwise provided for [2]

|  | C25B 11/02 |
· | characterised by shape or form [2]

|  | C25B 11/03 |
· · | perforated or foraminous [2]

|  | C25B 11/04 |
· | characterised by the material [2]

|  | C25B 11/06 |
· · | by the catalytic materials used (catalysts in general Fulltext... Hierarchy... Expanded...B01J) [2]

|  | C25B 11/08 |
· · · | Noble metals [2]

|  | C25B 11/10 |
· · | Electrodes based on barrier-type metals, e.g. titanium [2]

|  | C25B 11/12 |
· · | Electrodes based on carbon (carbon masses in general Fulltext... Hierarchy... Expanded...C04B 35/52) [2]

|  | C25B 11/14 |
· · · | Impregnation of carbon electrodes (Fulltext... Hierarchy... Expanded...C25B 11/06 takes precedence) [2]

|  | C25B 11/16 |
· · | Electrodes based on manganese dioxide or lead dioxide [2]

|  | C25B 11/18 |
· · | Mercury or amalgam electrodes [2]

|  | C25B 13/00 |
Diaphragms; Spacing elements [2]

|  | C25B 13/02 |
· | characterised by form or shape [2]

|  | C25B 13/04 |
· | characterised by the material [2]

|  | C25B 13/06 |
· · | based on asbestos [2]

|  | C25B 13/08 |
· · | based on organic materials [2]

|  | C25B 15/00 |
Operating or servicing of cells [2]

|  | C25B 15/02 |
· | Process control or regulation (controlling or regulating in general Fulltext... Hierarchy... Expanded...G05) [2]

|  | C25B 15/04 |
· | Regulation of the inter-electrode distance (electro-machining Fulltext... Hierarchy... Expanded...B23P) [2]

|  | C25B 15/06 |
· | Detection or inhibition of short circuits in the cell [2]

|  | C25B 15/08 |
· | Supplying or removing reactants or electrolytes; Regeneration of electrolytes [2]