|  | 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]

|  | C25F |
PROCESSES FOR THE ELECTROLYTIC REMOVAL OF MATERIALS FROM OBJECTS; APPARATUS [2]

|  | C25F |
Note(s) In this sub-class, an invention is classified in the last appropriate place. [2]

|  | C25F 1/00 |
Electrolytic cleaning, degreasing, pickling, or descaling [2]

|  | C25F 1/02 |
· | Pickling; Descaling [2]

|  | C25F 1/04 |
· · | in solution [2]

|  | C25F 1/06 |
· · · | of iron or steel [2]

|  | C25F 1/08 |
· · · | of refractory metals [2]

|  | C25F 1/10 |
· · · | of actinides [2]

|  | C25F 1/12 |
· · | in melts [2]

|  | C25F 1/14 |
· · · | of iron or steel [2]

|  | C25F 1/16 |
· · · | of refractory metals [2]

|  | C25F 1/18 |
· · · | of actinides [2]

|  | C25F 3/00 |
Electrolytic etching or polishing [2]

|  | C25F 3/02 |
· | Etching [2]

|  | C25F 3/04 |
· · | of light metals [2]

|  | C25F 3/06 |
· · | of iron or steel [2]

|  | C25F 3/08 |
· · | of refractory metals [2]

|  | C25F 3/10 |
· · | of actinides [2]

|  | C25F 3/12 |
· · | of semiconducting materials [2]

|  | C25F 3/14 |
· · | locally [2]

|  | C25F 3/16 |
· | Polishing [2]

|  | C25F 3/18 |
· · | of light metals [2]

|  | C25F 3/20 |
· · · | of aluminium [2]

|  | C25F 3/22 |
· · | of heavy metals [2]

|  | C25F 3/24 |
· · · | of iron or steel [2]

|  | C25F 3/26 |
· · · | of refractory metals [2]

|  | C25F 3/28 |
· · · | of actinides [2]

|  | C25F 3/30 |
· · | of semiconducting materials [2]

|  | C25F 5/00 |
Electrolytic stripping of metallic layers or coatings [2]

|  | C25F 7/00 |
Constructional parts, or assemblies thereof, of cells for electrolytic removal of material from objects (for both electrolytic coating and removal Fulltext... Hierarchy... Expanded...C25D); Servicing or operating [2]

|  | C25F 7/02 |
· | Regeneration of process liquids [2]