|  | C |
SECTION C — CHEMISTRY; METALLURGY

|  | C |
Note(s) In section C, the definitions of groups of chemical elements are as follows: 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 The following notes are meant to assist in the use of this part of the classification scheme. They must not be read as modifying in any way the elaborations. Section C covers: pure chemistry, which covers inorganic compounds, organic compounds, macromolecular compounds, and their methods of preparation; applied chemistry, which covers compositions containing the above compounds, such as: glass, ceramics, fertilisers, plastics compositions, paints, products of the petroleum industry. It also covers certain compositions on account of their having particular properties rendering them suitable for certain purposes, as in the case of explosives, dyestuffs, adhesives, lubricants, and detergents; certain marginal industries, such as the manufacture of coke and of solid or gaseous fuels, the production and refining of oils, fats and waxes, the fermentation industry (e.g., brewing and wine-making), the sugar industry; certain operations or treatments, which are either purely mechanical, e.g., the mechanical treatment of leather and skins, or partly mechanical, e.g., the treatment of water or the prevention of corrosion in general; metallurgy, ferrous or non-ferrous alloys. In the case of operations, treatments, products or articles having both a chemical and a non-chemical part or aspect, the general rule is that the chemical part or aspect is covered by section C. In some of these cases, the chemical part or aspect brings with it a non-chemical one, even though purely mechanical, because this latter aspect either is essential to the operation or treatment or constitutes an important element thereof. It has seemed, in fact, more logical not to dissociate the different parts or aspects of a coherent whole. This is the case for applied chemistry and for the industries, operations and treatments mentioned in Notes (1)(c), (d) and (e). For example, furnaces peculiar to the manufacture of glass are covered by class Fulltext... Hierarchy... Expanded...C03 and not by class Fulltext... Hierarchy... Expanded...F27. There are, however, some exceptions in which the mechanical (or non-chemical) aspect carries with it the chemical aspect, for example: Certain extractive processes, in subclass Fulltext... Hierarchy... Expanded...A61K; The chemical purification of air, in subclass Fulltext... Hierarchy... Expanded...A61L; Chemical methods of fire-fighting, in subclass Fulltext... Hierarchy... Expanded...A62D; Chemical processes and apparatus, in class Fulltext... Hierarchy... Expanded...B01; Impregnation of wood, in subclass Fulltext... Hierarchy... Expanded...B27K; Chemical methods of analysis or testing, in subclass Fulltext... Hierarchy... Expanded...G01N; Photographic materials and processes, in class Fulltext... Hierarchy... Expanded...G03, and, generally, the chemical treatment of textiles and the production of cellulose or paper, in section D. In still other cases, the pure chemical aspect is covered by section C and the applied chemical aspect by another section, such as A, B or F, e.g., the use of a substance or composition for: treatment of plants or animals, covered by subclass Fulltext... Hierarchy... Expanded...A01N; foodstuffs, covered by class Fulltext... Hierarchy... Expanded...A23; ammunition or explosives, covered by class Fulltext... Hierarchy... Expanded...F42. When the chemical and mechanical aspects are so closely interlocked that a neat and simple division is not possible, or when certain mechanical processes follow as a natural or logical continuation of a chemical treatment, section C may cover, in addition to the chemical aspect, a part only of the mechanical aspect, e.g., after-treatment of artificial stone, covered by class Fulltext... Hierarchy... Expanded...C04. In this latter case, a note or a reference is usually given to make the position clear, even if sometimes the division is rather arbitrary.

METALLURGY

|  | C22 |
METALLURGY (of iron Fulltext... Hierarchy... Expanded...C21); FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS (general methods or devices for heat treatment of ferrous or non-ferrous metals or alloys Fulltext... Hierarchy... Expanded...C21D; production of metals by electrolysis or electrophoresis Fulltext... Hierarchy... Expanded...C25)

|  | C22 |
Note(s) The codes of subclass Fulltext... Hierarchy... Expanded...C22K are only for use as indexing codes associated with subclasses Fulltext... Hierarchy... Expanded...C21D, Fulltext... Hierarchy... Expanded...C22C or Fulltext... Hierarchy... Expanded...C22F, so as to provide information concerning changing the physical characteristics of alloys. [6]

|  | C22B |
PRODUCTION OR REFINING OF METALS (making metallic powder or suspensions thereof Fulltext... Hierarchy... Expanded...B22F 9/00; electrolytic Fulltext... Hierarchy... Expanded...C25); PRETREATMENT OF RAW MATERIALS

|  | C22B |
Note(s) In this subclass, groups for obtaining metals include obtaining the metals by non-metallurgical processes, and obtaining metal compounds by metallurgical processes. Thus, for example, group Fulltext... Hierarchy... Expanded...C22B 11/00 covers the production of silver by reduction of ammoniacal silver oxide in solution, and group Fulltext... Hierarchy... Expanded...C22B 17/00 covers the production of cadmium oxide by a metallurgical process. Furthermore, although compounds of arsenic and antimony are classified in Fulltext... Hierarchy... Expanded...C01G, production of the elements themselves is covered by Fulltext... Hierarchy... Expanded...C22B, as well as the production of their compounds by metallurgical processes. Processes using enzymes or micro-organisms in order to: liberate, separate or purify a pre-existing compound or composition, or to treat textiles or clean solid surfaces of materials are further classified in subclass Fulltext... Hierarchy... Expanded...C12S. [5]

|  | C22B |
Subclass index
PRETREATMENT OF RAW MATERIALS | 1/00, 4/00, 7/00
PROCESSES FOR OBTAINING METALS | 3/00, 4/00, 5/00
REFINING OR REMELTING METALS | 9/00
OBTAINING SPECIFIC METALS | 11/00 - 61/00

|  | C22C |
ALLOYS (flints Fulltext... Hierarchy... Expanded...C06C 15/00; treatment of alloys Fulltext... Hierarchy... Expanded...C21D, Fulltext... Hierarchy... Expanded...C22F)

|  | C22C |
Note(s) In this subclass, the following terms or expressions are used with the meanings indicated: "alloys" includes also: metallic composite materials containing a substantial proportion of fibres or other somewhat larger particles; ceramic compositions containing free metal bonded to carbides, diamond, oxides, borides, nitrides or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides or sulfides, other than as macroscopic reinforcing agents. [4] "based on" requires at least 50% by weight of the specified constituent or of the specified group of constituents. [2] In this subclass, it is desirable to add the indexing codes of subclass Fulltext... Hierarchy... Expanded...C22K. The indexing codes should be unlinked. [6]

|  | C22C |
Subclass index
NON-FERROUS ALLOYS |
Manufacture | 1/00, 3/00
Based on or containing particular metals | 5/00 - 32/00
FERROUS ALLOYS |
Manufacture | 33/00
Master alloys | 35/00
Cast-iron alloys | 37/00
Iron alloys | 38/00
RADIOACTIVE ALLOYS | 43/00
AMORPHOUS ALLOYS | 45/00

|  | C22F |
CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS OR NON-FERROUS ALLOYS (surface treatment of metallic material involving at least one process provided for in class Fulltext... Hierarchy... Expanded...C23 and at least one process covered by this subclass Fulltext... Hierarchy... Expanded...C23F 17/00)

|  | C22F |
Note(s) In this subclass, it is desirable to add the indexing codes of subclass Fulltext... Hierarchy... Expanded...C22K. The indexing codes should be unlinked. [6]

|  | C22K |
INDEXING SCHEME ASSOCIATED WITH SUBCLASSES Fulltext... Hierarchy... Expanded...C21D, Fulltext... Hierarchy... Expanded...C22C OR Fulltext... Hierarchy... Expanded...C22F, RELATING TO CHANGING THE PHYSICAL CHARACTERISTICS OF ALLOYS [6]

|  | C22K |
Note(s) This subclass constitutes an indexing scheme associated with subclasses Fulltext... Hierarchy... Expanded...C21D, Fulltext... Hierarchy... Expanded...C22C or Fulltext... Hierarchy... Expanded...C22F. The indexing codes should be unlinked. [6] Attention is drawn to Chapter IV of the Guide which sets forth the rules concerning the application and presentation of the different types of indexing code. [6]