|  | 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.

CHEMISTRY

|  | C01 |
INORGANIC CHEMISTRY (processing powders of inorganic compounds preparatory to the manufacturing of ceramic products Fulltext... Hierarchy... Expanded...C04B 35/00; fermentation or enzyme-using processes for the preparation of elements or inorganic compounds except carbon dioxide Fulltext... Hierarchy... Expanded...C12P 3/00; obtaining metal compounds from mixtures, e.g. ores, which are intermediate compounds in a metallurgical process for obtaining a free metal Fulltext... Hierarchy... Expanded...C21B, Fulltext... Hierarchy... Expanded...C22B; production of non-metallic elements or inorganic compounds by electrolysis or electrophoresis Fulltext... Hierarchy... Expanded...C25B)

|  | C01 |
Note(s) In this class, in the absence of an indication to the contrary, a compound is classified in the last appropriate place. [3] 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]

|  | C01D |
COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM (metal hydrides Fulltext... Hierarchy... Expanded...C01B 6/00; salts of oxyacids of halogens Fulltext... Hierarchy... Expanded...C01B 11/00; peroxides, salts of peroxyacids Fulltext... Hierarchy... Expanded...C01B 15/00; sulfides or polysulfides Fulltext... Hierarchy... Expanded...C01B 17/22; thiosulfates, dithionites, polythionates Fulltext... Hierarchy... Expanded...C01B 17/64; compounds containing selenium or tellurium Fulltext... Hierarchy... Expanded...C01B 19/00; binary compounds of nitrogen with metals Fulltext... Hierarchy... Expanded...C01B 21/06; azides Fulltext... Hierarchy... Expanded...C01B 21/08; metal amides Fulltext... Hierarchy... Expanded...C01B 21/092; nitrites Fulltext... Hierarchy... Expanded...C01B 21/50; phosphides Fulltext... Hierarchy... Expanded...C01B 25/08; salts of oxyacids of phosphorus Fulltext... Hierarchy... Expanded...C01B 25/16; carbides Fulltext... Hierarchy... Expanded...C01B 31/30; compounds containing silicon Fulltext... Hierarchy... Expanded...C01B 33/00; compounds containing boron Fulltext... Hierarchy... Expanded...C01B 35/00; cyanides Fulltext... Hierarchy... Expanded...C01C 3/08; salts of cyanic acid Fulltext... Hierarchy... Expanded...C01C 3/14; salts of cyanamide Fulltext... Hierarchy... Expanded...C01C 3/16; thiocyanates Fulltext... Hierarchy... Expanded...C01C 3/20)

|  | C01D 1/00 |
Oxides or hydroxides of sodium, potassium, or alkali metals in general [2]

|  | C01D 1/02 |
· | Oxides

|  | C01D 1/04 |
· | Hydroxides

|  | C01D 1/20 |
· · | Preparation by reacting oxides or hydroxides with alkali metal salts

|  | C01D 1/22 |
· · · | with carbonates or bicarbonates

|  | C01D 1/24 |
· · · | from or via fluorides or silico-fluorides

|  | C01D 1/26 |
· · | Preparation from or via cyano coumpounds, e.g. cyanides, cyanamides

|  | C01D 1/28 |
· · | Purification; Separation

|  | C01D 1/30 |
· · · | by crystallisation

|  | C01D 1/32 |
· · · | by adsorption or precipitation

|  | C01D 1/34 |
· · · | with selective solvents

|  | C01D 1/36 |
· · · | by oxidation

|  | C01D 1/38 |
· · · | by dialysis

|  | C01D 1/40 |
· · · | by electrolysis

|  | C01D 1/42 |
· · | Concentration; Dehydration

|  | C01D 1/44 |
· · | Preparation in the form of granules, pieces, or other shaped products

|  | C01D 3/00 |
Halides of sodium, potassium, or alkali metals in general [2]

|  | C01D 3/02 |
· | Fluorides

|  | C01D 3/04 |
· | Chlorides

|  | C01D 3/06 |
· · | Preparation by working up brines, seawater or spent lyes

|  | C01D 3/08 |
· · | Preparation by working up natural or industrial salt mixtures or siliceous minerals

|  | C01D 3/10 |
· | Bromides

|  | C01D 3/12 |
· | Iodides

|  | C01D 3/14 |
· | Purification

|  | C01D 3/16 |
· · | by precipitation or adsorption

|  | C01D 3/18 |
· · | with selective solvents

|  | C01D 3/20 |
· · | by melting

|  | C01D 3/22 |
· | Preparation in the form of granules, pieces, or other shaped products

|  | C01D 3/24 |
· · | Influencing the crystallisation process

|  | C01D 3/26 |
· | Preventing the absorption of moisture or caking of the crystals

|  | C01D 5/00 |
Sulfates or sulfites of sodium, potassium, or alkali metals in general [2]

|  | C01D 5/02 |
· | Preparation of sulfates from alkali metal salts and sulfuric acid or bisulfates; Preparation of bisulfates

|  | C01D 5/04 |
· | Preparation of sulfates with the aid of sulfurous acid or sulfites, e.g. Hargreaves process

|  | C01D 5/06 |
· | Preparation of sulfates by double decomposition

|  | C01D 5/08 |
· · | with each other or with ammonium sulfate

|  | C01D 5/10 |
· · | with sulfates of magnesium, calcium, strontium, or barium

|  | C01D 5/12 |
· | Preparation of double sulfates of magnesium with sodium or potassium [2]

|  | C01D 5/14 |
· | Preparation of sulfites (Fulltext... Hierarchy... Expanded...C01D 5/04 takes precedence)

|  | C01D 5/16 |
· | Purification

|  | C01D 5/18 |
· | Dehydration

|  | C01D 7/00 |
Carbonates of sodium, potassium, or alkali metals in general [2]

|  | C01D 7/02 |
· | Preparation by double decomposition

|  | C01D 7/04 |
· · | with a fluoride or silico-fluoride (Fulltext... Hierarchy... Expanded...C01D 1/24 takes precedence)

|  | C01D 7/06 |
· | Preparation via sodium or potassium magnesium carbonate

|  | C01D 7/07 |
· | Preparation from the hydroxides [2]

|  | C01D 7/08 |
· | Preparation from or via cyano compounds of sodium or potassium (Fulltext... Hierarchy... Expanded...C01D 1/26 takes precedence)

|  | C01D 7/10 |
· | Preparation of bicarbonates from carbonates (ammonia-soda process Fulltext... Hierarchy... Expanded...C01D 7/18)

|  | C01D 7/12 |
· | Preparation of carbonates from bicarbonates

|  | C01D 7/14 |
· | Preparation of sesquicarbonates

|  | C01D 7/16 |
· | Preparation from compounds of sodium or potassium with amines and carbon dioxide

|  | C01D 7/18 |
· | Preparation by the ammonia-soda process

|  | C01D 7/22 |
· | Purification

|  | C01D 7/24 |
· · | Crystallisation

|  | C01D 7/26 |
· · | by precipitation or adsorption

|  | C01D 7/28 |
· · | with selective solvents

|  | C01D 7/30 |
· · | by oxidation

|  | C01D 7/32 |
· · | by dialysis

|  | C01D 7/34 |
· · | by electrolysis

|  | C01D 7/35 |
· | Varying the content of water of crystallisation or the specific gravity [2]

|  | C01D 7/37 |
· · | Densifying sodium carbonate [2]

|  | C01D 7/38 |
· | Preparation in the form of granules, pieces, or other shaped products

|  | C01D 7/40 |
· · | Influencing the crystallisation process

|  | C01D 7/42 |
· | Preventing the absorption of moisture or caking

|  | C01D 9/00 |
Nitrates of sodium, potassium, or alkali metals in general [2]

|  | C01D 9/02 |
· | Preparation by working-up natural salt mixtures

|  | C01D 9/04 |
· | Preparation with liquid nitric acid

|  | C01D 9/06 |
· | Preparation with gaseous nitric acid or nitrogen oxides

|  | C01D 9/08 |
· | Preparation by double decomposition

|  | C01D 9/10 |
· · | with ammonium nitrate

|  | C01D 9/12 |
· · | with nitrates of magnesium, calcium, strontium, or barium

|  | C01D 9/14 |
· · | of salts of potassium with sodium nitrate

|  | C01D 9/16 |
· | Purification

|  | C01D 9/18 |
· | Preparation in the form of shaped products, e.g. granules

|  | C01D 9/20 |
· | Preventing the absorption of moisture or caking

|  | C01D 13/00 |
Compounds of sodium or potassium not provided for elsewhere [2]

|  | C01D 15/00 |
Lithium compounds [2]

|  | C01D 15/02 |
· | Oxides; Hydroxides [2]

|  | C01D 15/04 |
· | Halides [2]

|  | C01D 15/06 |
· | Sulfates; Sulfites [2]

|  | C01D 15/08 |
· | Carbonates; Bicarbonates [2]

|  | C01D 15/10 |
· | Nitrates [2]

|  | C01D 17/00 |
Rubidium, caesium, or francium compounds [2]