|  | 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

CHEMISTRY

|  | C01 |
INORGANIC CHEMISTRY (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 the absence of an indication to the contrary, a compound is classified in the last appropriate place within this class. [3]

|  | C01C |
AMMONIA; CYANOGEN; COMPOUNDS THEREOF (salts of oxyacids of halogens Fulltext... Hierarchy... Expanded...C01B 11/00; peroxides, salts of peroxyacids Fulltext... Hierarchy... Expanded...C01B 15/00; thiosulphates, dithionites, polythionates Fulltext... Hierarchy... Expanded...C01B 17/64; compounds containing selenium or tellurium Fulltext... Hierarchy... Expanded...C01B 19/00; 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; compounds containing silicon Fulltext... Hierarchy... Expanded...C01B 33/00; compounds containing boron Fulltext... Hierarchy... Expanded...C01B 35/00)

|  | C01C 1/00 |
Ammonia; Compounds thereof

|  | C01C 1/02 |
· | Preparation or separation of ammonia

|  | C01C 1/04 |
· · | Preparation of ammonia by synthesis (preparation or purification of gas mixtures for ammonia synthesis Fulltext... Hierarchy... Expanded...C01B 3/02)

|  | C01C 1/08 |
· · | Preparation of ammonia from nitrogenous organic substances

|  | C01C 1/10 |
· · | Separation of ammonia from ammonia liquors, e.g. gas liquors

|  | C01C 1/12 |
· · | Separation of ammonia from gases and vapours

|  | C01C 1/14 |
· · · | Saturators

|  | C01C 1/16 |
· | Halides of ammonium

|  | C01C 1/18 |
· | Nitrates of ammonium

|  | C01C 1/20 |
· | Sulphides; Polysulphides

|  | C01C 1/22 |
· | Sulphites of ammonium

|  | C01C 1/24 |
· | Sulphates of ammonium (Fulltext... Hierarchy... Expanded...C01C 1/14 takes precedence)

|  | C01C 1/242 |
· · | Preparation from ammonia and sulphuric acid or sulphur trioxide [2]

|  | C01C 1/244 |
· · | Preparation by double decompostion of ammonium salts with sulphates [2]

|  | C01C 1/245 |
· · | Preparation from compounds containing nitrogen and sulphur [2]

|  | C01C 1/246 |
· · · | from sulphur-containing ammonium compounds [2]

|  | C01C 1/247 |
· · · · | by oxidation with free oxygen [2]

|  | C01C 1/248 |
· · | Preventing coalescing or controlling form or size of crystals [2]

|  | C01C 1/249 |
· · | Deacidifying the crystals [2]

|  | C01C 1/26 |
· | Carbonates or bicarbonates of ammonium

|  | C01C 1/28 |
· | Methods of preparing ammonium salts in general

|  | C01C 3/00 - C01C 3/00 |
Note(s) Salts of polybasic acids with ammonium and a metal as cations are classified as though the ammonium were hydrogen. Ammonium salts of complex acids (other than complex cyanides) which contain a metal in the anion are classified in the relevant groups of sub-classes Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...C01D-C01G according to the metal; complex ammine salts are also classified in the relevant groups of sub-classes Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...C01D-C01G according to the metal.

|  | C01C 3/00 |
Cyanogen; Compounds thereof

|  | C01C 3/02 |
· | Preparation of hydrogen cyanide

|  | C01C 3/04 |
· · | Separation from gases

|  | C01C 3/06 |
· | Stabilisation of hydrogen cyanide

|  | C01C 3/08 |
· | Simple or complex cyanides of metals

|  | C01C 3/10 |
· · | Simple alkali metal cyanides

|  | C01C 3/11 |
· · | Complex cyanides [2]

|  | C01C 3/12 |
· · | Simple or complex iron cyanides [2]

|  | C01C 3/14 |
· | Cyanic acid; Salts thereof

|  | C01C 3/16 |
· | Cyanamide; Salts thereof (dicyandiamide Fulltext... Hierarchy... Expanded...C07C 129/14)

|  | C01C 3/18 |
· · | Calcium cyanamide

|  | C01C 3/20 |
· | Thiocyanic acid; Salts thereof