|  | 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

|  | C02 |
TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (settling tanks, filtering, e.g. sand filters or screening devices, Fulltext... Hierarchy... Expanded...B01D)

|  | C02F |
TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general Fulltext... Hierarchy... Expanded...B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, Fulltext... Hierarchy... Expanded...B63J; adding materials to water to prevent corrosion Fulltext... Hierarchy... Expanded...C23F; treating radioactively-contaminated liquids Fulltext... Hierarchy... Expanded...G21F 9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes) [3]

|  | C02F |
Note(s) Processes using enzymes or micro-organisms classified in this subclass are not further classified in subclass Fulltext... Hierarchy... Expanded...C12S. [5]

|  | C02F |
Subclass index
CHEMICAL OR PHYSICAL TREATMENT | 1/00, 5/00
BIOLOGICAL TREATMENT | 3/00
AERATION OF STRETCHES | 7/00
TREATMENT OF SLUDGE | 11/00

|  | C02F 1/00 |
Treatment of water, waste water, or sewage (Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...C02F 3/00-C02F 9/00 take precedence) [3]

|  | C02F 1/02 |
· | by heating (methods of steam generation Fulltext... Hierarchy... Expanded...F22B; preheating boiler feed-water or accumulating preheated boiler feed-water Fulltext... Hierarchy... Expanded...F22D) [3]

|  | C02F 1/04 |
· · | by distillation or evaporation [3]

|  | C02F 1/06 |
· · · | Flash evaporation [3]

|  | C02F 1/08 |
· · · | Thin film evaporation [3]

|  | C02F 1/10 |
· · · | by direct contact with a particulate solid or with a fluid, as a heat transfer medium [3]

|  | C02F 1/12 |
· · · · | Spray evaporation [3]

|  | C02F 1/14 |
· · · | using solar energy [3]

|  | C02F 1/16 |
· · · | using waste heat from other processes [3]

|  | C02F 1/18 |
· · · | Transportable devices to obtain potable water [3]

|  | C02F 1/20 |
· | by degassing, i.e. liberation of dissolved gases (degasification of liquids in general Fulltext... Hierarchy... Expanded...B01D 19/00; arrangement of degassing apparatus in boiler feed supply Fulltext... Hierarchy... Expanded...F22D) [3]

|  | C02F 1/22 |
· | by freezing [3]

|  | C02F 1/24 |
· | by flotation (Fulltext... Hierarchy... Expanded...C02F 1/465 takes precedence) [3,5]

|  | C02F 1/26 |
· | by extraction [3]

|  | C02F 1/28 |
· | by sorption (using ion-exchange Fulltext... Hierarchy... Expanded...C02F 1/42; sorbent compositions Fulltext... Hierarchy... Expanded...B01J) [3]

|  | C02F 1/30 |
· | by irradiation [3]

|  | C02F 1/32 |
· · | with ultra-violet light [3]

|  | C02F 1/34 |
· | with mechanical oscillations [3]

|  | C02F 1/36 |
· · | ultrasonic vibrations [3]

|  | C02F 1/38 |
· | by centrifugal separation [3]

|  | C02F 1/40 |
· | Devices for separating or removing fatty or oily substances or similar floating material (cleaning or keeping clear the surface of open water from oil or like materials Fulltext... Hierarchy... Expanded...E02B 15/04; devices in sewers for separating liquid or solid substances from sewage Fulltext... Hierarchy... Expanded...E03F 5/14, e.g. for use in drains leading to the sewer Fulltext... Hierarchy... Expanded...E03F 5/16) [3,5]

|  | C02F 1/42 |
· | by ion-exchange (ion-exchange in general Fulltext... Hierarchy... Expanded...B01J) [3]

|  | C02F 1/44 |
· | by dialysis, osmosis or reverse osmosis [3]

|  | C02F 1/46 |
· | by electrochemical methods [3,5]

|  | C02F 1/461 |
· · | by electrolysis [5]

|  | C02F 1/463 |
· · · | by electrocoagulation [5]

|  | C02F 1/465 |
· · · | by electroflotation [5]

|  | C02F 1/467 |
· · · | by electrochemical disinfection [5]

|  | C02F 1/469 |
· · | by electrochemical separation, e.g. by electro-osmosis, electrodialysis, electrophoresis [5]

|  | C02F 1/48 |
· | with magnetic or electric fields (Fulltext... Hierarchy... Expanded...C02F 1/46 takes precedence) [3]

|  | C02F 1/50 |
· | by addition or application of a germicide or by oligodynamic treatment (Fulltext... Hierarchy... Expanded...C02F 1/467 takes precedence) [3,5]

|  | C02F 1/52 |
· | by flocculation or precipitation of suspended impurities [3]

|  | C02F 1/54 |
· · | using organic material [3]

|  | C02F 1/56 |
· · · | Macromolecular compounds [3]

|  | C02F 1/58 |
· | by removing specified dissolved compounds (using ion-exchange Fulltext... Hierarchy... Expanded...C02F 1/42; softening water Fulltext... Hierarchy... Expanded...C02F 5/00) [3]

|  | C02F 1/60 |
· · | Silicon compounds [3]

|  | C02F 1/62 |
· · | Heavy metal compounds [3]

|  | C02F 1/64 |
· · · | of iron or manganese [3]

|  | C02F 1/66 |
· | by neutralisation; pH adjustment (for degassing Fulltext... Hierarchy... Expanded...C02F 1/20; using ion-exchange Fulltext... Hierarchy... Expanded...C02F 1/42; for flocculation or precipitation of suspended impurities Fulltext... Hierarchy... Expanded...C02F 1/52; for removing dissolved compounds Fulltext... Hierarchy... Expanded...C02F 1/58) [3]

|  | C02F 1/68 |
· | by addition of specified substances, e.g. trace elements, for ameliorating potable water (medicinal water Fulltext... Hierarchy... Expanded...A61K) [3]

|  | C02F 1/70 |
· | by reduction [3]

|  | C02F 1/72 |
· | by oxidation [3]

|  | C02F 1/74 |
· · | with air (aeration of stretches of water Fulltext... Hierarchy... Expanded...C02F 7/00) [3]

|  | C02F 1/76 |
· · | with halogens or compounds of halogens [3]

|  | C02F 1/78 |
· · | with ozone [3]

|  | C02F 3/00 |
Biological treatment of water, waste water, or sewage [3]

|  | C02F 3/02 |
· | Aerobic processes [3]

|  | C02F 3/04 |
· · | using trickle filters [3]

|  | C02F 3/06 |
· · | using submerged filters [3]

|  | C02F 3/08 |
· · | using moving contact bodies [3]

|  | C02F 3/10 |
· · | Packings; Fillings; Grids (packing elements in general Fulltext... Hierarchy... Expanded...B01J 19/30, Fulltext... Hierarchy... Expanded...B01J 19/32) [3]

|  | C02F 3/12 |
· · | Activated sludge processes [3]

|  | C02F 3/14 |
· · · | using surface aeration [3]

|  | C02F 3/16 |
· · · · | the aerator having a vertical axis [3]

|  | C02F 3/18 |
· · · · | the aerator having a horizontal axis [3]

|  | C02F 3/20 |
· · · | using diffusers [3]

|  | C02F 3/22 |
· · · | using circulation pipes [3]

|  | C02F 3/24 |
· · · | using free-fall aeration or spraying [3]

|  | C02F 3/26 |
· · · | using pure oxygen or oxygen-rich gas [3]

|  | C02F 3/28 |
· | Anaerobic digestion processes [3]

|  | C02F 3/30 |
· | Aerobic and anaerobic processes [3]

|  | C02F 3/32 |
· | characterised by the animals or plants used, e.g. algae [3]

|  | C02F 3/34 |
· | characterised by the micro-organisms used [3]

|  | C02F 5/00 |
Softening water; Preventing scale; Adding scale preventatives or scale removers to water, e.g. adding sequestering agents (softening using ion-exchange Fulltext... Hierarchy... Expanded...C02F 1/42) [3]

|  | C02F 5/02 |
· | Softening water by precipitation of the hardness [3]

|  | C02F 5/04 |
· · | using phosphates (Fulltext... Hierarchy... Expanded...C02F 5/06 takes precedence) [3]

|  | C02F 5/06 |
· · | using calcium compounds [3]

|  | C02F 5/08 |
· | Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents [3]

|  | C02F 5/10 |
· · | using organic substances [3]

|  | C02F 5/12 |
· · · | containing nitrogen (Fulltext... Hierarchy... Expanded...C02F 5/14 takes precedence) [3]

|  | C02F 5/14 |
· · · | containing phosphorus [3]

|  | C02F 7/00 |
Aeration of stretches of water [3]

|  | C02F 9/00 |
Multistage treatment of water, waste water or sewage [3]

|  | C02F 9/00 |
Note(s) This group covers only those combined treating operations where the interest is directed to the relationship between the steps. [3] This group does not cover, for example, chemical treatment followed by settlement or biological treatment involving normal mechanical treatment. [3]

|  | C02F 11/00 |
Treatment of sludge; Devices therefor [3]

|  | C02F 11/02 |
· | Biological treatment [3]

|  | C02F 11/04 |
· · | Anaerobic treatment; Production of methane by such processes [3]

|  | C02F 11/06 |
· | by oxidation (incinerators or other apparatus for burning waste liquors, e.g. sulfite liquor from paper-making plant, Fulltext... Hierarchy... Expanded...F23G 7/04) [3]

|  | C02F 11/08 |
· · | Wet air oxidation [3]

|  | C02F 11/10 |
· | by pyrolysis [3]

|  | C02F 11/12 |
· | by de-watering, drying, or thickening [3]

|  | C02F 11/14 |
· · | with addition of chemical agents [3]

|  | C02F 11/16 |
· · | using drying or composting beds [3]

|  | C02F 11/18 |
· | by thermal conditioning (by pyrolysis Fulltext... Hierarchy... Expanded...C02F 11/10) [3]

|  | C02F 11/20 |
· · | by freezing [3]