C
SECTION C — CHEMISTRY; METALLURGY
 C

Note(s)

  1. 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

  2. Section C covers:
    1. pure chemistry, which covers inorganic compounds, organic compounds, macromolecular compounds, and their methods of preparation;
    2. 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;
    3. 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;
    4. 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;
    5. metallurgy, ferrous or non-ferrous alloys.
    1. 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.
    2. 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 C03 and not by class F27.
    3. There are, however, some exceptions in which the mechanical (or non-chemical) aspect carries with it the chemical aspect, for example:
    4. 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:
    5. 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 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, B01D)
 C02F
TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F 9/04)  [3]
 C02F

Note(s)

  1. Processes using enzymes or micro-organisms classified in this subclass are not further classified in subclass C12S[5]
  2. When classifying in this subclass, classification is also made in group B01D 15/08 insofar as subject matter of general interest relating to chromatography is concerned. [8]
 C02F
Subclass index
CHEMICAL OR PHYSICAL TREATMENT 1/00, 5/00
BIOLOGICAL TREATMENT 3/00
AERATION OF STRETCHES 7/00
MULTISTEP TREATMENT 9/00
TREATMENT OF SLUDGE 11/00
P:40 C02F 1/00
Treatment of water, waste water, or sewage (C02F 3/00-C02F 9/00 take precedence)  [3]
 C02F 1/02
·  by heating (methods of steam generation F22B; preheating boiler feed-water or accumulating preheated boiler feed-water 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 1/14
·  ·  ·  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 B01D 19/00; arrangement of degassing apparatus in boiler feed supply F22D)  [3]
 C02F 1/22
·  by freezing  [3]
 C02F 1/24
·  by flotation (C02F 1/461 takes precedence)  [3,5]
 C02F 1/26
·  by extraction  [3]
 C02F 1/28
·  by sorption (using ion-exchange C02F 1/42; sorbent compositions B01J)  [3]
 C02F 1/30
·  by irradiation  [3]
 C02F 1/32
·  ·  with ultra-violet light  [3]
 C02F 1/34
·  with mechanical oscillations  [3]
 C02F 1/38
·  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 E02B 15/04; devices in sewers for separating liquid or solid substances from sewage E03F 5/14, e.g. for use in drains leading to the sewer E03F 5/14)  [3,5]
 C02F 1/42
·  by ion-exchange (ion-exchange in general 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 1/469
·  ·  by electrochemical separation, e.g. by electro-osmosis, electrodialysis, electrophoresis  [5]
 C02F 1/48
·  with magnetic or electric fields (C02F 1/46 takes precedence)  [3]
 C02F 1/50
·  by addition or application of a germicide or by oligodynamic treatment (C02F 1/461 takes precedence)  [3,5]
 C02F 1/52
·  by flocculation or precipitation of suspended impurities  [3]
 C02F 1/54
·  ·  using organic material  [3]
 C02F 1/58
·  by removing specified dissolved compounds (using ion-exchange C02F 1/42; softening water C02F 5/00)  [3]
 C02F 1/60
·  ·  Silicon compounds  [3]
 C02F 1/62
·  ·  Heavy metal compounds  [3]
 C02F 1/66
·  by neutralisation; pH adjustment (for degassing C02F 1/20; using ion-exchange C02F 1/42; for flocculation or precipitation of suspended impurities C02F 1/52; for removing dissolved compounds C02F 1/58)  [3]
 C02F 1/68
·  by addition of specified substances, e.g. trace elements, for ameliorating potable water (medicinal water A61K)  [3]
 C02F 1/70
·  by reduction  [3]
 C02F 1/72
·  by oxidation  [3]
 C02F 1/74
·  ·  with air (aeration of stretches of water C02F 7/00)  [3]
 C02F 1/76
·  ·  with halogens or compounds of halogens  [3]
 C02F 1/78
·  ·  with ozone  [3]
P:30 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 B01J 19/30, B01J 19/32)  [3]
 C02F 3/12
·  ·  Activated sludge processes  [3]
 C02F 3/14
·  ·  ·  using surface aeration  [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]
P:50 C02F 5/00
Softening water; Preventing scale; Adding scale preventatives or scale removers to water, e.g. adding sequestering agents (softening using ion-exchange C02F 1/42)  [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]
P:60 C02F 7/00
Aeration of stretches of water  [3]
P:0 C02F 9/00
Multistep treatment of water, waste water or sewage  [3]
 C02F 9/00

Note(s)

  1. This group covers only those combined treating operations where the essential characteristic resides in the combination of treatment steps. [3]
  2. This group does not cover treatments where the essential characteristic resides in an individual step of the treatment, which treatments are covered by groups C02F 1/00-C02F 7/00. An example of such treatments is a treatment in which the essential characteristic resides in a chemical treatment step and in which the one or more other steps, such as filtration or settlement, are conventional. [3]
  3. In this group, in the absence of an indication to the contrary, classification is made in the last appropriate place. [7]
  4. Any individual step of a multistep treatment, which is not identified by the classification in the last appropriate place, and which is considered to represent information of interest for search, may also be classified in one or more of groups C02F 1/00-C02F 1/54 or C02F 1/66-C02F 7/00. This can, for example, be the case which it is considered of interest to enable searching of multistep treatments using a combination of classification symbols. Such non-obligatory classification should be given as "additional information". [8]
 C02F 9/02
·  involving a separation step  [7]
 C02F 9/08
·  at least one step being a physical treatment  [7]
 C02F 9/14
·  at least one step being a biological treatment  [7]
P:70 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, F23G 7/04)  [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 C02F 11/10)  [3]