CPC Definition - Subclass C21C

Last Updated Version: 2017.05
PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS (refining metals in general C22B 9/00)
Definition statement

This place covers:

all treatments of molten iron or steel, including the apparatuses specifically related thereto, e.g. converter, electric furnace.

References
Limiting references

This place does not cover:

Cast iron alloys

C22C 37/00

Ferrous alloy compositions

C22C 38/00

Dephosphorising or desulfurising
Definition statement

This place covers:

Also the specific treating agents

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Dephosphorising or desulfurising of molten ferrous alloys

C21C 7/064

Special rules of classification

In case the dephosphorising, desulfurising are more generally claimed and could also apply to ferrous alloys (incl. steel), C21C 7/064 should be attributed as well.

If the method of introduction is specifically claimed, the corresponding class in C21C 7/00 should be attributed

Removing impurities other than carbon, phosphorus or sulfur
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Removing impurities of ferrous alloys

C21C 7/04

General processes of refining metals

C22B 9/00 - C22B 9/22

Special rules of classification

In case the treatments to remove other impurities are more generally claimed and could also apply to ferrous alloys (incl. steel), C21C 7/04 or any appropriate class below should be attributed as well.

If the method of introduction is specifically claimed, the corresponding class in C21C 7/00 should be attributed

Constructional features of mixers for pig-iron
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Stirring devices for molten metal

F27D 27/00

Manufacture of cast-iron
Definition statement

This place covers:

Treatment of pig iron to obtain non-spheroidal cast-iron.

References
Limiting references

This place does not cover:

Cast-iron alloys (composition)

C22C 37/00 - C22C 37/10

Informative references

Attention is drawn to the following places, which may be of interest for search:

Making of cast-iron alloys

C22C 33/08, C22C 33/10

Making spheroidal graphite cast-iron
Definition statement

This place covers:

Also the nodularising agents

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Making of cast-iron alloys

C22C 33/08, C22C 33/10

Cast-iron alloys

C22C 37/00 - C22C 37/10

Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel {or stainless steel}
Definition statement

This place covers:

Also the manufacturing of stainless steels and ferro-alloys; apparatuses, in particular converters, which are specifically dedicated to the steel processing are classified within this group as well

References
Limiting references

This place does not cover:

Ferrous alloy compositions

C22C 38/00 - C22C 38/60

Special rules of classification

Indexing Codes C21C 5/00 - C21C 5/56 apply for additional information or in case no corresponding EC-subgroup exists.

Manufacture of steel in the converter {(C21C 5/005 takes precedence)}
Definition statement

This place covers:

Also the full plant lay-out.

Regulating or controlling the blowing
Definition statement

This place covers:

Converter processes in which the regulation or control of the blowing is claimed, be it from above, through the bath or a combination thereof, i.e. not specific to one of the methods ; the regulation or control can relate to the amount, the sequence, the composition etc of the gases.

Also post-combustion is considered as a means to control the blowing

Synonyms and Keywords

In patent documents, the following abbreviations are often used:

Post-combustion

after burning

Blowing from above (C21C 5/35 takes precedence)
Definition statement

This place covers:

Regulation or control of blowing ONLY from above, i.e. through a lance

References
Limiting references

This place does not cover:

Blowing through the bath (C21C 5/35 takes precedence)
Definition statement

This place covers:

Regulation or control of blowing only through the melt, i.e. through a tuyere or bottom

References
Limiting references

This place does not cover:

Tuyere details

C21C 5/48, B22D 1/005

Removal of waste gases or dust
Definition statement

This place covers:

The treatment of the off-gas

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Separation

B01D

In particular of solids from gases or vapours by gravity, inertia or centrifugal forces

B01D 45/00 - B01D 45/18

By filters

B01D 46/00 - B01D 46/54

By liquids

B01D 47/00 - B01D 47/18

By other means

B01D 49/00 - B01D 49/02

Purifying or modifying the chemical composition of combustible gases containing CO

C10K 1/00 - C10K 1/34, C10K 3/00 - C10K 1/06

Offtakes or separating apparatus for converter waste gases or dust
Definition statement

This place covers:

The installation required for capturing and treating of the off-gas.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Preventing escape from fumes from the area where they are produces, collecting or removing fumes therefrom

B08B 15/00 - B08B 15/04

Devices for conducting smoke or fumes for factories or large buildings

F23J 11/12

Arrangements for using waste heat, using or disposing of waste gas

F27D 17/00

Refractory linings
Definition statement

This place covers:

Apart from the lining itself, the equipment to make, apply or repair the lining, both of the vessel and of the taphole in particular.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Linings for furnaces in general, incl. making and repairing

F27D 1/00, F27D 1/16

Tapholes

F27D 3/15

Details or accessories
Definition statement

This place covers:

Lances, means for their handling; supporting means for the converter; cooling arrangements; tapholes, their opening and sealing; charging devices; measuring and sampling devices; support and transport devices for the converter; cleaning and skull removal.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Measuring the weight of the converter

C21C 5/46

Trunnions in generalbearings and accessories in general

F16C 11/02, F16C 17/00 - F16C 43/00

Charging of furnaces

F27D 3/00 - F27D 3/18

Travelling or movable supports for the charge

F27D 3/12

Tapholes, opening and sealing

F27D 3/15, C21B 7/12

Lances injecting a gas jet; injecting particulate material using a fluid jet

F27D 3/16, F27D 3/18

Devices or methods for removing incrustrations

F27D 15/00

Arrangements of controlling devices

F27D 19/00

Arrangements of monitoring devices

F27D 21/00 - F27D 21/04

Measuring, testing in general of weight of vibrations or ultra-, infra- or sonic waves radiation pyrometry other temperature measurements

G01, G01G, G01H, G01J 5/00 - G01J 5/62, G01K

Specific techniques for measuring or analysing materials by determining their chemical or physical properties

G01N

Bottoms or tuyéres of converters
Definition statement

This place covers:

Porous plugs and tuyeres

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Treatment of fused masses in a ladle, incl. with gases

B22D 1/00

Tilting mechanisms for converters
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Pivotal connections in general ;

F16C 11/00 - F16C 11/12

Bearings and accessories in general

F16C 17/00 - F16C 43/08

Manufacture of steel in electric furnaces ({C21C 5/005 takes precedence}; electric heating per se H05B)
Definition statement

This place covers:

Any type of electric heating : AC, DC, induction or plasma, incl. accessories as burners.

The manufacturing of alloyed steels, incl. ferro-alloys.

The charging of the electric furnace.

Multiple hearth furnaces.

The general lay-out of the melt shop.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Methods or apparatus for combustion using fluent fuel

F23C

Burners

F23D

Electrically heated hearth furnaces hearth furnaces in general and their accessories

F27B 3/08, F27B 3/00 - F27B 3/26

Arrangements of elements for electric heating in or on furnaces

F27D 11/00 - F27D 11/12

Electric heating elements or system

F27D 99/00

Electric heating in general

H05B

Special rules of classification

specific Indexing Codes exist for the presence/absence of a foam or a molten heel in the electric furnace

Manufacture of steel by other methods (making liquid steel by direct processes C21B 13/00 {; C21C 5/005 takes precedence})
Definition statement

This place covers:

Also methods starting from scrap (with/without preheating) not treated in electric (arc) furnaces

Treating molten ferrous alloys, e.g. steel, not covered by groups C21C 1/00 - C21C 5/00 (treating molten metals during moulding B22D 1/00, B22D 27/00; remelting ferrous metals C22B)
Definition statement

This place covers:

Treatments of refining or alloying by means of the treatment agents, the form thereof, purpose or the circumstances.

Metallic, carbonaceous or exothermic treatment agents.

Loose or compacted agents or cored wires.

Treatments in a ladle, under pressure or in a current of streaming metal;

special treatments of the slag.

References
Limiting references

This place does not cover:

Treating molten metals during moulding

B22D

Remelting of ferrous alloys

C22B

Informative references

Attention is drawn to the following places, which may be of interest for search:

Making tubes by bending sheet

B21D 5/00

Cored wires for welding, soldering

B23K

Removing impurities by adding a treating agent
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Removal of impurities from pig iron other than carbon, sulfur or phosphor

C21C 1/04

Dephosphorising; Desulfurising
Definition statement

This place covers:

Including specifically disclosed agents for desulfurising and dephosphorising

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Removal of phosphor or sulfur from pig iron

C21C 1/02

Decarburising
Definition statement

This place covers:

Including stainless steels

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Control and regulation of blowing in a converter

C21C 5/30 - C21C 5/35

Treatment with gases (C21C 7/06, C21C 7/064, C21C 7/068 take precedence)
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Refining metals by treating with gases

C22B 9/05

Use of slags or fluxes as treating agents (C21C 7/06, C21C 7/064, C21C 7/068 take precedence)
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Refining metals by treating with fluxes

C22B 9/10

Handling in a vacuum
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Refining of metals by applying a vacuum

C22B 9/04