Cooperative Patent Classification


CPC Definition - Subclass C21B

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Last Updated Version: 2017.05
MANUFACTURE OF IRON OR STEEL (preliminary treatment of ferrous ores or scrap C22B 1/00; electric heating H05B)
Definition statement

This place covers:

  • The production of iron or steel starting from iron ores, e.g. the production of pig-iron;
  • The recovery of by-products, e.g. slag, from these production methods;
  • Apparatus specially adapted therefore, e.g. blast furnaces, air heaters.
Relationships with other classification places

General metallurgical processes for obtaining metal from ores, and non-ferrous ores in particular, are treated in C22B.

Details of the apparatus which are of general interest to the group of installations, e.g. shaft furnaces, are also to be classified in F27B and/or F27D.

References
Informative references

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

Furnaces, kilns, ovens or retorts in general

Details or accessories of furnaces, kilns, ovens or retorts in general

Special rules of classification

In the group C21B 2100/22, reforming is based on a reaction with other hydrocarbon containing gases. In the group C21B 2100/24, shift reactions involve steam, water vapor, or water.

C21B 2100/40 concerns the specific purification and reuse of exhaust gases in metallurgical processes, while B01D 2258/025 concerns only the purification process in general of waste gases from metallurgy plants.

by applying additives, e.g. fluxing agents
Definition statement

This place covers:

Processes in which the additives can be added to dry products (e.g. pellets, briquettes), a metal melt or a slag.

Special rules of classification

The group overlaps with C21B 5/008, C21B 5/02, C21B 5/04, C21B 13/008: depending on whether the additives are generally applicable or related to a specific process either in the Blast Furnace (C21B 5/00) or in Direct Reduction process (C21B 13/00), double or single classification will apply.

Recovery of by-products, e.g. slag
Relationships with other classification places

Treatment of (metallurgical) slag is also classified in C04B 5/00 when artificial stone, cement, road material or like building materials are obtained therefrom.

Treatment of liquid slag (slag wool C03B; slag stones C04B)
References
Limiting references

This place does not cover:

Slag wool

Slag stone

Informative references

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

Processes or devices for granulating material

Cooling slag
Definition statement

This place covers:

Cooling covers both dry and wet methods of cooling.

References
Informative references

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

General arrangements of separating plants

Ingredients other than water added to the slag ; treatment with gases or gas generating material

Handling or treating discharged material

Making pig-iron in the blast furnace
Definition statement

This place covers:

Also the injection of additional (pure) oxygen and additional fuel; automatic control of the process; condition of the cokes or their characterisation; composition and distribution of the charge.

Using top gas in the blast furnace process (in coke ovens C10B)
References
Informative references

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

In coke ovens

Production of fuel gases by carburetting air or other gases without pyrolysis or of combustible gases containing carbon monoxide from solid carbonaceous fuels

Purifying or modifying the chemical composition of combustible gases containing carbon monoxide

Special rules of classification

In case the top gas is treated before being sent back into the furnace, this aspect is also classified : either by the relevant class in another field (specific, e.g. C10K 1/02, dust removal).

Blast furnaces (lifts associated with blast furnaces B66B 9/06)
Definition statement

This place covers:

Features which relate to the lay-out of the BF area or to repair ; also the evacuation and treatment of exhaust gases and the control and regulation of the top pressure.

References
Informative references

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

Separation

Filtering elements

Filtering material

Cleaning of gases from solids

Separating solids from solids by wet methods

Magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields

Centrifuges

Apparatus using free vortex flow, e.g. cyclones

Purfying or modifying the chemical composition of combustible gases containing carbon monoxide

Special rules of classification

Groups C21B 7/002 and C21B 7/005 concern evacuating and treating of exhaust gases from blast furnaces in general. Further classification is mandatory in groups C21B 2100/00 - C21B 2100/80.

with special refractories (refractory materials C04B)
References
Informative references

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

Refractory materials

Linings for furnaces
References
Informative references

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

Arrangements of linings in shaft furnaces

Linings or walls for metallurgical furnaces in general

Cooling; Devices therefor
Definition statement

This place covers:

Cooling devices for the walls and bottom including staves, plates, pipes, etc; also leakage detection.

References
Informative references

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

Cooling of linings of combustion chambers

Shaft furnaces with cooling arrangements

Linings or walls incorporating cooling arrangements

Cooling of furnaces or of charges therein

Heat exchange apparatus in which heat exchange media do not come into direct contact

Details of heat exchange apparatus of general application

Opening or sealing the tap holes
References
Informative references

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

Tapping equipment

Discharging devices, e.g. for slag
Definition statement

This place covers:

Runners and their accessories (roofs, heating etc); also equipment for transporting said runners.

References
Informative references

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

Charging or discharging liquid or molten material

Tuyéres
References
Informative references

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

Arrangements of tuyeres

with appliances for distributing the burden
Definition statement

This place covers:

All distribution means different from bell-and-hopper, i.e. including revolving chute.

References
Informative references

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

Transport or storage devices, including chutes, conveyor belts etc

Arrangements of devices for charging of shaft furnaces

Charging of particulate material

Charging directly from hoppers or chutes

Dust arresters
References
Informative references

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

Separation

Filtering elements

Filtering material

Cleaning of gases from solids

Separating solids from solids by wet methods

Magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields

Centrifuges

Apparatus using free vortex flow, e.g. cyclones

Purifying or modifying the chemical composition of combustible gases containing carbon monoxide

Removal of waste gases or dust (from converter)

Offtakes or separating apparatus for converter waste gases or dust

Test rods or other checking devices
Definition statement

This place covers:

Covers any measuring, controlling or observation devices

References
Informative references

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

Arrangements of monitoring devices, of indicators, of alarm devices for shaft furnaces

Arrangements of controlling devices

Arrangements of monitoring devices

Specific investigation or analysing means of materials by determining their chemical or physical properties

Making spongy iron or liquid steel, by direct processes
Definition statement

This place covers:

Direct reduction processes obtaining either sponge iron or molten iron or steel.

Inventions which concern the treatment of the reducing gases, the solid reductant, the ores, the reduced iron or the addition of fluxes or the treatment of the ores in a fluidised bed or lead to attainment of molten iron or steel.

References
Informative references

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

General purpose Fluidised Beds

General methods of reducing to metals: - by solid carbonaceous reducing agents;- by gases

Fluidised bed furnaces

Special rules of classification

When disclosed, the apparatus or group of apparatuses (C21B 13/14) in which the process takes place, should always be given a class

Details of apparatuses being part of the invention should be classified in the relevant apparatus class (F27B, F27D) when possible.

in hearth-type furnaces
Definition statement

This place covers:

Also rotary-hearth furnaces.

in electric furnaces
Definition statement

This place covers:

Also using a plasma.

Multi-stage processes {processes carried out in different vessels or furnaces}
Definition statement

This place covers:

Inventions in which different types of installations are used in sequence to arrive either at a solid or a molten product.

Other processes for the manufacture of iron from iron compounds (general methods of reducing to metal C22B 5/00; by electrolysis C25C 1/06)
Definition statement

This place covers:

Also processes involving nuclear energy or a chloride process.

References
Informative references

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

General methods of reducing to metals