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MANUFACTURE OF IRON OR STEEL (preliminary treatment of ferrous ores or scrap C22B 1/00 ; electric heating H05B)
Definition statement
This subclass/group 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.
Relationship between large subject matter areas

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.

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
General features in the manufacture of pig-iron (mixers for pig-iron C21C 1/06 )
by applying additives, e.g. fluxing agents
Definition statement
This subclass/group 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 within this group

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
Relationship between large subject matter areas

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 relevant to classification in this group
This subclass/group 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 subclass/group covers:

Cooling covers both dry and wet methods of cooling.

Informative references
Attention is drawn to the following places, which may be of interest for search:
General arrangements of separating plants
Handling or treating discharged material
Ingredients other than water added to the slag ; treatment with gases or gas generating material
Making pig-iron in the blast furnace
Definition statement
This subclass/group 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)
Informative references
Attention is drawn to the following places, which may be of interest for search:
In coke ovens
Purifying or modifying the chemical composition of combustible gases containing carbon monoxide
Production of fuel gases by carburetting air or other gases without pyrolysis or of combustible gases containing carbon monoxide from solid carbonaceous fuels
Special rules of classification within this group

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 subclass/group 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.

Informative references
Attention is drawn to the following places, which may be of interest for search:
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
Separation
Cleaning of gases from solids
B01D45/00TOB01D 53/00
Filtering elements
B01D24/00TOB01D 35/00
Filtering material
Purfying or modifying the chemical composition of combustible gases containing carbon monoxide
with special refractories (refractory materials C04B)
Informative references
Attention is drawn to the following places, which may be of interest for search:
Refractory materials
Linings for furnaces
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 subclass/group covers:

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

Informative references
Attention is drawn to the following places, which may be of interest for search:
Linings or walls incorporating cooling arrangements
Shaft furnaces with cooling arrangements
Cooling of furnaces or of charges therein
Cooling of linings of combustion chambers
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
Informative references
Attention is drawn to the following places, which may be of interest for search:
Discharging devices, e.g. for slag
Definition statement
This subclass/group covers:

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

Informative references
Attention is drawn to the following places, which may be of interest for search:
Charging or discharging liquid or molten material
Tuyéres
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 subclass/group covers:

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

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
Informative references
Attention is drawn to the following places, which may be of interest for search:
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
Separation
Cleaning of gases from solids
Filtering elements
Filtering material
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 subclass/group covers:

Covers any measuring, controlling or observation devices

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
Stoves for heating the blast in blast furnaces
Making pig-iron other than in blast furnaces
Making spongy iron or liquid steel, by direct processes
Definition statement
This subclass/group 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.

Informative references
Attention is drawn to the following places, which may be of interest for search:
General purpose Fluidised Beds
Fluidised bed furnaces
General methods of reducing to metals : - by solid carbonaceous reducing agents ;- by gases
Special rules of classification within this group

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 subclass/group covers:

Also rotary-hearth furnaces.

in electric furnaces
Definition statement
This subclass/group covers:

Also using a plasma.

Multi-stage processes [N: processes carried out in different vessels or furnaces]
Definition statement
This subclass/group 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 subclass/group covers:

Also processes involving nuclear energy or a chloride process.

Informative references
Attention is drawn to the following places, which may be of interest for search:
General methods of reducing to metals
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Last Modified: 10/11/2013