| 3/00 | General features in the manufacture of pig-iron (mixers for pig-iron C21C 1/06) |
| 3/02 | General features in the manufacture of pig-iron (mixers for pig-iron C21C 1/06) by applying additives, e.g. fluxing agents |
| 3/04 | General features in the manufacture of pig-iron (mixers for pig-iron C21C 1/06) Recovery of by-products, e.g. slag |
| 3/06 | General features in the manufacture of pig-iron (mixers for pig-iron C21C 1/06) Recovery of by-products, e.g. slag Treatment of liquid slag (slag wool C03B; slag stones C04B) |
| 3/08 | General features in the manufacture of pig-iron (mixers for pig-iron C21C 1/06) Recovery of by-products, e.g. slag Treatment of liquid slag (slag wool C03B; slag stones C04B) Cooling slag |
| 3/10 | General features in the manufacture of pig-iron (mixers for pig-iron C21C 1/06) Recovery of by-products, e.g. slag Treatment of liquid slag (slag wool C03B; slag stones C04B) Slag pots; Slag cars |
| 5/00 | Making pig-iron in the blast furnace |
| 5/02 | Making pig-iron in the blast furnace Making special pig-iron, e.g. by applying additives, e.g. oxides of other metals |
| 5/04 | Making pig-iron in the blast furnace Making slag of special composition |
| 5/06 | Making pig-iron in the blast furnace using top gas in the blast furnace process (in coke ovens C10B) |
| 7/00 | Blast furnaces (lifts associated with blast furnaces B66B 9/06) |
| 7/02 | Blast furnaces (lifts associated with blast furnaces B66B 9/06) Internal forms |
| 7/04 | Blast furnaces (lifts associated with blast furnaces B66B 9/06) with special refractories (refractory materials C04B) |
| 7/06 | Blast furnaces (lifts associated with blast furnaces B66B 9/06) with special refractories (refractory materials C04B) Linings for furnaces |
| 7/08 | Blast furnaces (lifts associated with blast furnaces B66B 9/06) Top armourings |
| 7/10 | Blast furnaces (lifts associated with blast furnaces B66B 9/06) Cooling; Devices therefor |
| 7/12 | Blast furnaces (lifts associated with blast furnaces B66B 9/06) Opening or sealing the tap holes |
| 7/14 | Blast furnaces (lifts associated with blast furnaces B66B 9/06) Discharging devices, e.g. for slag |
| 7/16 | Blast furnaces (lifts associated with blast furnaces B66B 9/06) Tuyères |
| 7/18 | Blast furnaces (lifts associated with blast furnaces B66B 9/06) Bell-and-hopper arrangements |