Raw iron is the first smelt produced in the blast furnace, and consists of the untreated iron obtained from iron ore. Raw iron is used as the charge material for the production of cast iron and for steel production. Hematite raw iron is used exclusively for foundry production. The standard material has the following chemical analysis:
- 2.50 to 3.00% Si,
- 0.70 to 1.00% Mn,
- max. 0.12% P,
- max. 0.04% S,
- 3.70 to 4.1% C.
Foundry raw iron
Foundry raw iron is also used in foundries, and differs from hematite manly with regard to the phosphorous content, which at 0.50 to 0.70% is 4 to 6 times higher. Specular pig-iron is a special raw iron with a significantly higher manganese content of from 6 to 30%. The normal analysis is:
- 4.00 to 5.00% C,
- 6.00 to 30.00% Mn,
- 0.10 to 0.15% P,
- up to 1.00% Si,
- up to 0.04% S.
Further types of raw iron
Low-carbon or high-carbon raw iron, Siegerland special raw irons, special raw iron for the production of cast iron with nodular graphite and charcoal raw iron. Raw iron is generally used in the form of pigs or ingots of approx. 20 kg in weight, or more rarely as 60 kg joined ingots consisting of 3 20 kg pigs.