Iron is produced in a blast furnace by mixing iron ore, coking coal and limestone. Impurities in the ore combine with the limestone to make slag which is a material used in road construction. The molten iron, which is 95% pure, is a key raw material for steel making.
- Scrap steel, including steel packaging, is fed into a large furnace or converter; this is where recycling takes place. The scrap generally accounts for around a quarter of the total content of the converter. In the production of some steels, such as stainless steel, the converter contains virtually 100% recycled steel.
- The molten iron is added to the scrap in the converter.
- A water cooled lance blows high-purity oxygen onto the metal to remove impurities. The converter is heated to about 2000 degrees celsius. In about 30 minutes the iron and used steel are carefully refined to make new high quality steel.
- The hot steel is poured out of the converter, continually cast into solid slabs, and rolled into coils.
The steel production process is continually being developed to ensure that the manufacture of steel cans remains an environmentally friendly option.