There are two different ways of producing steel. The processes differ by the raw material used in the process – iron ore-based or scrap-based.
In scrap-based production, carbon dioxide emissions are less than one-tenth of those generated in conjunction with iron ore-based steel production. Today, available scrap accounts for approximately 30% of the demand for new steel, this means we are dependent on both steel produced from scrap and steel made from virgin material, so-called ore-based production in blast furnaces. In 2050, it is estimated scrap-based steel will meet 50% of demand, which means that 50% of demand will continue to be met by steel made from virgin material.
At SSAB, we produce steel from iron-ore in the Nordics and from scrap in the US. In SSAB as a whole, an average of 45% scrap was used in steel production in 2014. SSAB uses approximately 20% of scrap in conjunction with steel production in the Nordics, and 100% in the US. The processes have entirely different environmental prerequisites.
1. Iron ore-based steel in Sweden and Finland
SSAB’s steel production in the Nordics is blast furnace-based. Hot metal is produced by the reduction of iron ore, through coke and coal being added to the blast furnaces. This process gives rise to carbon dioxide.
With current technology, it is not possible to produce steel without carbon dioxide being formed. The process has been continuously developed and improved to become extremely efficient, with process gases and waste energy being utilized for the production of electricity and district heat.
International comparisons show that SSAB’s blast furnaces are at the forefront as regards low carbon dioxide emissions per tonne of hot metal. There are several reasons for this: the use of high-grade raw materials in the form of iron-ore pellets, high-quality coke, and efficient processes in which the blast furnaces produce without disruption.
A large number of usable residuals, such as heating, gas, slag and dust, are recovered to minimize waste.
2. Scrap-based steel in the US
Steel is one of the most recycled materials in the world. SSAB’s plants in the US produce steel based exclusively on scrap. A certain amount of coal and natural gas is used in the production process, but in the main electricity is used for smelting the scrap.
All in all, carbon dioxide emissions are less than one-tenth of the emissions generated in conjunction with iron ore-based steel production.