The European Union and the UK produced around 38.5 million metric tonnes of ferrous slag in 2022, 99% of which could be used primarily as a building material and in fertilizers, claims Euroslag, the Duisburg-based European Association of ferrous slag producers and processors.

This means that the by-products of the steel industry have substituted more than 1.1 billion tons of natural rock over the period 2000 to 2022. In addition, the use of granulated blast furnace slag instead of Portland cement clinker has avoided the emission of 408Mt of CO2 over the same period.

Last year, blast furnace slag accounted for 21.3Mt of the 38.5Mt of ferrous slag. Of this, 17.57Mt – or 82.5% – was used in cement and concrete, 3.07Mt in traffic route construction and 0.66Mt for other uses. Of the total 17.0Mt of steelmaking slag, 12.07Mt – or 70.2% – went to traffic route construction, 2.20Mt to metallurgical work, 1.57Mt to fertilizer, 0.67Mt to cement and concrete, and 0.69Mt to other applications.

"Resource conservation through secondary raw materials, especially in the construction sector, and lower emissions of climate-damaging CO2 are of outstanding ecological and economic importance."

Thomas Reiche, chairman of EUROSLAG and managing director of the FEhs Building Materials Institute.

According to Thomas Reiche, chairman of EUROSLAG and managing director of the FEhS Building Materials Institute, "Resource conservation through secondary raw materials, especially in the construction sector, and lower emissions of climate-damaging CO2 are of outstanding ecological and economic importance."

Reiche said that the use of ferrous slags makes an important contribution to this and added that EUROSLAG is working multilaterally to master the enormous challenges in the coming years, 'above all the transformation of the steel industry, through research and adjustments to national and European regulations'.