The European steel industry produced 5.35 million tonnes of excess slag in 2012, which is currently landfilled and stored in factories, creating environmental challenges. However, the material is also reused in different industrial processes, such as insulating roads.
The multinational RESLAG project set out to develop four eco-innovative applications for steel slag in 2014–2019. The different solutions have now been demonstrated in pilots within end-user industries.
“When you utilise steel-industry side streams and reduce the consumption of primary raw materials and energy in production, you also reduce carbon dioxide emissions,” said Pertti Lintunen, senior scientist at VTT.
In a subproject led by Renotech and VTT, the researchers were able to utilise slag to produce refractory ceramics that are used in the linings of furnaces in the steel industry, as well as in the insulation masses of incinerators and power plant boilers.
“We have now reached a level where all the aggregates used in refractors were replaced with slag-based material and 10 per cent of the cement needed for production could be replaced,” commented Lintunen. “This was an excellent result when compared to what has been published on the subject around the world.”
The RESLAG project consists of 19 partners from Europe and Morocco and is funded by the European Union’s Horizon 2020 programme.