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Valuable products from steel industry slag – pilot under way in Finland


VTT Valuable products from steel industry slag

Renotech Oy and VTT Technical Research Centre Ltd are developing a method for the partial replacement of refractory ceramic raw material with slag from the steel industry.

Europe's steel industry generated around 21.4 million tons of slag in 2012. A quarter of this was not re-used. Slag is traditionally used in landfilling or for example as insulating material in the road constructions. The EU's RESLAG project is developing methods of using slag in various energy industry applications.

Finnish company Renotech Ltd is leading one of the piloting projects under RESLAG and is currently developing fire-resistant refractory ceramics alongside VTT Technical Research Centre of Finland. Around 5.5 million tons of refractory ceramics are made each year in Europe. It is estimated that about 70 percent is used by the iron and steel industry. Applications include the linings of smelting furnaces in the steel industry and insulation linings in incinerators and power plant boilers. One objective of the RESLAG project is to reduce the amount of primary raw materials used to make refractory ceramics, by partially replacing them with slag-based materials from the steel industry. The goal is to a develop a new, castable refractory mass which can withstand atmospheric temperatures of up to 1,200°C degrees.

Product performance is affected by the fact that the composition of side streams varies in the steel industry. For this reason, monitoring the properties of the raw materials used in new products is a key element of productisation.

"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. This improves the competitiveness of the steel industry, while creating new business and jobs in the areas of renewable energy, energy efficiency, metals recovery and refractory ceramics," says Senior Scientist Pertti Lintunen of VTT.

The project involves the development of solutions for increasing the proportion of domestic raw materials used in refractory ceramics. Most of these materials are currently imported.

The total budget of the EU's RESLAG project is EUR 9.7 million, EUR 863,000 of which has been allocated to VTT. The project will last 3.5 years (1 September 2015 to 28 February 2019) and will involve 19 partners.

RESLAG project

Pertti Lintunen, Senior Scientist,, tel +358 40 5370124

Renotech Oy
Bob Talling, CEO,, tel. +358 50 5581806