Published: July 14, 2022

Tapojärvi, a specialist in industrial circular economy, is developing new uses for industrial by-products and wTapojärvi, a specialist in industrial circular economy, is developing new uses for industrial by-products and waste in Europe. Three years ago, the company expanded its operations to Italy when the steel mill Acciai Speciali Terni (AST) and Tapojärvi signed a contract for the slag processing.

In the slag treatment process developed by Tapojärvi, metals from steel plant slag are separated and reusable materials are processed into commercial materials.

Recycling and commercialisation of slag decreases the amount of waste going to landfill and reduces carbon dioxide emissions, as well as the environmental impact of the extraction of natural resources and raw materials.

There is no precedent in Italy for a project to recover slag from stainless steel production.

End of Waste-status is a sign of high product quality

Before an industrial by-product ceases to be waste, the use, market, characteristics and potential of new products to meet the quality requirements of similar virgin products must be clarified. Products with end-of-waste status must not have any harmful effects on the environment or human health. In addition, all the criteria set out in the Regulation must be met in order for the substance or object to cease to be waste.

To obtain EoW-status, materials from slag must undergo a series of chemical and physico-mechanical analyses. The results must comply with all the parameters required by environmental legislation. In addition, achieving EoW-status requires a detailed design and definition of the production cycle and its associated processes.

Today, stainless steel slag processed by Tapojärvi in Italy has been awarded End of Waste status.

– Achieving EoW-status is an important milestone for us. We will be able to register and certify slag products and make them available on the European market. End of Waste status will enable us to start producing and selling environmentally sustainable slag products,” says Martti Kaikkonen, Managing Director of Tapojärvi Italia S.r.l.

In the future, slag from the steel mill in Terni will no longer be subject to waste regulation, but to product regulation applicable to commercialised slag. AST’s waste volumes will be significantly reduced and environmental values will be improved. In the future, the by-products from stainless steel production can be used, for example, in the chemical industry or as building materials.

Low-cost and environmentally friendly slag products on the market

By-products of carbon steel production already exist in Italy, but products from stainless steel slag have never been commercialised before.

– In Italy, Tapojärvi plays the role of a pathfinder. The clear benefits of the new slag-based products for the customers are, among other things, their lower price and the fact that they are environmentally friendly,” says Kaikkonen.

Tapojärvi estimates that the first products made from stainless steel slag can be made available on the market in January 2023. Slag-based products can be bought by cement plants, concrete manufacturers, asphalt plants and companies adjacent to the use of calcium products.