A collaboration that could mark a turning point in decarbonizing the cement industry: Swedish steel group SSAB and German cement producer Heidelberg Materials have launched a joint project to develop sustainable cement binders obtained from steel processing by-products. The initiative is part of both companies' circular economy strategy and aims to drastically reduce CO₂ emissions throughout the entire supply chain of construction materials.
The project focuses on valorizing steel slag, a secondary material that has so far been used only partially as a clinker substitute in cement production. Through innovative treatment and activation processes, SSAB and Heidelberg Materials intend to develop binders with technical properties equivalent to traditional cements according to CEM II or CEM III, but with a significantly reduced carbon footprint. The collaboration includes industrial-scale testing to validate regulatory compliance according to DIN EN 197-1 and ensure compatibility with exposure classes defined by DIN EN 206.
For SSAB, the project represents a piece of the decarbonization strategy for the entire production process, which includes the transition towards green steel production through direct reduction with hydrogen. The slag generated by this process has different chemical-physical characteristics compared to those from traditional blast furnaces, with a content of reactive oxides that could improve binding properties if properly processed. Heidelberg Materials, for its part, aims to reduce the clinker factor in its cement products and expand its portfolio of low-carbon binders, in line with European objectives for climate neutrality by 2050.
The partnership assumes particular relevance in the context of European regulation: with the entry into force of the CBAM mechanism (Carbon Border Adjustment Mechanism), cement and steel producers will have to report and offset embedded emissions in materials. The development of cement binders from steel slag with certified environmental product declarations (EPD) could offer designers and builders a concrete alternative to reduce the carbon footprint of buildings, especially in the context of circular economy and green public procurement.
According to available data, the global cement industry is responsible for approximately 8% of global CO₂ emissions, primarily due to clinker calcination. Partial or complete replacement of clinker with supplementary cementitious materials (SCM) derived from industrial by-products represents one of the most effective levers to reduce the environmental impact of the sector. Similar projects, such as the one between SSAB and Heidelberg Materials for the circular model based on steel slag, are gaining momentum across Europe, signaling a paradigm shift in the production of concrete with reduced carbon impact.
