Life Cycle Assessment (LCA) and eco design: towards optimized refractory materials for a green steelmaking process

Refractory materials by definition withstand high temperatures without relevant changes in their physical and chemical properties. Due to this behaviour, their use is necessary for various processes involving high temperatures and/or corrosive environment. Iron and steel industry is the main user of refractories, with a share of around 70% on the annual global production. Being one of the most energy-intensive and greenhouse gas (GHG) emitting sector, the development of new low-carbon steelmaking strategies is needed to be in line with the European Green Deal. In order to avoid a trade-off between the GHG emissions and other environmental burdens, the development should be based on a life cycle approach which examines the environmental impacts in an holistic way.
In this context, the present study aims to contribute to improve the environmental sustainability of steel production by reducing the impacts generated by the refractories used in the lining of the furnaces. Specifically, the project deals with the basic refractories used for the lining of the Electric Arc Furnaces (EAF), the core of the second major steel production route, which melts iron sources such as scraps and direct-reduced iron (DRI) using electric energy.
The Life Cycle Assessment (LCA) methodology has been chosen to quantify the environmental burdens generated during the life cycle of the refractories in a cradle-to-grave approach, from the raw materials sourcing, to the end of life. The results of the analysis will highlight the main impacting materials and processes, giving a deeper understanding of where to focus for more sustainable developments. Therefore, LCA is used as an eco-design tool to evaluate the effects of several improvement proposals along the life cycle of the refractories on the global environmental impact. First, strategies to optimize both raw material sourcing and production routes are evaluated. For the usage phase, it is studied how the change of the properties of the refractories can affect the operating conditions of the steel plant and the overall steel-related impacts. Finally, for the end of life, recycling solutions are investigated. Preliminary results will be presented regarding the classical production route.
In the framework of the new CESAREF (Concerted European action on Sustainable Applications of REFractories) European doctoral network, the presence of both refractories and steel producers will allow to access to representative data, task that usually constitutes the bottleneck in LCA studies. The ultimate goal is to exploit the joint effort to reduce the environmental footprint of refractory production for the steel industry throughout their entire life, thereby contributing to the decarbonation of steel production.