Instrumented indentation study of slag in view of a better valorization.

Highlights • BOF slag has a great potential of recycling. • BOF slag is a heterogeneous and complex material. • Mechanical properties of the different phases were determined using a coupled SEM-microindentation system. • The macro-mechanical properties were estimated from mixing laws and compared to macroindentation results. • The BOF Slag recycling can be optimized based on the knowledge of their mechanical properties. Abstract Steel slags are industrial by-products of an integrated steel plant, characterized by their high calcium, siliceous and ferrous content. They prove useful in many fields, such as civil engineering and in the process of steelmaking for the iron-rich phases. For a better valuation, it is important to optimize the separation of its phases. To separate these phases, mineral processing technologies such as grinding followed by magnetic separation are used. The overall goal of this work is to determine the mechanical properties of each phase to improve grinding performance. The results show that all compounds have been clearly identified and mechanically characterized, which has led to a better understanding of BOF (Basic Oxygen Furnace) slag. Finally, a mixture law using the mechanical properties calculated from each phase made it possible to estimate the overall mechanical properties of the BOF slag. [ABSTRACT FROM AUTHOR]