Abstract

Basic oxygen furnace slag (BOF slag) are by-products of the conversion of pig iron to steel. According to the high quantities produced, they are a valuable mineral resource for the construction, in form of aggregates or additions in certain hydraulic binders. However, they have chemical properties that directly control their stability or any hydraulic potential (free lime, etc...). A good knowledge of physico-chemical properties of BOF slag is a necessary preliminary step to their valorization. This work proposes a comprehensive methodology for the characterization of steel slag by complementary analytical techniques (XRF, XRD, TGA ...). Its application to a variety of BOF slag shows that they essentially contain C2S, C2F, Ca(OH)2, Fe1-xO, CaO. CaCO3, SiO2 and MgO are also detected in few quantities. But this composition may change by hydration and carbonation, these two reactions are related to storage temperature and humidity.

KEYWORDS

BOF Slag, chemical composition, valorisation, building material, free lime