A multidisciplinary approach for the assessment of the environmental behavior of Basix Oxygen Furnace slag used in road construction
Résumé
The production of steel slags in France was about 1.6 Mio.t in 2009, among them 0.735 Mio.t of Basic Oxygen Furnace (BOF) slags. The use of BOF slags has been restrined due to insufficient volume stability and lack of environmental regulation. The ECLIR research program has been launched in 2006 in order to implement a multidisciplinary approach for the assessment of the environmental behaviour of a BOF slag used in a civil engineering scenario. The main results of the study indicated that BOF slag contained relatively large amounts of chromium and vanadium which were mostly associated with stable phases consisting of iron oxides, and to a lesser extent, to more reactive calcium silicates. The monitoring of the quality of seepage water through a civil engineering structure built with a BOF slag, showed that these elements were present at very low concentrations and that the waters did not reveal real toxic effect. The atmospheric conditions were responsible for the carbonation of the surface layer of slag with a consequent decrease in permeability and increased leaching potential of vanadium.