Chemical Stabilization of Bof Slag for Reuse in Railway Pavement: Physical-Chemical Characterization, Mechanical and Leaching Tests

For each ton of steel produced, approximately 120 kg of steel slag are generated in the BOF (Basic Oxygen Furnace) process. In general, the recently produced steel aggregates have a volumetric expansion that leads the material to fragmentation and subsequent fines production. Such a result of this expansion, the use of slag in paving must be done in terms of processes for the free lime treatment. The main objective of this work is to evaluate the chemical stabilization of the unstable oxides using of steel melting aggregate in the liquid phase with the coke refractory, another residue within the steel manufacturing in integrated plants. XRD, EDS, X-ray fluorescence, SEM and textural analysis were performed to investigate the surface and the chemical constitution of the samples. The results obtained showed a significant reduction in the free lime content from stabilized material by the proposed methodology, enabling its uses in railway pavement. In addition, it was possible to conclude that the method fitted the treated sample in the regulamentation standardized limits with no indication of harmful leaching to the environment.