THERMAL-BEHAVIOR OF BASIC OXYGEN FURNACE WASTE SLAG

The traditional use of basic oxygen furnace (BOF) slag as an aggregate in road construction has been restricted due to the slag's expansive nature, attributed to the hydration of the calcium and magnesium oxides content. Consequently, a significant proportion of the slag is now being stockpiled. In the present work, the thermal behaviours of an industrial steelmaking BOF slag and of calcium and magnesium oxides, were examined in order to explore means of thermally stabilizing the slag and minimizing its susceptibility to hydration. Thermal analysis techniques, supplemented by Fourier transform infrared spectroscopy and X-ray diffraction, were used to study the materials in dry air, moist air and CO2. An optimum method for thermally treating the slag is proposed and the susceptibility of the treated slag to form hydroxides on hydration was found minimal.