ABSTRACT
The presence of free CaO in steel slag is the main reason for the volumetric instability of steel slag. In this paper, steel slag was pretreated by simulated natural aging, carbonize-tion treatment, steam treatment and water immersion treatment, and the effects of different aging methods on the f-CaO content were investigated; the distribution of f-CaO before and after aging treatment was analyzed by thermogravimetric analysis and petrographic microscopy. The results showed that steam conservation and carbonization effects treated the best results with relatively less treatment time. The simulated natural aging and water immersion treatment times are longer, but are suitable for treating large amounts of steel slag. The trace amount of calcium carbonate forms a calcium carbonate crust on the surface of the steel slag, which inhibits the rate of hydration reaction.
