Autoclave properties of kirschsteinite-based steel slag

The kirschsteinite-based steel slag is one kind of low-alkalinity steel slag. This steel slag hardly behaves as any hydraulicity. In this paper, the hydrothermal products and binding properties of this slag, after being subjected to autoclave treatments, were evaluated. The results show that a hydrothermal autoclave reaction could modify the binding behaviours of kirschsteinite-based steel slag. The main hydrothermal product of pure kirschsteinite-based steel slag was Fe-hydrogarnet, which exhibited poor binding strength. However, the system of quartz-kirschsteinite steel slag appeared to have excellent binding properties due to autoclave treatment, in which the kirschsteinite phase was hydrothermally changed into Fe-substituted tobermorite. Meanwhile, Fe-substituted tobermorite phase was still stable relative to xonotlite over 345 degreesC. (C) 2002 Elsevier Science Ltd. All lights reserved.