BF slag resistance of β-Si3Al3O3N5 material derived from Al salt cake

In the process of recycling of salt cake from secondary aluminium smelting, it was shown that a significant value addition can be made as β-Si3Al3O3N5 could be successfully synthesized from the rest product after water-leaching by silicothermal reduction method. In order to evaluate its refractory application, the corrosion behavior in blast furnace slag was investigated under static condition at 1400–1480 °C in the present work. The results show that the β-Si3Al3O3N5 material has good slag resistance. The apparent activation energy obtained for corrosion process is −388.7 kJ/mol, revealing a more complicated dissolution mechanism. The corrosion process is started with the dissolution of intergranular phase including the iron silicides and glassy phases in the specimens, which is aided by the softening at high temperature and the continuous attack from slag, then followed by the dissolution of β-Si3Al3O3N5 grains in the slag.