Effect of pretreated Al-Si alloy powder on the microstructure and properties of Al2O3-SiC-C castables for iron runner

In ferrotitanium slag-based Al2O3-SiC-C castables, owing to the presence of more impurities in the ferrotitanium slag, the liquid content at high temperatures is extremely high, which reduces the performance of the material. In this study, the Al-Si alloy powder was hydrated, and then pretreated Al-Si alloy powder (PASAP) was used to replace Si powder and micro-silica to reduce the content of liquid in the ferrotitanium slag-based Al2O3-SiC-C castables. Compared with the sample without PASAP, the sample with 5 wt% PASAP formed numerous whiskers in situ, and the hot modulus of rupture increased by 167%. Moreover, the decrease in the liquid content of the material and the dissolution of the molten slag by Al2O3 led to an increase in the slag viscosity. The slag corrosion index of the sample with 5 wt% PASAP is decreased by 67%.