Abstract

This work addressed the using alternative binders(calcium magnesium aluminate cement (CMA) or calcium aluminate cement (CAC)) in alumina-spinel castables containing different microsilica content (0 wt% or 1 wt%), in order to evaluate the influence of microstructure evolution on the corrosion resistance properties of final products. The static crucible test by convert slag (C/S=2) were conducted, and XRD, SEM and thermodynamic calculation etc. were carried out. The results showed that adding microsilica (1wt%) decreased the apparent porosity and the median pore size of matrix of castables in the same binder system. Meanwhile for same microsilica content, the apparent porosity and the median pore size of matrix in the CMA-bonded castables were smaller than that of CAC-boned castables. Furthermore, the results indicated that CMA-boned castables shown better corrosion resistance than that of CAC-boned castables. The optimized matrix distribution of micro-crystal spinel and reasonable pore size distribution were obtained in CMA-boned castables. And the refine texture was responsible for the improvement in the corrosion resistance performances.