Effect of Ultrafine Spinel Sources on Slag Resistance and Microstructure of Alumina-spinel Castables

摘要

In order to clarify the effect of ultrafine spinel sources on slag resistance and microstructure of alumina-spinel castables,using tabular alumina and spinel as coarse aggregates, tabular alumina powders, spinel powders,calcium aluminate cement,spinel containing cement,spinel micro-powder and reactive alumina ultrafines as matrix,alumina-spinel castables used for RH snorkels were prepared by changing the particle size and sources of preformed spinel. The effects of different ultrafine spinel sources( CMA72,spinel micro-powder) on the properties of alumina-spinel castables were investigated. Thermal shock resistance and slag resistance of specimens were compared by the residual strength rate( 1 100 ℃,air cooling 1 cycle) and static crucible method. The microstructure and the slag corrosion resistance mechanism of the specimens were analyzed by SEM and EDS. The result shows that slag resistance of alumina-spinel castables can be improved by adding ultrafine preformed spinel,such as CMA72,and spinel micro-powder. The introduction of ultra-fine preformed spinel has little effect on HMOR of alumina-spinel castables,but has negative effect on TSR. ultra-fine and dispersive preformed spinel in the matrix and fine microstructure are the main reasons for the improvement of slag resistance of castables.