Investigation of the influence of impurities typical in secondary raw materials on the behavior of high alumina castables – Part 1: Design of the castables, setting properties and high temperature fracture behavior

Abstract

The research was carried out using a primary high alumina raw material that was selectively spiked with typical elements found in secondary raw materials. These artificially spiked raw materials were processed into cement-free high alumina monolithics by 1:1 substitution of the corresponding high alumina matrix fraction in the formulation. Regardless of the impurity, the rheology and setting behavior of the developed model refractory castables showed a very high degree of comparability with the reference material. The same workability allowed the production of comparable test pieces for hot wedge splitting tests. The effects on high temperature fracture behavior observed in this study can therefore be attributed solely to the impurities.