MICROSTRUCTURAL CHANGES IN CALCIUM ALUMINATES CEMENT BONDED CASTABLE SYSTEMS

摘要

In many applications, Calcium Aluminate cement (CAC) bonded castables are used at temperature below 1200°C. Except for some specific cases, this means that the sintering reactions have barely started. This paper presents new results on the influence of the microstructure of conventional alumina castables. Results of phase composition evolution, pores size distribution are presented. This illustrates how the formulation parameters influence the microstructure, which is at the origin of the properties of the castable. Is is shown that for conventional castable, 80% Al_2O_3 cement provides an optimized solution for the binding system. Despite important phase modifications, these binders are able to give strength to the castable, even when sintering has not completely transformed the microstructure. In conventional castables, 80% Al_2O_3 containing cement provide for an optimized solution of the binding system.