Properties of alumina based low-cement self flowing castable refractories

The main aspects that determine flowing properties of self flowing alumina based low-cement castables are determined. From the point of view of particle size distribution, different particle size distributions are compared by using Andreassen model according to n-value. The n-values are varied as 0.20, 0.21, 0.22, 0.23, 0.24 and 0.25 to define which one corresponds to the best flowing properties. The prepared castables are fired at different temperatures. Rheological and physical properties of prepared castable refractories were examined. It is found that the self flowing refractory which is prepared by using 0.23 n-value has the best self flowing properties. In addition to these studies, different alumina types which affect the aggregate system, and the roles of additives (calcined alumina, microsilica) are also examined by using n = 0.23 value. Finally SEM studies are performed to investigate the microstructure of these self flowing castables.