Effect of CaO on Thermomechanical Behavior of SiC Based Self-Flowing Castables

In this study the use of hydratable alumina binder (Alcoa) instead of Calcium Aluminate (CA) cement as binder in the production of SiC based self-flowing castable has been investigated. Spent SiC particles were classified into different fractions following crushing and grinding operations and have been utilized as aggregate. Tabular alumina, calcined monodipersed alumina, and hydratable alumina/CA cement were used as binder matrix. Anorthite (CaO.Al2O3.2SiO2) a gehlenithe (2CaO.Al20O.2SiO2) phases were formed according to the CaO-Al2O3-SiO2 three phase diagram. Molten phase negatively affects refractoriness of the materials. For that reason, by using hydratable alumina instead of CA cement mullite binder was created. Mullite was studied by SEM. In addition to CA cement supplementary samples, molten phase produced with CaO lessened the value of the hot modulus of rupture (HMOR). Hydratable alumina binder added samples at 1450 DGC, however amplified the values of HMOR. It was concluded that the refractories acquired can be used as kiln furniture for porcelain sector.