The special binding mechanism developed provides higher density, lower porosity and higher strengths compared with conventional castables. $ ho$-alumina was employed as a binder materials and nano-sized clay colloidal was added to enhance the drying strength preparing for the alumina vibrated castable. Lower water requirement for casting results in a denser product. The mechanical properties with dimensional stability and corrosion resistance behaviors have been improved by controlling the matrix compositions of the castable. The modulus of rupture and compressive strength after heat treatment at 150$0^{circ}C$ are 92.34 kgf/$ extrm{cm}^2$ and 370 kgf/$ extrm{cm}^2$ respectively. The activation energy of mullite formation is 11.47 kcal/mol.