Workability and setting parameters evaluation of colloidal silica bonded refractory suspensions

The efficiency of colloidal silica as a binder agent for castable matrix suspension in the presence of different setting agents and curing temperatures was evaluated. The tests were carried out trough rheometric techniques according to a systemic approach specifically developed for ceramic systems (oscillatory and normal force tests). Colloidal silica performed well as a binder agent for refractory suspensions when a suitable additive was selected. Among the additives analyzed, magnesium oxide was the most suitable for the evaluated systems. MgO addition in the range of 0.3–0.6 wt% and curing temperature of 25 °C were the suggested parameters for alumina and microsilica systems.