As cast refractories are a group of heat resistant materials that attracted much more attentions comparing to refractory bricks due to easy and quick installation, possibility of application in lower thicknesses and localized maintenance potential even at elevated temperatures. Such refractories usually contains silicon soil, spinel soil, tandish coating material or even alumina materials that have been utilized in induction furnaces, tandish and ladles. As-cast refractories are pre-mixed materials that encompass refractory granule, matrix, binder and auxiliary materials. At a specific time, such materials mixed with a fluid (usually water) and transfer with vibration to a special container (increase system) for producing final product. Colloidal binders are one of the most conventionally-used binders applied in producing as-cast refractories. During setting process, gelation, as the key strengthening mechanism of ceramic precursors, takes place as such colloidal binders’ mixes with other involved refractory particles yielding chains of colloidal materials. Colloidal suspended silica stay stable due to electrostatic repulsion between particles. The presence of nano particles in nano scale in colloid used in as-cast refractories causes enhanced gelation as well as increase in their strength.