Silica for foundary or steel making
acts as a very good insulator . is also used for insulation of molten metal in tundish and ladle in slab caster . The temperature of molten metal in the ladle is around 1400 degrees centigrade and above . When this metal flows from ladle to tundish , the temperature drops to around 1250 degrees . This reduction in temperature leads to choking and causes breakdown in the slab caster.
When this is spread as a coating over the molten metal in the tundish and in ladle , it acts as a very good insulator and the temperature is maintained and does not cool down quickly , hence reducing the breakdown time of the casting .