What is firebricks which is used in Down's Cell? What is its role?
Firebrick is a ceramic material that is used for lining furnaces and kilns.
Firebrick is stable at high temperatures and has low thermal conductivity.
A Downs cell operates at 600 °C. It consists of a steel shell lined with firebrick.
The firebrick serves three functions:
It protects the steel shell from the corrosive effects of the molten
It acts as a thermal insulator, thus keeping the heat inside the cell and promoting energy efficiency
It acts as a self-sealing lining. The firebrick is thick enough that if a crack develops, the electrolyte freezes in the crack before it reaches the steel shell.