The perlite insulating bricks used for the lining of aluminum electrolytic cells are made from expanded perlite and special binders. In addition to providing sufficient rigidity and mechanical stability, they also offer excellent insulation and low thermal conductivity, enabling them to withstand high temperatures and chemical corrosion, while possessing good mechanical strength and wear resistance. During the aluminum electrolysis process, the alumina in the electrolyte generates a large amount of heat, and the perlite boards act as an insulating layer to help maintain stable temperatures within the electrolytic cell.