Silicon Nitride Heater Protection Tube SG-28 Silicon Nitride Ceramic has become the preferred material for protection tube of electric heater in aluminum processing industry due to its excellent high temperature performance and corrosion resistance. ï?¬Due to its high temperature strength and strong thermal shock resistance, Silicon Nitride Ceramic can withstand the heat load of a high temperature burner, and the corrosion of molten aluminum for a long time, and the service life is more than one year; ï?¬Silicon Nitride Ceramics almost do not react with the aluminum liquid, so it will not pollute the aluminum liquid, which is conductive to improve the purity of aluminum liquid under high temperature. Compared with the traditional upper radiation heating method,the efficiency of immersive heating is 30%-50% higher and the overheated oxidation of the upper molten aluminum can be reduced by 90%.