Chemicals that can corrode aluminum silicate refractory fiber include fluorine, fluoride, vanadium and other heavy metals, phosphoric acid, strong alkaline, etc.

     2. Vanadium and other heavy metals. Vanadium and other heavy metals in inferior fuel will corrode aluminum silicate refractory fiber when burning. This corrosive material comes from vanadium pentoxide (V203), which is solid at room temperature but melts at about 690 ℃. The liquid slag is adsorbed in the pore structure of the fiber and reacts with aluminum silicate in the fiber. After reaction, a hardened shell will be formed on the hot side of the fiber lining. After a period of time, the hardened shell will fall off from the unreacted fiber layer of the fiber blanket, and the chemical reaction will continue on the exposed fresh fiber surface.The reaction rate depends on the following factors, such as the concentration of heavy metals, time, porosity of materials and temperature. There is no clear concentration boundary to define whether the reaction occurs or not. In general, it is high heavy metal concentration for a long time that shortens the life of refractories. When the temperature is higher than 690 ℃, vanadium pentoxide will react with the fiber, but the reaction speed is affected by the above factors. With the continuous chemical reaction, it is necessary to replace the hot surface materials regularly. In particular, vanadium pentoxide corrodes fibers, but vanadium in alkaline compounds will form more corrosive slag at very low temperatures, resulting in faster degradation of aluminum silicate refractory fiber. Generally, fuels with high heavy metal content also contain alkali.

     Next issue we will continue to introduce which chemicals will affect aluminum silicate refractory fiber.