The performance of aluminum silicate ceramic fiber blanket is different from other traditional insulation materials, and it has the following characteristics:
1. High temperature resistance is good. According to the different types of raw materials, the use temperature of aluminum silicate fiber blankets can be divided into three types: low temperature type (below 900 ℃), standard type (below 1200 ℃), and high temperature type (1400~1600 ℃), which is much higher than the use temperature of fibrous insulation materials such as rock wool and glass wool (500~700 ℃).
2. The thermal conductivity of aluminum silicate fibers is very low in high temperature areas, and they have excellent insulation and thermal insulation effects. At 1000 ℃, its thermal conductivity is only 15% of that of refractory clay bricks and about 38% of that of lightweight clay bricks. However, its thermal conductivity is closely related to temperature, bulk density, slag ball content, and fiber diameter.
2.1 The thermal conductivity of aluminum silicate fibers decreases with the increase of bulk density, but the magnitude of the decrease gradually decreases. Even when the bulk density exceeds a certain range, the thermal conductivity no longer decreases and tends to increase.
2.2 At different temperatures, there is a small thermal conductivity and corresponding small bulk density.
2.3 The small thermal conductivity corresponds to a small volumetric weight value that increases with temperature.
3. Small unit weight generally ranges from 90 to 220 kg/m3, which is only equivalent to 1/5 to 1/3 of lightweight refractory bricks.
4. Good thermal stability is due to the elasticity of aluminum silicate fibers, which are longer fibers. Even if the temperature changes sharply, structural stress will not be generated. Moreover, their products are porous materials with interwoven fibers, and the expansion of individual fibers can be absorbed by the products themselves. Therefore, with appropriate construction techniques, sufficient strength and resistance to rapid cooling and heating can be achieved.
5. Good chemical stability, except for strong alkalis, hydrofluoric acid, and phosphoric acid, it is almost not corroded by other chemicals. Aluminum silicate fibers exhibit excellent chemical stability in oxidizing and neutral atmospheres. The chemical stability of the reducing atmosphere, alkali metal oxides, and sulfides is relatively poor, and crystallization is prone to occur, leading to deterioration of fiber performance. The chemical stability of aluminum silicate fibers mainly depends on their chemical composition and impurity content. The following table lists the chemical stability of three different components of aluminum silicate fibers. From the table, it can be seen that pure Al2O3 fibers have good chemical stability, while SiO2 has little effect on chemical stability when fluctuating in the range of 50% to 60%.