Ceramic fiber insulating refractory materials are widely used in insulating and heat-resistant materials of various types of thermal furnace. Since its bulk density is much lower than other refractories, it has a small heat storage and good heat insulation performance, which will greatly reduce the energy loss and bring a revolution to thermal furnaces in terms of energy saving if it is used as the lining materials of thermal furnaces. On the other hand, its application techniques and methods also bring a revolution to the masonry of the thermal furnaces.
The Present Situation of Ceramic Fiber Insulating Refractory Materials
Ceramic fiber first appeared in 1941, the United States Babu and Wilcox companies made the ceramic fiber by melting the natural kaolin into fiber with the help of electric arc kiln. In the late 1940s, another two American companies produced aluminum silicate fiber and it was used for the aviation industry for the first time. In the 1960s, the United States developed a variety of ceramic fiber products, which were used in the lining of industrial furnaces. In the 1970s, ceramic fiber began to be produced and used in our country, and its applied technology was rapidly promoted in the 1980s. However, the operating temperature of ceramic fiber was mainly below 1000 ℃ and the application technology was relatively simple and backward.
After the 1990s, with the promotion and application of zirconium fiber as well as polycrystalline alumina fiber, the operating temperature of ceramic fiber was increased to about 1200℃, but due to the product quality defects and backward application technology, the application fields and methods of ceramic fiber were limited, for instance, polycrystalline alumina fiber could not be made into fiber blanket.
Zirconium fiber is a widely used and cost effective aluminum silicate fiber produced by the melting method, which can be used as linings of various thermal furnaces. Currently, the qualities and application development of domestic products in this respect are still relatively backward. Now, there emerges chrome-containing fibers abroad, the operating temperature of which is higher than zirconium-containing fiber. However, we have not seen any report about this respect yet in our country.
The Shortcomings and Prospect of Insulating Refractory Materials
Although the ceramic fiber
plays an important role in the insulation and refractory of the high-temperature industry, there also exists lots of production defects of it. In particular, it is inhalable and harmful for environment and human body. Some foreign companies even strengthened the restrictions of amorphous ceramic fiber use. At present, a kind of bio-soluble amorphous ceramic fiber appears in the insulation refractory market and this super fiber (siO2-CaO-MgO ceramic fiber) is a non-polluting and environmental friendly material. The trend of ceramic fiber products tends to be non-polluting, refined and multi-functional in the future, especially the use of high value-added, high tech-contained functional fine ceramic fiber with the help of new technology and new materials.