Research And Development Of Fiber Castable (Plastic Materials)

Today Alumino-silicate fiber, as an integral part of modern industrial furnace refractory insulation materials, is very important for saving the energy resource and improving consersation efficiency. The traditional alumino-silicate fiber is mainly manufactured into approved products, such as boards, felts and blankets. However, these shaped products can not be used to build the complex site of the kiln, due to its lower strength and the restriction of the worse construction conditions. In this paper, a low thermal conductivity and high-strength alumino-silicate fibers castable (plastics materials) has been developed.It is emphasized on studying the relationship between the composition and the properties of the silicate fibers castable. The major research contents include the effects of the fiber aggregate (such as lightweight mullite, floating beads, ceramic and vermiculite), the matrix (such as mullite,α-Al2O3 powder,corundum powder and clay powder), fine silicon power, expanders (optional Kyanite) and binder (the combination of high-alumina cement and silica sol) on the performance of castable. In the experiments, high-alumina fiber is chosen as the raw material.The results indicate that: (1) the particle shape and density of the aggregate have great influence on strength, line changes and thermal conductivity of the fiber casting material. Because of irregular particles shape of lightweight mullite aggregate and formation of stable A3S2 phase after sintering, the fiber castables adding the lightweight mullite possess the better comprehensive performance. (2) The bulk density, the activity and the sintering ability of the matrix also affect the fiber castable properties. Whenα-Al2O3 powder has been introduced into the plastics materials, the fiber castables have higher strength and lower line change. (3) The strength and line change of the castables are also depended on the content of fine silicon power, and expander whose optimum dose are 3-4% and 5-6%, respectively. The mixture of the high-alumina cement and silica sol as a complex combination enable the fibers castable excellent properties.