The Use of nano-scaled Alumina in Alumina-based Refractory Materials

摘要

The results show that nano-scaled fumed alumina isable to promote the sintering process. An improvement of the mechanical properties of both shaped and unshaped refractory materials can be observed as a result. Considering the amount of the additive there is an optimum in the range between 0.1 and 0.5 weight-%. A fully new aspect is the utilization of nano-scaled fumed alumina dispersions as a novel inorganic binder for refractory castables. For these applications stable dispersions with high solid contents are used. These materials are dust-free and easy to handle. Of a great technological importance is the fact that only relatively small quantities of the alumina-dispersion are able to provide a sufficient binding-strength for the alumina-based castables. By using a dispersion of fumed-alumina it is possible to produce cement-free materials according to a common processing route. This kind of castable does not contain any calcium oxide and is characterized by a high corrosion resistance and very good mechanical properties at elevated temperatures.