The Refractory Tradition

retention of their form an integrity under their own weight at temperatures up to 1,500 °C (or even higher)  

resistance to high-temperature corrosion in aggressive environment (liquids, gases and slag)  

low thermal conductivity which ensures thermal insulation of the hot interior of high-temperature furnaces and reactors  

resistance to sudden temperature changes (thermal shocks), to which many refractory linings are subjected. 

In the case of refractory materials made of oxide ingredients, the reactions are mainly an acid-base ones in materials based on SiC and Si3N4, oxidation-reduction reactions also take place. In general, the intensity and rate of the acid-base reactions is highest when one of the substances involved is acidic and the other basic. The rate decreases when the acidity or basicity of the substances is similar. This is illustrated in the example in Table 2.5, in which shown is the dissolution rate of an acidic refractory material in a molten basic FeO. 

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