Adição de microssílica e a secagem de concretos refratários Microsilica addition and the drying of refractory castables

Abstract

A microssílica é o material superfino (Microsilica is the most used superfine material (<1µm) in the refractory castables, because it improves its flow, packing density and green mechanical strength. At high temperatures many other advantages are observed, such as the superior corrosion and thermal shock resistances, due to the mullite phase formed by the reaction between alumina and microsilica in the working conditions. Nevertheless, papers relating to the effect of microsílica addition during drying stage are scarce, specifically concerning the explosion behavior. Therefore, the purpose of this work was to establish the relationship between microsílica content and curing temperature variation with some refractory castables' properties. The results showed that higher contents of microsilica on the refractory castables composition promote higher mechanical strength and a reduction of permeability, modifying the castable explosion behavior. The properties evaluated were also effected by the curing temperature applied.

Keywords

• concretos refratários
• microssílica
• temperatura de cura
• refractory castables
• microsilica
• curing temperature