Improving thermo-mechanical properties of tabular alumina castables via using nano structured colloidal silica

Abstract

Great attempts were made to reduce the amount of calcium aluminate cement (CAC) content in refractory castables to improve their hot strength. Using more than 2-3 wt% CAC may cause low melting phases formation in the refractory matrix leading to weak thermo-mechanical propereties of the castables. Colloidal Silica can affect the structure of refractory castables to achieve superior thermo mechanical properties. Replacing calcium aluminate cement (CAC) by colloidal silica as a water base binder, speeds up drying, reduces the amount of liquid phase at high temperatures and may lead to mullite formation, which will increase the hot strength of the refractory castables. In this research, the influence of colloidal silica addition on bulk density, apparent porosity and HMOR of a tabular alumina based refractory castable containing have been studied. The results showed that samples containing colloidal silica have higher hot strength compared to those containing only CAC as binder due to the better compaction, less liquid phase formation at high temperature. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/20571