The modified phenolic resin was synthesized by sol-gel process using in-situ formed nanosized silica. The improved phenolic resin was characterized by IR and TG-DTA analyses .The results show that the interaction between SiO2 nanoparticles and phenolic resin lead to the decrease of concentration of phenolic hydroxyl groups, and introduce the impurity atom Si to the phenolic resin molecule chain, which promotes the heat resistance and stability of phenolic resin. The physicochemical property analyses show that the magnesite-carbon brick using this modified phenolic resin as binder possesses a low apparent porosity and a high bulk density and compression strength.
