关键词: 刚玉质浇注料, 硅溶胶, 铝酸盐水泥, 结合剂

Abstract: Combining the advantages of aluminate cement and silica sol to improve the mechanical properties of castables is a cheap and simple optimization strategy.Corundum castables were prepared with brown corundum and dense corundum as the main raw materials,and silica sol and aluminate cement as the binders.The effect of the aluminate cement addition (0,1%,2%,3% and 4%,by mass,respectively) on the castables was studied.The results show that the hydration of aluminate cement promotes the coagulation and condensation reactions of silica sol,while Si—O—Ca and Si—O—Al chemical bonds are formed,which accelerates the formation of a stable three-dimensional network structure.With the increase of the aluminate cement addition,the cold strength of the samples after curing at 110 ℃ increases,that after heat treatment at 1 100 and 1 400 ℃ first increases and then decreases,the hot modulus of rupture after heat treatment at 1 400 ℃ decreases rapidly,the cold modulus of rupture after thermal shock first increases and then decreases slightly,and the strength retention ratio gradually increases.The silica sol bonded sample with 1% aluminate cement has the best comprehensive performance.

Key words: corundum castables, silica sol, aluminate cement, binder