Effects of CaCO₃ Addition Amount on Properties and Microstructure of Corundum Castables after Sintering

Corundum Castables were prepared using tabular corundum particles,white corundum fines by electric smelting,cement of pure calcium aluminate,ultrafine alumina,CaCO3 powders as raw materials.Effects of CaCO3 powders addition and sintering temperature on the physical properties,phase composition and microstructure of sintered corundum castables were investigated.The results show that when CaCO3 addition amount increased and sintering temperature rose,the production of CA6 whose grains grew up with a plate-like structure increased,generating volume expansion followed by the increase of apparent porosity and linear change rate,and the decrease of bending strength and crushing strength.