Corrosion behavior of slags with different basicities to corundum spinel castables
The slag corrosion resistance of castables is closely related to the basicity of steel slag.Sintered corundum,defective spinel micropowder,active α-Al2O3 micropowder,fused magnesia fine powder,and calcium aluminate cement(Secar 71)were used as the main raw materials to prepare corundum spinel castables.The slag resistance test was conducted using the static crucible method at 1 600 ℃ for 3 h,and the amount and composition of the liquid phase were thermodynamically simulated.The slag corrosion re-sistance of the corundum spinel castables against the three slags with different basicities(1.6,2.3,and 7.6)was studied.The results show that the high basicity slag has limited solubility to corundum spinel castables;it is easy to form high melting point phases such as spinel solid solution and calcium hexalumi-nate at the interface between slag and castables,forming a dense layer to prevent slag penetration and corrosion;the solubility of corundum spinel castables is high in low basicity slag;spinel solid solution,calci-um hexaluminate or other high temperature phases can't form until the slag and the castables reach a high reaction degree,thus an effective dense layer can't form to prevent the corrosion and penetration of slag into the castables.Therefore,corundum spinel castables have better slag corrosion resistance to high ba-sicity slags than low basicity slags.