In　a　multipurpose　refining　process，refractory　lining　has　been　exposed　to　severe　condition　and　magnesia-chromite　direct　bonded　bricks　are　damaged　heavily．The　bricks　are　wom　and　splled　structurally　by　penetration　of　CaO-CaF2 injected　flux．Based　on　this　fact，we　have　developed　low　permeable　magnesia－chromite　direct　bonded　bricks　to　avoid　the slag　penetration． 　To　manufacture　the　bricks，we　blent　Fe-Cr　powder　to　the　green　body．The　powder　was　oxidized，reacted　with　magnesia，expanded　and　made　secondary　spinels．The　bricks　are　durable　because　of　the　high　resistance　to　the　slag　penetration　and　the　wear　rate　is　less　than 25% from　the　conventional　one　on　slag　line in　a　vacuum　induction　furnace．

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