Unfire brick for melting steel electric furnace top

BDL-80 BDL-75
AL2O3% ≥80 ≥75
Refractoriness ℃ ≥1780 ≥1780
initial softening point under load 0.2Mpa ℃ ≥1530 ≥1520
Apparent porosity % ≤18 ≤18
Cold compressive atrength MPa ≥≥60 ≥55

Castable material for ladle

GBJ-1 GBJ-2 GBJ-3
AL2O3% ≥30 ≥70 ≥90
MgO% ≥60 ≥11 ≥7
Bulk density
g/cm3 110℃×24h ≥2.9 ≥2.9 ≥3.0
1000℃×3h ≥2.85 ≥2.80 ≥2.90
1550℃×3h ≥2.8 ≥2.88 ≥2.95
cold compressive strength
MPa 110℃×24h ≥45 ≥60 ≥45
1000℃×3h ≥45 ≥50 ≥50
1550℃×3h ≥40 ≥60 ≥70

MPa Modulus of repture 110℃×24h ≥6 ≥5 ≥7
1000℃×3h ≥7 ≥8 ≥5
1550℃×3h ≥8 ≥5 ≥8
Change of curve
% 1000℃×3h ≤0.5～1.2 ≤0.5～1.5 ≤0～0.8
1550℃×3h ≤0～0.2 ≤0～0.2 ≤0～0.2
purpose Steel cover and bottom Middle and small size steel cover integer Middle and small size steel cover dreg line