Silicate series alumina shaped product for hot blast stove AL2O3% Refracto-riness ℃ Apparent porosity % Cold compressive strength Reheat-ing linear change Initial softening point under load 0.2MPa?0h Creep rate not more than Fire clay bricks for hot blast heater RN-42 ≥42 ﹥1760 ≤24 ≥30 1450℃?h 0～-0.4 ≥1400 RN-40 ≥40 ﹥1740 ≤24 ≥25 1350℃?h 0～-0.3 ≥1350 RN-36 ≥36 ﹥1700 ≤26 ≥25 1350℃?h 0～-0.5 ≥1300 High alumina bricks for hot blast heater RL-65 ≥65 ﹥1790 ≤22(24) ≥50 1500℃?h 0～-0.4 ≥1500 RL-55 ≥55 ﹥1770 ≤22(24) ≥45 1500℃?h 0～-0.4 ≥1470 RL-48 ≥48 ﹥1750 ≤22(24) ≥40 1450℃?h 0～-0.4 ≥1420 Low creep fire day bricks for hot balst heater DRN-130 ≥48 ﹥1760 ≤20(23) ≥60 1400℃?h ?.2 ≥1520 1300℃ ≤0.8 DRN-125 ≥45 ﹥1750 ≤20(23) ≥60 1400℃?h ?.2 ≥1500 1250℃ ≤0.8 Low creep high alumina bricks for hot blast heater DRL-135 ≥65 ﹥1790 ≤20(23) ≥70 1450℃?h 0～-0.4 ≥1550 1350℃ ≤0.8 DRL-140 ≥65 ﹥1790 ≤19(23) ≥75 1450℃?h 0.2～0.1 ≥1600 1400℃ ≤0.8 DRL-145 ≥70 ﹥1790 ≤19(23) ≥80 1500℃?h 0.2～0.1 ≥1650 1450℃ ≤0.8 DRL-150 ≥75 ﹥1790 ≤18(23) ≥85 1500℃?h 0.2～0.1 ≥1700 1500℃ ≤0.8