... (mainland)Grain shapeRound ball shapeColorBrown- blackAl2O3≥75%SiO28-12%Fe2O3≤5%TiO2≤3.5%Refractoriness≤1790 °CAngle factor≤1.1Thermal expansion0.13% (10 ... min at 1000°C)PH6.5-7.5Packing density1.95-2.05g/cm 3SizeAFS20, 25, 30, 35, 40, 50, 60, 75 ... -35AFS:40≤50-2020-4020-4010-30≤10≤235-45AFS:50≤3≤1525-4025-4510-20≤10≤5≤345-55AFS:60≤1025-4030 ...