Items L-1000 L-1260 L-1420 L-1600  Working temp() 1000 1260 1200 1350 Max. Working temp() 1260 1260 1350 1450 Bulk density (g/cm3) 160-250 160-250 160-250 160-250 Thermal shrinkage for24hrs  d 1150 1250 1350 1400 4 4 4 4 Chemical components% Al2O3 45~47 47~49 53~55      38~54 SiO2+Al2O3 97~98.5 98~99 98.5~99 83~89 ZrO2 - - 10~18 -