In the past the flux of molten steel was controlled in Stopper method but recently with the enlargement of the ladle,
growth in technology such as continuous casting, and deteriorating in working environment, Sliding Gate was recently
introduced for precision casting.

Sliding Gate is the very important refractory that directly controls the flux of molten steel. Al2O3-C series used to be
more used as the strong characteristic was required due to the thermal shock when injecting, the abrasion from the hot metal flow, and chemical erosion, but recently, Al2O3-ZrO2-C series is developed with longer life span and the security of the operating environment is dramatically improved .