PURPOSE: To provide plugging material easily dropped at the time of opening a nozzle without any problem to contamination in molten steel.
CONSTITUTION: In the plugging material 1 for preventing clogging in a sliding nozzle mainly containing CaO-MgO clinker having CaCO3 film on the surface, a hole of an upper plate 5 of the sliding nozzle and an upper nozzle 4 connected with inlet side of the upper plate, by packing structure for sliding nozzle hole packing the above plugging material 1 and the other packing material 2 mainly containing SiO2 raw material as the surface layer part on the above packing material 1, the nozzle clogging due to sintering and invasion of the molten steel is prevented without any problem to the contamination in the molten steel, and pouring of the molten steel at the time of opening the nozzle hole, is facilitated.
EJIRI MITSURU
TAMEHIRO TAIZO
YAMAGUCHI TSUNEO
NIPPON STEEL CORP