PURPOSE: To readily control tapping temperature without enlarging furnace volume and continuously discharge molten slag at a constant temperature, by providing an auxiliary chamber, divided from a main chamber with a weir and having specific auxiliary electrodes and tapping outlet.
CONSTITUTION: A molten slag 11 is charged from a main raw material charging inlet 3 provided at the fixed ceiling 2 into a main chamber 1 of an electric furnace for producing rock wool until a weir 6 is dipped in the molten slag 11. An auxiliary raw material is charged from a secondary raw material charging inlet 4 and heated by main electrodes 5 to increase temperature to a given value, e.g. 1,500W1,600°C, and the high-temperature molten slag 11 is discharged through a communicating hole 12 provided under the weir 6 into a specially installed auxiliary chamber 7. The final temperature control is carried out by auxiliary electrodes 9 to discharge the molten slag 11 at a constant temperature from a tap hole 10.
MARUKAWA YUJO
TATENO MASAKI
