PURPOSE: To obtain the flux which is good in slag exfoliation property and prevents occurrences of pits and blow holes, by mixing specified amounts of alumina, carbonate, fluorite, magnesia, wollastonite, lead glass, etc.

CONSTITUTION: The flux is prepared by mixing (by weight) 5W20% alumina, 0.5W15% carbonate, 5W25% fluorite, 15W30% magnesia, 20W35% wollastonite, 0.01W1.0% lead glass (containing 10W80% PbO), and ≤40% deoxidizer and alloying agent. BaCO3, CaCO3, LiCO3, etc. can be used as the carbonate, and metallic manganese, ferroaluminum, ferroniobium, etc., can be used as the deoxidizer and alloying agent. The required flux is obtained by mixing and granulating these raw materials with a binder, such as water glass, etc., and then calcining at 300W500°C temperature usually.