METHOD FOR DEPHOSPHORIZING MOLTEN METAL, DEPHOSPHORIZING AGENT WITH LOW-TEMPERATURE SLAG FORMING PROPERTY THEREFOR, AND MANUFACTURING METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To form a slag forming environment suitable for realizing a slag forming synergistic action, when using calcium-ferrite suitable for dephosphoriz ing and quicklime together. SOLUTION: This method for dephosphorizing the molten metal is characterized by charging calcium-ferrite CaO-Fe2 O3 into the molten metal, simultaneously with or slightly earlier than charging quicklime CaO, of which the charging amount is equal to or less than that of the calcium-ferrite. Then, the calcium- ferrite 6 melts earlier than the quicklime 5, forms a low-temperature region in the molten metal under an oxidizing atmosphere, and accelerates dephosphorization. The calcium-ferrite preferably includes quicklime of 25-40 wt.%, iron oxide of 50-70 wt.%, and alumina of 2-10 wt.%.