METHOD FOR PRODUCING SLAG

摘要

PROBLEM TO BE SOLVED: To provide a method for separating and recovering slag having high content of a CP phase by phase-separating the CP phase and FeO phase in the slag and further separating and recovering the slag consisting essentially of remaining FeO phase as an iron source. SOLUTION: The method for producing the slag includes: a first step of dephosphorizing molten iron to obtain slag in which the ratio of CaO to P2O5by concentration is expressed by CaO/P2O5≤5; a second step of cooling the slag at≤5°C/min average cooling rate in a temperature ranging from a temperature at which the slag is started to be solidified to a temperature at which the whole slag is solidified to solidify and crystallizing 3CaO-P2O5phase and/or 4CaO-P2O5phase (CP phase) in the slag after the solidification; and a third step of separating the slag pulverized after the second step into the slag consisting essentially of the CP phase and the slag consisting essentially of FeO to recover the slag consisting essentially of the CP phase. COPYRIGHT: (C)2009,JPO&INPIT