1998 Volume 38 Issue 8 Pages 781-788
The CaO–MnO–SiO2–PO2.5(–MgO, FetO) slags were equilibrated with liquid copper alloys in a molybdenum crucible under a flowing CO2/H2 atmosphere in the temperature range of 1573 to 1673 K.
The activity coefficient of PO2.5, γPO2.5, and the phosphate capacity, CPO43-=(%PO43-)/PP21/2PO25/4, of the slags were expressed as follows:
log γPO2.5 = –2.59 {(%CaO)+0.33(%MnO)+0.55(%MgO)–0.90(%FetO)–0.77(%PO2.5)}/(%SiO2)+1400/T–5.75
log CPO43- = 2.60{(%CaO)+0.33(%MnO)+0.55(%MgO)–0.90(%FetO)–0.77(%PO2.5)}/(%SiO2)+40400/T–6.48
The phosphorus distributions between hot metal and the slag were examined, based on the thermodynamic data obtained in the present study. From comparison with the plant data, it was concluded that the thermodynamic data obtained in the present study are satisfactorily applicable to the thermodynamic assessment of hot metal pretreatment with high MnO slag.
