抄録
The effects of CaO, MgO, MnO and SiO2 on the activity coefficient of P2O5 in dilute solution of P2O5 in FetO were determined at 1370°C by the use of a mass spectrometer-Knudsen cell combination. The activity of P2O5 was determined by the use of the following chemical equilibrium. Iron vapor in equilibrium with solid iron was used as internal standard.
PO ( g )+ P2O5( in slag ) = 3PO2(g)
aP2O5 = K·P3PO2PPO=K'·(I+PO2/I+Fe)3(I+PO/I+Fe)
The interaction parameters have been calculated from the activity coefficient of P2O5 with the aid of the least square method. The obtained results are as follows.
εCaOP2O5 = - 23 ± 3 εMgOP2O5 = - 20 ± 2
εMnOP2O5 = - 13 ± 1 εSiO2P2O5 = - 4 ± 1
These interaction parameters are for dilute solution of P2O5 in FetO.
