MOLECULAR-DYNAMICS SIMULATION OF DILUTE-SOLUTIONS OF MEO AND MEF2 IN THE CAO-CAF2 SYSTEM

Models of oxide-fluorides CaO-CaF2 with additions of MeO and MeF2 were constructed and investigated by molecular dynamics method at 1 873 K. It was found out that the CaO-CaF2 system is close to the ideal solut ion. Structure of oxide-fluorides is topologically dense, total coordi nation number for Ca2+ ions changes from 5.2 to 6.8. The Ca-Me-O-F sys tem (Me=Mg, Fe, Sr and Ba) was simulated by replacement of a few Ca2ions by the same number of Me2+ ions. Activity coefficients of MeO and MeF2 solutes in the CaO-CaF2 system were calculated and discussed in terms of basicity (acidity) of the solution. Analysis of MeO and MeF2 activity coefficients in the CaO-CaF2 system showed that with respect to MeO oxides, the CaO-CaF2, system could be considered as a basic sol ution for CaO mole fraction above 0.8-0.9. Al lower CaO concentration the CaO-CaF2 system behaves as an acidic solution. With respect to MeF 2 solutes, the CaO-CaF2 system may be regarded as a basic solution at about all compositions except the vicinity of pure CaF2.