カスピダイン(3CaO・2SiO_2・CaF_2)の熱含量測定 Measurement of Heat Content of Cuspidine (3CaO・2SiO_2・CaF_2)
The powder used as lubricant in continuous casting processes contains mainly CaO，SiO_2 and CaF_2. Cuspidine (3CaO・2SiO_2・CaF_2)is therefore formed usually after the powder melts. Only the information on crystal structures，lattice constants and phase equilibria has been reported for the cuspidine，but the heat capacity of it has not been measured yet. In the present work，the heat content of the cuspidine was measurered from 1104K to 1827K using the drop calorimeter. The heat content of the cuspidine was obtained as follows: △H_s=0.382T-135±15kJ/mol (solid phase) △H_l=0.854T-810±25kJ/mol (liquid phase) From these results，the enthalpy of melting at 1683K is 119 kJ/mol，and the entropy of melting is estimated to be 70.7 J/mol.K.
高温学会誌 26(4), 145-148, 2000-07-20