The limestone is calcined by an electric resistance furnace at 1 150 ~ 1 250 龙 to manufacture quickened lime for test. The activity of lime is measured according to standard ZBQ27002-85

and the beginning melting temperature

hemisphere temperature

flow property temperature

and the differential scanning calorimetry ( DSC) curves of samples of mixed lime and blast furnace slag are determined by the melting-point-rate apparatus and the high temperature synthetic thermal analyzer. Results show that with heating at 1 150 X. for 2 h the activity of lime is highest that is 417 mL； as the basicity (CaO/SiO

2

) is constant

with increasing the activity of lime the beginning melting temperature

hemisphere temperature and flow property temperature of mixed furnace slag decrease; as the activity of lime is constant with increasing the basicity the beginning melting

temperature

hemisphere temperature and flow property temperature of mixed furnace slag first decrease then increase； with increasing the activity of lime

the endothermic peak of formed 2CaO·SiO

2

and the exothermic peak of formed 3 CaO·SiO

2

occur at lower temperature. With simulated calculation by using Factsage software the results are in accord with experimental results.