Under the situation of the stricter policy of energy conservation and emission reduction,and the national awareness to environment protection,the limestone could be used as the slag-making materials and coolant,directly charged into the converter steelmaking furnace. It owns important significance to investigate the effect of rapid heating of limestone at 1 350- 1 500 ℃ on the spalling behavior of limestone particles and the spatter of molten melts. The influences of calcination temperature,heating time and particle size on the explosion behavior were conducted through a 25 k W carbon-tube furnace in the laboratory. And the results showed that the temperature and heating time had significant effects on the explosion of solid samples,while the influence of particle size was not obvious. When the temperature and calcination time increased,the cracks on the surface of samples obviously became more and bigger,and the solid particles were probably broken into smaller parts. Based on the thermal stress caused by temperature gradient due to rapid heating and the escape pressure of CO2 from the carbonate decomposition,the corresponding mechanisms were also discussed briefly.