Abstract: In order to make effective use of the limestone with small particles（~10 mm），the method of static calcination was used to calcine the limestone sample of which the particle size was at 0.5~10 mm，and the influence of calcining temperature， calcining time，and particle size on the activity of calcined product was analyzed.Results showed that: calcining temperature and time could both affect the lime activity.With low calcining temperature and short time，limestone can not be completely calcined，and the activity of lime was low；with high temperature and long time，limestone would be easily over burnt，and activity of lime was still not high，and the higher the temperature was，the sooner over-burning appeared.The product of the best activity can be obtained when the limestone sample was calcined for 60 min at 950 ℃.The particle size of limestone also had effect on calcined product′s activity，and lime activity did not increase with particle size on a single increasing trend，but rather roughly first increased，then decreased.In this test the best lime activity appeared when particle size was at 2~3 mm.

Key words: limestone, calcination, lime, activity, particle size