Abstract: Abstract：In this paper, calcination experiments of limestones from three sources were carried
out，their micro-structures analyzed. Then，the obtained activated lime was used for converter
dephosphorization experiments. The experimental results show that: 1）The grades and grain
sizes of limestones from the three sources are different，the limestone No. 1 has a higher impurity
content；limestone No. 3 has the largest grain size，No. 2 the second，while limestone No. 1 has
the minimum among the three；2）the higher the grade and the larger the grain size of limestone，
the higher the activity of the calcined lime is and the less residue is left after hydrolysis reaction —
the results indicate that the residue of lime No. 3 is 96.1 g less than that of lime No. 1；3）the lime
with a high impurity content and low activity affects the slagging and dephosphorization rate of the
converter - the dephosphorization rate of lime No. 3 is 9.8% higher than that of No. 1 on average.

Key words: Limestone, Grain size, Activity, Dephosphorization rate