1989 Volume 75 Issue 3 Pages 462-469
Four kinds of limestones produced from different areas in Japan were calcined in a laboratory muffle furnace over the temperature range of 900-1 200°C and holding times from 0 to 120 min. The effects of calcination conditions on the reactivity with water and on the desulphurization reaction of hot metal were investigated.
The lime calcined from the crystalline limestone was little affected by calcination conditions and indicated good reactivity with water even by calcination at 900°C. The lime calcined from the microcrystalline limestone was much affected by calcination conditions, and only the lime calcined at the temperature higher than 1 100°C indicated the same good reactivity with water as the lime calcined from the crystalline limestone. It means that the calcination condition depends on the structure of limestone in order to get good reactivity of lime with water.
The burnt lime having a good 1 min value of reactivity with water indicated a good desulphurization efficiency for hot metal. The observed changes in reactivity of burnt lime with water and hot metal could be attributed to the structure of burnt lime, i. e. existence of cracks of μm order in width.
