Calcination Characteristics of Limestone in relation with the reactivity of Quick Lime

Abstract

The present work is focused on the calcination characteristics of limestone at the temperature range of 7500C to 9000C with one hour soaking followed by the derived quick lime is fully hydrated to slaked lime. The carbonate derived and hydroxide derived nascent lime differ reactivity in a significant extent. The carbonate derived lime in single stage process is less susceptible to hydration than hydroxide derived lime in double stage process. Limestone when calcined at 9500C, the derived lime shows 1.2 percent weight gain but hydroxide when calcined at 5700C, the derived lime shows hydration affinity of 5.2 percent weight gain. The surface area of born lime decreases with Calcination temperature of both carbonate and hydroxide. The high reactivity of hydroxide derived lime is due to higher surface area of newly born CaO than from carbonate as well as hydroxide derived lime form at comparatively lower temperature than carbonate. The hydration affinity increases with increasing surface area.