Precipitation of calcium carbonate from hydrated lime of variable reactivity, granulation and optical properties

Different sources of lime for the production of precipitated calcium carbonate were studied. The reactivity of lime, its optical properties and those of the final products are reported and discussed, and a comparison made between lime from different sources. The influence of the temperature of hydration water on the optical properties and particle sizes after hydration and precipitation was also studied. It was found that coarser granulations of lime have better optical properties than finer granulations. The hydration temperature does not have an appreciable impact on the optical properties, but influences the intermediate, i.e. the calcium hydroxide particle sizes and subsequently the particle sizes of the precipitated calcium carbonate. Furthermore. the maximum temperatures of lime hydration from different European sources do not vary significantly, but they differ in the kinetics of the hydration process. (C) 2009 Elsevier B.V. All rights reserved.