The role of organic matter of carbonate rocks in the reactivity of the produced quicklime

The gray and white crystalline limestones from Agios Panteleimonas Florina have almost the same mineralogical composition. They are mainly composed of calcite (96%), while the percentage of the contained organic matter is 0.8% in the gray and 0.09% in the white crystalline limestone. After heating both crystalline limestones at 500°C no serious change was observed concerning their mineralogical composition. However, the velocity of P waves and the porosity in the gray limestone are changed significantly while this trend is not noticed in the white limestone. These changes are mainly attributed to the burning of organic matter, which is contained with greater percentage in the gray crystalline limestone. At 1000°C both crystalline limestones are completely calcined. The dissociation of calcite and dolomite increases significantly the porosity of the produced quicklime. The quicklime from gray crystalline limestone presents higher porosity value (by 5.2 percentage units) and it is more reactive (by 4.9 percentage units) in comparison with the quicklime from white crystalline limestone. This difference in the reactivity is mainly attributed to the difference in the percentage of organic matter contained in the two crystalline limestones.