Abstract:
Calcite and dolomite are the most abundant minerals in carbonatite, limestone
and marble in Sri Lanka. Primarily, they are used in ceramic, steel, cement,
paint and coating, food additives, pharmaceutical, PVC and latex
manufacturing industries as essential raw materials. However, mineralogical
and chemical composition and the impurity incorporations of the selected
calcite/ dolomite raw materials have a specific action in the manufacturing
process and the final product quality. Importantly, different aspects of the
manufacturing processes have critically depended on the CaCO3 and MgCO3
content. Previous studies have only focused on the geological occurrence and
distribution of the calcite and dolomite deposits. Therefore, the present study
aims to conduct a mineralogical and chemical evaluation of currently mining
calcite and dolomite deposits in Sri Lanka. Mineralogical and chemical
analyses were performed by X-ray diffraction and X-ray fluorescence
techniques respectively. Except few, most of the selected deposit
compositions have shown the 2:1 ratio of Calcite: Dolomite. Further, quartz is
present as the major impurity mineral while forsterite, phlogopite, iron-oxide,
kaolinite, and illite, are present as associated impurity minerals. Considering
the industrial suitability, Kolambagearaba, Moratuwagama, Ulpathaha and
Okkampitiya deposits are suitable for the ceramic, paint, PVC and latex
industry due to the high Ca with low Mg and silica content. Though silica is
present, raw materials from Naula, Palapathwala, Kaudupalella and Ulpathaha
deposits are suitable for the ceramic industry.
