Abstract:
In recent years, significant attention has been paid to natural calcite resources as a
viable CaCO3 reservoir for various industrial applications. Despite extensive marble
occurrences in the Highland Complex (HC) of Sri Lanka, their usage is limited to a few
conventional industries owing to their chemical heterogeneity and dolomitic nature.
However, the marbles exposed in Balangoda area of the Ratnapura District, Sri Lanka,
consist of large-scale Calcite Deposits (CDs). In this study, we aimed to estimate the
economic potential of these CDs-bearing marbles by studying their extent, mineralogy
and chemical composition. More than 40 rock samples from the CDs and marble were
investigated for their mineralogy and chemistry on a petrographic microscope, X-ray
diffractometer (XRD), and wavelength dispersive X-ray fluorescence spectrometer
(WD-XRF). The CDs-bearing marble band extends about 40 km, and minable
quantities of CDs are well exposed in the areas of Illukpelessa, Rajawaka, Piyangiriya,
Hapugasthenna, Kottimbulwala, Weligepola, Galpaya, Koswatiya, and Udawalawa.
These CDs occur as intermittent bands and isolated pockets within the marble and
consist of medium to very coarse (1 cm to 12 cm) grained calcite crystals. The majority
of the calcite grains are inclusion-free, although a few contain trace amounts of
graphite, apatite, and/or diopside inclusions. The CDs can easily be distinguished from
marble and silicate impurities owing to their distinct textural characteristics. The
associated marble is composed of dolomite (80 %) and calcite (15%) with lesser silicate
impurities. Based on the elemental analyses, the CDs consist of CaO (54.64-55.07
wt.%) with a negligible amount of MgO (0.38-1.14 wt.%), SiO2 (0.7-0.18 wt.%), and
Fe2O3 (0.03-0.11 wt.%) and can be characterized as high-grade calcite ore. These
results imply that the CDs are economically potential CaCO3 sources, which could be
utilized in the production of Ca-based chemical products such as Grounded Calcite
Carbonate (GCC) and Precipitated Calcium Carbonate (PCC).
