Abstract:
The central region of Sri Lanka hosts extensive marble deposits with significant
mineralogical and geochemical variations across different locations. Understanding
these differences is essential for assessing the potential and practical applications of Sri
Lankan marble on a large scale. This study investigates the economic potential of
marbles from Naula, Matale, Digana, Ampitiya, and Balangoda, employing X-ray
Diffractometry, Thermogravimetric Analysis, Atomic Absorption Spectrophotometry,
and Wavelength Dispersive X-ray Fluorescence analyses. The study identifies three
types of carbonate formations: (i) dolomitic marbles, (ii) calcite-rich marbles, and (iii)
monomineralic calcite deposits. Dolomitic marbles are prevalent in the studied areas,
whereas calcite-rich marbles and calcite deposits are concentrated in specific geological
areas. Both dolomitic marble and calcite deposits are sufficiently abundant for
economic mining. Dolomitic marbles have a CaO content of 30.5–34.24 wt% and MgO
content of 13.3–21.82 wt%, making them suitable for industrial applications MgO
extraction and precipitation of CaCO₃ (PCC) due to their high MgO and low impurity
levels (SiO₂: 0.48–2.31 wt%; FeO: 0.003–0.5 wt%). Calcite-rich marbles, with CaO
content ranging from 49.69–51.79 wt% and MgO content between 3.54–4.35 wt %, are
not economically viable for large-scale production due to their limited thickness and
restricted distribution. The calcite deposits in Balangoda primarily consist of coarse
crystalline calcite, with 94.18–98.73 wt% CaCO₃, and ball-milled calcite yields over
90% of particles in the 1–10 μm range, with low levels of impurities (MgO: 0.31–1.96
wt%; FeO: 0.05–0.25 wt%; SO₂: 0.3–1.15 wt%). This makes it ideal for use as Ground
Calcium Carbonate (GCC) in paper, rubber, and paint industries. These findings
highlight the substantial economic potential of Sri Lankan dolomitic marble and calcite
deposits, offering promising opportunities to reduce dependency on GCC, PCC, and
MgO imports.
