Abstract:
The geochemistry of Sri Lankan feldspar has been investigated through
several studies, but none of them have examined the chemical composition of
major mining sites based on industrial needs. This study evaluates the
chemical composition and impurity mineral incorporation of Sri Lanka's major
feldspar mining sites. Five major mining sites atMathele-Naula, Sewanagala,
Weli-Oya, Owala-Kaikawela and Badalkubura were identified for the study.
Ten samples were collected overall, with multiple samples taken from each
site with varying compositions by preliminary mineralogical observations.
Samples were powdered using a planetary ball mill and sieved below 125 μm
and directed for the analysis. Crystallinity and mineral phase identification
were completed by X-ray diffraction (XRD) analysis (RigakuUltima IV,
CuKα1 – λ= 1.5432 Ǻ) and X-ray fluorescence (XRF) analysis (Rigaku
NEXCG, with 20mm diaphragm). Microcline feldspar is the major compound
found in Mathale-Naula (59.68%),Sewanagala (41.36%), Welioya
(54.06%),and Owala-Kaikawela (78.14%) mining sites. However, the mining
site at Badalkubura is composed of albite (40.44%). In addition, quartz and
muscovite mica are common in most mines as impurity incorporations.
Further, the feldspar samples collected from the Weli-Oya mine have the
maximum crystallinity compared with other samples. Hence, Owala-
Kaikawela and Mathale-Naula mines are suitable for the ceramic and
porcelain industry, while Badalkubura mine is suitable for the glass industry.