Determining the Characteristics of the Calcite Intrusions in the Southern Part of Eppawala Deposit and its Applicability for the Industries

Abstract

Eppawala is the only phosphate deposit that is currently being mined in Sri Lanka and is composed of mainly two parts northern and southern. The ongoing phosphate mining process in the southern part has resulted in the exposure of fresh carbonatite embedded with large apatite crystals and those intrusions need to be removed before continuing further phosphate mining in that area. Therefore, we need to address a suitable method to use those calcite intrusions properly. In this paper, we are discussing the characteristics of calcite matrix such as critical anions (fluoride, chloride), P2O5 content, heavy metals, oxides, and the suitability of applying those removing calcite boulders for further industries including the fertilizer industry. Ion selectivity, titration, colorimetry, and induced coupled plasma spectrophotometry were used for analyzing the characteristics respectively for fifteen samples from three different boulders in the southern part. Results from critical anions and heavy metal percentages proved the absence of toxicity in calcite matrix and oxides percentages showed that it can be applied directly in its natural form only for the fertilizer industry by a quantitative comparison whereas upgrading processes need to be implemented to meet the specifications in other industries.