Economic appraisal of iron ore deposit in Buttala, Sri Lanka: Preliminary mineral and chemical evidences

Iron ore deposits have greater industrial significance since they supply raw material for steel based industries and such applications are majorly based on their mineral and chemical characteristics. Therefore, initial clear understandings on mineralogy and geochemistry of these ores would be advantageous. Present study aimed to investigate the mineral and chemical composition of the iron ore deposit exposed in Buttala, Monaragala District, Sri Lanka and to assess its economic potential. Sampling was carried out systematically along the ridge of ore containing mountain and from the host rocks. Textural and weathering characteristics of the ore samples were determined in hand specimen scale. Detail mineralogy was analyzed on X-Ray Diffractrometer (XRD) analyzer while elemental characterization was performed on X-Ray Florescence (XRF) spectrometer. Spatial distributions of iron and gangue elements of the ore were mapped using the Quantum GIS software. The deposit is mostly exposed as fresh ore bodies along the ridge of mountain and is hosted in garnet biotite gneiss. As indicated by the XRD results, common minerals of the ore deposit are magnetite and hematite with minor amounts of spinel, ilmenite and goethite. Average Fe2O3 content of the ore deposit is 78.84 wt. % with 55.14 wt. % of calculated Fe content. The spatial distribution of iron is higher at the northern and southern parts of the ridge than its middle part. The resulted Fe content of the ore is greater than many of the other iron ore deposits in Sri Lanka and comparable to the high grade iron ore deposits found elsewhere in the world. Concentrations of common gangue constituents of Al2O3, SiO2, TiO2 and MgO are 7.54 wt. %, 4.40 wt. %, 3.6 wt. % and 2.54 wt. % respectively. Contents of S and P, which are considered as common deleterious elements are negligible. Therefore, the Buttala iron ore deposit is magnetite and hematite containing, high grade iron ore deposit with greater economic potential.