Fractionation of Pb in Soil of Abandoned Pb Mine by SEM-EDX and XRD

Abstract

Mining activity has been associated with environmental pollution problem all through ages. Rhandirmwyn  Pb mine was one of the most important mine site areas in South Wales. At present, the mine waste an   adits in the area are regarded as main sources of Pb pollution in the area. Therefore, scanning electron  microscopy coupled with energy dispersive X-ray spectrometer (SEM-EDX) were used for the  identification of fractional forms of Pb that are liable to leach out/down from the soil matrix of the  abandoned mine site to surface-andunderground water bodies of the nearby localities, and to determine its association with soil components using X-ray diffraction (XRD). Among the fractional forms of Pb, Galena, Anglesite, Cerussite, Mimetite and Pyromorphite were identified as the fractions of Pb found in the soils of Nantymwyn (Rhandirmwyn) abandoned mine, of which Anglesite was the most abundant fraction observed. Being the most soluble fraction of Pb among the five Pb minerals observed dissolution of this fraction from the abandoned mine is highly possible and could be a source of contamination of soils and surface-and-ground water sources of localities in the vicinity of the spoil mines. However, results of XRD indicated that the bulk chemistry of the soil samples is dominated by quartz followed by aluminosilicates (comprise of illite and kaolinite and traces of pyrite, albite and orthoclase), all of which could be sink for Pb and could possibly influence the mobility of the metal.

Keywords: Fractionation, mineralogy, Rhandirmwyn mine, environment, pollution