Determination of Heavy Metals present in Amalgamation Tailings of Traditional Gold Mining In Sudan

Abstract

Currently, the traditional gold mining in Sudan becomes one of the primary resources of the economics. The major aim of the present study was to physico-chemically characterize the amalgamation tailing samples (locally known as Karta) of the traditional gold mining areas concerning the hazardous heavy metals. The samples were collected from seven common mining areas located in Northern Sudan (between river Nile state and Red Sea state). The targeted mining areas include Almigal, Nouraya, Mine6, Jabel Aseida, Alkiles, Hajor Almurat and Gabgaba. The collected samples were characterized using different analytical techniques, which include atomic absorption spectroscopy (AAS), direct mercury analyzer (DMA), X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and Specific gravity analysis. The results have shown that Mine 6 contains the lowest concentration of gold; 1.820 ppm, while the highest concentration was found in Almigal sample; 199.4 ppm. In addition, the results revealed the existence of high concentrations of mercury in all samples; however, the level of mercury in Almigal sample was out of limit of detection. Several elements were also detected including Fe, Ca, Ba, Rb, Sr, Zr, Zn, Ti, Cr, Mn, Pb, Cu, Y, Nb, and As in the amalgamated samples with significant variations based on location. The FT-IR analyses have demonstrated closely similar absorption peaks for all samples except some variations in Gabgaba sample. Finally, the XRD analyses which were carried out for two samples only (Almigal and Mine6) illustrated that the major constituent of these samples was quartz with percentage close to 98% and 76% in Almigal and Mine6 samples, respectively.