Study of the Leaching Characteristics of Tailing Materials

Column and agitation leaching tests were performed in the laboratory to investigate the leaching characteristics of tailing material from a carbon-in-leach plant under different conditions.Distilled water, rainwater, and acidified solutions of pH 5 and pH 3 were used as the leaching reagents to determine the mobilization of some heavy metals. The effluents from the columns using the various leaching reagents were analysed for Pb, Cr, Cd, Hg, Zn, Cu, Ni, Fe, Mn, Mg, and Ca using AAS. Plots of concentration against cumulative bed volume of these elements were used to compare the mobilization of the different heavy metals under these conditions.It was realized that the mobility of various metals into the aqueous contracting environment in a tailings dam depends on the conditions in the tailings dam. The results show that the concentrations of Pb, Hg, Cr, Mn, Ni and Fe in the effluent from the columns were in certain cases above the maximum permissible levels as given by Ghana EPA general effluent quality guidelines for discharges into the natural water bodies from mining and mineral processing.