Geotechnical Evaluation of Mine Wastes for Utilization in Embarkment Construction in Jos, Central Nigeria

Nigeria is abundantly blessed with solid mineral resources such as copper, gold, and tantalite, which are essential for the economic growth of the country. The extraction of these mineral resources comes with the generation of huge amount of waste. This study examines the possibility of utilizing some mine wastes from Jos, Nigeria, in embankment construction by subjecting them to relevant laboratory geotechnical experiments. The results indicates that the overburden materials contain clay-sized fraction ranging 5-20%, while the sand fraction ranged 42-82%, which is an indication of the predominance of sand size particles. On the other hand, the clay-sized particles in the tailings range 5-21%, while the sand fractions range 65-80%. The overburden materials recorded liquid limit values ranging 26-48% and plasticity index ranging 6.3-21%, while the liquid limit and plasticity index of the tailings range 23-32.8% and 6.2-11.6%, respectively. The maximum dry density (MDD) and optimum moisture content (OMC) of the overburden materials vary 1.84-1.98 mg/m3 and 1.4-17.2%, respectively, with an average of 1.89 mg/cm3 and 16%. On the other hand, the tailings recorded MDD ranging 1.88-2.06 mg/m3 with their OMC ranging 14.4-16% with an average 14.86%. The soaked California bearing ratio (CBR) of the overburden materials range 27-32%, while that of tailings ranges 25-32%. The geotechnical evaluation of the overburden materials and tailings reveals that most of the materials are suitable for embankment construction. However, the high linear shrinkage of some wastes renders them unsuitable.