Potential use of Zambian clay and laterite as soil liner in tailings dam construction

Tailings are discharged directly into rivers, valleys, and surrounding due to the absence of tailing containments at artisanal and small-scale mining sites leading to environmental pollution. Synthetic liners are expensive, however, compacted natural soil has been found to be more cost-effective. This study aimed to undertake a laboratory evaluation of natural clay and laterite from Zambia as a potential soil liner. The laterite soil sample was grouped into three depending on the range of particle size and was designated as LS₁, LS₂ and LS₃. Results from the test indicate that the hydraulic conductivity of LS₂ and LS₃ were in the order of 10^-9m/s, LS₁ was in the order of 10^-8m/s at hydraulic gradients of 11 and 15. At a hydraulic gradient of 17.6, the hydraulic conductivity of LS₂ and LS₃ increased to an order of 10^-8m/s. The hydraulic conductivity of the clay sample was within 10^-10m/s at the different hydraulic gradients.