Re-Design of Mine Tailings Storage Facility for Adamus Resources Limited

Abstract

The suitability of a centerline or upstream design as a sustainable option for construction of future raises for the existing Life of Mine (LoM) downstream Tailings Storage Facility (TSF) at Adamus Resources Limited (ARL) was investigated using Slope/W in GeoStudio Software. Review of technical information, evaluation of the performance of the existing Stage 6 dam, and geotechnical investigations of available construction materials were undertaken in this research. Insights were gained about the TSF’s life cycle and current bearing capacity for intended future raises. Viable geotechnical parameters were established to define construction material specifications as well as input data for modelling the new designs. The British Standards Institute (BSI) standards were adopted for all the material testing protocols carried out at the Council for Scientific and Industrial Research-Building and Road Research Institute (CSIR-BRRI) laboratory in Kumasi. The scope of modelling covered the original downstream as well as the centerline and upstream options. The geometric design and stability analysis focused only on the southern and northern embankments of the TSF. The modelling outputs yielded reliable Stability Factors of Safety (FoS) for all designs investigated, above the regulatory criteria. Subsequently, a semi-quantitative multi-criteria evaluation was used to select the preferred option between the centreline and upstream alternatives. The results showed that technically, economically and by regulatory compliance, the centreline design is a better alternative and therefore recommended for adoption by ARL.