OPERATIONS •
The increased storage capacity resulting from the completion of the expansion and the extension of the LOM to 2040 will enable the continued re-mining of old tailings in the region .
TSF design integrity An Engineer of Record was appointed to the facility to ensure a robust design , which included the operation phase and safe closure of the facility , and considered technical , social , environmental and local economic context .
Conrad Freese , senior project manager at MWS explained , “ Detailed stability modelling was undertaken for the facility . The inclusion of a High Density Poly EthylenePolyethylene ( HDPE ) geomembrane liner into the composite clay liner system of the TSF added complexity to the design and construction process . The design also includes an extensive under-drainage system on top of the barrier system where piping ( 87km in length ) is being installed to drain water out over the next 100 years , to ensure there is no ground water contamination .
“ The design was analysed by an independent technical reviewer ; a dam breach analysis was done to determine the consequence of failure ; and the design was reviewed by the Dam Safety office . A licence to construct was then issued and an Engineer of Record was appointed for the construction period of the facility .”
TSF construction An experienced contractor was selected and awarded the construction contract as the construction site was exposed to climatic conditions and challenges . The winds in the dry season and rainfall during the wet season disrupted progress . “ The size of the construction footprint creates a large catchment area and requires proactive planning to manage the accumulated rainwater ,” said Freeze , noting that these environmental issues were addressed , and a quality system was established to ensure quality control and assurance during the construction phase .
Socio economic development Freese emphasised that a process of engaging community members was undertaken before construction as employment creation for local communities was a priority , with 30 % of the construction budget spent with local contractors by the end of 2024 .
“ Because community expectations were high , the challenge was to balance the available economic opportunities with demand ,” he added . “ Sourcing and selecting local suppliers and contractors who met the minimum commercial criteria and who had some construction experience added to the challenge , however , the main contractor successfully selected companies in the area , and in many cases , upskilled local SMMEs .”
Operation Freeze added , “ The experienced Engineer of Record responsible for the design and construction phases , will be appointed for the operations phase of the tailing facility too , to ensure comprehensive
The inclusion of a High Density Poly EthylenePolyethylene ( HDPE ) geomembrane liner into the composite clay liner system of the TSF added complexity to the design and construction process .
www . africanmining . co . za African Mining Publication African Mining African Mining • March 2025 • 21