The construction of the 996-metre-level station at the bottom of Shaft 1 was completed in July 2020. The completed Shaft 1 is located approximately 350 metres away from a high-grade area of the Platreef orebody that is planned for bulk-scale, mechanized mining. The three development stations that will provide initial, underground access to the high-grade orebody have also been completed on the 750-, 850-, and 950-metre levels.
The changeover construction at Shaft 1, initially delayed following the September 14, 2020 accident, is progressing to plan and is on schedule for commencement of rock hoisting early in 2022. All equipment for the shaft changeover has been procured and is on site. The detailed engineering designs for the shaft changeover have been completed, reviewed and approved. The changeover work within the shaft will be conducted by Platreef’s experienced owners team.
The winder that was used to successfully sink Shaft 1 will be converted and re-equipped to function as the permanent rock, personnel and material winder for the life of mine. The shaft will be equipped with two 12.5-tonne skips (with hoisting capacity of 825,000 tonnes per year) and an interchangeable personnel and materials cage to accommodate the movement of personnel and materials up and down the shaft during the initial phase of mining.
The shaft will be equipped using rope guides for the main rock, personnel and materials conveyances. The stage and winder ropes used during the sinking phase have been removed, and the equipping stage, new permanent guide-ropes and the new permanent hoisting ropes have been delivered to site.
Further to this, an auxiliary winder will be installed mainly to function as a man winder during the main rock hoisting cycle.
The construction of the winder foundations is underway and will be completed in time for the auxiliary winder installation and commissioning. The headgear, both winders, equipping stage, conveyances and control systems will comply with the highest industry safety standards, with proven and tested safety and redundancy systems in place.
Newly-designed rock chutes will connect the conveyors feeding the concentrator plant and the waste rock area, from where the rock will be converted to cemented backfill and also used for protection berms to contain storm water and reduce noise emissions.
The new ropes and the newly-designed and constructed equipping stage will be installed in the shaft by specialist contractors. The equipping in the shaft barrel is scheduled to commence at the end of March 2021 for completion by end of February 2022.
Following the completion of the changeover work in the underground stations, and establishment of the ore and waste passes, lateral underground mine development will commence toward high-grade ore zones.
Early-works surface construction for Shaft 2 began in 2017. It includes the excavation of a surface box-cut to a depth of approximately 29 metres below surface and construction of the concrete hitch for the 103-metre-tall concrete headgear (headframe) that will house the shaft’s permanent hoisting facilities and support the shaft collar.
Platreef’s budget for 2021 is $59 million, which includes $10 million for commencement of headframe construction for Shaft 2.