Project ‘Bespin’ is a great example of doing just that. The project was approved in December and marks the end of an era for the existing Bucket Wheel Excavators (BWE’s) at the Waikato North Head (WNH) minesite. In 2023, a Dry Mining Unit will be installed, replacing the BWE’s, transitioning the site into a single unit of mining rather than two BWE mining units. The future mine plan required the BWE’s to increase mining output from the current 5Mtpa to +10Mtpa. This would have required trucking operations to supplement the BWE to keep up. In addition to this, the mining operations are moving further away from the processing plant. This, with the combined impact of additional trucking, was making our WNH operation more complex, and increasingly expensive to operate.
The project took a wholesale view, starting at the orebody resource, and finishing with selecting a mining method that delivered the most value. Improving iron unit recovery was a key decision making factor – the more iron units recovered the less mining is required. Although the Dry Mining Unit has a lower mining cost, the value of the project for the most part was driven by the selective mining capability of the Dry Mining Unit, which allows higher grade resources to be mined sooner, significantly reducing the mined tonnes required in the next five years. The project also has other key value points that reduce existing and future risks, of both cost, and sustainability, but also increase the mine life through better recoveries and access to areas previously sterilised by conveyors and tailings.