Cerro Corona mine

The new LoM extension is significant in leveraging the Resource to Reserve conversion to approximately 80% and increasing the Reserve by 49%. A scoping study to assess further opportunities for additional growth will be undertaken in 2018. This now positions Cerro Corona as a long-term, key asset in the Group and will anchor the region as it continues to assess district exploration potential and further growth opportunities.

The life extension is to be achieved through a combination of placing a higher density tailing material, along with an increase in the dam wall elevation of the current TSF to 3,803m amsl (which adds two years life to the existing TSF) and in-pit tailings (which adds five years). These improvements come at minimal additional capital expenditure and results in a 58% or 1.4Moz increase in equivalent Reserves.

The previously reported LoM plan was constrained by the availability of tailings and waste storage capacities rather than by the depletion of the economically viable Mineral Resource.

The PFS focused on the following key elements to facilitate the life-of-mine extension:

  • Optimisation of the current tailings storage facility (TSF) to 3,803m amsl from the current 3,800m amsl and an increase in settled slurry density; both of which allow additional tailings volume to be deposited
  • Development of an in-pit TSF, which will require accelerated mining and stockpiling of ore
  • A new mining sequence and new pit geotechnical design
  • Optimisation of waste storage facilities (WSF) and ore stockpiling capacity

A final pit design, divided into a number of mining phases, was developed based upon a series of pit optimisations and the constraints of tailings, waste and stockpiling capacities. The mining schedule encompasses a significant ramp up in the rate of material movement. Initially this will be accommodated through expanding the current fleet of 35 tonne dump trucks and 70 tonne excavators. However, as the movement rate rises further it is expected that the operation will transition to larger equipment. As the mining rate increases the lower value portion of the ore mined, in excess of the processing capacity at any time, will be stockpiled for treatment after the completion of mining.

The next phase of work in 2018 will focus on three key themes underpinning the FS:

  • Prioritising all of the works required to acquire the permits as per the schedule requirements
  • Completing detailed engineering to enable a greater level of certainty in delivering a fully optimised project
  • Value optimisation to maximise the value and return on the investment