Chatree comprises multiple open pits with two carbon-in-leach processing plants able to process 5.5 Mtpa.
Ore will be initially sourced from low grade stockpiles before mining operations recommence in September 2023.
- Chatree was an established open pit mining operation using conventional open pit mining methods and a locally based mining contractor. Conventional open pit mining and contract mining is also assumed for the restart of operations. The Competent Person considers the mining methods to be appropriate for the deposit.
- Pit optimization was undertaken using Whittle Four-X pit optimization, with consideration of all operating costs, commodity prices, mine recovery and dilution factors, metallurgical recoveries, process throughputs, and mining rate limits. Limits were placed on pit optimization to prevent mining within 20 m of the tailing storage facilities. A revenue factor 1.12 optimal pit shell was used as the basis of the final pit designs. Stage mining was used to smooth material movements for scheduling.
- Detailed pit designs were completed for all pits, designed following pit slope recommendations of O’Bryan 2013 and dual lane haul ramps, except for the final benches, which have been designed with one way access to reduce stripping requirements.
- Bench height selection is appropriate for the deposit and expected mining equipment, with both ore and waste to be blasted on 9 m benches then mined in 3 m fl ........
