Mining involves open pits at Coyote Central (20 months) and Sandpiper (6 months), together with underground production from Coyote Central (initially 5 years) with all operations commencing during the 7 month processing facility refurbishment period.
Open pit mining by a contractor. Owner operator underground mining using dry hire equipment.
The open pit design process included the following steps:
• Open pit design:
- The Coyote open pit includes a dual lane ramp for the top 50m, reducing to a single lane with passing bays at berm RL’s. Pit walls and berms were designed according to the specified geotechnical parameters;
- No ramp is required for the Sandpiper cutback as the existing ramp provides sufficient access. Given the small-scale of the proposed cutback the optimisation shell was used in place of an open pit design.
• Other infrastructure designs including waste dumps, water storage dams, topsoil storage stockpiles, and mine ore pads.
• Load and haul production was scheduled based on the capability of a combination of 200t and 100t class excavators and 100t rigid trucks, mining 2.5m flitch heights, with consideration of haulage distance to stockpile locations.
The Coyote Central underground mine will be accessed from a portal near the base of the existing open pit, adjacent to the existing portal (which is likely to have collapsed due to being submerged).
The decline is in the footwall 3 ........