According to the 2016 Technical Report on the Pre-Feasibility Study.
To assess reasonable prospects for eventual economic extraction, it was assumed that the Zafranal deposit would be mined utilizing open pit mining methods under a conceptual scenario of 55,000 tonnes per day production using conventional flotation to produce a concentrate grading 28% copper with credit for gold.
The proposed Zafranal mine will develop two open pits (Zafranal Main and Victoria) with a combined area of 2.47 km2. The final pits will be 2.6 km long and 1.0 km wide and shall reach a maximum depth of 554 m.
Final pit design
The final pit design reflects the decision to employ a stripping contractor for the pre-mine and
early production years (to Year 4), in that the bench height and block size (SMU) were tailored
for the use of medium-sized diesel powered equipment.
Mine design parameters:
- Haul road width - 38-26 m;
- Maximum haul road grade - 10%;
- Bench height - 12 m;
- Nominal minimum mining phase width - 100 m;
- Continuous inter-ramp vertical height - 144 m;
- Safety berm - 25 m.
The road width of 38 m will accommodate the selected 220 t trucks for two-lane traffic. NCL used a maximum 10% road gradient, which is common in the industry for this type of truck. A traffic analysis was carried out on the pit design and for those segments of ramp in the bottom benches of a phase with fewer than 12 tru ........
