OFFICIAL Table 1 – Comparison of sub level stoping layouts (values per stope level) Parameter Value for base case Value for optimized case Stope Length [m] 50 80 Tonnage per Stope [t] 90 000 144 000 Tonnage from Development [t] 5 910 000 8 340 000 Tonnage from Stope [t] 49 500 000 79 200 000 Total tonnage [t] 55 410 000 87 540 000 Development [m] 54 750 77 300 Development length per 1000 t production [m/1000t] 1.11 0.98 Extraction Ratio 46% 53% 5.3. Modelling approach (planning and geomechanics) Mine scheduling simulations were completed using GEOVIA’s MineSched for both layouts to derive feasible mining sequences. The resulting sequences informed numerical stress analyses conducted with FLAC3D. Drift conditions were evaluated using the Rockwall Condition Factor (RCF) framework (after Jager and Ryder, 1999) as a preliminary indicator of excavation performance and support demand (Figure 4). 5.4 Production potential and sequencing constraints The overarching target is 5.0 Mt ROM per year. Scheduling results show that a single stope level cannot sustain the required annual production rate for either stope length scenario due to sequencing dependencies between stopes and levels (c.f. Figure 3). A feasible concept is to define a mining region comprising ten stope levels, split into two sets of five by a 30 m sill pillar (Figure 2, right side). The sill pillar reduces interdependence, enabling mining to proceed in parallel in the upper and lower five-level stacks (e.g., starting at stope level 6 for the upper stack while also mining stope level 1). This achieves the production target within one mining region, but implies approximately doubled equipment and workforce to operate two horizons concurrently. 5.5 Rock-mechanics implications (RCF-based drift condition screening) RCF results from the final mining stage indicate: ● Centre pillar drifts exhibit comparably low RCF values, suggesting good conditions, potentially stable even with minimal support (Figure 4). ● Barrier pillar drifts show less favorable conditions (higher RCF demand), indicating that ground support is required to achieve acceptable operational conditions (Figure 4).
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