Figure 7 – Improvement in ROM fragmentation Calibrated site-specific models were used along with site observations and analysis of historical operating data to identify and evaluate opportunities in the grinding and flotation circuits considering the improved ROM fragmentation from drill and blast optimization. The Phase I grinding circuit was investigated first, as Phase II did not commence operation until 2020. The site-specific models were used to simulate possible circuit changes and optimization strategies. The simulations conducted for the Phase I grinding circuit included the following: • Sim 1 – Increase SAG mill pebble ports size and pulp lifter discharge capacity. • Sim 2 – Sim 1 + optimized SAG mill ball charge. • Sim 3 – Sim 2 + reduced the closed side setting (CSS) of both pebble crushers to 11 mm. • Sim 4 – Sim 3 + increased ball mill power. • Sim 5 – Sim 4 + wider primary crusher CSS. The simulations indicated the throughput of the Phase I grinding circuit could be increased up to 14% while maintaining the current product grind size (~P80 197 µm), as can be seen in Figure 8 which shows the cumulative benefits of all recommendations.
RkJQdWJsaXNoZXIy MTM0Mzk2