integrated simulations, with a strong emphasis on implementation feasibility and sustainability of results. 2.1 Integrated Mine-to-Process Optimization The optimization project was structured into sequential and interlinked stages, each building upon the outcomes of previous work: • Mine and ROM fragmentation optimization, including review and optimization of drill and blast practices. • Phase I grinding circuit assessment and optimization, supported by plant surveys, modelling, and throughput forecasting. • Phase II grinding circuit modelling and optimization, following commissioning of the second grinding line in 2020. • Flotation circuit auditing, modelling, and debottlenecking, to manage the downstream impacts of increased throughput and coarser grinding product size. • Implementation and validation, including prioritization of quick-win initiatives and definition of major CAPEX projects. This staged approach ensured technical consistency and progressive implementation. 2.2 Ore Characterization and ROM Fragmentation Ore hardness and breakage characteristics are key drivers of blasting and comminution performance. Available ore characterization data were consolidated and expanded over time, including Bond Ball Work Index (BWi), SAG Power Index (SPI), Drop Weight Index (DWi), and JK Axb parameters. During early optimization stages, where detailed test work was limited, validated Hatch inhouse comminution relationships were applied to derive representative breakage parameters. This was subsequently complemented by a comprehensive geometallurgical testing program, including SMC and Bond tests across the main alteration domains, confirming the estimated values and improving confidence in the model inputs. The results (Table 1) demonstrate the increased ore hardness compared to the values used for design, and thus the capacity limitations of the comminution circuits due to treating this harder material. Table 1 – Summary of Breakage Test Results Test Unit Design 2014 Samples 2019 Survey 2022 Geomet Testwork Bond Ball Work Index BWi (kWh/t) 12.9 13.3 14.3 13.2 14.2 14.2 SAG Power Index SPI (minutes) 75 129 120 99 - - Drop Weight Index DWi (kW/m3) 6.2* 8.9* 8.5* 7.5* 7.3* 7.0 *Estimated from Hatch in-house relationships. ROM fragmentation is a critical upstream variable influencing SAG mill performance. Optimizing the blast intensity based on ore characteristics (structure and strength) and adjusting crusher gap accordingly, can achieve a finer SAG mill feed and subsequently allow optimization of grinding circuit throughput. This optimization approach has been successfully applied in many
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