Mill liners were treated as maintenance-driven consumables, with consumption estimated from installed liner mass and scheduled replacement intervals, resulting in a constant mass flow when normalised to throughput. Grinding media consumption was considered operation-driven. Media addition responds to mill power and operating intensity; therefore, wear-rate relationships reported in the literature and practice were applied and converted to mass-based intensities (kg/t ore) for inventory purposes. Although data pathways differ, both converge on a consistent mass-based representation compatible with carbon calculations. Combined carbon results by scenario Total carbon intensity for each scenario was obtained by summing electricity- and consumable-related contributions. Table 3 presents combined results for selected scenarios. Table 3 – Consumable and electricity emission Across Selected Scenarios Scenario Through put (tph) Specific Energy (kWh/t) CO₂e Consu mables (kg/t) CO₂e Electricity (kg/t) Total CO₂e (kg/t) Δ vs Base (%) Base Case 86.6 19.60 2.10 13.33 15.4 Sim 1 92.4 18.83 2.01 12.81 14.8 -3.9% Sim 5 96.6 18.36 1.96 12.49 14.4 -6.3% Sim 7 96.6 20.08 2.14 13.66 15.8 2.5% Sim 8 101.0 20.51 2.18 13.94 16.1 4.7% 4.4.2 Interpretation of Results Including consumables increases absolute carbon intensity by approximately 15% relative to electricity-only results. Incorporating material-related emissions reduces differentiation between scenarios. While ranking remains consistent with specific energy trends, integration of material-related emissions establishes a structural emissions baseline that cannot be reduced through energy optimisation alone. Site constraints or additional investments required to achieve the lowest specific energy configuration may delay implementation, leading operators to prioritise higherthroughput options such as Sim 8. When carbon intensity is considered, an alternative configuration such as Sim 7 may provide a more balanced outcome, maintaining strong production performance while delivering lower overall carbon emissions. 4.5 Considerations for Interpretation and Key Insight This example applies average consumable-use values and does not simulate wear mechanisms or scenario-specific changes in liner or grinding media performance. Replacement intervals reflect operational averages rather than dynamic responses to varying process conditions. The purpose is illustrative: to demonstrate how consumables can be integrated into optimisation-based carbon indicators using available operational data without implying predictive accuracy for site-specific wear behaviour. Despite these simplifications, inclusion of consumables materially alters both
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