1639 The introduction of in-place mining in the plan also significantly increased the production compared with the conventional base case with a positive impact on project economics. Under conventional mining, only stopes that satisfied the economic and processing requirements of the surface route were selected. When ILR and IMR were introduced, additional stopes became economically accessible because material could either be upgraded before processing or recovered through in-mine leaching. This expanded the recoverable portion of the orebody and created a more diversified production profile. Figure 7 summarises the economic impact of the IPM scenarios. The conventional mining base case at 5 Mtpa remained below the zero-NPV line, indicating that the project would be marginal under the reference conventional mining configuration. Introducing ILR moved the project into positive value by rejecting waste before surface processing which reduced OPEX from lower material transport requirements and reduced outlay for tailings disposal, while improving the grade fed to the concentrator plant thereby improving recovery potential. Adding IMR created an additional step-change in value because copper could be recovered without requiring all material to follow the conventional haulage and milling pathway. Leaching of tailings and waste used to backfill empty stopes allowed the operation to recover copper long after mining was completed. Figure 7 – Impact of ILR and IMR on case study economics One of the main benefits of deploying ore sorting ahead of the processing plant was to reduce the amount of material feeding the plant. Even though the addition of ore sorting by itself turned the project economics from negative NPV to slightly positive, the full potential could only be reached if the mining rate could be increased to take advantage of the processing capacity created by leaving some of the low grade waste underground. When bottlenecks were shifted, the value increased further because the mine plan, processing capacity and recovery pathways became better aligned with the new material flows created by IPM. Importantly, the data should be interpreted as a relative comparison rather than a universal forecast. Because the conventional base case is negative, percentage uplift values must be presented carefully. The main message is that ILR can move a marginal conventional case into positive value, while the combined ILR + IMR configuration can materially change the project economics by increasing recoverable value and improving the use of mining and processing capacity. 4. CONCLUSIONS & FURTHER WORK This study established a modelling capability to evaluate the impact of IPM technologies within underground mine planning and project evaluation. The framework enabled conventional mining to be compared with hybrid configurations incorporating ILR and IMR, capturing their effects on stope selection, material routing, processing requirements, recovery pathways, backfill interactions and project value. The case study demonstrated that ILR and IMR should be evaluated as system-level changes to the mine-to-process value chain rather than as isolated technologies. ILR improved project value by enabling
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