35 The results should therefore be interpreted as indicative of potential value and key sensitivities. 3. CASE STUDY: HYBRID IN-PLACE MINING OF A REAL OREBODY 3.1 Case study description This case study applied the evaluation framework to an archetype deep iron-oxide copper-gold (IOCG) orebody. The deposit was treated as a greenfield underground mining project, with surface processing, waste handling and mine support infrastructure located to support efficient connection with the underground material handling system. The purpose was to assess how IPM pathways could affect stope selection, production profile, material routing and project value in a realistic geological and mine planning context where orebody geometry, grade distribution, stope accessibility, processing capacity and sequencing constraints interact. The assessment was not intended to produce a feasibility-level design, but to compare the relative impact and value drivers of CM, ILR and IMR configurations under a consistent techno-economic framework. Primary data sources included a three-dimensional block representation of the IOCG orebody, incorporating copper grade distribution, lithological domains, mineralisation style and available geotechnical information. Associated mine planning and trade-off study documents and available test work reports were also used to construct the scenarios. Mineralised material sent to surface was assumed to be treated through conventional comminution, classification and flotation circuits, producing concentrate and tailings streams. Capital and operating cost estimates were developed from benchmarked project information and cut-off grade assumptions, with an expected accuracy consistent with early-stage evaluation. The orebody was characterised by strong geological and mineralogical heterogeneity, with higher copper grades in the upper part of the ore body that decreased steadily with depth below surface. Copper grade distribution and mineralisation style were used to support the identification of zones potentially more suitable for conventional mining, underground upgrading through ILR, or IMR. Three main configurations were compared. A schematic of the resulting flowsheet for the full hybrid mine is provided in Figure 5. • Base Case: CM only, copper production was derived from conventionally mined material processed through the surface plant. • CM + ILR: selected stopes or material streams were upgraded using ore sorting before surface processing, A constraint was imposed to limit the number of ILM stopes to 30 % of all mined stopes. • CM + ILR + IMR: copper was recovered through multiple pathways, including conventional mining, upgraded ILR material and in-mine leaching of low grade waste and concentrator tailings. It was assumed that less than 50 % of the tails could be used for backfill.
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