OFFICIAL Figure 19 – Fragmentation Modelling Table 7 – Pattern Expansion Sensitive Analysis Ore Dilution Control Using Blast Movement Modeling Context and Objectives Santa Luz’s orebody has strong structural control with economically viable domains differentiated by total organic carbon (TOC): dacitic material (TOC < 0.5) and carbonaceous material (TOC > 0.5). Carbonaceous material is associated with preg‑robbing—a phenomenon in which naturally occurring organic carbon (and some clay minerals) adsorb the dissolved gold cyanide complex from slurry, pulling gold out of solution and thereby reducing recovery. In the resin‑in‑leach (RIL) process, ion‑exchange resins are mixed with the slurry to adsorb the gold cyanide complex directly in the leach tanks; when preg‑robbing is present, the carbonaceous matter competes with the resin for the gold complex, lowering resin loading and increasing losses unless the blend is controlled. In practice, post‑blast mixing between these domains was increasing dilution and driving variability in plant feed. Site tracking in the second half of 2023 recorded 18.4% dilution, above the 15% target. The project’s objective was to reduce dilution and stabilize blend quality by mining the post‑blast reality rather than in‑situ polygons, aligning dig boundaries with TOC‑based domains to improve the reliability of grade sent to the crusher. Bulk Explosi ve Patte rn Incre ase (%) P80 Variat ion (%) Effective Energy (MJ/t) Or e Wast e Standar d Basel ine - 0.6 6 0.48 High Energy 0.0% -9.3% 0.7 3 0.54 6.0% -4.9% 0.6 9 0.50 10.0 % -2.8% 0.6 7 0.48 13.0 % -1.2% 0.6 5 0.47 17.0 % 2.2% 0.6 3 0.46
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