1975 dropped from 4.45 minutes to 3.87 minutes, an improvement of about 13% over the monitoring period. These outcomes provided a clear basis for adopting high‑energy explosives as the permanent standard in Santa Luz Mine. During the monitoring phase—and in the subsequent months of 2025—direct drilling‑and‑blasting cost savings of approximately US$ 300,000 were realized, driven primarily by fewer drilled meters and reduced explosive mass per tonne, all while maintaining or enhancing downstream performance. Figure 131 – Powder Factor and P80 Figure 132 – Loading times (EX1200) Interpretation of the results highlights important operational learnings that are relevant to the broader paper. First, field performance exceeded the conservative upper bound suggested by modeling for ore domains. While BDA signaled potential fragmentation risk at 17% pattern widening, the combination of precise burden control, improved energy coupling through QA/QC on charge placement and stemming, and disciplined timing execution enabled widening up to about 18% with improved P80. This outcome underscores the influence of energy distribution within the hole and across the blast on rock‑mass breakage. Second, the relationship between nominal energy‑per‑tonne and fragmentation quality proved non‑linear in practice. Even as effective MJ/t decreased modestly with wider spacing, fragmentation improved, indicating that the optimized placement and confinement of energy can outweigh reductions in nominal energy quantity when QA/QC and timing are well executed. Third, domain specificity remained essential. Waste responded optimally to smaller pattern increases, consistent with its lean powder‑factor baseline and rock‑mass characteristics; this domain‑aware discipline prevented over‑extension and safeguarded quality. From a safety perspective, fewer holes and reduced bench residence time lowered crew exposure without introducing adverse events. The operational chain benefited from the integrated approach: improved 301 447 220 485 249 393 201 437 100 200 300 400 500 PF (g/t) P80 (mm) PF (g/t) P80 (mm) Ore Waste Baseline Results 4.09 3.92 3.60 3.89 3.96 3.76 3.00 3.50 4.00 4.50 5.00 Oct-24 Nov-24 Dec-24 Jan-25 Feb-25 Mar-25 Loading Time (min) Results Baseline
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