1970 Table 47 - Initial drill‑and‑blast parameters by sector Sector I II III IV Diameter (in) Custom 4 ½” 4 ½” 4 ½” Burden (m) 2.2 3.0 3.5 Spacing (m) 2.6 3.6 4.2 Stemming (m) 4.0 4.0 3.5 Bench Height (m) 5.0 10.0 10.0 MIC (kg) 18.0 65.0 89.0 Powder Factor (kg/t) 0.226 0.223 0.223 In addition to a customized production blast design, the solution combined electronic initiation—to deliver precise timing and consistent burden relief—with an end‑to‑end, feedback‑driven planning and QA/QC workflow that connects timing scenarios, blasthole locations, explosive charges, and on‑bench compliance checks. Monte Carlo–based vibration modeling supported preventive adjustments before firing, and high‑speed video analysis/fragment analytics were used to observe trajectories and verify confinement, timing, and stemming. Measurements from each production blast were then reconciled against the design, and the insights fed back into subsequent blasts—informing incremental updates to pattern selection, MIC limits, stemming dimensions, and timing while preserving safety and compliance. A complete monitoring methodology was implemented to control the project’s key indicators— vibration, flyrock, and powder factor—integrated into the same closed‑loop QA/QC workflow used for design and execution. Signature holes and monitored trial blasts were used to calibrate the baseline vibration model; event‑based measurements captured PPV at the administrative area and at the dam during production blasts; and post‑blast verification confirmed fragments throwing distances. Blast video analysis and fragment analytics supported refinements to confinement, stemming, and timing, while the digital QA/QC process ensured design‑to‑execution fidelity and provided traceability from planned parameters to measured outcomes. This feedback loop informed incremental adjustments to pattern selection, bench configuration, MIC limits, and stemming dimensions. 3.2 Optimization of Drilling and Blasting with High-Energy Explosives 3.2.1 Context and Objectives As part of continuous improvement process, since it returned to operation Santa Luz mine has been implementing blasting solutions to improve safety, increase production rates and reduce costs. One of the first initiatives was implementing electronic initiation, this project generates significant benefits in safety and costs. But the need to increase production rates and reduce costs require another stage in drill and blast optimization. To overcome these challenges a change in the bulk explosive used in the mine was proposed. Changing from a standard explosive to a high-energy option can enable pattern expansion and cost reductions while maintaining fragmentation quality.
RkJQdWJsaXNoZXIy MTM0Mzk2