Year: 2026 | Month: September | Volume: 13 | Issue: 9 | Pages: 123-134
DOI: https://doi.org/10.52403/ijrr.20260914
Blast Fragmentation Prediction and Explosive Selection Using the Kuz-Ram Model: The Case of the Diack Basalt Quarry (Senegal)
Moumar DIEYE1, Ablaye THIAM2, Abdoul Aziz NDIAYE1, Rokhaya Sall MBAYE2, Souleye SENE2
1École Nationale Supérieure des Mines et de la Géologie (ENSMG), Université Cheikh Anta Diop de Dakar, Dakar, Senegal,
2Technical Direction, EPC MINEEX, Dakar, Senegal
Corresponding Author: Moumar DIEYE
ABSTRACT
This study addresses the prediction of blast fragmentation at the Diack basalt quarry, in the commune of Ngoundiane (Senegal), where basalt is extracted for aggregate production. On site, it was observed that the fragmentation obtained after blasting is not always satisfactory: the presence of oversize boulders often requires the use of a rock-breaker, accelerates crusher wear and increases energy consumption, thereby raising operating costs. The aim of this work was to determine whether the Kuz-Ram model could predict this fragmentation and guide the selection of an explosive better suited to this hard basalt, so as to minimise the occurrence of oversize boulders. To this end, four explosives (ANFO, BLENDEX 70, NITRAM 5 and EXPLUS 90) were compared while keeping exactly the same blast geometry, in order to isolate the effect of the explosive alone. The data used come from laboratory tests on core samples, a structural field survey and the blast records of EPC MINEEX. The rock factor obtained (A = 8.31) confirms that the rock is hard, while the uniformity index (n = 1.29), governed by geometry, indicates a moderately uniform fragmentation. The results show that EXPLUS 90 yields the finest fragmentation (P80 = 486 mm, with only 28.6% of boulders larger than 400 mm) and is the only explosive to simultaneously meet the two industrial requirements set (P80 < 500 mm and oversize at 400 mm < 30%). It was also observed that the charge mass loaded per hole can outweigh the relative weight strength of the explosive. On this basis, an optimal blast pattern, applicable without modifying the existing equipment, is proposed, with the recommendation that it be validated through field measurements.
Keywords: fragmentation; blasting; Kuz-Ram model; basalt; blast pattern; explosive; optimisation.
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