Geometric analysis of blasting using C.J. Konya method to get the ideal target fragmentation in pit Main Ridge PT. J Resources Bolaang Mongondow site in Bakan, North Sulawesi

Abstract PT J Resources Bolaang Mongondow (JRBM) is a gold mining company located in North Sulawesi Province, Indonesia. The rocks in PT JRBM have high hardness and poor efficiency for direct excavation processes, prompting the company to apply the drilling and blasting method. Problems occur when the size of the blasting fragmentation results in the Pit Main Ridge does not match the PT JRBM fragmentation target of P80 measuring 10 cm. This study aims to provide recommendations for blasting geometry that produces fragmentation according to PT JRBM’s target. The actual blasting data were processed using the Split desktop 4.0 software, and the recommended geometry was calculated using the C.J. Konya and Kuz-Ram methods, then the results of both methods were compared. The results showed that the average size of the actual fragmentation size of P80 was 16.44 cm, which mismatched PT JRBM’s target of 10 cm. In contrast, the recommended geometry using C.J. Konya method resulted in 84.655% of the fragmentation was 10 cm. Therefore, C.J. Konya method was recommended for blasting at the Main Ridge Pit of PT JRBM.