Analisis Geometri Peledakan Terhadap Ukuran Fragmen Overburden pada Tambang Batubara Pit Kasturi PT Multi Tambangjaya Utama

Abstract

Blasting activities have been conducted for a period of 15 days at Pit Kasturi, necessitating an analysis of the blasting geometry applied to the size of overburden fragments, which may not be optimal. The objective of this study was to determine the actual powder factor, predict the theoretical fragment size, analyze the actual fragment size distribution, and provide recommendations for optimal blasting geometry design. The research methods employed included the calculation of the actual powder factor, theoretical prediction of fragment size using the Kuz-Ram Model, analysis of the actual fragment size distribution with the aid of image processing software, and recommendations for geometry based on R. L. Ash and ICI Explosive Orica calculation simulations. The findings indicated an average actual powder factor of 0.20 kg/m³, accompanied by substantial variation. The Kuz-Ram Model prediction yielded an average fragment size of 70.34 cm, whereas the actual analysis revealed that 50.13% of fragments were larger than 60 cm (oversize), indicating the inadequacy of the applied geometric design. The simulation of the recommended geometry using ICI Explosive Orica theory resulted in improved prediction outcomes, with an average fragment size of 34.60 cm and a minimal oversize percentage of 31.55%. However, it was observed that a greater number of blast holes were required. Consequently, it can be determined that the optimisation of geometric parameters, particularly those related to burden and spacing, is imperative for obtaining uniform fragmentation that conforms to the required standards. This, in turn, enhances operational efficiency and reduces the cost of handling large-sized materials.