Investigation of the relationship between the specific charge and Bond Work Index: A case study

Research on blasting efficiency typically focuses on analyzing particle size distribution to evaluate blast fragmentation by examining blasting parameters. However, studies investigating the impact of blasting on downstream processing steps, particularly grinding efficiency, remain limited. This study emphasizes the effects of blast fragmentation on the efficiency of limestone processing and grinding operations. To achieve this, seven distinct blasting events were monitored in a limestone quarry, with specific charge values ranging from 0.33 to 0.49 kg/m³. The particle size distribution of the blasted material was assessed by capturing muck pile photographs and analyzing them using Wipfrag software. For each blast, the average particle size was calculated. Additionally, samples collected from the post-blast muck piles were subjected to laboratory-based Bond work index tests, yielding Bond work index values ranging from 7.8 to 13.8 kWh/T. The effects of specific charge on mean particle size and Bond work index were analyzed through regression analyses. The results revealed a strong correlation, with an 88% correlation between specific charge and average particle size and an 80% correlation between specific charge and Bond work index. The findings of this study clearly demonstrate the interrelationship between blasting and grinding processes.