Investigating rock fragmentation in distributed spherical air-gap blasting technique

Abstract

The high density of site-mixed emulsion explosives, which consume excessive explosives to fragment soft to medium-hard rock, has always been a matter of concern to mine operators. Therefore, the authors have conceptualized a novel technique called distributed spherical air-gap blasting, which reduces the amount of explosives consumed. In this paper, a comparative evaluation of the rock fragmentation caused by the distributed spherical air-gap blasting technique, conventional blasting technique, and other contemporary techniques for explosive consumption reduction is presented.The analysis indicates that the conventional technique has the maximum percentage of particles <100 mm and an exceptionally low percentage of D10, D20, and D50 sizes. The percentage of particles in the size range of 100–800 mm is the highest for the distributed spherical air-gap blasting technique. The blasts carried out using plastic-tube, air-decking, and plastic-bottle techniques exhibited a substantial percentage of particles in the >800-mm size range.