Critical Analysis of Powder Factor in Dragline Bench Blasting: A Case Study

Abstract

The importance of powder factor has been of immense importance in the field of fragmentation by blasting. Quick, accurate powder factor measurement is essential for any mining project. The fragment size of the muck pile plays an immense role in productivity because heavy machinery is deployed to load this muck pile, and it depends on explosive energy utilization. The main aim of the present study is to evaluate the powder factor for dragline bench blasts with a D-cord initiation system and shock tube initiation system. The present study has been conducted in one of the largest opencast coal mines of Northern Coalfields Limited, Singrauli, a subsidiary of Coal India Limited. A series of ten blasts were studied in the field. For evaluation of powder factor, patch area measurement method and theoretical methods were used. In the theoretical method, all parameters related to powder factor were noted by the blaster report. In the patch area measurement method, length of the cut, width of cut, bench height, and hole depth were measured by steel tape. From the results and the bar charts, it can be said that the powder factor obtained in mine as per the patch area measurement method is lower than theoretically computed. The reason is the assumption of the regular geometry of the blasted patch in the theoretical computation. © 2022, The Institution of Engineers (India).