Energy Factor-Based Blast Design in Large Opencast Coal Mines

Abstract

Large surface coal mines in produce millions of tons of coal per annum, moving millions of cubic meters of overburden to mine the coal.  Much of this volume is blasted in the form of benches, a common mining technique (Gustafsson, 1973). Blasting is a part of Large Opencast Coal Mine (LOCCM) operations, and is scheduled based on production requirements. With dragline pits, equipment size and operating parameters allow engineers to use tall benches and methods like cast blasting or production dozing to assist with moving blasted material. Changes in scale of equipment and speed of production scheduling have brought about a multi-dimensional shift in the planning process for drilling and blasting team at large surface coal mine operations. So, the problem is that while equipment scale and pace of planning have drastically changed over the last decade blast design and the explosive selection criteria has not changed significantly. Work done by eminent researchers such as Richard Ash and Calvin Konya set the standard for today’s scientific bench blast design practices. Recently, the explosive’s engineering community has largely occupied themselves with applying technology to subsets of the design problem – how to improve or measure fragmentation (M. Monjezi, 2009), how to use technologically advanced methods to design blasts (Y. Azimi, 2010) (P.D. Katsabani, 2005), the public’s perception of mining (Hoffman, 2013). Explosives research for surface coal mining has essentially ignored bench blasting; the industry has not notably recognized the fundamental differences in scale and operational tempo that separate large surface mine blast from regular quarry-scale bench blasting. There is a vast scope of research in the field for explosive energy-based design for better fragmentation with less risk.