AN INITIATION SYSTEM FOR REDUCTION OF ENVIRONMENTAL IMPACTS IN OPEN PIT BLASTING

摘要

Ever growing demand of coal and mineral with sprawl of urbanisation and increased environmental consciousness of human being have compelled opencast mining projects to run under cons traints. With increases in atripping ratio, size of equipment has also increased considerably with increase of blast size. This has compelled to use such system of blasting which will produce either no flyrock or very less fly rock with minimum projection, ground vibration, noise and good fragmentation. Objective of this research work was to establish knowledge on shock tube in hole delay blasting by studying post blast parameters in opencast coal mines. In this study one open cast mine was selected and number of blasts were conducted and observed. Ten blasts were initiated with conventional detonating cord while rests of the blasts were initiated with shock tube NONEL system. As the mine and bench, where studies conducted were same, strata conditions were similar. Detailed investigation was done to study influence of shock in hole delay blasting on post blast parameters such as fly rock generation, ground vibration and noise using high speed video camera and ground vibration recorders. On the basis of above study major conclusion has been drawn that the shock tube in hole delay blasting is a better system of initiation over conventional system of initiation with respect to ground vibration, air over pressure and flyrock generation. Since it is a non destructive type of initiation system and with the undertaken study we can say that non-electric shock tube initiation system is no doubt an eco-friendly initiation system for explosives used in open cast mines.