Effect of blast design parameters on fragmentation - an application of Kuz Ram Model

Abstract

The most important aspect of blasting is fragmentation. The fragmentation has a direct effect on the cost of loading, hauling and crushing operations. In the past many technologies have been used to predict and measure the rock fragmentation like different blasting models, image analysis etc. Rock fragmentation depends on the explosive parameters; rock condition such as rock mass properties, local geological condition, in situ fracturing and blast design parameters.This paper identifies the relevance of Kuz-ram model for mean fragment size estimation and the effect of charge factor and rock properties on it. It also discusses usefulness of Kuz-Ram model on deciding blast design parameters under a given condition when mean fragment size and charge factor are to be maintained. In this study with drill hole diameter 250 mm the value of uniformity index obtained 0.65 which indicates the dust and boulder situation and most suitable value of uniformity index 0.75 is obtained for the blast hole diameters 125 mm and 165 mm. It is also observed that the maximum boulder size increases rapidly above the blast hole diameter 125 mm.