ABSTRACT
The extra explosive energy used in cast blasting reduces the amount overburden to be handled by the machinery but increases the risk of damage to the underlying coal seams. This damage may lead
1 INTRODUCTION
In India, coal production in the past was mainly coming from underground mining. But currently, the share of opencast to the total coal production is estimated to be around 90 percent in 2011. Since more opencast mines are coming up in the coal sector, the projected target of coal production by surface mining will demand removal of larger volume of overburden. In view of increasing volume of overburden judicious selection of the stripping method becomes more important (Runge, 1981; Atkinson, 1992; Chironis, 1981). Even a small reduction in unit cost in overburden removal
to reduced coal recovery and may reverse much of the benefit sought from cast blasting damage and loss. A large amount of explosives is detonated during cast blasting with complex time series which creates problems in terms of increased vibration, unstable post blast high-wall and in even some cases loss of revenue for excessive dozing if not planned well (Sahai, 1996; Worsey & Giltner, 1987; Brent, et. al., 2003; Sanchidrian, et. al., 2007).
