Application of Controlled Blasting (Pre-splitting) Using Large Diameter holes in Sarcheshmeh Copper Mine

Abstract

Due to competitive minerals market, cost effective mining is of a prime
importance. In the direct mining costs, in open pit mining, drilling and blasting are
one of the biggest single line items in mining budget. In recent years, the tendency has
been to minimize mining costs by reducing costs for blasting in which using
controlled blasting on the final wall of an open pit mine is also involved.
In the past few years, research has been developed to replace small diameter
controlled blasting holes by large diameter holes as the size of production blasting
holes due to costs reduction concerns as well as avoiding various drilling equipment.
In Sarcheshmeh copper mine, pre-splitting controlled blasting technique was
applied using long hole diameter of 251 mm. 8 tests were carried out to obtain the
optimum values for parameters such as spacing, charge length (decoupled or
decoupled-deck), coupling ratio and stemming regarding different types of rocks.
Accounting for stability and costs effectiveness, the results achieved were very
promising.