Influence of rock mass properties on blasting efficiency

The purpose of this paper is to determine the influence of rock mass properties on the blasting efficiency which is ratio of the block size distribution of the rock mass to the block size distribution of the muck-pile. The proposed methodology of blasting efficiency in this study is to compare physical and mechanical properties of the rock mass and block fragmentation under the same blasting conditions in Ki{dotless}rka borax mine. Intact rock properties, block size of rock mass before blasting and muck pile after blasting were found to measure blasting efficiency. Firstly, intact rock properties, which are unit volume weight, water absorption, uniaxial compressive strength, tensile (Brazilian) strength, cohesion and internal friction angle, were tested for each mining bench. Secondly, block sizes of rock masses in respect to discontinuity boundaries were measured and muck pile photos were taken in order to determine Block Fragmentation (BF) which is to separate the rock mass block size by blasting and that of the corresponding muck pile. Thirdly, statistical analysis between rock mass properties and block fragmentation were developed and these analysis test results have shown that a good relation between block fragmentation and Brazilian tensile strength and internal friction angle were found. As a result, block fragmentation in the same blasting conditions and other rock properties can be estimated from the best empirical correlations with the rock properties. © 2009 Academic Journals