New parameter for the assessment of blasting efficiency

Abstract

The efficiency of a blast depends very widely on three groups of parameters: rock mass, blast geometrical parameters and energy distribution in space (borehole bottom, column energy) and time (delays between holes and rows). According to the expected results from a blast, there are several definitions for the term efficiency. The criterion for the block size reduction in the muck pile is often considered as important, because generally it has a great influence on the efficiency of all the operations after the blast. In this paper, a new parameter for the assessment of the blast efficiency is proposed, based on the relative comparison of area delimited by the RosinRammler curves of the in situ rock mass and of the muck pile. This parameter is then compared to others previously established, namely the fragmentation index and the surface energy ratio (Hamdi et al. 2001).

Experimental analysis of fragmentarion, vibration and rock movement in open pit blasting = Análisis experimental de la fragmentación, vibraciónes y movimiento de la roca en voladuras a cielo abierto

“…Nevertheless if parallelogram particles whose sides are in the ratio 1:a:b (with a ≥1 and b≥1) are assumed, A is smaller. Ouchterlony et al (2003) based on the work of Hamdi & du Mouza (2000) calculates the surface area generated in the blast by an integral instead of the summation in 7-3 using the Rosin-Rammler distribution. In such formula the mean size and the uniformity parameter of the size distribution curve affect inversely to the specific surface area (m 2 /m 3 ) generated by the blast.…”

Evaluación de la energía de los explosivos mediante modelos termodinámicos de detonación

“…El índice introducido por Hamdi et al (2000) para la evaluación de la eficiencia de la voladura está basado en la comparación de las superficies obtenidas derivando las curvas ajustadas para la roca in situ y la pila de escombro. El cálculo teórico del área delimitada por las curvas proporciona la definición del parámetro SFI (índice de la energía de fragmentación):…”