1. Introduction
The main objective of rock blasting in open pit mines is optimal
rock fragmentation. One of the key metrics of an optimal blasting
operation is the size distribution of crushed rocks. If the in situ
rocks are over crushed, this implies over estimated design param
eters which results in higher costs and consequent difficulties in
the following operations i.e. loading, hauling, crushing, and min
eral processing. However, if the in situ rocks are under
similar difficulties will arise in the subsequent operations. One of
the main constraints, in an open pit mine, for the size of crushed
rocks is the accepting size of the primary crusher. In Golegohar
mine No.1, the primary crusher can accept rock fragments up to
1.5 m. Hence, in case that the blast operation results in larger rock
fragments, a secondary blasting operation on the produced boul
ders will be inevitable. This translates into higher costs and longer
production cycles which decreases the mine productivity. Osanloo
and Hekmat investigated the effect of rock fragments sizes on sho
vel productivity in mine No.1 of Golegogar [1]. Morin and Ficarazzo
applied Monte Carlo simulation technique to predict rock fragmen
tation based on Kuz
et al. used artificial neural networks (ANN) for prediction of rock
fragmentation [3,4]. Monjezi modeled rock fragmentation in mine
No.1 of Golegohar using Fuzzy logic [5]. Gheibie et al. modeled rock