Influence of the rock mass structure and the blasting technique on blast results in the Heliopolis quarry

Abstract

Purpose. To find a relative methodology which will help the systematic analysis of the parameters influencing the blasting plan and a better understanding of the mechanisms of fragmentation of rocks with explosives. Methodology. The approach uses the Kuz-Ram model to predict blast performance. Three models were used to consider the effect of blast plan geometry on the quality of blast rock fragmentation. A new blasting plan is proposed using the Langefors method and the Kuz-Ram empirical model. The results obtained were compared with those of previous blasts. Findings. The research results show that the optimal fragmentation of 89.2 % with a balance between fine particles of 5.7 % and outsized blocks of 5.1 % of rocks by explosive in the Heliopolis aggregates quarry is highly dependent on the type and quantity of explosive used, the direction of initiation, and the cracks caused by the waves of shock (back effects). Originality. The present work is concerned with the problem of the quality of rock blasting which will ultimately affect the costs of drilling, blasting and the efficiency of all mining operations. Parameters influencing the processes of rock fragmentation during mining operations are specified. Practical value. The purpose of blasting is to disaggregate the material in order to facilitate its recovery by the extraction equipment. It is therefore necessary to correctly define the blasting plan by optimizing these geometric parameters, the nature and the quantity of explosive, the initiation sequences aim to have the right particle size distribution.