ODM: a new approach for open pit mine blasting evaluation

Abstract

In open pit mines, the blasting operation should be effectively optimized at the lowest possible total cost, providing technical specifications and the required safety norms. The optimization demand measurement (ODM) value of blast should be evaluated by considering blast results and other mine unit operations, comprehensively. The present research proceeds by taking into consideration seven blast results including degree of fragmentation, muckpile, overbreak, boulders, bench floor and toe conditions, environmental considerations and misfires. Consequently, these results have been rated and classified. In the ODM, a value could be assigned to each blast, with lower values corresponding to better results of the blasting operation. The ODM procedure indicates a relationship between blasting results, drilling and loading performances. The specific mine unit operations index and the blast block situation rating are introduced in order to determine the ODM value. The blast results evaluation and its effects on the mining operation are analyzed by utilizing the blast results matrix [ζ], the performance matrix [P] and the ODM matrix [O]. Based on the results as well as considering optimization, blasts are classified into five modes: very good, good, relatively weak, weak and very weak. Thereafter, the ODM procedure is applied to the blasting operation at an Iranian iron ore open pit mine (Chador Malu), with nine blast blocks. In summary, this approach could help design engineers to recognize the optimization demand of the blasting operation at different mining conditions.