Influence of Rock Mass Properties on Blast-Induced Rock Movement

摘要

In most metalliferrous open pit mines with heterogeneous orebodies, blast-induced rock movement is a crucial outcome that has unfavorable impact on ore and waste segregation in the post-blast muck pile, resulting in either ore loss (the ore is misclassified as waste and sent to the waste rock dump) and/or ore dilution (waste is misclassified as ore and sent to the processing plant). While many studies have been carried out to assess the influence of blast design parameters on blast-induced rock movement, the influence of rock mass characteristics in these studies have been overlooked.rnThis work presents the results of blast-induced rock movements recorded in more than 500 blast locations at Detour Lake Gold (DLG) mine in Canada. Using statistical analysis, the influence of variation of rock mass properties (i.e. rock type, intact rock strength, and intensity of rock structures) on the blast-induced rock movements were investigated. The analysis shows that the intact rock strength has significant impact on the blast-induced rock movement, whereas no relationship can be seen between the fracture frequency of rock mass and the magnitude of blast-induced rock movement. It also establishes a methodology for systematic analysis of these inter-related issues at an operating mine.