Quantification of blasting parameters and the relationship to heterogeneous and anisotropic nature of jointed rock masses

点击翻译按钮获取中文摘要

In mining operations, drilling and blasting are commonly used for rock fragmentation. Different parameters can influence the response of rock masses to blasting energy and consequently the rock fragmentation results. These parameters include physical and geomechanical properties of rock masses, properties of explosives, blast design, timing contours and boundary conditions of the blast. Accurate prediction of blast-induced rock fragmentation has remained a challenging issue due to the complex interaction between these parameters. In addition, in narrow vein open pit mines, where the mineralization occurs in the form of fault or shear hosted narrow veins, bench blasting can result in excessive ore loss and dilution. Any improvement in blast-induced rock fragmentation and blast-induced ore loss/dilution requires a good understanding of rock mass heterogeneity and anisotropy. The size and shape distribution of the in-situ rock blocks and intact rock bridges that make up a jointed rock mass have an important influence on fragmentation and blasting performance. This research project aims to investigate the effect of spatial variability and anisotropy of rock mass geomechanical properties on their response to explosive action. In this research project field and laboratory data will be collected from the Detour Lake open pit mine located in northern Ontario. This includes mapping of the joint networks in different rock domains, measurement of intact rock properties, recording current blast design, type of explosives used at the mine, etc. In addition, blast movement monitoring will be carried out at the mine site for different rock mass domains to measure the blast-induced rock movement. The collected data will be subjected to a detailed statistical analysis to better understand the correlation between rock mass properties and their behaviour during blasting. The results would allow development of alternative strategies to reduce and control ore loss and dilution while improving rock mass fragmentation. Overall, this will have a very positive impact on the economic and technical aspect of open pit mine planning.