Effect of blasted rock particle size on excavation machine loading performance

Earthmoving (i.e. excavation, loading and transportation of material) makes up a major portion of surface mining operations. Today, there is a wide array of equipment used to perform excavation and loading tasks in open pit mines. However, the performance of these machines is often not fully optimized since the excavated material characteristics have not been thoroughly investigated. In this study, results of some parts of a research project that is undertaken to quantify the factors effective on excavation machines' loading performance are presented. The research project originally consisted of performing mine site visits and collecting video camera images from typical front-end loader, cable shovel, and hydraulic shovel applications. In the study, the video images were carefully scanned to obtain machine loading cycle times and amount of hourly production whilst video images of the material being loaded were successively captured, scaled and processed to obtain rock fragmention size distributions of muckpile in the vicinity of blasted benches. Regression analysis on site-specific data was statistically performed in order to investigate, if exists, possible linear relationships between machine performance parameters and particle size of blasted rock. The results suggested that there was little to be gained by attempting to match the performance of loading machines (loading cycle time and maximum production) with only size features (maximum and 63% passing) of excavated material.