Particle modeling simulation of thermal effects on ore breakage

The present study is primarily motivated to attain a better understanding of the microwave-assisted breakage in mining for the purpose of enhancing the excavation efficiency on the earth. The research results also offer NASA a new concept in manufacturing efficient excavators in exploration and in situ resource utilization in space. The ores are usually composed of non- and microwave-absorbing materials, e.g. calcite and pyrite. In this paper, first a thermal-based particle modeling (PM) is developed based on the first author’s previous work that could only account for mechanical parameters [G. Wang, M. Ostoja-Starzewski, Computational Materials Science 33 (2005) 429–442]. A global averaged fracture density concept is also defined so as to easily evaluate the total breakage effect of ores. Then the developed thermal-based PM is applied to a study of an ore material with a mixture of calcite and pyrite subject to a microwave exposure to explore microwave heating, thermal conduction, expansion, thermally induced fracturing and strain/stress curves associated with different input energy powers. Via this study, efficiency of fracturing and grinding on ores containing different calcite/pyrite ratios will be obtained. Finally, mechanical fracture approach performed on pyrite/calcite samples with different heating times is numerically simulated to investigate if and how much mechanical energy can be saved from the breakage cost resulting from thermal weakening of the material strength in advance.