CHARACTERIZATION OF PARTICLE DAMAGE AND SURFACE EXPOSURE OF A COPPER ORE PROCESSED BY JAW CRUSHER, HPGR AND ELECTRO-DYNAMIC FRAGMENTATION

摘要

Heap bioleaching is gaining importance as a low cost technology for processing low grade ores and tailings. Furthermore, it can be employed to process large particles and aggregates. Nevertheless, only grains at the surface are exposed to the leaching solution. The present work aims at investigating the effect of different crushing methods in the generation of cracks in order to improve the surface exposure of copper sulphides. A method for the microstructural characterization of samples composed by macroscopic particles, i.e., around 1 mm or more in a resolution better than 1 μm, is employed. This method involves large cross-sections preparation, image acquisition on SEM, automatic mosaicing, and image processing and analysis. The results show that it is possible to increase the copper sulphide minerals exposure through the generation of cracks by secondary crushing for a given particle size range.