Automated Mineralogy Applied to Exotic Cu Deposits in Northern Chile

摘要

In northern Chile, large-scale Cu-porphyry deposits dominate the Cu mining industry. Supergene processes on such deposits produce secondary enrichment and/or exotic mineralization that comprises different species of copper minerals and mineraloids (refered to as black-copper and green-copper ores). The analysis and subsequent definition of Cu-bearing minerals from these deposits is extremely complex due to the fine scaled textures as well as the compositional variation. The detailed automated mineralogy study of sampes from El Tesoro, Radomiro Tomic, Mina Sur, and El Abra deposits using new micro-XRF techniques (e.g. M4 TORNADO~(AMICS)) or traditional e-beam techniques (e.g. QEMSCAN) have allowed updated classifications and demonstrates it is possible to correctly classify the various complex Cu-mineral phases, identify fine-scaled textures, and accurately determine Cu concentrations. The resultant wealth of reliable and accurate information can be used to classify and understand Cu mineralisation and distribution within the deposit and thus support geological and metallurgical understanding and modelling.