The energy needed to concentrate minerals from common rocks: The case of copper ore. (15th August 2019) - Jose-Luis, Palacios
Abstract: A way to assess today's mineral patrimony is to evaluate how much mining energy is saved today because of having concentrated mines instead of finding the minerals dispersed throughout the crust. This can be assessed through the so-called exergy replacement costs (ERC), which are a measure of the exergy required to extract and concentrate minerals from barerock. Previous studies evaluated such exergy using a theoretical approach. In this paper, from a mineral processing point-of-view through a model developed with HSC Chemistry 9.4.1, we calculated the energy needed to concentrate copper from common rocks at average crustal concentrations. In the model, current state-of-the-art technologies for copper concentration were considered. The results were then compared to the theoretical value obtained before for the ERC of copper and helped to update it. The updated ERC value is of one order of magnitude greater than the original one. This difference in magnitude enhances, even more, the issue of ore grade decline in terms of the associated spiraling energy required for mining. It also reveals the importance of valuing properly the mineral heritage of nations and the effort that should be placed for increasing secondary metal production. Highlights: The energy required to concentrate copper-ore from crustal concentrations was calculated. This energy represents the ultimate effort required when mines become depleted. HSC Chemistry software was used to model the comminution and flotation processes. The results were compared to theoretical values obtained previously. New values are significantly greater than the previous ones.