Authors: Rui N. Rosa, Diogo R.N. Rosa
Addresses: Physics Department and Geophysics Center, University of Evora, 7000-671 Evora, Portugal. ' INETI-Geociencias, Estrada da Portela, Alfragide, 2720-866 Amadora, Portugal; Geology Department and CREMINER, University of Lisbon, 1749-016 Lisboa, Portugal
Abstract: Mineral deposits are considered as natural capital whose value can be assessed in exergy terms. Historical industry experience provides evidence that exploitation of mineral deposits and the beneficiation of ores are essentially energy intensive. The persisting decline of the grade of the developed deposits demands increasing exergy replacement and processing costs. The results demonstrate how far processed ores and concentrates are from ideal behaviour, and technologies from reversibility conditions. The exploitation of mineral resources of declining quality for mineral commodities imply a long time trend of increasing mass and exergy inputs spent per unit product output, in line with a law of |diminishing returns| on invested exergy.
Keywords: exergy; entropy; mineral resources; ore grade; recovery ratio; concentration.
International Journal of Exergy, 2008 Vol.5 No.5/6, pp.532 - 555
Published online: 17 Oct 2008 *Full-text access for editors Access for subscribers Purchase this article Comment on this article