Beyond a tonnage perspective for the assessment of mineral resources. Focus on latin america and the caribbean
- Autores: Jose Luis Palacios Encalada
- Directores de la Tesis: Alicia Valero Delgado (dir. tes.), Antonio Valero Capilla (dir. tes.)
- Lectura: En la Universidad de Zaragoza ( España ) en 2019
- Idioma: español
- Tribunal Calificador de la Tesis: Marcin Szega (presid.), Sergio Uson Gil (secret.), Wojciech Stanek (voc.)
- Programa de doctorado: Programa de Doctorado en Energías Renovables y Eficiencia Energética por la Universidad de Zaragoza
- Materias:
- Enlaces
- Tesis en acceso abierto en: Zaguán
- Resumen
Minerals are essential to maintain the lifestyle of modern society. Currently, almost all the elements of the periodic table are used in the manufacture of electrical and electronic devices While the consumption of minerals is increasing, there is also a rapid increase in the loss of mineral capital of the countries and regions where they metals are produced. At the same time, geological deposits with higher ore-grades have already been already exhausted, and the energy consumption for metal production has also increased.
The concern about the importance and depletion of non-fuel mineral resources have long attracted the attention of researchers, who have established some methodologies for the assessment of mineral resources. These methodologies have their respective advantages and disadvantages. In the present work, based on the literature review, these methods have been classified into three categories: by weight, by wholesale price and methodologies based on energy principles.
The most common method for valuing non-fuel mineral resources has probably been according to price. This method does not reveal the real value of minerals, in addition prices are volatile because they are subject to several factors such as supply and demand, geopolitical aspects and speculation, among others. Although the assessment of non-fuel minerals according to their weight, has had a comprehensive development and have allowed realizing important estimations, primarily through methodologies of Material Flow Analysis (MFA) and its variant EW-MFA.
Among the disadvantages of these methods are that according to this perspective a ton of iron is equal to one ton of gold. However, the geological shortage of gold or the higher energy requirement for processing is not taken into account. An alternative for an adequate evaluation of mineral resources is based on energy laws. Particularly noteworthy are the methodologies based on the Second Law of Thermodynamics, Exergy. The latter takes into account not only the quantity but also the quality of the resources. Based on that, a division of Exergoecology proposes the evaluation of non-fuel minerals not only taking into account the chemical exergy, but also the exergy of mineral resources concerning their concentration. In this regard, the concept of exergy replacement cost (ERC) has been established. ERC estimates the energy needed to concentrate minerals from a state of dispersion, coined as Thanatia. The calculation methodology for the ERC for different metals has been based on a statistical analysis of energy consumption information for metal processing and extrapolations. Although the reported values of ERC have been influential in estimating the loss of mineral wealth, they fail, because of their method of calculation in a more accurate estimation of valuing mineral resources. In this regard, a new methodology for calculating ERC is necessary, which takes into account mineral processing criteria and current technologies. Therefore, in the present doctoral thesis, a method is established to estimate more precise values of the ERC in the function of the analysis of the mining-metallurgical processes for the concentration of minerals. This has been done through computer models made from a well-known computer software HSC. Based on the availability of information and the requirements of metals for new technologies, three key metals produced in Latin America and the Caribbean have been selected. These metals are iron, copper, and gold. For these three metals, the new ERC values are determined from HSC and a comparison is made with the previous values. Although at a qualitative level the importance of metals is the same concerning the last and new values of ERC, their difference is in orders of magnitude. Emphasis is also placed on the search for sustainable mechanisms for the production of metals, as well as recycling. Finally, it is revealed the importance of continuing with the elaboration of more models in HSC to estimate more precise values of ERC for the rest of the minerals.
