Sustentabilidade mineral no setor português da Faixa Piritosa Ibérica

ABSTRACT: The Iberian Pyrite Belt (IPB) is one of the most important volcanogenic massive sulphide districts in the world and has been mined during more than 5 000 years. Its early and rich mining history is known to have been very important in Tartessian and Roman times when working the oxidation and cementation zones of the deposits for gold, silver and copper preferentially took place in the outcropping deposits. Even after continuous metal extraction for more than 5000 years, the IPB retains exceptionally large metal reserves. The IPB remains a hub of continued research and exploration and as a consequence, sulphide reserves in the IPB are being continuously increased with new discoveries: Aguas Teñidas, Lagoa Salgada, Las Cruces, Migollas, Masa Valverde, Vallejin, Las Cruces, Semblana and Monte Branco, La Magdalena and Sesmarias. While today's mining activities are focused in massive and stockwork ores and confined to 7 Portuguese and Spanish districts: Aljustrel, Neves-Corvo, Sotiel-Migollas, Rio Tinto, Aznalcollar Los Frailes, Tharsis and Las Cruces, the IPB retains a large potential for non-traditional (or accessory ores) products. In light of the critical raw materials and the concepts of the circular economy, the IPB has the potential to be an important source of accessory metals; sourced from both primary and secondary ores and mine waste, that fall both in the strategic and critical domains. Metals like indium, selenium, germanium, rhenium and the precious metals are targets to seek in future exploration scenarios within the IPB, particularly in the Portuguese sector and in key near mining areas.RESUMO: A Faixa Piritosa Ibérica (FPI) é uma das mais importantes províncias de sulfuretos maciços do mundo e tem sido explorada durante mais de 5 000 anos. A sua rica história de mineração é conhecida por ter sido muito importante nos tempos Tartessianos e Romanos, onde o trabalho ocorreu principalmente sobre os jazigos aflorantes, nomeadamente nas suas zonas de oxidação e cimentação dos depósitos de ouro, prata e cobre. Mesmo após a extração contínua de metais por mais de 5000 anos, a FPI mantém reservas de metal excecionalmente elevadas. A FPI contempla hoje todo o seu potencial favorável à prospeção mineral, observando-se uma intensa atividade extrativa e, consequentemente, um aumento das reservas, patente em novas descobertas como Águas Teñidas, Lagoa Salgada, Las Cruces, Migollas, Masa Valverde, Vallejin, Las Cruces, Semblana e Monte Branco, La Madalena, Sesmarias e Elvira. Embora a lavra ativa esteja atualmente limitada a 7 concelhos portugueses e espanhóis como Aljustrel, Neves-Corvo, Sotiel-Migollas, Rio Tinto, Aznalcollar-Los Frailes, Tharsis e Las Cruces, a FPI mantém um grande potencial para produtos minerais não tradicionais (ou acessórios). À luz das matérias-primas críticas e dos conceitos da economia circular, a FPI tem o potencial para ser uma importante fonte de metais acessórios, que se inserem nos domínios estratégicos e críticos, os quais são observados quer em minérios primários e secundários, quer em escombreiras mineiras. Metais como índio, selénio, germânio, rénio e elementos preciosos são alvos a serem procurados em cenários futuros de prospeção dentro da FPI, em particular no seu setor português e, sobretudo, em áreas de near mining exploration.info:eu-repo/semantics/publishedVersio

Mineral Resources: Stocks, Flows, and Prospects

This chapter focuses on metals as they provide the clearest example of the challenges and opportunities that mineral resources present to society, in terms of both primary production and recycling. Basic concepts, information requirements and sources of consumer and industrial resource demand are described as well as the destabilizing effects of volatile resource prices and supply chain disruptions. Challenges facing extraction of in-ground resources and production of secondary resources are discussed and scenarios for the future considered. The results of the scenarios indicate that particularly energy and, as well, water and land requirements could become increasingly constraining factors for metal production. Key research questions are posed and modeling and data priorities discussed, with an emphasis on areas that require novel concepts and analytic tools to help lessen negative environmental impacts associated with minerals. The challenge of sustainability requires collaboration of practitioners and analysts with a multidisciplinary understanding of a broad set of issues, including economics, engineering, geology, ecology, and mathematical modeling, to name a few, as well as policy formulation and implementation.

Solar energy in the minerals processing industry: identifying the first opportunities

Solar energy, particularly electricity generated from the solar resource, has long been thought to be amongst the most expensive energy products. However, in a climate of electricity shortages and pressures on industries to reduce energy-related greenhouse gas emissions, many previous truths are being challenged. In the solar energy field there have emerged several technical and market innovations, thus making it more attractive. This could be of interest to many mining operations which are located in desert-type environments with high solar insolation and far from electricity grids. The objective of this dissertation is to evaluate the use of the available solar energy technologies at utility scale to supply the high energy demand of selected minerals processing industries by co-locating a solar power plant with a minerals processing operation. The effect on how the use of a utility scale solar energy use affects fuel transportation energy and conversion and transmission line losses is assessed. The study analyses the energy usage of different typical minerals processing operations, to identify the processing areas that are likely to benefit from the use of solar energy. Comminution, hot leaching processes and electrowinning circuits are shown to be the most energy intensive areas. Comminution requires high voltage AC power which can be supplied by the solar thermal (ST) technology which converts solar heat to steam which then drives a turbine. Process steam generation can also be achieved directly from ST technology. Electrowinning on the other hand requires low voltage DC electrical output, which can be generated directly using Photovoltaic (PV) technology. Five minerals processing operations, chosen to represent a range of different types of processes and energy supply scenarios, are profiled and their energy requirements quantified as a basis for establishing the extent to which solar energy can augment energy supply in different cases in this industry

Application of life cycle assessment to estimate environmental impacts of surface coal mining

Coal plays an important role in meeting the energy needs of the World. Given its abundance and low cost, its use is bound to increase with the growing energy demand. Despite its importance, there are concerns over coal\u27s environmental burdens. In order to extract and use coal in a sustainable manner, sustainability assessment has to be comprehensive. Life Cycle Assessment (LCA) provides systematic and quantifiable measures for assessing environmental burdens of products and processes. Extensive LCA work has been done on coal use, particularly in electricity generation, but, the coal mining stage has been neglected, for the most part. This has resulted in data gaps in the life cycle inventory (LCI) of coal and, consequently, in the LCIs for electricity and other products that are linked to coal. The situation has resulted in incomplete assessments of the sustainability of coal extraction and use, and potential for suboptimal strategies for reducing the potential impacts of coal, especially in the mining stage. The aim of this study was to employ the general principles of the ISO 14040-49 series LCA standards, adapting them where necessary, to estimate the cradle-to-gate life cycle impacts of coal from surface mining in the United States. Five strip mines that produce bituminous coal were used as case studies. The study assessed the life cycle water use, land use, energy use, abiotic resource depletion and climate change impacts for each mine and compared the performances of the mines based on the impacts. For the studied mines, the life cycle potential water use impact is 178 liters/tonne of processed coal at the mine gate. The potential land use impacts range from 3 to 10 m²- year/tonne. The potential energy use impacts vary from 97 to 181 MJ/tonne, the abiotic resource depletion impacts vary from 7.8 to 9.4 kg Sb-equivalent/tonne, and the climate change impacts range from 38 to 92 kg CO₂-equivalent/tonne. This study provides insight into contributions of mining processes to the impacts of coal. The results of the study contribute the much needed information to fill the data gaps in the LCI of coal, and provide baseline information that can aid the coal mining industry and public policy makers in the development of strategies and policies to sustainably exploit coal --Abstract, page iii

Exergy Cost Assessment in Global Mining

El desarrollo económico, social y tecnológico de la sociedad actual está fuertemente ligado a la extracción de recursos minerales. Una sociedad en constante crecimiento que consume estos recursos rápida e ilimitadamente. El continuo incremento de la demanda mundial de recursos minerales se debe en gran medida al crecimiento económico de China y otros países asiáticos, que demandan una gran cantidad de materias primas en los sectores de la construcción, la infraestructura y la manufactura. El agotamiento de los recursos naturales no renovables es la consecuencia de este progreso y constituye el mayor reto al que se enfrentará la industria minera. De ahí que la disponibilidad futura de los recursos minerales está adquiriendo importancia en los planes estratégicos de los gobiernos. Una vez que los minerales han sido extraídos, una serie de procesos que consumen grandes cantidades de energía son necesarios para producir materias primas utilizables. El requerimiento energético de la extracción de minerales y en su posterior procesamiento depende principalmente de la calidad y composición del mineral. Considerando la disminución en la ley mineral a nivel global, los consumos energéticos y los impactos ambientales se han venido incrementando continuamente. Adicionalmente, es necesario procesar más material para obtener una cantidad equivalente de metal. En este sentido, uno de los factores críticos que la industria minera tendrá que afrontar será la disponibilidad de energía para la extracción y el procesamiento de los minerales. Por lo anterior, es de suma importancia analizar y entender los procesos de la industria minera para determinar las posibles mejoras cuando se tiene en cuenta el factor de escasez de las materias primas. La primera actividad puede realizarse a través de un enfoque termoeconómico. La Termoeconomía ha sido utilizada tradicionalmente para la optimización de plantas termoeléctricas haciendo uso de la exergía como unidad de medida. En esta tesis doctoral, el análisis termoeconómico es adaptado y modificado, teniendo en cuenta la complejidad de los procesos mineros y metalúrgicos, en los cuales se presentan flujos de materias primas y energía. Cuando se considera el factor de escasez de los recursos minerales en este tipo de análisis, es necesario incluir una variable adicional. Esto se lleva a cabo a través del enfoque Exergoecológico propuesto por Valero et al. (2003). Conceptualmente, el metódo Exergoecológico permite realizar una evaluación de los recursos minerales utilizando los costos exergéticos de reposición, los cuales representan la exergía requerida para restituir los minerales que han sido totalmente dispersados en la corteza terrestre una vez que su vida útil ha terminado, al estado inicial de composición y concentración en el que se encuentran en las minas. De ahí que esta tesis tiene como objetivo principal adaptar y aplicar metodologías termoeconómicas que permitan realizar un Análisis de Ciclo de Vida absoluto de los recursos minerales: un análisis convencional de la “cuna” a la puerta de entrada (producción de las materias primas refinadas) y un análisis adicional de la “tumba” a la “cuna”, en el cual se cuantifique el factor de escasez de los minerales. El análisis exergético de los recursos minerales y los procesos metalúrgicos de la industria de la minería realizados en esta tesis, requirió el establecimiento de una serie de objetivos. El primero de ellos fue realizar un estudio detallado de las tecnologías y los consumos energéticos asociados a la industria minera y metalúrgica. Un segundo objetivo fue analizar la influencia del aprendizaje tecnológico y la disminución de la ley mineral en la disponibilidad de los recursos minerales, con el objetivo de conocer si la adquisición de experiencia a través del tiempo, ha sido capaz de evitar el aumento en la demanda de energía que presentan los procesos extractivos y de metalurgia. Los resultados obtenidos de las dos actividades anteriores, permitieron una importante mejora del método Exergoecológico: los costos exergéticos de reposición que tradicionalmente habían sido evaluados de manera estática, pudieron ser actualizados considerando la tendencia del decremento de la ley mineral. Una mejora adicional presentada en esta tesis fue resolver el problema de asignación de costos entre productos, subproductos y residuos que comúnmente aparecen en la industria minera y metalúrgica. Considerando los nuevos costos exergéticos de reposición obtenidos, se propuso un nuevo procedimiento de asignación de costos que será utilizado en el análisis termoeconómico aplicado a los procesos mineros y metalúrgicos. Otro objetivo de esta tesis, consistió en la integración del análisis termoeconómico realizado a través del Costo Termoecológico desarrollado por el grupo del ITC de la Silesian University of Technology, para combinar las ventajas de ambos enfoques para el análisis de la industria minera. Finalmente, cada objetivo descrito anteriormente fue aplicado a diferentes casos de estudio

Responsible Sourcing of Materials Required for a Resource Efficient and Low-carbon Society

Understanding future supply and demand of raw materials and the associated environmental and social implications is essential to supporting the transition towards greenhouse gas neutrality by 2050. In this Special Issue, we present a range of research papers with a focus on future outlooks of material supply and use, the consideration of associated environmental and social implications, and issues of raw material criticality and a circular economy. These are complemented by an editorial paper that provides, amongst other aspects, an overview of the corresponding policy and institutional framework. Knowledge of materials availability, their use patterns in modern economies, and associated environmental and social trade-offs is essential for informed decision-making in support of the necessary transition towards more resource-efficient and greenhouse-gas-neutral societies in the coming years

Renewable energy in copper production: A review on systems design and methodological approaches

Renewable energy systems are now accepted to be mandatory for climate change mitigation. These systems require a higher material supply than conventional ones. Particularly, they require more copper. The production of this metal, however, is intensive in energy consumption and emissions. Therefore, renewable energy systems must be used to improve the environmental performance of copper production. We cover the current state of research and develop recommendations for the design of renewable energy systems for copper production. To complement our analysis, we also consider studies from other industries and regional energy systems. We provide six recommendations for future modeling: (a) current energy demand models for copper production are overly simplistic and need to be enhanced for planning with high levels of renewable technologies; (b) multi-vector systems (electricity, heat, and fuels) need to be explicitly modeled to capture the readily available flexibility of the system; (c) copper production is done in arid regions, where water supply is energy-intensive, then, water management should be integrated in the overall design of the energy system; (d) there is operational flexibility in existing copper plants, which needs to be better understood and assessed; (e) the design of future copper mines should adapt to the dynamics of available renewable energy sources; and (f) life cycle impacts of the components of the system need to be explicitly minimized in the optimization models. Researchers and decision-makers from the copper and energy sector will benefit from this comprehensive review and these recommendations. We hope it will accelerate the deployment of renewables, particularly in the copper industry