Magnesium and aluminum sulfates in salt efflorescences from acid mine drainage in the Iberian Pyrite Belt (SW Spain)

Proceedings IMWA 2016, Freiberg/Germany | Drebenstedt, Carsten, Paul, Michael (eds.) | Mining Meets Water – Conflicts and Solutions.The current study is focused on AMD-precipitates that compose the typical magnesium and aluminum sulfate assemblages in the Spanish sector of the Iberian Pyrite Belt (SW Spain). The main objectives are identify and describe the composition, morphology and paragenetic relationships of these sulfate phases. From the methodological pint of view, sampling procedure covered the entire metallogenetic province, including five selected representative mines and eight river basins, which are the main receptors of the acid mine drainage discharges. The mineralogical analyses were performed by X-Ray diffraction and electron microscopy. The obtained results showed the extraordinary abundance of aluminum sulfates with acicular habit, from the series pickeringite-apjhonite-halotrichite. They form typical assemblages with other aluminum sulfates, such as alunogen and tamarugite, and with the Mg sulfates: epsomite and hexahydrite. Moreover, the paragenetic relationships indicate the late occurrence of acicular Alsulfates from the halotrichite group.Financial support for this research was provided by the Andalusian Autonomous Government Excellence Project, code P06-RNM-02167. This work was also co-funded by the European Union through the European Regional Development Fund, based on COMPETE 2020 (Programa Operacional da Competitividade e Internacionalização), project ICT (UID/GEO/04683/2013) with reference POCI-01-0145-FEDER-007690 and national funds provided by Fundação para a Ciência e Tecnologia.info:eu-repo/semantics/publishedVersio

Resurgence of inner solutions for perturbations of the McMillan map

A sequence of “inner equations” attached to certain perturbations of the McMillan map was considered in [MSS09], their solutions were used in that article to measure an exponentially small separatrix splitting. We prove here all the results relative to these equations which are necessary to complete the proof of the main result of [MSS09]. The present work relies on ideas from resurgence theory: we describe the formal solutions, study the analyticity of their Borel transforms and use ´Ecalle’s alien derivations to measure the discrepancy between different Borel-Laplace sums.Preprin

Acid mine drainage in semi-arid regions: the extent of the problem in the waters of reservoirs in the Iberian Pyrite Belt (SW Spain)

There are many reservoirs in the Iberian Pyrite Belt (IPB), SW Spain, which receive contributions from watercourses affected by acid mine drainage processes, characterised by low pH values and high concentrations of heavy metals and sulphates. When they reach the reservoirs, the waters increase its pH, which will cause most of the metal load carried by the mining channel to precipitate into the reservoir itself and accumulate on its floor. The silting of reservoirs is an environmental problem which can affect the loss of storage capacity, their general functioning and aquatic ecosystems. A study of these is vital to allow both preventative and corrective measures to be established. Climatic conditions are the most significant external controlling factors in terms of the degree and type of mining pollution. The study area presents characteristics typical of the semi-arid Mediterranean climate, with annual precipitation of around 630 mm/year; moderate temperatures with average annual values of 17.1 W C and a temperature range of 50 W C. The aim of this study is to carry out a physical–chemical characterization of the waters where they enter the reservoirs located in the IPB over the course of a hydrological year and to establish possible interdependencies between the various parameters.Financial support for this research was provided by DGCICYT National Plan, project no. CGL2010-21268-C02-01.info:eu-repo/semantics/publishedVersio

Mineralogical controls on mobility of rare earth elements in acid mine drainage environments

Supplementary data related to this article can be found at https://doi.org/10.1016/j.chemosphere.2018.04.095.Rare earth elements (REE) were analyzed in river waters, acid mine waters, and extracts of secondary precipitates collected in the Iberian Pyrite Belt. The obtained concentrations of the REE in river water and mine waters (acid mine drainage - AMD) were in the range of 0.57 μg/L (Lu) and 2579 μg/L (Ce), which is higher than previously reported in surface waters from the Iberian Pyrite Belt, but are comparable with previous findings from AMD worldwide. Total REE concentrations in river waters were ranged between 297 μg/L (Cobica River) and 7032 μg/L (Trimpancho River) with an average of 2468 μg/L. NASC (North American Shale Composite) normalized REE patterns for river and acid mine waters show clear convex curvatures in middle-REE (MREE) with respect to light- and heavy-REE. During the dissolution experiments of AMD-precipitates, heavy-REE and middle-REE generate the most enriched patterns in the solution. A small number of precipitates did not display MREE enrichment (an index Gdn/Lun < 1.0) in NASC normalized pattern and produced relatively lower REE concentrations in extracts. Additionally, very few samples, which mainly contained aluminum sulfates, e.g., pickeringite and alunogen, displayed light-REE enrichment relative to heavy-REE (HREE). In general, the highest retention of REE occurs in samples enriched in magnesium (epsomite or hexahydrite) and aluminum sulfates, mainly pickeringite.Financial support was provided by the Andalusian Autonomous Government Excellence Project, code P06-RNM-02167. This work was also co-funded by the European Union through the European Regional Development Fund, based on COMPETE 2020, project ICT (UID/GEO/04683/2013), reference POCI-01-0145-FEDER-007690, national funds provided by FCT. Post-Doctoral Fellowship through Erasmus Mundus SAT program and Young Scientist Research Grant (SEAS-2015−14) of the National University of Mongolia were supported for T.-O. Soyol-Erdene. The authors also appreciate the valuable comments and suggestions made by the anonymous reviewers

Cost and energy efficient reconfigurable embedded platform using Spartan-6 FPGAs

Modern FPGAs with run-time reconfiguration allow the implementation of complex systems offering both the flexibility of software-based solutions combined with the performance of hardware. This combination of characteristics, together with the development of new specific methodologies, make feasible to reach new points of the system design space, and make embedded systems built on these platforms acquire more and more importance. However, the practical exploitation of this technique in fields that traditionally have relied on resource restricted embedded systems, is mainly limited by strict power consumption requirements, the cost and the high dependence of DPR techniques with the specific features of the device technology underneath. In this work, we tackle the previously reported problems, designing a reconfigurable platform based on the low-cost and low-power consuming Spartan-6 FPGA family. The full process to develop the platform will be detailed in the paper from scratch. In addition, the implementation of the reconfiguration mechanism, including two profiles, is reported. The first profile is a low-area and low-speed reconfiguration engine based mainly on software functions running on the embedded processor, while the other one is a hardware version of the same engine, implemented in the FPGA logic. This reconfiguration hardware block has been originally designed to the Virtex-5 family, and its porting process will be also described in this work, facing the interoperability problem among different families

Postguerra y contracultura. Identidades en la ética aplicada

The article analyses the role of cultural identities in Applied Ethics. Biotechnologies have been actually valued from different perspectives in Europe and in the United States. Since Nazi research and the politics of racial hygiene have shown the role of science under dictatorship. Nazi Doctors acted as soldiers. Therefore The Nürnberg Code claimed respect for human rights in Medicine, to protect individuals in clinical research. However American Doctors considered the Code suitable for a different context. Norms for a “barbaric” research, far away from the American standards. But in the United States radiations experiments have ignored laws and moral standards. Decades later, the Constitutional Treaty for the European Union emphasizes the value of dignity and personal integrity in the fields of Medicine and Biology. The informed consent and the prohibition of Eugenics connect then the future and the past.El artículo analiza el papel de las identidades culturales en la Ética aplicada. Las biotecnologías han sido valoradas efectivamente desde distintas perspectivas, en Europa y en Estados Unidos. Pues la investigación y la política de higiene racial durante el Nacionalsocialismo mostraron el papel desempeñado por la ciencia en la dictadura. Los médicos nazis actuaron como soldados. Por ello, el Código de Nürnberg reclamó respecto por los derechos humanos en Medicina, a fin de proteger a los ciudadanos en la investigación. Los médicos norteamericanos consideraron que el Código era adecuado para otro contexto, sin embargo. Normas para una investigación “bárbara”, alejada de los estándares americanos. Pero en Estados Unidos los experimentos con radiación ignoraron leyes y estándares morales. Décadas mas tarde, el Tratado constitucional para la Unión Europea insiste en el valor de la dignidad y de la integridad personal en Medicina y Biología. El consentimiento informado y la prohibición de practicas eugenésicas conectan, por tanto, el futuro con el pasado

Spatial behavior of acid mine drainage in a peculiar stream : physical-chemical evolution from the source until the temporarlly receptor in the Iberian Pyrite Belt

Publicado em "Proceedings of the Energy and Environment Knowledge Week 2014 (E2KW2014), ISBN 978-84-697-1162-0"The Iberian Pyrite Belt is a vast concentration of massive sulphide, located in the SW of the Iberian Peninsula. Historically, this area has undergone an intense mining activity, which has left a huge amount of mining facilities and unrestored waste dumps. Mineral-water interaction in the waste dumps is responsible for the generation of acid mine drainage (AMD), causing a strong impact in the water systems. The AMD occurs when the sulfide minerals are in the presence of atmospheric oxygen and humidity, suffering oxidation reactions. As a consequence, metals and acidity are mobilized into the receiving watercourses. Such conditions have created a unique scenario in the world by the extreme degradation that characterizes the network of channels and streams in the IPB. In this context, widely described in the scientific literature, the present study aims to monitoring a singular channel affected by AMD (Campanario stream), from its origin (in the waste dump) to its confluence with an unpolluted stream. Such monitoring procedure will allow characterizing the physicochemical evolution and the mineral-water processes that regulate it

Four abandoned mines, one acid mine drainage affected river and an unsolved issue for a water supply reservoir

Publicado em "Proceedings of the Energy and Environment Knowledge Week 2014(E2KW2014)". ISBN 978-84-697-1162-