RM - Comunicações em actas de encontros científicos internacionais
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- Abandoned mine slags analysis by EPMA WDS x-ray mappingPublication . Guimarães, Fernanda; Rosado, L.; Morais, C.; Candeias, A. E.; Pinto, A. P.; Mirao, JoseThe mining activity on the Iberian pyritic Belt (Portugal and Spain) started before Phoenician times, became particularly intense during the Roman occupation of the Iberian Peninsula (for gold) and after the industrial revolution (for gold, copper, zinc, lead and sulphur). The commonest ore of this region is a massive polymetalic sulphide accumulation, where pyrite (FeS2) is the main mineral, with variable concentrations of chalcopyrite (CuFeS2), sphalerite (ZnS), galena (PbS), arsenopyrite (FeAsS2), other sulphides and sulfosalts which include minor elements like Mn, Co, Ni, Se, Cd, Sb, Te, Hg and Bi. Some of the main and minor elements of these ores are hazardous and the drainage basins of pollutant source areas often induce health concerns in the resident population. Electron microprobe study followed previous optical and XRD analysis of the slags. The study focused on the identification of phases how sulphide and meta11ic phases are distributed within the material and infer about leachable elements during weathering. Electron microprobe X-Ray maps show evidences of different behavior between the elements: Ca and Zn are completely leached; iron is retained in oxyhydroxides, lead and arsenic precipitate as sulphates. Electron microprobe studies are essential to understand complex materials as earth materials. Nevertheless, care is required to a correct interpretation of data and most quantitative compositional data are not trustworthy.
- Ancient glazed ceramic tiles : a long-term, study from the remediation of environmental impacts to the non-destructive characterization of materialsPublication . Figueiredo, M. Ondina; Silva, Teresa; Veiga, JPSince the involvement in a national research project in 1995-1997 with the partnership of the National Tile Museum in Lisbon, until a recent European project with partners from Mediterranean countries which cultural patrimony entails glazed ceramic tiles, the authors have been active in the non-destructive characterization of ceramic and vitreous materials used to manufacture ancient decorated tiles (16th-19th century) through the access to the European Synchroton Research Facility (ESRF, Grenoble/France). As an input to the preservation of this important cultural patrimony through the improvement of restoration techniques, a synopsis is presented of the work so far developed.
- Blue pigments in XVI-XVII century glazes : a comparative study between portuguese faiences and chinese porcelainsPublication . Figueiredo, M. Ondina; Silva, Teresa; Veiga, JP; Prudêncio, Maria Isabel; Dias, Maria Isabel; Matos, M. A.; Pais, A. M.
- Blue pigments in XVI-XVII century glazes : a comparative study between portuguese faiences and contemporary chinese porcelains manufactured for portuguese marketPublication . Figueiredo, M. Ondina; Silva, Teresa; Veiga, JP; Prudêncio, M. Isabel; Dias, M. Isabel; Matos, Maria Antónia; Pais, Alexandre Manuel
- Characterization of placer gold deposits from central Portugal : preliminary resultsPublication . Ehser, Anja; Borg, Gregor; de Oliveira, Daniel Pipa Soares; Rosa, Diogo; Salgueiro, Rute
- Chemical elements variation in leaves with different development stages of Cistus plants from S. Domingos mine area, South PortugalPublication . Batista, Maria Joao; Gonzalez-Fernandez, Oscar; Abreu, Maria Manuela; Carvalho, L.Soils and leaves of Cistus ladanifer L. and Cistus salviifolius L. in different stages of development (young and mature) were sampled in different sites of the S. Domingos mine. The soils are thin and were developed on heterogeneous materials of metallurgical slags, gossanous materials and weathered host rocks. In general, mature leaves have higher concentrations of As, Cu, Fe, Mn, Pb and Zn than young leaves. Nevertheless, in Moitinhos site the young leaves have higher concentrations of As, Cu and Mn than mature leaves. Near the mining buildings C. ladanifer leaves have higher concentrations of As in mature leaves than C. salviifolius. The Pb concentrations in mature leaves are significantly higher and C. ladanifer contain two fold more than C. salviifolius leaves. Cistus plants show different behaviour on the trace elements uptake and translocation. This knowledge is useful in order to implement remediation programs in mine areas of the Mediterranean region using these pioneer plants.
- A critical look at raw materials criticalityPublication . de Oliveira, Daniel Pipa SoaresABSTRACT: In the eve of the proposed Critical Raw Materials Act published in March of 2023, Europe has realized that even with already predicted exponential growth in raw materials supply, the situation remains critical with regards provision of these (critical) raw materials (CRM). The various initiatives led by the EU Commission starting with the Raw Materials Initiative in 2008, the various CRM lists (2011, 2014, 2017, 2020 and 2023), the launch of several dedicated CRM task forces (e.g., ERECON), alliances (E.G., ERMA) and the objectives of the EU Green Deal mean that in a few short years, 7 in fact, the EU needs to find new sources for CRM. An impossible task.
- Exposure to ionizing radiation and dangerous substances inside buildings related to construction productsPublication . Carvalho, F.P.; Paiva, J.V.; Carvalho, Jorge; Batista, Maria JoaoABSTRACT: The use of many materials of geological origin and recycled materials in the construction of buildings faces an increasing demand and stricter regulation for quality control. Construction products are requested to meet safety standards including those for radon exhalation and gamma radiation emission, amongst other dangerous substances, because if unchecked they could deteriorate the quality and safety of the indoor environment. Construction products shall pass testing for radioactivity in order to meet those standards and to maintain a high ranking position in the international markets.
- Geoquímica urbana na cidade de Lisboa : controle de dados climatológicos na dispersão de poeiras contaminadasPublication . Bartolomeu, A. S.; Reis, A. P.; Patinha, Carla; Dias, A.; Cachada, A.; Prazeres, Cátia; Sousa, A. J.; Silva, E. Ferreira da; Batista, Maria Joao
- Gold in the Lousal mine, Iberian Pyrite Belt, PortugalPublication . de Oliveira, Daniel Pipa Soares; Guimarães, Fernanda; Matos, João Xavier; Rosa, Diogo; Rosa, Carlos J. P.; Castelo-Branco, José MárioRecent exploration boreholes in the Lousal Mine, located within the Portuguese sector of the Iberian Pyrite Belt (IPB) yielded marked concentrations in gold/electrum in a section of core consisting of banded metasediments with massive pyrite. Preliminary research indicates that the gold is associated with native bismuth and bismuthinite and is clearly late in the paragenetic sequence occurring in fine chalcopyrite (± covellite)-bismuthinite-gold filled veinlets within the dominant and more massive pyrite. The pale yellow gold grains are fine, seldom reaching more than 6 ..m in length and half of that in thickness. EPMA results indicate that silver concentrations in gold grains can be as high as 27 wt.%. The results show similarities with conclusions drawn from the IPB on the Spanish side where gold of Co-Bi geochemical association is found as electrum with abundant to common Co and Bi minerals. These associated with pyrite and/or chalcopyrite are characterized by an abundance of sedimentary facies and show that the gold association formed at high temperature (>300 °C) during the initial phases of massive sulphide formation.
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