69 research outputs found

    Fabrication of glass-based products as remediation alternative for contaminated urban soils of Barcelona

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    Peer ReviewedObjectius de Desenvolupament Sostenible::12 - ProducciĂł i Consum ResponsablesPostprint (published version

    Mineralogical characterization of Sn deposits from the Santa Fe District, Bolivia

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    The Sn-Zn-Pb-Ag Japo-Santa Fe-Morococala ore deposit is located in the Central Andean Belt province. The ore mineralization is hosted in a Paleozoic metasedimentary sequence and porphyritic Oligocene-Miocene igneous rocks. Ore minerals occur in veins and disseminations. Two types of ore mineralization are distinghished: (1) An early Sn mineralization and (2) a late Sn and Zn-Pb-Ag mineralization. Mineral association consists mainly of quartz, pyrite, cassiterite, other sulfides and sulfosalts. Cassiterite, up to 0.25 wt% In, constitutes the earliest mineralization. Galena and sphalerite are the main sulphide minerals. Sphalerite shows up 0.24 wt% In. Stannite group is represented by stannoidite, kësterite, and sulfides of the Sn-Cu-Zn-Fe-S system. Sulfosalts include sakuraiite, potosiite, franckeite, freibergite, tetrahedrite, myargyrite, boulangerite, jamesonite, zinckenite, cylindrite and andorite. In this deposit, after an epigenetic magmatic stage, a long greisen-hydrothermal event took place with several episodes of metal deposition.Peer ReviewedPostprint (published version

    MINROCIND una eina d’aprenentatge presencial e interactiva dels jaciments de roques i minerals industrials a Catalunya: eina d'aprenentatge presencial i/o interactiu en el àmbit dels ensenyaments de la mineralogia i petrologia aplicada

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    Es presenta un nou material didàctic elaborat per a assolir l’aprenentatge de les roques industrials. Consta d’una part física i una altra virtual. La primera està constituïda per una mostra de roca polida i la seva làmina prima, per a ser utilitzada a les pràctiques a classe o pel autoaprenentatge. La part virtual és una base de dades interactiva amb fitxes amb les característiques bàsiques de la roca, i de les seves pedreres. S’inclouen les pedreres més importants de Catalunya. Més endavant es preveu ampliar-lo a altres àrees.Postprint (published version

    Fe in P-doped basaltic melts: a Mössbauer spectroscopy study

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    The addition of P to a basalt causes a change in the environment of Fe. At low P contents iron is located in the glass structure and the Fe3+/Fe2+ ratio is about 80/20. Further addition of P causes a collapse of the glass structure related to a phase separation that triggers the crystallization of a more reduced iron-containing phosphate phase with a crystalline structure similar to that of stanfieldite, and Mössbauer parameters similar to those of the alluaudite group, together with the formation of a Fe3+-Fe2+ disordered phase. Their presence increases the viscosity of the melt.Peer ReviewedPostprint (published version

    Glass-ceramic crystallization from tailings of the Morille tungsten deposit, Spain

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    Peer ReviewedObjectius de Desenvolupament Sostenible::12 - ProducciĂł i Consum ResponsablesPostprint (published version

    MineralogĂ­a del depĂłsito de Sn del distrito de Santa Fe, Bolivia

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    El depósito de Sn-Zn-Pb-Ag de Japo-Santa Fe-Morococala se encuentra en la provincia metalogenética del cinturón Central Andino. La mineralización se encuentra encajada en una secuencia metasedimentaria paleozoica y rocas ígneas porfídicas del Oligoceno-Mioceno. Las menas se encuentran en vetas y diseminaciones. Se distinguen dos tipos de mineralización: (1) una mineralización temprana de Sn y (2) una mineralización tardía de Sn y Zn-Pb-Ag. La asociación mineral consiste principalmente en cuarzo, pirita, casiterita, sulfuros y sulfosales. La casiterita, hasta 0,25% en peso de In, constituye la mineralización más temprana. La galena y la esfalerita son los principales sulfuros. La esfalerita presenta 0,24% de In. Los minerales del grupo de la estannita están representados por estannoidita, kersterita y sulfuros del sistema Sn-Cu-ZnFe-S. Las sulfosales incluyen sakuraiita, potosiita, franckeita, freibergita, tetrahedrita, myargyrita, boulangerita, jamesonita, zinckenita, cylindrita y andorita. En este depósito, después de una etapa magmática epigenética, se produjo un largo evento greisen-hidrotermal con varios episodios de deposición de metales.Peer ReviewedPostprint (published version

    Potential of tungsten tailings as glass raw materials

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    Glasses from different types of tungsten mine tailings were obtained and studied to determine their ability to be used as raw materials of commercial glass. Tailings of granitic composition from Barruecopardo, of calc-silicate wastes from Morille, and of schists and quartz from Panasqueira, were used as raw materials. The addition of CaCO3 and NaCO3 was necessary for the manufacture of the glass. Samples were characterised by XRF, XRD, HSM and DTA-TG. Furthermore, the expansion coefficient, Vickers microhardness and leaching properties were measured. The results show that all the tungsten mine tailings used were suitable for the manufacture of commercial glass, with the addition of calcium and soda. The calc-silicate tailing needs less additive content to produce a glass. Also, they present lower workability temperatures and higher durability. Glasses obtained from all the tested tailings retain the potentially toxic elements in their structure and prevents the environmental pollution.Peer ReviewedPostprint (author's final draft

    The importance of mineralogical knowledge in the sustainability of artisanal gold mining: a mid-south Peru case

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    Mineralogy and gold processing techniques from several mining areas of the Nazca-Ocoña gold belt, Mid-South Peru, were investigated to assess the efficiency of gold extraction methods in relation to their mineralogy. The deposits from this belt are intrusion gold related to mineralization in quartz veins. Native gold occurs as micrometric grains encapsulated in pyrite and in minor amounts in other sulfides and quartz. Electrum is found mainly in fractures of pyrite and attains up to 35 wt. % Ag. In addition to these occurrences, gold tellurides also occur and they are abundant in San Luis. Gold processing is carried out by amalgamation with mercury and/or cyanidation. The comparison of the gold grade in the mineralizations and in the residual tailings indicates that a significant amount of gold is not recovered using the mercury amalgamation process and also, in the case of the gold recovery by cyanidation, except when cement was added to the cyanide solution. This was due to an increase in the pH that favours the dissolution of the gold matrix. In the cyanidation process carried out in tailings previously treated with mercury, part of the mercury retained in them is released to the atmosphere or to the cyanidation fluids.Peer ReviewedPostprint (published version
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