36 documents found, page 1 of 4
Copiapite group: occurrence and properties in mining contamination scenarios
Barroso, Ana; Valente, Teresa; antunes, Isabel Margarida; Reis, Amelia; Correia Neves, IsabelABSTRACT: The copiapite group shows a wide range of chemical compositions, allowing the identification of several mineral phases (e.g., aluminocopiapite and magnesiocopiapite). These minerals, typically observed in mining environments, are formed from evaporation and acid mine drainage (AMD) precipitation. In these areas, the copiapite has been studied to comprehend its ability to store some potentially toxic e...
Índices multi-elementares como abordagem para avaliação da qualidade dos sedime...
de Vicq Ferreira da Costa, Raphael; Valente, Teresa; Leão, Lucas; Leite, Mariangela; Nalini Jr., HerminioRESUMO: Os objetivos deste estudo foram avaliar a qualidade ambiental e o estado ecológico dos sedimentos fluviais do Quadrilátero Ferrífero através do cálculo de índices de qualidade multielementares para os elementos As, Cd, Cr, Cu, Pb e Zn. Além disso, como as bacias hidrográficas da região foram historicamente antropizadas pela mineração, o presente estudo também visa avaliar uma possível associação com min...
Potential accumulation of strategic elements in mining dams : from remining to ...
Gomes, Patrícia; Valente, Teresa; Gazire Lemos, marianaABSTRACT: Raw materials, from oil to industrial minerals, are essential to the efficient functioning of the world economy. However, the extraction of base metals, for example, allowed the mobilization and accumulation of large amounts of reactive wastes, triggering critical environmental problems. The Iberian Pyrite Belt, one of the largest metallogenetic provinces in the world, is an example of this, as it pre...
O chumbo na Província Mineira do Quadrilátero Ferrífero, Brasil: mapeamento geo...
de Vicq Ferreira da Costa, Raphael; Valente, Teresa; Leão, Lucas; Leite, Mariangela; Nalini Jr., HerminioRESUMO: A crescente industrialização associada à expansão da mineração tem proporcionado a poluição dos reservatórios ambientais, dentre os quais o Pb se destaca pelo seu caráter neurotóxico. No Quadrilátero Ferrífero, Minas Gerais, Brasil, o Pb ocorre principalmente associado ao Fe, que possui ampla distribuição e altas concentrações na região. Nesse contexto, um estudo regional realizou a coleta e análise de ...
Acid mine drainage precipitates from mining effluents as adsorbents of organic ...
Oliveira, Marta S. F.; Assila, Ouissal; Fonseca, António; Parpot, Pier; Valente, Teresa; Rombi, Elisabetta; Neves, Isabel C.Acid mine drainage (AMD) is one of the main environmental problems associated with mining activity, whether the mine is operational or abandoned. In this work, several precipitates from this mine drainage generated by the oxidation of sulfide minerals, when exposed to weathering, were used as adsorbents. Such AMD precipitates from abandoned Portuguese mines (AGO, AGO-1, CF, and V9) were compared with two raw ma...
A comparison of analytical methods for the determination of soil pH: case study...
Faria, Maria; Bertocco, Tamires; Barroso, Ana; Carvalho, Manuela; Fonseca, Felícia; Matos, Cristina Delerue; Figueiredo, Tomás deWildfires can cause serious imbalances in ecosystems, primarily at the soil level, making it vulnerable to degradation processes such as erosion. During and after a fire, changes occur in soil properties, including pH, which affects the solubility and availability of nutrients. Currently, there is a great diversity of protocols, some involving normalized standards, to determine soil pH, but there is no consensu...
Combinação de métodos geofísicos, geoquímicos e geoespaciais para estudo de loc...
Oliveira, Rui Jorge; Pinho, Catarina; Caldeira, Bento; Fonseca, Rita; Valente, Teresa; Vieira, João; Silva, Natália; Borges, José FernandoUma colaboração entre o Laboratório de Geofísica e Sismologia e o Laboratório AmbiTerra da Universidade de Évora estudou, entre 2013 e 2014, uma área nas imediações de uma unidade de tratamento de zinco, no Brasil, cujos níveis de poluição em Arsénio e metais potencialmente tóxicos são muito elevados. Esse estudo consistiu na análise geoquímica de solos em diversos pontos da área de estudo. Foram também realiza...
Geoenvironmental Study of Gold Mining Tailings in a Circular Economy Context – ...
Lemos, Mariana; Valente, Teresa; Marinho Reis, Paula; Fonseca, Rita; Dumont, J.M; Ferreira, G.M.M.; Delbem, I.D.We characterized the tailings from the Santa Barbara tailings dam, which is located in Minas Gerais, southeastern Brazil, to: (i) identify its chemical, mineralogical, and metallurgical properties, and (ii) perform an environmental evaluation of the water at the surface of the tailings facility. The potential recovery of elements such as Sb, As, and Au was also considered for potential tailings reuse. The water...
ENVIRONMENTAL CHARACTERIZATION OF GOLD MINING TAILINGS TO PREVENT ACID MINE DRA...
Lemos, Mariana; Valente, Teresa; Marinho Reis, Paula; Fonseca, Rita; Delbem, Itamar; Ventura, Juliana; Magalhães, MarcusTwo different types of tailings from Au metallurgical treatment were studied for their acid mine drainage potential and elements mobility: flotation and leaching tailings from an already deactivated circuit, accumulated in the Cocuruto tailings dam circuit (old circuit); and roasted and leaching tailings form a current plant (current circuit), in Minas Gerais, Brazil. Detailed characterization of both types ind...
Characterization of Arsenical Mud from Effluent Treatment of Au Concentration P...
Lemos, Mariana; Valente, Teresa; Fonseca, Rita; Gregório Filho, José; Dumont, José Augusto; Ventura, Juliana; Delben, ItamarThe determination of the general properties of arsenical mud was carried out in effluent treatment plant of an Au metallurgical facility, located in Nova Lima, Minas Gerais, Brazil. This effluent, which comes from the calcination stage, is treated via Fe-coprecipitation / lime-neutralization and thus mud with high As concentration is generated. Instrumental methods were applied to investigate physical-chemical ...