Please use this identifier to cite or link to this item: http://hdl.handle.net/1822/25578

TitleGeochemistry and mineralogy of ochre-precipitates formed as waste products of passive mine water treatment
Author(s)Valente, Teresa Maria Fernandes
Antunes, M.
Braga, M. A. Sequeira
Pamplona, J.
KeywordsOchre-precipitates
Mine water
Metals
Arsenic
Concentration factors
Issue date2011
PublisherGeological Society of London
JournalGeochemistry-Exploration Environment Analysis
Abstract(s)Passive systems with constructed wetlands are designed to simulate natural attenuation processes in order to treat mine water in a long-term and cost-effective manner. In this way, they are especially appropriate to treat mine water discharging from abandoned mines. This paper presents geochemical and mineralogical data obtained from a recently constructed passive system in the Jales abandoned mine, north Portugal. It shows the role of fresh ochre-precipitates, formed as waste products from the neutralization process, in the retention of trace elements. Chemical analysis of these waste products revealed strong enrichment factors for metals and arsenic, relative to the water from which they precipitate. The mineralogical study shows that ochre-precipitates are poorly ordered iron-rich material, such as ferrihydrites, that occur as small spherical aggregates (<0.1 μm in diameter). Heating experiments on these precipitates gave rise to hematite and to a crystalline arsenate. This provides evidence for the scavenging of arsenic by means of a precursor arsenic-rich amorphous compound. The results reveal that ochreprecipitates are wastes of environmental concern, which should be taken into account when considering the possibilities for reuse or disposal
TypeArticle
URIhttp://hdl.handle.net/1822/25578
DOI10.1144/1467-7873/09-IAGS-009
ISSN1467-7873
Peer-Reviewedyes
AccessRestricted access (UMinho)
Appears in Collections:CIG-R - Artigos (Papers)

Files in This Item:
File Description SizeFormat 
Valente_etal_Geochemistry-ExplorationEnvironmentAnalysis_2010.pdf
  Restricted access
Resumo83,86 kBAdobe PDFView/Open    Request a copy!

Partilhe no FacebookPartilhe no TwitterPartilhe no DeliciousPartilhe no LinkedInPartilhe no DiggAdicionar ao Google BookmarksPartilhe no MySpacePartilhe no Orkut
Exporte no formato BibTex mendeley Exporte no formato Endnote Adicione ao seu ORCID