Portal de Periódicos da CAPES

Artigo Acesso aberto Produção Nacional Revisado por pares

BIBTEX RIS

Óxidos de ferro e monazita de areias de praias do Espírito Santo

2005; Brazilian Chemical Society; Volume: 28; Issue: 2 Linguagem: Inglês

10.1590/s0100-40422005000200013

1678-7064

Flávia dos Santos Coelho, Paulo Rogério da Costa Couceiro, Ana Lúcia Lopes, José Domingos Fabris,

Iron oxide chemistry and applications

ESPIRITO SANTO, BRAZIL.Sand samples collected from two sampling sites on Guarapari and Iriri beaches, state of Espírito Santo, Brazil, were studied in an attempt to better describe their chemical and mineralogical compositions and radioactive behaviors.The sands were found to contain about 6 (Guarapari) and 2 dag kg -1 (Iriri) of rare earth and thorium that, if allocated to the monazite-(Ce) structure, lead to the averaged formulae ( ) 4 4 0,033 3 0,024 3 0,040 3 0,177 3 0,209 3 0,012 3 0,494 PO Th Sm Pr Nd La Gd Ce + + + + + + + and ( ) 4 4 0,024 3 0,032 3 0,044 3 0,190 3 0,227 3 0,474 PO Th Sm Pr Nd La Ce + + + + + +. From Mössbauer spectroscopy data, the magnetic fractions of these sands were found to contain stoichiometric hematite (47.4 dag kg -1 , from Guarapari, and 25.1 dag kg -1 , from Iriri) and magnetite (44.1 and 58.8 dag kg -1 ).The specific α and β radiation activities were also measured for both samples.