Iron oxides and monazite from sands of two beaches in Espirito Santo, Brazil

Química Nova

Universidade Federal de Minas Gerais, Belo Horizonte¹  Coelho, Flávia dos Santos¹  Couceiro, Paulo Rogério da Costa¹  Lopes, Ana Lúcia¹  Fabris, José Domingos¹ 

关键词: iron oxides;    rare earth;    Mö;    ssbauer.;   

DOI  :  10.1590/S0100-40422005000200013

学科分类：化学（综合）

来源: Sociedade Brasileira de Quimica

【 摘 要 】

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 Ce3+0,494Gd3+0,012La3+0,209Nd3+0,177Pr3+0,040Sm3+0,024Th4+0,033 (PO4) and Ce3+0,474La3+0,227Nd3+0,190Pr3+0,044Sm3+0,032Th4+0,024 (PO4). 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 a and b radiation activities were also measured for both samples.

【 授权许可】

Unknown