%0 Journal Article
%T Effectiveness of selective chemical treatments on concentrating magnetic minerals of samples from a nickel-ore peridotite mantle
%A Lelis
%A Maria de F¨¢tima F.
%A Gon£¿alves
%A Cl¨¢udia M.
%A Fabris
%A Jos¨¦ D.
%A Mussel
%A Wagner N.
%A Serrano
%A William A. Pacheco
%J Journal of the Brazilian Chemical Society
%D 2004
%I Sociedade Brasileira de Qu¨ªmica, SBQ
%R 10.1590/S0103-50532004000600015
%X two magnetic samples, collected at 5 m and 52 m from the top of a weathering mantle developing on peridotite, from the cerro matoso (7¡ã  54' 31" n 75¡ã 33' 23" w) mining area for nickel, department of cordoba, colombia, were submitted to magnetic separation with a hand magnet in the laboratory. the so concentrated samples were found to contain intimately associated magnetic and non-magnetic minerals. the magnetic phases were further concentrated by selective chemical treatments with 5 mol l-1 naoh to remove silicates, and with a mixture citrate - bicarbonate - dithionite, to remove non-magnetic iron oxides. powder x-ray diffractometry, rt m£¿ssbauer spectroscopy, saturation magnetization measurements, scanning electron microscopy, energy dispersive spectroscopy and optical microscopy analyses were used to give a mineralogical description of the magnetic phases. the chemical treatments were effective on concentrating iron oxides so to improve the mineralogical analysis of this nickel ore. m£¿ssbauer analysis revealed that naoh selectively removed silicates and chromite from samples, whereas cbd dissolved hematite, goethite, and partially oxidized non-stoichiometric magnetite.
%K m£¿ssbauer spectroscopy
%K magnetization
%K naoh-treatment
%K cbd-treatment
%K iron oxide
%K spinel.
%U http://www.scielo.br/scielo.php?script=sci_abstract&pid=S0103-50532004000600015&lng=en&nrm=iso&tlng=en