DEMIN - Departamento de Engenharia de Minas

URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/510

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2010 - 20162

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Autor: search.filters.author.Alexandrino, Júnia SoaresAssunto: search.filters.subject.Zeta potential

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Agora exibindo 1 - 2 de 2
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    Dispersion degree and zeta potential of hematite.
    (2016) Alexandrino, Júnia Soares; Peres, Antônio Eduardo Clark; Lopes, Gilmara Mendonça; Rodrigues, Otávia Martins Silva
    The dispersion degree of the mineral particles in the pulp is especially relevant regarding the performance of the cationic reverse flotation of iron ores. The gangue minerals should remain dispersed while hematite particles should be selectively flocculated. The present study addressed determinations of dispersion degree and zeta potential of hematite in the presence of different dispersants, classified as organic polymeric (natural and synthetic), organic monomeric, and inorganic. Special attention was paid to results achieved at pH 10, used in plant practice. For natural organic polymers, correlation was observed between the dispersion degree and the increase in the negative value of zeta potential. Some synthetic organic polymers enhance the dispersion of hematite particles despite not affecting significantly the zeta potential. Sodium silicates, irrespectively of the SiO2/Na2O ratio, at pH 10, did not impact significantly either the dispersion degree or the zeta potential.
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    Kaolinite microflotation and zeta potential measurements in the presence of ammonium quaternary salts.
    (2010) Rodrigues, Otávia Martins Silva; Araujo, Armando Corrêa de; Peres, Antônio Eduardo Clark; Alexandrino, Júnia Soares; Lopes, Gilmara Mendonça
    Studies on kaolinite flotation are being driven by Chinese bauxite characteristics, presenting low alumina:silica weight ratios. This paper addresses the effect of the presence of cetyl pyridine chloride (CPC) and cetyl trimethyl ammonium bromide (CTAB) on kaolinite floatability and zeta potential. The reagents were dosed at three concentrations and the best floatability results were achieved at the highest concentration level (1x10-4 mol/L). Zeta potential determinations showed that both quaternary salts (CPC and CTAB) shift the kaolinite zeta potential to more positive values the specific collectors adsorption onto the mineral surface.