Chelating reagents for flotation

Marabini, A.M.; Ciriachi, M.; Plescia, P.; Bárbaro, M. B.

doi:10.1016/j.mineng.2007.03.012

Cited by 106 publications

(25 citation statements)

References 3 publications

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“…Most of new reagents found effective for low grade ores were chemicals capable of interacting with specific ions in mineral lattice. [3][4][5] Pyrochlore [(Na,Ca) 2 Nb 2 O 6 (OH,F)] is currently the most important commercially exploitable niobium containing mineral, which usually co-exists and associates with carbonate rocks in the Earth's crust. In the processing of the carbonatite niobium ores, significant amounts of fines are generated due to the friable nature of the niobium oxide minerals and the soft carbonatite rock matrix.…”

Section: Introductionmentioning

confidence: 99%

Adsorption behaviour of sodium hexametaphosphate on pyrochlore and calcite

Liu

2013

Canadian Metallurgical Quarterly

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FTIR, XPS and zeta potential measurements were performed on pyrochlore and calcite to study the adsorption mechanisms of sodium hexametaphosphate (NaHMP). While no hexametaphosphate could be detected on the FTIR spectra of NaHMP treated pyrochlore or calcite, the observed chemical shifts of the binding energies of Ca 2p 5/2 (0?25 eV) and P 2p (0?20 eV) electrons indicated that the hexametaphosphate groups formed a complex with calcium on calcite. The complex seemed soluble in water leaving a low concentration of its residue on calcite surface after water washing, thus undetectable by FTIR. The binding energy shifts of Nb 3d 5/2 (0?13 eV) and Ca 2p 5/2 (0?10 eV) electrons on NaHMP-treated pyrochlore were within instrumental resolution, therefore, NaHMP was not strongly bound to pyrochlore. The zeta potentials of pyrochlore and calcite were both lowered in the presence of NaHMP. However, for pyrochlore, the zeta potential drop occurred mainly in the acidic pH range, while the drop for calcite was independent of pH, indicating possible chemisorption of NaHMP on calcite. The work explained the selective depressive function of NaHMP in the hydroxamic acid flotation of carbonatite niobium ores.On a effectué des mesures de FTIR, de XPS et de potentiel zê ta du pyrochlore et de la calcite afin d'é tudier les mé canismes d'adsorption de l'hexamé tahosphate de sodium (NaHMP). Bien qu'on ne puisse pas dé tecter d'hexamé taphosphate dans les spectres de FTIR du pyrochlore ou de la calcite traité s au NaHMP, les dé calages chimiques observé s des é nergies de liaison des électrons de Ca 2p 5/2 (0?25 eV) et de P 2p (0?20 eV) indiquaient que les groupes d'hexamé taphosphate formaient un complexe avec le calcium sur la calcite. Le complexe semblait soluble dans l'eau, laissant une faible concentration de son ré sidu à la surface de la calcite aprè s lavage à l'eau, donc indé tectable par FTIR. Les dé calages de l'é nergie de liaison des é lectrons du Nb 3d 5/2 (0?13 eV) et du Ca 2p 5/2 (0?10 eV) du pyrochlore traité au NaHMP se situaient dans les limites de ré solution de l'instrument. Donc, le NaHMP n'é tait pas fortement lié au pyrochlore. Les potentiels zê ta du pyrochlore et de la calcite s'abaissaient tous deux en pré sence de NaHMP. Cependant, la chute de potentiel zê ta du pyrochlore se produisait principalement dans la gamme de pH acide, alors que la chute pour la calcite é tait indé pendante du pH, indiquant la possibilité d'une chemisorption du NaHMP sur la calcite. Ce travail explique la fonction sé lective et dé pressive du NaHMP lors de la flottation à l'acide hydroxamique des minerais de carbonite de niobium.

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Section: Introductionmentioning

confidence: 99%

Adsorption behaviour of sodium hexametaphosphate on pyrochlore and calcite

Liu

2013

Canadian Metallurgical Quarterly

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“…OHA species can be adsorbed on the nonpolar part of the former OHA species through hydrogen bonds [17,19]. Therefore, at a pH of about 6.5, the multi-layer adsorption of OHA species and the relative increase of the perovskite surface's active metal cations significantly increase the flotability of the perovskite [39][40][41][42][43]. OHA species can be adsorbed on the nonpolar part of the former OHA species through hydrogen bonds [17,19].…”

Section: Microflotation Experimentsmentioning

confidence: 99%

Activation Mechanism of Lead Ions in Perovskite Flotation with Octyl Hydroxamic Acid Collector

2018

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The activation mechanism of lead ions (Pb 2+ ) in perovskite flotation with an octyl hydroxamic acid collector was systematically investigated using microflotation experiments, zeta-potential measurements, adsorption tests, Fourier transform infrared (FT-IR) analysis, and X-ray photoelectron spectroscopy (XPS) analysis. The results of microflotation experiments and adsorption tests indicate that the presence of Pb 2+ can promote the adsorption of octyl hydroxamic acid (OHA) on the perovskite surface and enhance the flotability of perovskite under weakly acidic conditions. The maximum recovery of 79.62% was obtained at pH 6.5 in the presence of Pb 2+ , and the maximum recovery of 57.93% was obtained at pH 5.7 without Pb 2+ . At pHs below 7, lead species are mainly present as Pb 2+ and PbOH + in the solution; besides this, the relative content of titanium increases on the perovskite surface. The adsorption of Pb 2+ and PbOH + on the perovskite surface makes the zeta-potential of perovskite shift positively, and increases the number of activated sites on the perovskite surface. FT-IR and XPS analyses confirm that OHA chemisorbs on the surface of Pb 2+ -activated perovskite and forms hydrophobic Pb-OHA complexes, which improve the flotability of perovskite.

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“…[11,12,14] To find a collector with specificity for a given surface, the interaction with the entire surface needs to be considered; [15] it is not enough to consider only its complexation chemistry with the surface metal ion(s). [16,17] For that purpose collector molecules with two functional groups [18,19] have been synthesized and evaluated in order to achieve mineral specificity in flotation separation of calcium minerals. These anionic surfactants [20,21] have only one hydrophobic tail while the polar part consists of two carboxyl groups with varying distance between them (Figure 1).…”

Section: Introductionmentioning

confidence: 99%

Selective flotation of calcium minerals using double-headed collectors

Patra

Taner

Bordes

et al. 2018

Journal of Dispersion Science and Technology

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A study was performed involving a series of double-headed carboxylate collectors with varying distance between the head groups (one, two or three carbon atoms). A collector with the same alkyl chain length but with only one carboxylate group was also included. All these were aminoacid based amphiphiles and the polar head group was connected to the hydrophobic tail via an amide linkage. Selective flotation recovery of different calcium minerals using these collectors was investigated. The double-headed collector with one carbon atom between the carboxylate groups was an apatite and fluorite specific reagent while the monocarboxylate surfactant showed high specificity for calcite. The flotation behavior of a simple conventional collector of the same alkyl chain length, a fatty acid salt, was also determined under identical flotation conditions in order to understand the effect of the amide group. Complementary experiments (f potential measurements, adsorption isotherm determinations) were also performed for these reagents. In order to shed light on the selectivity obtained with the dicarboxylate surfactants, the distances between the head groups were calculated and compared with the distances between neighboring calcium atoms on the surface of the minerals. It was found that the high degree of selectivity could be rationalized by perfect matching of these distances. To the best of our knowledge this is the first study where flotation selectivity in complex calcium mineral systems has been explained in terms of molecular recognition governing the interaction between the collector and the mineral surface.GRAPHICAL ABSTRACT ARTICLE HISTORY

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Chelating reagents for flotation

Cited by 106 publications

References 3 publications

Adsorption behaviour of sodium hexametaphosphate on pyrochlore and calcite

Adsorption behaviour of sodium hexametaphosphate on pyrochlore and calcite

Activation Mechanism of Lead Ions in Perovskite Flotation with Octyl Hydroxamic Acid Collector

Selective flotation of calcium minerals using double-headed collectors

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