Electrokinetic properties of hydroxyapatite under flotation conditions

Vučinić, D.R.; Radulović, Dragan; Deušić, S.

doi:10.1016/j.jcis.2009.11.024

Cited by 57 publications

(25 citation statements)

References 75 publications

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“…In Figure 5B, it can be observed that, in the absence of surfactant, the zeta potential of the precipitate is negative in the whole pH range, due to the prevalence of negatively charged species in the Stern layer of the electrical double layer of hydroxyapatite, as proposed by Vucinic et al (2010). In the presence of 20 mg L -1 Na-oleate, the precipitate charge became more negative in the whole pH range studied.…”

Section: Effect Of Ph On the Phosphate Recoverymentioning

confidence: 59%

“…The monohydroxy complex CaOH+ is present in notable concentrations above pH 11, while calcium hydroxide precipitates above pH 13.3 (Somasundaran et al, 1985). Vucinic et al (2010) evaluated the electrokinetic properties of hydroxyapatite and presumed that the surface ions Ca2+, PO43-and OH-are the species that participate in the surface reactions, similar to those reactions that occur in the bulk.…”

Section: Effect Of Ph On the Phosphate Recoverymentioning

confidence: 99%

“…In the pH range from 5 to 9, oleate ions (Ol-) and ion-molecule complexes H(Ol)-2 are the dominant species, whereas at pH >9 the dominant ions are Ol-and dimers Ol22-. Based on the distributions of the species mentioned above, in the pH range from 4 to 6, the increase in the negative zeta potential of the precipitate indicates the chemisorption of oleate ions and neutral molecules, oriented with head groups toward the solid, and with hydrocarbon chains toward the water solution, forming hemimicelles and rendering the surface hydrophobic, and therefore more floatable (Nunes et al, 2011;Vucinic et al, 2010). In the pH range from 7 to 9, the oleate ions and the ion molecule complex, oriented with head groups toward the solid and associated due to the chain-chain interaction into hemimicelles make the precipitate surface more hydrophobic and more floatable (Vucinic et al, 2010).…”

Section: Effect Of Ph On the Phosphate Recoverymentioning

confidence: 99%

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Electroflotation of precipitated phosphate from synthetic solution

Cruz

Monte

Dutra

2017

Braz. J. Chem. Eng.

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-The phosphate recovery from a 20 mg L -1 Na2HPO4 solution through precipitation with Ca(OH)2 followed by electroflotation was evaluated. X-ray diffraction and particle size measurements indicated that the precipitates were a mixture of hydroxyapatite and calcium-deficient hydroxyapatite, with size ranging from 3 to 10 mm. Electroflotation with Na-oleate as surfactant was used to recover the precipitates. The surfactant adsorption was evaluated through zeta potential measurements. The influence of Na-oleate concentration, pH and bubble size on phosphate recovery was investigated. In the absence of Na-oleate, a phosphate recovery of 50% was achieved, while in the presence of 20 mg L -1 of Na-oleate it was increased to 90%, at pH 11. The phosphate recovery also increased with Ca(OH)2 concentration increase and bubble size decrease, reaching 100% at 300 mg L -1 Ca(OH)2 and bubble size around 39 µm.

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Section: Effect Of Ph On the Phosphate Recoverymentioning

confidence: 59%

Section: Effect Of Ph On the Phosphate Recoverymentioning

confidence: 99%

Section: Effect Of Ph On the Phosphate Recoverymentioning

confidence: 99%

See 1 more Smart Citation

Electroflotation of precipitated phosphate from synthetic solution

Cruz

Monte

Dutra

2017

Braz. J. Chem. Eng.

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“…Hence, the effect of calcium ions on the zeta potential of minerals was studied. Previous studies were focused separately on the zeta potential measurements of apatite [26,27], dolomite [24,28], and quartz [29] in the presence of calcium ions. In fact, the zeta potentials varied due to different ionic strength, experimental apparatus, sample preparation process, etc.…”

Section: Zeta Potentials Of Pure Minerals In the Presence Of Calcium mentioning

confidence: 99%

Effects of Metal Ions on the Flotation of Apatite, Dolomite and Quartz

et al. 2018

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Abstract:The effects of Ca 2+ , Mg 2+ , Al 3+ , and Fe 3+ on the flotation behaviors of apatite, dolomite and quartz were investigated through a micro-flotation test, and the influence of calcium ions on the flotation of these minerals was further elucidated by solution chemistry study, zeta potential measurement, and X-ray photoelectron spectroscopy (XPS) analyses. The results indicate that an appropriate amount of Ca 2+ and Mg 2+ can improve the floatability of apatite but had a negligible effect on the flotation performance of dolomite, whereas Al 3+ , Fe 3+ , and excessive amounts of Ca 2+ decreased the recovery of apatite and dolomite. The studied metal cations can activate quartz at a particular pH. It can be inferred from solution chemistry and zeta potential measurement that the influence of metal ions on the flotation of different minerals should be attributed to the adsorption of various hydrolysis species on the mineral surfaces. XPS analyses reveal that calcium ions can enhance the adsorption of anionic collector on apatite and quartz surfaces, and there are no apparent changes to be observed on the surface of dolomite in the absence and presence of calcium ions at a concentration of 2.5 × 10 −3 M, which was in good agreement with the micro-flotation results.

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“…Minerals 2017, 7, 150 2 of 11 sorption processes such as precipitation/coprecipitation, adsorption, and ionic substitution [15,16]. Although some reagents, such as sodium silicate, starch, and carboxymethyl cellulose, have a good inhibiting effect on dolomite flotation, there is no selectivity in the flotation separation of magnesite from dolomite in practice, which is probably due to the two minerals' similar surface properties and dissolved species [17,18].…”

Section: Flotation Testsmentioning

confidence: 99%

Elimination of the Adverse Effect of Calcium Ion on the Flotation Separation of Magnesite from Dolomite

et al. 2017

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Abstract:The separation of magnesite from dolomite was studied by flotation tests, X-ray photoelectron spectroscopy (XPS), and zeta potential measurements in the presence of calcium ion (Ca 2+ ) dissolved from dolomite. Sodium oleate (NaOL) was used as collector, and sodium carbonate (Na 2 CO 3 ) and sodium hexametaphosphate (SH) were used as regulators. The results showed that SH had a good selective inhibition ability in pure mineral flotations of magnesite and dolomite. While in the presence of Ca 2+ dissolved from dolomite, magnesite and dolomite were both inhibited by SH. The separation of magnesite from dolomite cannot be realized because Ca 2+ can adsorb on the surface of magnesite in the form of CaCO 3 and change the surface properties of magnesite. Thus, the magnesite flotation was depressed. When the sequence of reagent addition was changed to add SH prior to Na 2 CO 3 , a complex was made by Ca 2+ reacting with SH, which avoided the adsorption of Ca 2+ on the magnesite surface and prevented the changing of the magnesite's surface properties. Then, after adjusting the solution pH with Na 2 CO 3 , the flotation separation of magnesite from dolomite could be achieved.

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Electrokinetic properties of hydroxyapatite under flotation conditions

Cited by 57 publications

References 75 publications

Electroflotation of precipitated phosphate from synthetic solution

Electroflotation of precipitated phosphate from synthetic solution

Effects of Metal Ions on the Flotation of Apatite, Dolomite and Quartz

Elimination of the Adverse Effect of Calcium Ion on the Flotation Separation of Magnesite from Dolomite

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