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Synthesis of a novel hydroxamic acid flotation collector and its flotation separation of malachite against quartz

Sun Xin, Huang Lingyun, Wu Dandan, Hu Bo, Zhang Mei, Li Yaming, Tong Xiong

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 4

art. no. 149427

EN

This paper proposes a promising chelating collector, phenyl propyl hydroxamic acid (BPHA), to directly float malachite for the separation of malachite against quartz. The flotation performance and mechanism was investigated via microflotation tests, as well as through contact angle, Scanning Electron Microscopeand Energy Dispersive Spectrometer (SEM–EDS), zeta potential, adsorption capacity, Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS) analyses. The results of microflotation tests showed that BPHA has a strong ability to collect malachite and a significant selectivity against quartz. The contact angle tests showed that BPHA effectively adsorbed onto the mineral surface and could improve the hydrophobicity of the malachite surface. SEM–EDS and adsorption capacity analyses further indicated that BPHA adsorbed onto the surface of malachite. The FR-IR results suggested that BPHA could react with Cu2+ ions and facilitate strong chemical adsorption onto the surface of malachite. Furthermore, zeta potential and XPS analyses provided clear evidence that BPHA exhibited a stronger affinity for malachite and a weaker interaction with quartz.

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Study on a novel hydroxamic acid as the collector of rhodochrosite

Zhao G., Dai T., Wang S., Zhong H.

Physicochemical Problems of Mineral Processing

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2018

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Vol. 54, iss. 2

428--439

EN

A novel collector, tert-butyl benzohydroxamic acid (TBHA), was first introduced in rhodochrosite flotation. The performance of TBHA was investigated by the density functional theory (DFT) calculation along with the micro flotation test, zeta potential determination and XPS analysis, compared with benzohydroxamic acid (BHA). TBHA has stronger affinity to the mineral than BHA in terms of frontier molecular orbital, atomic net charge and bond population. The substitution of tert-butyl group on the benzene ring improves the affinity of the hydroxamic acid to the mineral. TBHA exhibits excellent collecting ability to rhodochrosite with a recovery of about 99% at a concentration of 3.89×10-4 mol/dm3 and pH 6.5. The hydroxamic acid molecules are adhered on mineral surfaces by chemical adsorption, resulting in negative shifts for the zeta potential of rhodochrosite with the presence of the collector. Chemical adsorption can be also confirmed from XPS analyses that the atomic concentration ratios of C and O to Mn on the treated mineral surfaces were increased and the binding energy of Mn3s was decreased. The experimental data achieve excellent agreement with the computational analyses.

3

Behavior and mechanism of collophane and dolomite separation using alkyl hydroxamic acid as a flotation collector

Yu J., Ge Y., Hou J.

Physicochemical Problems of Mineral Processing

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2016

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Vol. 52, iss. 1

155--169

EN

Flotation response of collophane and dolomite using alkyl hydroxamic acid (AH) (chelating collector) was investigated in the paper. The experiments were performed using pure and artificially mixed minerals as well as a real phosphate ore. Their separation mechanisms were studied by means of zeta potential measurements, infrared analysis, adsorption measurements, thermodynamics, and quantum chemical calculations. The results indicated that AH exhibited an excellent performance in the flotation separation of collophane from dolomite in neutral medium. The P2O5 grade of the concentrate increased from 19.84% to 30.51% without any other reagents when the pH value was about 7. The zeta potential and adsorption studies showed that the adsorption of AH at the cellophane/aqueous interface was greater than that at dolomite surface, which was the essential reason that separation of collophane from dolomite. The results of Fourier Transform Infrared (FTIR) spectrum and thermodynamics calculation indicated that the adsorption of AH at collophane was attributed to the chemical bonding. Moreover, AH molecule formed O-O five-membered ring with calcium ion on the collophane surface.