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DFT study of coadsorption of fatty acid and kerosene on fluorapatite (001) surface

Du Weifan, Li Xianbo, Zhang Qin

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 1

art. no. 161890

EN

The adsorption of fatty acid, kerosene and fatty acid-kerosene on fluorapatite (001) surface were investigated by density functional theory (DFT) calculations. The results showed that the single fatty acid could form stable chemisorption on fluorapatite (001) surface by the O of fatty acids bonding with Ca1 site. The single kerosene could not be stably adsorbed on fluorapatite (001) surface because the H of kerosene did not form hydrogen bond with the O of PO43- on (001) surface (Osurf). For the coadsorption conformation, the chemisorption of fatty acid-kerosene on fluorapatite (001) surface was contributed by the interaction between O of fatty acids and Ca1, the H of kerosene did not bond with the Osurf, but the carbon chain length of kerosene has a large influence on the coadsorption. Compared with the coadsorption of fatty acid-decane, the adsorption of butyric acid-tetradecane and octanoic acid-tetradecane on fluorapatite (001) surface have greater adsorption energies and overlapping region of DOS between O 2p and Ca 4d, indicating that there is a synergistic effect between fatty acid and tetradecane. Meanwhile, the collaborative effects exist between the molecules of fatty acids. The interpenetrating adsorption of fatty acid and kerosene on the fluorapatite surface could improve the adsorption strength and density. The flotation test further confirmed that the single kerosene could not collect fluorapatite, but it could be collected by the single fatty acid. Besides, the synergistic effect between fatty acid and kerosene could increase the flotation recovery of fluorapatite.

2

Activation mechanism of tantalum niobium flotation by lead ions in a combined collector flotation system

He Mingfei, Li Shuangke, Cao Miao, Gao Yude, Bu Hao, Meng Qingbo

Physicochemical Problems of Mineral Processing

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2021

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Vol. 57, iss. 1

29--38

EN

The effect of lead ions on the flotation activation of tantalum niobium ore (TNO) was studied by micro-flotation, adsorption capacity experiments, solution chemical composition calculations, and infrared spectral analysis. The experimental demonstrated that the combined collector of salicylhydroxamic acid (SHA) and ammonium dibutyl dithiophosphate (ADDP) resulted in a strong collection capacity for TNO in the presence of lead ions. The solution chemistry calculations determined that the dominant source of lead ions in the aqueous solution was Pb(OH)+ at a pH of 8, which was conducive to the adsorption and interaction of SHA and ADDP anions. In the lead ion activation system, the combined reagent co-adsorbed onto the TNO surface, causing a large negative shift in the zeta potential. The co-adsorption mechanism of the combined collector consisted of complex chemisorption between SHA and the TNO surface active particles, while the main adsorption of ADDP is physisorption.

3

Zastosowanie inwersyjnej chromatografii gazowej w badaniach koadsorpcji – adsorpcja metanolu na Amberlyście 15

Słomkiewicz P. M.

Camera Separatoria

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2011

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Vol. 3, No. 1

103--114

PL

Opisano aparaturę do dozowania różnej wielkości próbki dwóch adsorbatów do pomiarów koadsorpcji. Pomiary koadsorpcji wykonano dla metanolu na powierzchni sulfonowanego kopolimeru styrenowo-diwinylobenzenowego Amberlyst 15 pokrytej zaadsorbowaną wodą. Wyznaczono stałe równowagi i entalpie adsorpcji.

EN

The apparatus for dosage different size of sample of two adsorbatesforcoadsorption measurementswas described. The measurements were executed for methanol coadsorption on the surface of sulfonated styrene-divinylobenzenecopolymerAmberlyst 15 covered with adsorbed water. The equilibrium constants and enthalpies of adsorptionwere determined.