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1

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

100%

He M. , Li S. , Cao M. , Gao Y. , Bu H. , Meng Q.

Physicochemical Problems of Mineral Processing

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2021

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tom 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.

2

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

88%

Du W. , Li X. , Zhang Q.

Physicochemical Problems of Mineral Processing

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2023

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tom 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.

3

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

63%

Słomkiewicz P. M.

Camera Separatoria

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2011

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tom 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.

4

The role of F A1:Ag+ defects in laser light generation and coadsorption of CO and halogen atoms at the KCl and KBr surface sites. First principles calculations

63%

Abdelrazik S. , Shalabi A.

Open Physics

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2007

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tom 5

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nr 4

611-636

EN

FA1:Ag+ color center at the low coordination (100) and (110) surface sites of KCl and KBr thin films play an important role in providing tunable laser oscillation and adsorbatesubstrate interactions. Double-well potentials at this site are investigated using ab initio molecular electronic structure calculations. The calculated Stokes shifted (optical transition bands), opticaloptical conversion efficiencies, the probability of orientational destruction, exciton (energy) transfer and Glasner-Tompkins empirical rule suggest that laser light generation is sensitive to (i) the lattice anion, (ii) the coordination number of surface ions, and (iii) the choice of the basis set centered on the anion vacancy. The adsorbate-substrate interactions were found to be dependent on the electronegativity of the adatom and on the lattice anion. Optimised geometries and the coadsorption of CO and (F, Cl, Br, I) on KCl and KBr (100) crystals are presented. Calculated chemisorption energies for CO on the (halogen atom/defect free sites of KCl and KBr (100) crystals) showed that the coadsorption of halogen atom tends to block other adsorbate-substrate interactions at the nearest neighbour sites. Thus if halogen atom coverage increases, the CO prefers to be adsorbed on the K+ site of the KCl and KBr (100) surfaces and on KBr relative to KCl.