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Wyszukujesz frazę "low rank coal" wg kryterium: Temat


Wyświetlanie 1-3 z 3
Tytuł:
Effect of the degree of polymerization of nonylphenol polyoxyethylene ether on the dewatering of low-rank coal
Autorzy:
Li, Lin
He, Meng
Liu, Mingpu
Lin, Mengyu
Hu, Shanpei
Yu, Hao
Wang, Qingbiao
You, Xiaofang
Powiązania:
https://bibliotekanauki.pl/articles/1449205.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
low-rank coal
NPEO
dewatering
adsorption
long-flame coal
Opis:
In this study, we investigated the effect of the hydrophilic ethylene oxide chain lengths (i.e., degree of polymerization) of nonylphenol polyoxyethylene ether (NPEO-x, x = 8, 10, and 12) on the dewatering of low-rank coal slime through dewatering and adsorption experiments and X-ray photoelectron spectroscopy (XPS) measurements. The dewatering experiments showed that the adsorption of NPEO changed the water content of the low-rank coal slime: NPEO-8 achieved the best effect, followed, in decreasing order, by NPEO-10 and NPEO-12. Adsorption experiments revealed that the adsorption isotherms of NPEO-x on the low-rank coal surface conform with the Langmuir model, and its adsorption kinetics follow the pseudo-second-order kinetic equation. Furthermore, the adsorption is a spontaneous process and controlled by both intraparticle diffusion and liquid film diffusion. The XPS results showed that the adsorption of NPEO-x decreased the content of oxygencontaining groups and, thus, improved the hydrophobicity of the low-rank coal surface. Further, the use of NPEO-x with a low degree of polymerization (x = 8) improves the hydrophobicity of the coal surface and decreases the water content of low-rank coal slime.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 4; 723-736
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adsorption behavior and XPS analysis of nonylphenol ethoxylate on low rank coal
Autorzy:
You, Xiaofang
Ma, Chuandong
Li, Zhihao
Lyu, Xianjun
Li, Lin
Powiązania:
https://bibliotekanauki.pl/articles/109627.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
low rank coal
nonylphenol ethoxylate
adsorption isotherm
adsorption kinetics
XPS
Opis:
In this work, low rank coal was used for the removal of nonylphenol ethoxylate with fifteen ethylene oxide groups (NPEO15) from aqueous solutions at different contact times, temperatures, and initial adsorbent concentrations. The adsorption isotherms showed good fit with the Langmuir equation. Maximum adsorption capacities calculated at 308, 318, and 328 K were 23.64, 29.41, and 35.71 mg g–1, respectively. The changes in the free energy of adsorption (ΔG°), enthalpy (ΔH°), and entropy (ΔS°) were calculated in order to predict the nature of adsorption. The results of the thermodynamic analysis indicated that a spontaneous process took place, driven synergistically by both enthalpy and entropy. The adsorption kinetics of NPEO15 were consistent with a pseudo-second order reaction model. XPS results showed that the oxygen functional groups on the low rank coal surface were significantly covered by NPEO15. Furthermore, while the content of C–C/C–H functional groups increased significantly, that of C–O functional groups decreased after absorption. These results clearly indicate that low rank coal is more hydrophobic and displays better floatability.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 3; 721-731
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structure and dynamics of water adsorbed on the lignite surface: Molecular dynamics simulation
Autorzy:
You, Xiaofang
He, Meng
Cao, Xiaoqiang
Lyu, Xianjun
Li, Lin
Powiązania:
https://bibliotekanauki.pl/articles/109688.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
low rank coal
water molecule
oxygen-containing functional groups
molecular dynamics
Opis:
The effects of oxygen-containing functional groups on the structure and dynamic properties of water molecules near a lignite surface were investigated through molecular dynamics (MD) simulations. Because of its complex composition and structure, a graphite surface containing hydroxyl, carboxyl, and carbonyl groups was used to represent the lignite surface model. According to X-ray photoelectron spectroscopic (XPS) results, the composing proportion of hydroxyl, carbonyl and carboxyl is 21:13:6. The density profiles of oxygen and hydrogen atoms indicate that the brown coal surface characteristics influence the structural and dynamic properties of water molecules. The interfacial water is much more ordered than bulk water. The results of the radial distribution functions, mean square displacements, and local self-diffusion coefficients for the water molecules in the vicinity of three oxygen-containing functional groups confirmed that carboxyl groups are the preferential adsorption sites.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 1; 10-20
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-3 z 3

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