Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "Li, Y.J." wg kryterium: Autor


Wyświetlanie 1-9 z 9
Tytuł:
Galvanic contacting effect of pyrite on xanthate adsorption on galena surface: DFT simulation and cyclic voltammetric measurements
Autorzy:
Ke, B.
Chen, J.
Li, Y.
Chen, Y.
Powiązania:
https://bibliotekanauki.pl/articles/110904.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
adsorption
DFT
galvanic interaction
pyrite surface
galena surface
cyclic voltammetric measurements
Opis:
The effect of galvanic interaction between pyrite and galena on xanthate adsorbing on the galena surface has been investigated by means of density functional theory (DFT) and cyclic voltammetric measurements. The calculated results show that differences in the contact site and contact distance between galena and pyrite can affect the intensity of the galvanic interaction, and the relationship between the intensity of galvanic interaction and the adsorption ability of xanthate on galena surface has been studied in detail. In general, the galvanic interaction between pyrite and galena surface can enhance the adsorption of xanthate on the galena surface. The adsorption energies of xanthate on the galena surface decrease with the decrease of contact distance, and when the contact distance is lower than 4 Å, the adsorption energies decrease significantly at Pb-Pb, Pb-S and S-S sites. In particular, at the contact distance of 3 Å, a sharp decrease of adsorption energy is observed at the Pb-Pb contact site; in this case, the negative shift of the Pb-S bonding range and DOS non-locality at Pb-Pb contact site are significantly greater than that of the S-S or Pb-S contact sites. The cyclic voltammetric measurements reveal that the galvanic interaction between galena and pyrite improves the adsorption of xanthate on galena surface, which is in good agreement with the DFT results.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 3; 826-836
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An innovative methodology for recycling iron from magnetic preconcentrate of an iron ore tailing
Autorzy:
Yu, J.
Han, Y.
Gao, P.
Li, Y.
Yuan, S.
Li, W.
Powiązania:
https://bibliotekanauki.pl/articles/110888.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
magnetic preconcentrate
iron ore tailing
iron recycling
fluidized magnetization roasting
magnetic separation
Opis:
Iron ore tailing is a kind of hazardous solid waste produced by iron and steel industry. In order to separate and recycle iron from the magnetic preconcentrate of an iron ore tailing, an innovative technological route of fluidized magnetization roasting followed by low-intensity magnetic separation was proposed in this paper. The effects of roasting temperature, dosages of reducing gas CO and fluidizing gas N2 on recovery rate of iron were carried out and optimized. The results showed that the hematite was almost reduced to magnetite by a gas mixture of 4 m3/h CO and 1 m3/h N2 at roasting temperature of 540 °C. Under the optimized conditions, a magnetic concentrate assaying 61.4 wt% Fe with a recovery rate of 81.8% was obtained from the magnetic preconcentrate of an iron ore tailing. The iron chemical phase, X-ray diffraction (XRD), and optical metallographic microscope analyses revealed that siderite was converted to magnetite successfully after roasting, and some coarse magnetite-hematite interlocking particles were formed due to insufficient reaction time, which could also be recovered by magnetic separation after liberating from gangue minerals.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 3; 668-676
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of calcination temperature on activation behaviors of coal-series kaolin by fluidized bed calcination
Autorzy:
Yuan, S.
Han, Y.
Li, Y.
Gao, P.
Yu, J.
Powiązania:
https://bibliotekanauki.pl/articles/109800.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
coal-series kaolin
fluidized bed calcination
calcination temperature
activation behaviors
Opis:
This paper is aimed at investigating activation behaviors for coal-series kaolin using fluidized bed calcination as a novel method. The properties of calcined products at different temperature by fluidized bed calcination were evaluated by determination of weight loss rate, whiteness, chemical oxygen demand (COD), aluminum dissolution degree. The thermal behaviors and reaction mechanism were characterized by thermo gravimetric-differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), particle size distribution (PSD) and scanning electron microscopy (SEM). The results showed that calcination temperature was essential factor determining the properties and crystallinity of calcined products using fluidized bed calcination. Coal-series kaolin transformed into irregular and amorphous metakaolin with excellent properties as calcined at 600-900 °C, which attributed to the dehydroxylation of kaolinite and combustion of carbon/organic matter. Calcined kaolin eliminated activity ascribed to the recrystallization into mullite when calcination temperature was over 1000 °C. It was believed that fluidized bed calcination was an efficient thermal activation technology for coal-series kaolin and the calcination temperature should be controlled accurately.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 2; 590-600
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flotation behavior of hard-to-separate and high-ash fine coal
Autorzy:
Xing, Y.
Gui, X.
Liu, J.
Cao, Y.
Zhang, Y.
Li, S.
Powiązania:
https://bibliotekanauki.pl/articles/110585.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
flotation behavior
fine coal
Fuerstenau upgrading curve
energy input
selectivity
Opis:
The flotation behavior of hard-to-separate and high-ash fine coal was investigated using conventional flotation with constant power input. A new flotation process, based on energy input and distribution, was designed to lower the ash content of concentrate. The results obtained using Fourier transform infrared (FTIR) analysis show that the coal samples have good floatability because of many hydrophobic and few hydrophilic functional groups. Under a constant power input, a large number of ash-forming materials floated into a froth product at the start of flotation. Based on the Fuerstenau upgrading curves, it was determined that the 0.25-0.074 mm size fraction range showed the worst selectivity when compared with 0.50-0.25 mm and -0.074 mm size fractions. The desired concentrate with an ash content of 13.98%, 27.59% of ash recovery, and 80.01% combustible matter recovery could be obtained by transferring the excess energy of the flotation-conditioning stage to the pre-conditioning stage and increasing the power input step-by-step in the flotation-conditioning stage at equal total energy consumption.
Źródło:
Physicochemical Problems of Mineral Processing; 2016, 52, 2; 703-717
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of intergrown particle liberation on difficult-to-separate coking coal flotation
Autorzy:
Gui, X.
Liu, J.
Cao, Y.
Xing, Y.
Deng, Y.
Li, S.
Powiązania:
https://bibliotekanauki.pl/articles/109875.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
liberation
particle size
coking coal
hydrophobicity
Opis:
Flotation tests with intergrown particle liberation were conducted to explore a separation method of difficult-to-separate coking coal from the Tangshan Kailuan mine in China. The particle size distribution, density and coal petrography were investigated. The difficult-to-separate coking coal sample resulted in intergrown particles, such as non-liberated coal and rocks. Thus, intergrown coal particle liberation and re-separation tests were conducted. The results showed that grinding time had a great effect on the flotation performance. Grinding prompted coal to dissociate and improve the surface hydrophobic properties of minerals. However, heterogeneous fine silt covered the surface of coal particles when coal was ground too long. The inorganic mineral particles were over-ground and reduced the contact angle of coal. The results of coal rock dissociation and laboratory re-separation tests showed that clean coal combustible recovery increased through intergrown particle liberation and re-separation.
Źródło:
Physicochemical Problems of Mineral Processing; 2016, 52, 1; 279-294
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of oxidation on the wetting of coal surfaces by water: experimental and molecular dynamics simulation studies
Autorzy:
Li, E.
Lu, Y.
Cheng, F.
Wang, X.
Miller, J. D.
Powiązania:
https://bibliotekanauki.pl/articles/109792.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
wettability
oxidation
molecular dynamics simulation
hydrogen bonding
contact angles
coal surfaces
Opis:
The wettability of coal surfaces by water continues to be one of the key factors which determines the success of coal flotation. Consequently, oxidation of coal surfaces is a fundamental issue of interest. In this work, the effect of oxidation on the wetting of coal surfaces and the interaction between water molecules and oxygen-containing sites at the coal surface was investigated based on advancing/receding contact angle measurements and molecular dynamics simulations. For the simulation studies, a flat coal surface was constructed with the assistance of the molecular repulsion between graphite surfaces and the assembly of Wiser coal molecules. Our results indicated that the simulated advancing and receding contact angles were very similar, and both of them decreased, as expected, with an increase of hydroxyl sites at the coal surface. The good agreement between the simulated advancing/receding contact angles and the experimental receding contact angle values suggested that the configuration of the systems and the set of parameters for the simulation were appropriate. The spreading of water is mainly due to the hydrogen bonds formed between the interfacial water molecules and the hydroxyl sites at the coal surface. The hydroxyl groups show stronger hydration capacity than other oxygen-containing groups according to the calculated hydrogen bonds and interaction energies.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 4; 1039-1051
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flotation of long flame coal pretreated by polyoxyethylene sorbitan monostearate
Autorzy:
Ni, C.
Xie, G.
Li, Z.
Bu, X.
Peng, Y.
Sha, J.
Powiązania:
https://bibliotekanauki.pl/articles/110299.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
flotation
hydrophobicity
low rank coal
Tween 60
pretreatment
Opis:
In this investigation, polyoxyethylene sorbitan monostearate (Tween 60) was used to improve flotation of fine long flame coal. The flotation recovery of long flame coal could be increased when long flame coal was either pretreated or conditioned with Tween 60 in a flotation cell for a period before the addition of collector. Fourier Transform Infrared (FTIR) technique was used to indicate surface properties of long flame coal. The results of FTIR show that there are many oxygen functional groups on the sur-face. Contact angle measurements were used to indicate changes in hydrophobicity of coal surface before and after Tween 60 and/or diesel pretreatments. The results of contact angle measurements show that hydrophobicity of coal can be increased by Tween 60. Tween 60 can also enhance adsorption of diesel on the coal surface, and hence floatability of long flame coal can be further improved. Tween 60 primarily enhances the flotation recovery of low density coal fractions (<1.5 and 1.5-1.8 kg/dm3). However, the increase in flotatation recovery is less significant with an excessive addition of Tween 60.
Źródło:
Physicochemical Problems of Mineral Processing; 2016, 52, 1; 317-327
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of sodium petroleum sulfonates with different molecular weights for flotation of kyanite ore
Autorzy:
Chen, B. Z.
Gao, H.
Li, Y.
Jin, J.
Ren, Z.
Wang, W.
Powiązania:
https://bibliotekanauki.pl/articles/109492.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
evaluation
sodium petroleum sulfonate
kyanite
flotation kinetics
entrainment
Opis:
The flotation performance of sodium petroleum sulfonates with different molecular weights was evaluated for flotation of a kyanite ore, by investigating valuable mineral recovery-grade, flotation kinetics and gangue entrainment. The results indicated that the higher molecular weight of agent, the higher final cumulative kyanite recovery was, with the maximum value of 72% being obtained with KY-3 with the molecular weight of 438. The final cumulative kyanite grade initially increased, and then decreased with the molecular weight increasing. In other words, the maximum final cumulative kyanite grade (i.e. 89.05%) was obtained with KY-2 with the molecular weight of 392. The kyanite flotation kinetics followed the first order kinetics well, while the modified flotation rate constant showed a decreasing trend after the initial increase as the molecular weight increased. In addition, the overall entrainment degree decreased with decreasing molecular weight of sodium petroleum sulfonates. The use of KY-2 in kyanite flotation was an attractive option in comparison with KY-1 and KY-3.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 2; 956-968
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of float-sink and progressive release flotation of ground products of coal middlings
Autorzy:
Xie, W.
He, Y.
Luo, C.
Zhang, X.
Li, H.
Yu, J.
Wang, H.
Shi, F.
Powiązania:
https://bibliotekanauki.pl/articles/109500.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
coal middlings
float-sink
progressive release flotation
XPS
EDX
Opis:
An additional recovery of coking coal middlings can be utilized for increasing of the concentrate yield of coking coal. A combined flow sheet of comminution and flotation can realize this target. To investigate the effect of grinding process on further flotation of ground products, progressive release flotation tests were used to compare with the float-sink tests, which were regarded as a criterion. Coal middlings were ground by wet-milling with iron balls to <0.5 mm. Curves of ash vs. cumulative yields of sized products indicated that the concentrate yield of coal separated by progressive release flotation was lower than that of coal benefited by the float-sink test, with the same ash for four size fractions (0.5-0.25 mm, 0.25-0.125 mm, 0.125-0.074 mm and <0.074 mm). Distributions of elements conducted by energy disperse spectroscopy (EDX) showed that associated kaolinite was liberated and exposed on the surface. It led to the shift of local surface property from hydrophobicity to hydrophilicity. Meanwhile, analyses of chemical property performed by an X-Ray photoelectron spectrometer (XPS) depicted that the hydrophilic mineral FeOOH, which generated in the grinding process, was adsorbed on the coal surface. Flotation of the ground products were worsened due to the increase of hydrophilicity of the coal surface.
Źródło:
Physicochemical Problems of Mineral Processing; 2015, 51, 2; 675-684
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-9 z 9

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies