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Wyszukujesz frazę "Wu, Dandan" wg kryterium: Autor


Wyświetlanie 1-5 z 5
Tytuł:
DFT and TOF-SIMS study of the interaction between hydrogen sulfide ion and malachite (–201) surface
Autorzy:
Mao, Yingbo
Wu, Dandan
Huang, Lingyun
Powiązania:
https://bibliotekanauki.pl/articles/1447053.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
malachite
hydrogen sulfide ions
sulfidation
DFT
TOF-SIMS
Opis:
In this paper, the mechanism of interaction between hydrogen sulfide ions and malachite was investigated using density functional theory (DFT) calculations and time of flight secondary ion mass spectrometry (TOF-SIMS). The DFT calculations showed that HS− adsorption on the malachite (−201) surface was stronger than that of S adsorption resulting from the higher number of electron transfers in the solution which accelerated the sulfidation reaction rate. Density of states (DOS) analysis showed that the near Fermi level was jointly contributed to by the Cu 3d, O 2p, O 2S, and S 3P orbits after adsorption of HS− on the malachite (–201)surface. It was found that the 2p orbital of O and the 3p orbital of S overlapped, indicating that S not only reacted with Cu, but also with O. The TOF-SIMS detected S− and CuS2− fragment ion peaks in the 0−150 m/z negative segment of mass spectra. TOF-SIMS also showed that copper sulfide films of certain thicknesses were formed, demonstrating the effectiveness of hydrogen sulfide sulfidation in flotation processes.
Źródło:
Physicochemical Problems of Mineral Processing; 2021, 57, 5; 71-79
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Enhanced sulfidation of chrysocolla with ammonium carbamate and its effect on flotation
Autorzy:
Wang, Ziang
Wu, Dandan
Cao, Jing
Chen, Huiqin
Powiązania:
https://bibliotekanauki.pl/articles/24085837.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
chrysocolla
ammonium carbamate
surface modification
sulfidation
Opis:
In this study, flotation experiments, zeta potential, XPS, AFM, SEM-EDS, and contact angle measurements were performed to study the influence of ammonium carbamate (CH6N2O2) on the sulfidation flotation of chrysocolla. The results of the sulfidation flotation experiments showed that the recovery of chrysocolla increased more than 40% on the optimal condition after adding ammonium carbamate. In addition, the zeta potential of samples with ammonium carbamate was clearly higher than ores for pH > 6, which was due to the complexation reaction between ammonium carbamate and copper ion on the surface of chrysocolla samples. The activity of copper adsorption has also been improved. Furthermore, the XPS data indicated that the content of Cu-S compounds on the mineral surface has been significantly enhanced after ammonium carbamate complex sulfidation. The chemical analysis of the solution led to the same conclusion. The AFM results showed that ammonium carbamate had a positive impact on the adsorption of minerals surface, and increased the flotation recovery. It can be deduced from the SEM-EDS analysis that the surface of chrysocolla better combined with S–, and more Cu-S components were generated on the surface, which led to 1.04% increase of S atomic concentration. Finally, the contact angle measurements showed that the water contact angle of chrysocolla after adding ammonium carbamate could reach 90.4°, which proved that the sulfidation improved the floatability of the chrysocolla sample.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 3; atr. no. 168573
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dissolution kinetics of hemimorphite in methane sulfonic acid
Autorzy:
Zhang, Qian
Wen, Shuming
Feng, Qicheng
Nie, Wenlin
Wu, Dandan
Powiązania:
https://bibliotekanauki.pl/articles/110482.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
hemimorphite
methane sulfonic acid
dissolution
kinetics
Opis:
Hemimorphite has a large content of zinc, but its recovery using flotation alone is low. Nowadays, hydrometallurgical and pyrometallurgical methods are used to treat zinc ores. In this work, the leaching and dissolution kinetics of hemimorphite by using methane sulfonic acid (MSA) as an alternative leaching reagent was investigated. The effects of several experimental parameters including reaction temperature, MSA concentration, particle size, and stirring speed were also analyzed. Results showed that zinc leaching increased with increased reaction temperature, MSA concentration, and stirring speed, as well as decreased particle size. The mechanism of hemimorphite dissolution in MSA solutions may be a new variant of the shrinking-core model. Based on experimental data and kinetics, the apparent activation energy was determined to be 49.50 kJ/mol. The rate of reaction equation was also obtained to describe the process and found that the MSA concentration largely influenced the leaching of hemimorphite.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 1; 1-9
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis of a novel hydroxamic acid flotation collector and its flotation separation of malachite against quartz
Autorzy:
Sun, Xin
Huang, Lingyun
Wu, Dandan
Hu, Bo
Zhang, Mei
Li, Yaming
Tong, Xiong
Powiązania:
https://bibliotekanauki.pl/articles/2146909.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
flotation
collector
malachite
hydroxamic acid
direct flotation
adsorption
Opis:
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.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 4; art. no. 149427
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new scheme of the environmental classification standards for the bronze cultural relic’s preservation in museums
Autorzy:
Li, Dandan
Zhou, Hao
Xu, Fangyuan
Yan, Ying
Wu, Laiming
Cai, Lankun
Powiązania:
https://bibliotekanauki.pl/articles/28407393.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
QCM
temperature
humidity
indoor exposure
cultural relics
mikrowaga kwarcowa
temperatura
wilgotność
ekspozyja w pomieszczeniach
zabytki kultury
Opis:
The environmental risk classification of the metal relics is usually determined by the corrosion rate of the metal but it is difficult to monitor the deterioration of the metal relics directly. A strong relationship exists between indoor exposure, the air quality classification of atmospheric corrosion, and the actual deterioration of metal relics. The copper-silver hanging plate method requires a long period of environmental exposure and has certain hysteresis, thus reflecting the current environmental quality of the museum in real time poses some difficulties. However, the application of the environmental reactivity monitor (ERMs) based on the piezoelectric effect can solve the above problems. The invented quartz crystal microbalance (QCM) reactivity monitoring device is applied to study the influence of temperature and humidity on the corrosion of the bronze-simulated materials and the relationship between the corrosion depth rate of the bronze-simulated materials and the frequency change of the crystal oscillator. Then, the recommended classification range of temperature and humidity and the airquality classification standards for the preservation environment of the bronze cultural relics in museums are proposed.
Źródło:
Environment Protection Engineering; 2023, 49, 4; 45--59
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-5 z 5

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