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Wyszukujesz frazę "Liu, Dianwen" wg kryterium: Autor


Wyświetlanie 1-8 z 8
Tytuł:
Adsorption of lead ion on the hydrated rutile (110) surface: a DFT calculation study
Autorzy:
Zou, Heng
Cao, Qinbo
Chen, Xiumin
Liu, Dianwen
Powiązania:
https://bibliotekanauki.pl/articles/109829.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
rutile
hydrated surface
lead ion
adsorption
density functional theory
Opis:
The adsorption behavior of lead species on the hydrated rutile surface was investigated with inductively coupled plasma mass spectrometry (ICP-MS) measurements and density functional theory (DFT) calculations. ICP-MS experiments suggested that lead species can be readily absorbed by the rutile powder in water at pH 6.5. From the ICP-MS results and the species distribution of Pb2+, it was concluded that Pb2+ was the major lead species adsorbing at the rutile/water interface at the pH of 6.5. DFT calculation results indicated that Pb2+ could adsorb at four different sites on the surface. At each site, water molecules or OH groups were involved in the reaction with Pb2+. The water molecules/OH groups on the rutile surface play an important role during the adsorption of Pb2+ on the hydrated rutile surface.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 4; 951-959
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influences of process water chemistry on reverse flotation selectivity of iron oxides
Autorzy:
Tang, Min
Wang, Dong
Wu, Yan
Liu, Dianwen
Powiązania:
https://bibliotekanauki.pl/articles/2175429.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
water chemistry
ion distribution
iron oxides
reverse flotation
Opis:
It is critical for water quality in flotation as it dramatically influences the chemical/electrochemical properties of mineral surfaces and their interactions with reagents. Many potential variations could alter the water chemistry: water recirculation, mineral dissolutions, reagent additions, etc. This study aimed to identify the key elements from the recycled water sources affecting the separation efficiency in a typical industrial flotation circuit of iron oxides through a series of bench/micro flotation tests, zeta potential measurement, etc. The built-up and distribution of the dominant cations/anions in the process water from the roughers in the flotation system was also analyzed and recorded by Inductively Coupled Plasma-Optical Emission (ICP-OES) for a period of about three months when the operations were stable. The flotation results pointed out that a concentrate with a sharp increase of 6.0% Fe recovery and 2.5% SiO2 content was obtained by using the recycled tailing water only in comparison by using fresh water. In contrast, a slight uptrend in the grade of Fe but a substantial loss of near 6.5% Fe recovery occurs by using the treated sewage water alone instead. This could attribute to the ion distributions in these water sources, in which Ca2+, Fen+, Mg2+ or SO42ions were determined as the key ions influencing the flotation behaviors of the iron ore. But the competitive effects of Fe3+ ions were more significant than the ones of Ca2+ or Mg2+ ions. And the occurrence of starch could deteriorate the dilution of silicates in concentration induced by Fe3+/Fe2+ ions. It can be explained by zeta potential measurement or solution chemistry of those ions, indicating that at 8.5-9.0, the coating of the precipitates of Fe(OH)3(s) induced by iron ions alters a reverse on the zeta potentials of quartz. The presence of SO42-ions, however, has a positive role in reducing the possibility of slime coating on silicates due to acting as a chelating agent of iron ions.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 6; art. no. 151839
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Binding features of N-hexadecanoylglycine on two terminations of fluorapatite (001) surface and their effect on fluorapatite flotation
Autorzy:
Zou, Heng
Liu, Dianwen
Cao, Qinbo
Chen, Xiumin
Powiązania:
https://bibliotekanauki.pl/articles/1845208.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
fluorapatite
adsorption
amino acid-based collector
density functional theory
Opis:
N-hexadecanoylglycine (C16Gly) is a newly synthesized collector, which can be used as an efficient collector for fluorapatite (FA) rather than for dolomite. To extend our knowledge regarding the C16Gly collector, the contact angle method was employed to understand the flotation selectivity of C16Gly in the FA and dolomite system. On the other hand, the possible binding models of C16Gly anion on Ca-rich and PO4-rich terminations of FA (001) surface were investigated with density functional theory calculations to reveal the interaction between the C16Gly and the FA surface. Results showed that C16Gly anion could interact with these two terminations to generate 12 low-energy configurations, including bidentate, tridentate and chelating binding models. The C16Gly anion preferred to adsorb onto the Ca-rich termination, which is caused by the weaker electrostatic repulsion force between the C16Gly anion and the PO4 groups on this termination. The adsorption of C16Gly on these terminations was more stable than that on the dolomite (104) surface, which is one of the reasons for the preferential flotation of FA from dolomite using C16Gly as a collector. These findings provide further insights into the selectivity of C16Gly during the flotation of FA and dolomite.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 5; 949-959
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New insights into pyrite-hydrogen peroxide interactions during froth flotation: experimental and DFT study
Autorzy:
Cao, Qinbo
Yan, Wenchao
Wen, Shuming
Liu, Dianwen
Li, Yanjun
Powiązania:
https://bibliotekanauki.pl/articles/2200334.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
hydrogen peroxide
oxidization
pyrite flotation
adsorption models
DFT
Opis:
Hydrogen peroxide (H2O2) is an efficient depressant for pyrite (FeS2) flotation. However, the depressing mechanism of H2O2 is not fully understood. In this paper, the depressing capacity of H2O2 for pyrite was examined by flotation tests. Results revealed that pyrite flotation could be inhibited by H2O2 at pH 6.4. The pyrite powder in H2O2 solution enhanced the release of O2 from H2O2. However, the O2 concentration in the solution was less than that of H2O2; thus, H2O2 is the major oxidant in the solution. Moreover, density functional theory calculations were performed to study the interactions between H2O2 and hydrated pyrite (100) surface. The H2O2 molecule tended to react with the pyrite surface to generate one S=O bond and an H2O molecule. The possible binding models of O2 molecules on the pyrite (100) surface were also studied for comparison. The O2 dissociation on the pyrite surface was more favorable than the adsorption of O2 as a whole. In addition, the orbital interaction in the S=O bond raised from the reaction of H2O2/O2 with the pyrite surface was also investigated by the density states analysis. These results provide some insights into the oxidizing effect of H2O2 in pyrite flotation.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 1; art. no. 157409
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of preoxidation on copper flotation from copper-lead mixed concentrate
Autorzy:
Peng, Zeng
Haiyun, Xie
Yanling, Jin
Pei, Zhang
Jialing, Chen
Liu, Dianwen
Powiązania:
https://bibliotekanauki.pl/articles/24085956.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
copper-lead mixed concentrate
peroxidation
separation of copper and lead
response surface methodology
Opis:
Flotation separation of galena and chalcopyrite is always a difficult problem in mineral processing. In this paper, the selective preoxidation of galena and chalcopyrite with sulfuric acid was developed, and then the two minerals were completely separated by flotation. The surface oxidation mechanism of galena and chalcopyrite with sulfuric acid was analyzed by Fourier transform infrared spectroscopy (FT-IR) and Atomic Force Microscopy (AFM), and the results showed that hydrophilic oxide film was formed on the galena surface, while the surface of chalcopyrite is still hydrophobic sulfide film, which led to the separation of the two minerals by flotation. In addition, the Response Surface Methodology (RSM) was used to analyze the influence of main preoxidation parameters on the flotation separation of copper-lead concentrate, and the parameters were further optimized, as follows: sulfuric acid concentration of 5.3 mol/L, oxidation temperature of 101.8 °C and time of 48.3 min. The mixed concentrate containing Cu 11.57% and Pb 16.75% was preoxidized under the above conditions, and the flotation separation verification results showed that Cu concentrate with Cu grade of 18.09% and recovery of 95.41%, and Pb concentrate with Pb grade of 44.96% and recovery of 95.94% was obtained respectively. This paper provides a new method of preoxidation combined flotation to achieve high-efficiency separation of copper-lead mixed concentrate.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 2; art. no. 163253
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dissolution kinetics of malachite in ethylene diamine phosphate solutions
Autorzy:
Shen, Peilun
Liu, Ruizeng
Liu, Dianwen
Zhan, Xiaolin
Jia, Xiaodong
Song, Kaiwei
Powiązania:
https://bibliotekanauki.pl/articles/110214.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
malachite
organic amine
ethylene diamine phosphate
dissolution
kinetic
Opis:
Ethylene diamine phosphate (EDP), as a synthetic organic reagent, was used for the first time to leach malachite, and a new method of using organic amine to leach copper oxide ore was developed. The effects of stirring speed, particle size, reagent concentration, and reaction temperature on EDP-dissolution malachite were investigated. Results showed that malachite rapidly dissolved in EDP solution. The malachite-dissolving rate also increased with increased reagent concentration, increased reaction temperature, and decreased particle size. Stirring speed exhibited nearly no effect on EDP-induced malachite dissolution. The leaching kinetics was found to follow the shrinking-core model, and dissolution was controlled by surface chemical reaction with an activation energy of 52.63kJ×mol−1. A semiempirical rate equation was obtained to describe the dissolution process expressed as 1-(1-XCu)1/3=0.0149(CEDP)0.7814 × (Pmalachite)−0.7982×exp(−6.3308/T) ×t.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 4; 1039-1048
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Classification techniques and parameter optimization of Cyclone Continuous Centrifugal Separator for hematite ore
Autorzy:
Zhang, Pei
Xie, Haiyun
Jin, Yanling
Chen, Jialing
Zeng, Peng
Li, Yuanhong
Chen, Luzheng
Liu, Dianwen
Powiązania:
https://bibliotekanauki.pl/articles/2200335.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
hematite
Cyclonic Continuous Centrifugal Separator
CCCS
classification
Response Surface Methodology
Opis:
The Cyclonic Continuous Centrifugal Separator (CCCS) is a new type of separation equipment developed based on cyclonic continuous centrifugal separation technology and combined with the separation principle of the fluidized bed. Taking hematite as the research object, the main parameters and conditions of the best hematite classification were determined through the classification test by using CCCS. Based on the classification test, the significance order of each process parameter and their interaction with hematite classification efficiency of the underflow products was analyzed with the Response Surface Methodology, the optimal process parameter of hematite classification was obtained and a multiple regression equation was established. The optimized process conditions were as follows, feeding pressure 55.48 kPa, backwash pressure 9.79 kPa, and underflow pressure 31.94 kPa. Under these conditions, the average hematite ore classification efficiency of coarse fraction (-2~+0.15mm), medium fraction (-0.15~+0.074mm) and fine fraction (-0.074mm) were 85.08%, 65.10% and 51.41%, respectively, and the relative errors with the predicted values were 1.6%, 4.0% and 2.5%, respectively. The results showed that the analytical model has good predictive performance. This research provides a certain prospect for the application of Cyclonic Continuous Centrifugal Separation to hematite ore classification. it provides a reference for the application of the Response Surface Methodology in the classification of hematite by Cyclonic Continuous Centrifugal Separation.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 1; art. no. 158864
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Role of ammonium phosphate in improving the physical characteristics of malachite sulfidation flotation
Autorzy:
Ibrahim, Ayman M.
Jia, Xiaodong
Cai, Jinpeng
Su, Chao
Yu, Xingcai
Zheng, Qifang
Peng, Rong
Shen, Peilun
Liu, Dianwen
Powiązania:
https://bibliotekanauki.pl/articles/2200339.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
malachite sulfidation
sample preparation
ammonium phosphate
sodium sulfide
floatability
physical characteristics
Opis:
In this study, ammonium phosphate ((NH4)3PO4) was employed to realize improvement by modifying the physical characteristics of the malachite surface, ensuring sustainable flotation throughout the flotation operations, and enhancing the flotation process to be more stable. Furthermore, various techniques, including X-ray photoelectron spectroscopy, were intensely used to investigate the configuration and physico-chemical surface characteristics through micro-flotation experiments, contact angle and zeta potential measurements, and XRD, ToF-SIMS, EPMA, and FTIR spectrum analyses. The FTIR findings showed that new characteristic peaks of -C(=S)-N.H. groups formed and adsorbed on the surfaces of malachite at 1636 cm-1. The -CH2 groups throughout the flotation process, further promoted the attachment of the CH3 ligand to the Cu2+ ion, and the XPS analysis confirmed this. Consequently, it can be concluded that (NH4)3PO4 played a substantial part in the improved recovery rate, as demonstrated and confirmed by the methods carried out in this study. Thus, it was used to modify the physical properties surface before adding Na2S to efficiently enhance malachite floatability and reduce the loss rate of malachite. Regarding the alterations in the physical characteristics which occurred to the malachite surface, and as a consequence of increasing the recovery results of flotation, the malachite sample treated initially with (NH4)3PO4 exhibited micro flotation results with a considerably greater flotation recovery than malachite treated initially with only Na2S ions.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 1; art. no. 161510
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-8 z 8

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