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Wyszukujesz frazę "flotation mechanism" wg kryterium: Temat

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    Wyświetlanie 1-8 z 8
    Tytuł:
    New insights into the promotion mechanism of $(NH_4)_2SO_4$ in sulfidization flotation: a combined experimental and computational study
    Autorzy:
    Chen, Daixiong
    Liu, Mengfei
    Hu, Bo
    Dong, Yanhong
    Xue, Wei
    He, Peng
    Chen, Fang
    Zhu, Jianyu
    Zhang, Chenyang
    Powiązania:
    https://bibliotekanauki.pl/articles/1446762.pdf
    Data publikacji:
    2021
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    malachite
    promotion
    sulfidization
    flotation
    mechanism
    Opis:
    Ammonium sulfate ((NH4)2SO4) exhibits promoting effects in malachite sulfidization flotation. However, the promotion mechanism remains poorly understood. In this study, micro-flotation tests, zeta-potential measurements, scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM-EDS), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and materials studio simulation (DFT) were used to investigated the promotion mechanism of $(NH_4)_2SO_4$. Micro-flotation test demonstrates that the recovery of malachite from 73% increased to 83%, when the (NH4)2SO4 was added. Contact angle and zeta potential test results indicate that addition of $Na_2S•9H_2O$ changes the surface properties of malachite and provide the conditions for adsorption of butyl xanthate (BX). After promoting the sulfidization by $(NH_4)_2SO_4$, BX is more effective in improving the hydrophobicity. SEM-EDS and AFM results show that $(NH_4)_2SO_4$ can improve performance and stability of sulfidization. X-ray photoelectron spectroscopy indicates that after sulfidization, polysulfides and cuprous were appeared in malachite surface, infers that a redox reaction occurs between sulfur and copper on the surface of malachite. After addition of $(NH_4)_2SO_4$, the percentage of polysulfides and cuprous were increased, it implies $(NH_4)_2SO_4$ can accelerate the redox reaction. Computational results show that after adding $(NH_4)_2SO_4$, the adsorption energy of HS- on the malachite surface is reduced, implies that $(NH_4)_2SO_4$ can improve the stability of HS-adsorption on the surface of malachite.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2021, 57, 5; 57-70
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Study of flotation behavior and mechanism of cervantite activation by copper ions
    Autorzy:
    Wang, J.
    Wang, Y.
    Fu, K.
    Xu, L.
    Wang, Z.
    Sun, H.
    Xiao, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/110228.pdf
    Data publikacji:
    2018
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    flotation
    cervantite
    copper ions
    activation mechanism
    Opis:
    Copper-ion activation plays a highly important role in cervantite (Sb2O4) flotation. Without metal-ion activation, cervantite cannot be floated by sodium oleate. In this study, flotation tests were conducted to study the effect of Cu2+ on the flotation behaviours of cervantite and quartz (SiO2) as the main gangue mineral. Metal-ion adsorption capacities, zeta potentials, solution chemistry and X-ray photoelectron spectra were analyzed to study the adsorption behavior and mechanism of copper ions and sodium oleate interaction with the minerals surfaces. The results demonstrate that under weakly acidic conditions, cervantite can be flotated and separated from quartz by the addition of copper ions. The reason is that copper ions can be selectively adsorbed on the cervantite surface under weakly acidic conditions, thereby promoting the adsorption of sodium oleate onto the cervantite surface by chemical adsorption. Conversely, copper ions are weakly adsorbed on quartz surfaces below pH 6.1, and sodium oleate cannot be adsorbed on quartz surfaces by chemical adsorption. The hydroxy copper species are integral to the selective activation of cervantite over quartz.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2018, 54, 3; 814-825
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Dispersive effect of low molecular weight sodium polyacrylate on pyrite-serpentine flotation system
    Autorzy:
    Zhao, K.
    Yan, W.
    Wang, X.
    Gu, G.
    Deng, J.
    Zhou, X.
    Hui, B.
    Powiązania:
    https://bibliotekanauki.pl/articles/110158.pdf
    Data publikacji:
    2017
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    dispersant
    serpentine
    flotation
    surface potential
    dispersion mechanism
    Opis:
    In this work, the dispersive effect of low molecular weight sodium polyacrylate (PAAS) on serpentine, and its dispersion mechanism were systematically investigated through zeta potential measurements, micro and batch flotation as well as adsorption tests. At pH 5, where flotation of iron sulphide was routinely performed, pyrite and serpentine minerals were oppositely charged, and therefore they were attracted to each other. Slime coatings of serpentine adhered to the surface of pyrite, decreasing the adsorption density of a collector on the pyrite surface, but also reducing the flotation recovery. PAAS increased the flotation recovery of pyrite by promoting dispersion between pyrite and serpentine. The effective flotation separation of pyrite from the refractory iron sulphide ore was possible by using PAAS as a dispersant. Anionic PAAS adjusted the surface potential of serpentine through adsorption on the serpentine surface and changed the interaction between pyrite and serpentine particles from attractive to repulsive, and then dispersed pyrite and serpentine.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2017, 53, 2; 1200-1213
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Influencing mechanisms of sodium hexametaphosphate on molybdenite flotation using sea water
    Autorzy:
    Wang, Lizhangzheng
    Li, Yubiao
    Fan, Ruihua
    Fan, Rong
    Powiązania:
    https://bibliotekanauki.pl/articles/109351.pdf
    Data publikacji:
    2019
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    sodium hexametaphosphate
    flotation
    molybdenite
    sea water
    mechanism
    Opis:
    Flotation using sea water has been considered as a promising alternative to concentrate molybdenite (MoS2) under alkaline conditions due to scarcity of fresh water and increasingly strict regulations on the quality of discharged water. However, the MoS2 recovery with sea water during flotation has not been satisfactory, owing to the depressing effects from the hydrophilic metallic species onto MoS2 surface. This study combines experimental and theoretical studies of MoS2 flotation to investigate how the physicochemical properties of MoS2 vary with the addition of a dispersant, sodium hexametaphosphate (SHMP), and in sea and fresh water. Our experimental results show that the addition of SHMP during flotation has increased the recovery of MoS2, via reducing the adsorption of the hydrophilic metallic precipitation onto MoS2 surface. The DLVO calculation confirms that the addition of SHMP increases the floatability of MoS2 by dispersing the formed hydrophilic metallic precipitation (Mg(OH)2 colloids) from the MoS2 surface, via reversing attraction force to repulsion force, thereby improving MoS2 flotation recovery.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2019, 55, 5; 1091-1098
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Activation of quartz flotation by Cu2+, Ni2+ in the sodium ethylxanthogenate (EX) system
    Autorzy:
    Liu, Yang
    Tong, Xiong
    Xie, Rui-Qi
    Xie, Xian
    Song, Qiang
    Fan, Pei-Qiang
    Powiązania:
    https://bibliotekanauki.pl/articles/24085981.pdf
    Data publikacji:
    2023
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    quartz
    flotation
    ions activation
    sodium ethylxanthogenate
    adsorption mechanism
    Opis:
    During the flotation of metal sulfide minerals, due to the interference of unavoidable ions, the quartz also partially floats in some cases. The studies on the mechanism of quartz being activated and floating up are still insufficient. In this study, the influence of the Cu2+ and Ni2+ unavoidable ions on the floatation of quartz was studied by micro-flotation experiments, adsorption detection, zeta potential measurement, solution composition calculation, infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) analyses, and atomic force microscopy (AFM) observation. This provides a theoretical reference for further understanding the mechanism of sodium ethylxanthogenate and quartz surface, as well as the development of a new quartz depressant. The results of flotation showed that after activation by Cu2+ (1×10-4 mol/dm3) and Ni2+ (5×10-5 mol/dm3), the quartz was captured by sodium ethylxanthogenate (EX: 1.4×10-4 mol/dm3) under alkaline conditions (pH=10), while the best recoveries were obtained as 80% and 43%, respectively. The results of adsorption and zeta potential measurements showed that the precipitation rate of Cu2+ was greater than that of Ni2+ under alkaline conditions. Additionally, both Cu2+ and Ni2+ electrostatically adsorbed on the quartz surface and changed the zeta potential of quartz. The solution composition calculation further showed that Cu(OH)+, Cu(OH)2(s), and Ni(OH)+, Ni(OH)2(s) were the main components in the solution under alkaline conditions. The FT-IR and XPS analyses and AFM observations demonstrated that Cu and Ni species adsorbed on O atoms on the quartz surface, providing active sites for EX adsorption, and EX combines with Cu and Ni species on the quartz surface to generate -O-Cu-EX and -O-Ni-EX complexes. Finally, the quartz floated up due to the formation of hydrophobic products and firm adsorption.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2023, 59, 2; art. no. 166368
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effect of N-carboxybutyl chitosan on the flotation separation of apatite from dolomite
    Autorzy:
    Rao, Yubei
    Liu, Shanhui
    Gao, Jiewang
    Zhao, Yu
    Saffari, Pooya
    Kang, Shuo
    Liu, Zuwen
    Powiązania:
    https://bibliotekanauki.pl/articles/1446183.pdf
    Data publikacji:
    2021
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    apatite
    dolomite
    flotation
    N-carboxybutyl chitosan (CBC)
    mechanism analysis
    Opis:
    With high-grade apatite resources exhausted and economic development, enhancing the apatite quality from calcium gangue such as dolomite has a great significance for production. However, it is difficult to separate apatite from dolomite effectively due to the similar surface properties. In this study, the N-carboxybutyl chitosan ($CBC$) was tested as a potential selective depressant to separate apatite from dolomite in the sodium oleate ($NaOL$). Flotation results of single mineral and artificially mixed mineral confirmed the selective depression effect of CBC. The depression mechanism of $CBC$ was investigated using wettability analysis, Fourier Transform Infrared ($FTIR$), and X-ray Photoelectron Spectroscopy ($XPS$) analyses. The results indicated that the $CBC$ adsorption quantity and intensity on the dolomite surface more than that on the apatite surface, which was due to $CBC$ absorbed on apatite surface by hydrogen bonding, while absorbed on dolomite surface mainly through chemical chelating between $Ca$ on the mineral surface and -COO- on the depressant. These adsorption differences led to the flotation separation of the two minerals.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2021, 57, 4; 27-35
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Enhancing low-rank coal flotation using a mixture of dodecane and n-valeraldehyde as a collector
    Autorzy:
    Liu, Zechen
    Liao, Yinfei
    An, Maoyan
    Lai, Qingteng
    Ma, Longfei
    Qiu, Yuliang
    Powiązania:
    https://bibliotekanauki.pl/articles/109432.pdf
    Data publikacji:
    2019
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    mixed collector
    oxygen-containing functional groups
    adsorption mechanism
    low rank coal
    flotation
    Opis:
    Low-rank coals are difficult to float using common hydrocarbon oily collectors, such as dodecane and diesel. In this investigation, a mixture of dodecane and n-valeraldehyde was used as a collector to enhance low-rank coal flotation. The changes of the contact angle and surface functional groups of low-rank coal were measured before and after different collectors’ adsorption to indicate its absorption mechanism. Surface tension of different collectors was also measured to identify its spreading performance. The results showed that the flotation performance using the mixture as a collector was much better than that using dodecane or n-valeraldehyde solely. When used the mixture of dodecane and n-valeraldehyde as collector, dodecane primarily covers the hydrophobic sites while n-valeraldehyde primarily covered the hydrophilic sites by hydrogen bond promoting adsorption of dodecane at these sites. There existed synergistic effect between dodecane and n-valeraldehyde. Additionally, n-valeraldehyde can reduce the surface tensions to improve the spreading performance of mixed collector on low-rank coal surface. The improvement both in adsorption and spreading was responsible for the enhancement of low-rank coal flotation by using the mixture.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2019, 55, 1; 49-57
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Aglomeracja olejowa skały magnezytowej z udziałem mieszaniny jonowych surfaktantów
    The oil agglomeration of magnesite rock with participation of ionic surfactants mixtures
    Autorzy:
    Bastrzyk, A.
    Polowczyk, I.
    Sadowski, Z.
    Powiązania:
    https://bibliotekanauki.pl/articles/1819093.pdf
    Data publikacji:
    2013
    Wydawca:
    Politechnika Koszalińska. Wydawnictwo Uczelniane
    Tematy:
    aglomeracja olejowa
    mieszaniny jonowe
    fines cleaning wastes
    coal recovery
    adsorption
    dolomite
    calcite
    oleate
    suspensions
    flotation
    mechanism
    tension
    Opis:
    In this study, the adsorption of surfactant onto the magensite rock and the oil agglomeration of this mineral in aqueous suspension were investigated. The various concentration ratios of cationic and anionic surfactant were used. The results were evaluated by the recovery of carbonates in agglomerates. It was found that the process selectivity was highly dependent on the surfactants concentration ratio, pH, and the amount of salt added. The best separation of quartz from magnesite rock was observed at pH 9. The addition of larger quantity of sodium oleate (15.2 mg/gsolid) led to the increase of carbonates content in agglomerates up to 32.4%. However, the largest carbonates recovery was in the presence of 6.0 mg/gsolid of NaOl.
    Źródło:
    Rocznik Ochrona Środowiska; 2013, Tom 15, cz. 2; 1441-1459
    1506-218X
    Pojawia się w:
    Rocznik Ochrona Środowiska
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-8 z 8

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