Effect of oxidation processing on the surface properties and floatability of Meizhiyou long-flame coal

Chen, Songjiang; Tang, Longfei; Tao, Xiuxiang; Chen, Liang; Yang, Zhao; Li, Lulu

doi:10.1016/j.fuel.2017.08.053

Cited by 51 publications

(25 citation statements)

References 27 publications

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“…It can be seen from Figure 8 and Table 4 that the C-bonding energy of the raw lignite and modified lignite samples was mainly in the range of 282-290 eV. Both the lignite and the modified lignite were divided into three peaks under the best fitting state at almost the same position, which can be considered as the same species, and the peaks were aromatic hydrocarbon or aromatic-substituted alkane at 284.7 eV, the carbon-oxygen single bond at 286.3 eV, and the carbon-oxygen double bond at 288.4 eV [16,17].…”

Section: Distribution Of Oxygen Chemical Functional Groups Of Lignitementioning

confidence: 99%

Effect of Nitric Acid Modification on Characteristics and Adsorption Properties of Lignite

et al. 2019

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The objective of this research was to explore the changes of the pore structure and surface properties of nitric-modified lignite and base the adsorption performance on physical and chemical adsorbent characteristics. To systematically evaluate pore structure and surface chemistry effects, several lignite samples were treated with different concentrations of nitric acid in order to get different pore structure and surface chemistry adsorbent levels. A common heavy metal ion contaminant in water, Pb2+, served as an adsorbate probe to demonstrate the change of modified lignite adsorption properties. The pore structure and surface properties of lignite samples before and after modification were characterized by static nitrogen adsorption, X-ray diffraction, Scanning electron microscope, Fourier transform infrared spectroscopy, zeta potential, and X-ray photoelectron spectroscopy. The experimental results showed that nitric acid modification can increase the ability of lignite to adsorb Pb2+. The adsorption amount of Pb2+ increased from 14.45 mg·g−1 to 30.68 mg·g−1. Nitric acid reacted with inorganic mineral impurities such as iron dolomite in lignite and organic components in coal, which caused an increase in pore size and a decrease in specific surface areas. A hydrophilic adsorbent surface more effectively removed Pb2+ from aqueous solution. Nitric acid treatment increased the content of polar oxygen-containing functional groups such as hydroxyl, carbonyl, and carboxyl groups on the surface of lignite. Treatment introduced nitro groups, which enhanced the negative electrical properties, the polarity of the lignite surface, and its metal ion adsorption performance, a result that can be explained by enhanced water adsorption on hydrophilic surfaces.

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Section: Distribution Of Oxygen Chemical Functional Groups Of Lignitementioning

confidence: 99%

Effect of Nitric Acid Modification on Characteristics and Adsorption Properties of Lignite

et al. 2019

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“…When its concentration exceeded a certain value, the surface tension of the solution remained at about 41 mN/m. This is because if the concentration of surfactant exceeds a certain value, micelles are produced [23]. As seen in Figure 14, the emulsified kerosene can produce a large number of bubbles in the froth zone compared to that of the kerosene and sec-Octyl alcohol combination.…”

Section: Generation Of a Stable Frothmentioning

confidence: 99%

“…The impeller speed, airflow rate, and flotation time were 1900 r/min, 0.25 m 3 /h, and 3 min, respectively. A detailed description of the working process of the mechanical flotation cell is reported in the literature [23,24].…”

Section: Flotation Testmentioning

confidence: 99%

Enhancement of Flotation Performance of Oxidized Coal by the Mixture of Laurylamine Dipropylene Diamine and Kerosene

Zhang

Niu

et al. 2021

Minerals

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Conventional hydrocarbon oil cannot adhere effectively to oxidized coal, resulting in a low yield of clean coal. In this study, a high-speed homogenizer was used to emulsify LDD (laurylamine dipropylene diamine) and kerosene, which enhanced the flotation efficiency of oxidized coal. The flotation results showed an increase from 4.12% (only kerosene) to 23.33% (emulsified oil). An increase in contact angle indicated that the mixture reagent can increase the hydrophobicity of coal particles, which is attributed to the adsorption of LDD onto the coal particle surface and the decrease of the oil droplet A lower surface tension of LDD allows it to produce a stable layer of froth than the layer generated by kerosene alone.

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“…e peak near 3450 cm −1 is corresponding to the broad infrared absorption band of phenolic/ alcoholic hydroxyl groups in coal molecules due to the formation of hydrogen bond between O-H groups [19]. e peak near 3030 cm −1 derives from C-H stretching vibration in benzene ring.…”

Section: Ftir Analysismentioning

confidence: 99%

“…Due to the limited measurement precision of XPS, no significant difference can be observed between the hydroxyl group and the ether group. C1 s peaks for two coal samples are shown in another oxygen, namely, C�O and O�C-O, respectively [18][19][20]. Since both functional groups bear an oxygen atom, an equation regarding the oxygen in the C-O bond could be established from the peak-split result.…”

Section: Xps Analysismentioning

confidence: 99%

A Comparative Study on the Wettability of Two Coal Samples during Deep Burial Metamorphism

Yan

Bai

Feng

et al. 2020

Journal of Chemistry

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In order to investigate the effect of deep burial metamorphism on the wettability of coal during deep burial metamorphism, a superficial coal sample (∼90 m) and a deep coal sample (∼490 m) collected from two main mining seams were selected to simulate the deep burial metamorphism process. The wettability of two coal samples during deep burial metamorphism was investigated by X-ray photoelectron spectroscopy (XPS), FTIR, zeta potential, and contact angle measurements. Besides, comprehensive DLVO interaction analyses between two coal samples from different mining depths were carried out through the zeta potentials measurements under different pH values. The XPS results demonstrate that the content of surface oxygen atom and oxygen-containing functional group for superficial coal tends to be higher than that of deep coal. The FTIR results indicate that the peak intensity of oxygen-containing functional groups for the superficial is higher than that of deep coal, implying the stronger surface hydrophobicity of deep coal compared to superficial coal. The contact angle of superficial coal is lower than that of deep coal. The zeta potential and DLVO theory analyses of superficial particles and deep coal particles indicate that deep burial metamorphism process might be favorable for bubble-particle collision and attachment, while might be unfavorable for the wetting process oppositely. Based on the surface chemistry characterization and theory analyses, this study is expected to give a theoretical insight into the efficient processing or dedusting process of coals experiencing different deep burial metamorphism processes in the future.

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Effect of oxidation processing on the surface properties and floatability of Meizhiyou long-flame coal

Cited by 51 publications

References 27 publications

Effect of Nitric Acid Modification on Characteristics and Adsorption Properties of Lignite

Effect of Nitric Acid Modification on Characteristics and Adsorption Properties of Lignite

Enhancement of Flotation Performance of Oxidized Coal by the Mixture of Laurylamine Dipropylene Diamine and Kerosene

A Comparative Study on the Wettability of Two Coal Samples during Deep Burial Metamorphism

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