Ultrafine coal dewatering: Relationship between hydrophilic lipophilic balance (HLB) of surfactants and coal rank

Hassas, Behzad Vaziri; Karakaş, Fırat; Çelik, M.S.

doi:10.1016/j.minpro.2014.10.010

Cited by 52 publications

(7 citation statements)

References 31 publications

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“…The value of 10 is the threshold between hydrophilic and lipophilic systems [41]. Hydrophilic surfactants present high values while lipophilic surfactants present low HLB values [42,43]. According to HLB differences (Table 1), EO10 is the most hydrophilic surfactant, followed by EO7, EO6PO3 and EO3PO6.…”

Section: Configuration Proposal For Surfactants On Microbubblesmentioning

confidence: 99%

Aphrons Obtained From Different Nonionic Surfactants: Properties and Filtration Loss Evaluation

Gomes¹,

Alves²,

Nunes³

et al. 2017

ChChT

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Abstract.1 Aphrons were produced using nonionic surfactants by applying a differential pressure. Bubble size distribution was obtained from optical microscopy using FIJI-ImageJ2 program. The aim of this work was to correlate surfactants structures with aphrons properties (density and viscosity), size distribution and the number of bubbles. API fluid loss tests were based on standard proceedings specifications for water-based drilling fluids of Petrobras/Brazil. The structure of the nonionic surfactants showed a great influence on the fluid properties and the performance of the fluid contributing with a filtrate reduction up to 31% with the systems that were presented between 1088 and 1850 bubbles with diameters ranging from 33 to 104µm. These systems were produced by poly(ethylene oxide) with 7 ethylene oxide units, a poly(ethylene oxide)-b-poly(propylene oxide) with 6 ethylene oxide units and 3 propylene oxide units.

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Section: Configuration Proposal For Surfactants On Microbubblesmentioning

confidence: 99%

Aphrons Obtained From Different Nonionic Surfactants: Properties and Filtration Loss Evaluation

Gomes¹,

Alves²,

Nunes³

et al. 2017

ChChT

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“…Long-flame coal is a typical type of low-rank coal and is an important part of China's coal energy resources. Compared with bituminous coal, low-grade coal has higher inherent moisture, and this is even higher when in contact with water (Vaziri Hassas et al, 2014;. This water content depresses the calorific value achieved during combustion, resulting in energy waste.…”

Section: Introductionmentioning

confidence: 99%

“…In some investigations, surfactants have been shown to improve the hydrophobicity of coal surface (Ahmet et al, 1995;X. Liu et al, 2017;You, He, Zhu, et al, 2019) and reduce the moisture content of the filter cake (Singh, 1997(Singh, , 1999StrohandStahl, 1990;Vaziri Hassas et al, 2014). The dewatering of flotation coal concentrates with different degrees of fineness was investigated by Stroh (StrohandStahl, 1990) using nonionic alkylpolyalkylene oxides and anionic sulfosuccinate surfactants.…”

Section: Introductionmentioning

confidence: 99%

“…The results showed that the moisture content significantly decreased at surfactant concentrations close to the critical micelle concentration (CMC). The dewatering of lignite and sub-bituminous and bituminous coal was studied by Hassas (Vaziri Hassas et al, 2014) using Triton-X series surfactants and three other reagents that had the same hydrophobic-lipophilic balance (HLB) value. It was found that, for the fine particles with lower hydrophobicity, such as lignite and subbituminous coals, surfactants with higher HLB values (about 10) achieved the optimum dewatering.…”

Section: Introductionmentioning

confidence: 99%

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Effect of the degree of polymerization of nonylphenol polyoxyethylene ether on the dewatering of low-rank coal

Li¹,

He²,

Liu³

et al. 2020

Physicochem. Probl. Miner. Process.

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In this study, we investigated the effect of the hydrophilic ethylene oxide chain lengths (i.e., degree of polymerization) of nonylphenol polyoxyethylene ether (NPEO-x, x = 8, 10, and 12) on the dewatering of low-rank coal slime through dewatering and adsorption experiments and X-ray photoelectron spectroscopy (XPS) measurements. The dewatering experiments showed that the adsorption of NPEO changed the water content of the low-rank coal slime: NPEO-8 achieved the best effect, followed, in decreasing order, by NPEO-10 and NPEO-12. Adsorption experiments revealed that the adsorption isotherms of NPEO-x on the low-rank coal surface conform with the Langmuir model, and its adsorption kinetics follow the pseudo-second-order kinetic equation. Furthermore, the adsorption is a spontaneous process and controlled by both intraparticle diffusion and liquid film diffusion. The XPS results showed that the adsorption of NPEO-x decreased the content of oxygencontaining groups and, thus, improved the hydrophobicity of the low-rank coal surface. Further, the use of NPEO-x with a low degree of polymerization (x = 8) improves the hydrophobicity of the coal surface and decreases the water content of low-rank coal slime.

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“…When a quaternary ammonium salt surfactant adsorbs to the coal surface, the quaternary ammonium salt side forms a directional and tight adsorption layer on the coal surface, making the alkyl group far away from the coal surface. This kind of adsorption can reduce the hydrophilicity of the coal and inhibit the water reabsorption after drying [19][20][21]. Quaternary ammonium salt surfactants are commonly used in the coal washing stage [22].…”

Section: Introductionmentioning

confidence: 99%

Quantum Chemical Study on the Influence of Dodecyl Trimethyl Ammonium Bromide on the CH4 Adsorption of Coal

et al. 2020

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The adsorption of dodecyl trimethyl ammonium bromide (DTAB) on coal can affect the wettability of coal and change the water absorption of coal. After DTAB treatment, the change in the CH4 adsorption capacity of coal is worth further study. To reveal the microscopic mechanism of the influence of DTAB on the CH4 adsorption capacity of coal, we employed the density functional theory (DFT) with the 6-311 G (d, p) basis set. DFT-based computations interpreted the adsorption process of CH4 and DTAB on coal molecules and determined the stable structure, adsorption distance, Mulliken overlapping populations, and adsorption energies of the two adsorption configurations. The results showed that the adsorption energies of CH4 and DTAB on the molecular model of coal were 2.15 and 42.69 kJ/mol and the adsorption stability distances were 0.261 and 0.238 nm, respectively. The DTAB–coal configuration was more stable than the CH4–coal configuration. When there was competitive adsorption between DTAB and CH4 on coal, the coal molecules preferentially adsorb the DTAB. Infrared spectroscopy and adsorption experiments were also carried out, and the calculation results of quantum chemistry are consistent with the experimental results.

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Ultrafine coal dewatering: Relationship between hydrophilic lipophilic balance (HLB) of surfactants and coal rank

Cited by 52 publications

References 31 publications

Aphrons Obtained From Different Nonionic Surfactants: Properties and Filtration Loss Evaluation

Aphrons Obtained From Different Nonionic Surfactants: Properties and Filtration Loss Evaluation

Effect of the degree of polymerization of nonylphenol polyoxyethylene ether on the dewatering of low-rank coal

Quantum Chemical Study on the Influence of Dodecyl Trimethyl Ammonium Bromide on the CH4 Adsorption of Coal

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