International Journal of Coal Preparation and Utilization
·
2024
·
IF 2
Xiangyun Sun,Qifa Lu,Jiakun Tan,Long Liang,Haiyang Gao,Guangyuan Xie,Yaoli Peng
This study investigates the flotation performance of coal gasification fine slag in the presence of metal ions with different valences. The impact of metal ions on the surface topography, wettability, zeta potential, functional group, and particle size distribution of coal gasification fine slag were analyzed. The results demonstrated that K+, Ca2+, Mg2+, and Al3+ all have a positive effect on flotation, with Al3+ being particularly effective. At a concentration of 0.2 mol/L, Al3+ increased the recovery of combustible matter in coal gasification fine slag from 66.70% to 91.05% compared to deionized water. Metal ions reduce the absolute value of the gasification fine slag potential, compress its double layer while increasing its surface hydrophobicity. Higher ion concentration leads to a closer-to-zero potential and increased hydrophobicity. Additionally, Al3+ promote diesel adsorption onto coal gasification fine slag. This work explains the effects of metal ions on coal gasification fine slag flotation.
研究领域:
矿物加工工程
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Zili Yang,Yangchao Xia,Yanzhen Fu,Qinshan Liu,Ming Li,Xiahui Gui
Effective inhibition of clay minerals remains a challenge in the flotation separation of fine coal with high ash content. The quest for efficient, environmentally friendly, and cost-effective depressants to improve the flotation efficiency of fine coal-slime has become a focus of current research. Humic acid (HA), a macromolecular organic compound widely present in nature, is known for its non-toxic, low-cost, and biodegradable properties. In this study, the potential selective depressant HA was utilized to enhance the recovery of low-ash clean coal in the coal-kaolinite system. Adsorption and inhibition mechanisms were explored through contact angle measurements, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM) methods. Flotation tests demonstrated that HA, at varying dosages, significantly increased combustible matter recovery while reducing ash recovery compared to conventional flotation. Optimal conditions, with an HA dosage of 750 g/t, resulted in a combustible matter recovery of 40.56 % and an ash content of 17.77 % in the clean coal. Contact angle measurements confirmed that high-dosage HA significantly reduces the coal surface hydrophobicity, resulting in a rapid decline in the recovery of combustible matter. It did not significantly alter the contact angle of kaolinite, however, across the entire range of HA dosages. Furthermore, XPS studies revealed that the reduction in hydrophobicity on the coal surface after HA adsorption is mainly attributed to the coverage of surface carbon–carbon/carbon-hydrogen groups (C–C/C–H) and the increased presence of carbonyl groups (C = O). Additionally, the study found that HA predominantly adsorbs on the Si-OH groups of kaolinite. Finally, AFM results showed that the primary mechanism underlying the altered heterocoagulation behavior between coal and kaolinite is HA’s effect on their interaction forces. The optimal flotation results achieved at the HA dosage of 750 g/t are primarily attributed to the consistent presence of repulsive forces during the approach process and weak adhesion forces during the retraction process between coal and kaolinite, thus reducing kaolinite coating on the coal surface. These findings provide a promising direction for utilizing HA to enhance flotation deashing of high-ash coal-slime.
研究领域:
矿物加工工程
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2024
·Vol. 17
·期 6
·1431
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IF 3.1
Bao Mi,Hui Zhao,Meng Lu,Yi Zhou,Yongjie Xue
The massive stockpiling of electrolytic manganese residue (EMR) has caused serious environmental pollution. In this study, EMR, coal gangue (CG), and fly ash (FA) were used as raw materials to obtain the optimal mix ratio based on Design-Expert mixture design. The effects of activator modulus, liquid–solid (L/S) ratio, and curing temperature on the mechanical properties of geopolymers were investigated. The results showed that the compressive strength of the prepared geopolymer was 12.0 MPa, and the 28d leaching of Mn was 0.123 mg/L under the conditions of EMR:CG:FA = 0.43:0.34:0.23, L/S = 0.9, a curing temperature of 60 °C, and a curing time of 24 h. This indicates that the geopolymer is an environmentally friendly material with high compressive strength. The mineral composition of the geopolymer is mainly hydrated calcium silicate and geopolymer gel. In addition, a more stable new mineral phase, MnSiO3, was generated. The Fourier transform infrared (FTIR) spectrogram showed that the peak at 1100 m−1was shifted to 1112 cm−1, which indicated that a geopolymerization reaction had occurred. Through scanning electron microscopy (SEM) and energy dispersive spectrum (EDS) analysis, it was identified that the geopolymerization produced a large amount of amorphous gelatinous substances with a relatively dense structure, the major elements being oxygen, silicon, aluminum, calcium, and sodium.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CLAY SCIENCE
·
2023
·
IF 5.6
Jingfeng He,Xin Zhang,Qiang Bai,Shibo Huang,Hao Chen,Chengjing Guo,Lingtao Zhu,Bin Yang
As a vital non-metallic mineral resource , cleaning and purification of coal-series kaolin is of importance for the following processing and utilization. This research focused on surface modification to enhance the decarbonization performance of coal-series kaolin by triboelectric separation. The effect of citric acid or kerosene on the surface modification and charging performance of kaolinite and coal was explored through Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and charge-to-mass ratio measurements. The results indicated that owing to the adsorption of citric acid or kerosene, the decreased O content and the increased C content of coal enhanced the positive charge on the coal surface, while the decreased Al and Si content of kaolinite improved the negative charge on the kaolinite surface, which enlarged the charge-to-mass ratio gap between coal and kaolinite. Meanwhile, citric acid improved the charging performance of kaolinite and coal more significantly than kerosene. Furthermore, the influence of plate voltage, feeding speed, and friction wheel rotating velocity on the decarbonization performance of coal-series kaolin after surface modification was studied by triboelectric separation. The separation results indicated that surface modification with citric acid or kerosene improved the triboelectric separation efficiency of coal-series kaolin, and citric acid could realize the more effective separation of coal-series kaolin than kerosene. For 0.125–0.25 mm, 0.074–0.125 mm, and −0.074 mm coal-series kaolin, with citric acid modification, the valuable component recovery was 81.91%, 82.21%, and 82.83%, respectively, and the decarbonization efficiency was 44.66% (increased by 6.56%), 47.19% (increased by 7.00%), and 14.88% (increased by 2.53%), respectively. Our study provides vital guidance for enrichment and purification of coal-series kaolin resource via triboelectric separation.
研究领域:
矿物加工工程
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材料科学与工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Ningning Zhang,Mengyan Cheng,Rui Han,Zhen Li,Anning Zhou,Hong Wang
Coal gasification fine slag (CGFS) is a large solid waste in the field of coal chemical industry, and the separation of its carbon and ash is a prerequisite for the large-scale utilization of CGFS. At present, the flotation separation process of CGFS faces the prominent bottleneck of high consumption of traditional non-polar hydrocarbon oil collectors and poor flotation effect. To address this challenge, three fatty acids, oleic acid (OA), n-decanoic acid (DA), and naphthenic acid (NA), were used in this study to compound with the nonpolar hydrocarbon oil dodecane, respectively, as novel collectors for CGFS flotation. The effect and action mechanism of the composite collectors on CGFS flotation were investigated through flotation experiments as well as surface/interfacial tension, laser particle size, heat of wetting, FTIR, XPS, and induction time tests. The results show that the composite collectors can enhance the flotation effect of CGFS while reducing the chemical consumption. The addition of polar fatty acids can effectively reduce the interfacial tension of the collector-water system and thus increase the dispersion of the collector in water. Meanwhile, the addition of fatty acids makes the composite collector contain both polar and nonpolar groups. The polar groups form hydrogen bonds with the oxygen-containing groups on the residual carbon surface to mask the hydrophilic region, and the nonpolar groups are exposed to the slurry to enhance the hydrophobicity of the residual carbon surface, which makes the residual carbon adhere to the air bubbles more easily and thus facilitates its flotation recovery from CGFS. This study has important theoretical guidance for the efficient separation and resource recovery of CGFS.
研究领域:
化学工程
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Xu Zhao,Weixing Li,Xiaorong Zhang,Yingfang Xue,Jingbo Mu,Dongfang Xu,Weipeng Li,Yanming Wang,Shenjun Qin,Zhixiao Zhang
Lightweight ceramic proppants are prepared using coal gangue, fly ash, and bauxite as raw materials, and a mixture of manganese dioxide and magnesium oxide is used as composite additives. The total content of the coal gangue and fly ash in the raw materials reaches up to 70 wt%. The effects of coal gangue and fly ash precalcination, sintering temperature, and composite additive content on the phase compositions, microstructures, and performances of the resulting ceramic proppants are studied in detail. The ceramic proppant prepared at 1285 °C using 1 wt% of the composite additive is composed of quartz, corundum, and mullite. It also presents the desired sphericity, roundness, and microstructure. The apparent density, bulk density, and breakage ratio of the ceramic proppant described above are 2.55 ± 0.06 g/cm 3 , 1.03 ± 0.02 g/cm 3 , and 8.30 ± 0.68% at 35 MPa, respectively. This ceramic proppant belongs to lightweight ceramic proppants and meets the requirement of the 5K grade in the standards of SY/T 5108-2014 and API STD 19C-2018.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2020
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IF 3.99
Lei Wu,Guansheng Qi,Wei Lu,Zhenglong He,Jialiang Li,Jinliang Li,Min He
In the process of coal mining, coal spontaneous combustion in the gob area poses serious threats to the safety of mine production. Besides, coal combustion also produces a large amount of greenhouse gas CO 2 , which triggers a series of ecological environment problems. In order to solve these two problems, the idea of mineralizing CO 2 with the alkaline industrial waste calcium carbide slag and then sending the foams to the gob area for coal spontaneous combustion prevention was proposed in this study. First, the effects of calcium carbide slag foaming under the action of different types of foaming agents, including sodium dodecyl sulfate (SDS), sodium dodecyl benzene sulfonate (SDBS), polyoxyethylene fatty alcohol sodium sulfate (AES), and octyl decyl glucoside (APG0810), were tested and analyzed. Furthermore, the effects of water glass (WG), sodium alginate (SA), polyvinyl alcohol 1799 (PVA), cement, and silica micro-powder on the foam stability were analyzed by investigating the stability coefficient and drainage volume of calcium carbide slag foam. On this basis, the configuration scheme of calcium carbide slag foam with high efficiency and good stability was determined. The experimental results on CO 2 mineralization and coal spontaneous combustion inhibition reveal that the prepared calcium carbide slag foam can rapidly absorb CO 2 . Moreover, after calcium carbide slag foam treatment, the spontaneous combustion tendency of the coal sample is significantly reduced.
研究领域:
矿业工程
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环境科学
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材料科学
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
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2022
·
IF 8.943
Yanjie Niu,Jie Xu,Zekai Miao,Fanhui Guo,Yixin Zhang,Jianjun Wu
From the perspective of environmental protection and resource utilization, the feasibility of treating m -cresol wastewater with coal gasification fine slag (GFS) as particle electrodes in an electrocatalytic system was evaluated to achieve the purpose of treating waste with waste. Characterization by scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET), Raman, and fourier transform infrared spectroscopy (FTIR) confirmed that the GFS featured a diverse inorganic framework, large specific surface area (as large as above 155 m 2 g −1 ), hierarchical porous structure, and plenty of catalytic sites. The Venn diagram method was used to systematically propose the following distribution modes of residual carbon (RC) and ash in GFS: discrete distribution, embedded distribution, crosslinked distribution, and association and bonding. Only 8 g L −1 of GFS particle electrodes prevented the formation of a yellow sticky passivation film on the anode. Compared to the two-dimensional electrocatalytic system (47.89%), the wastewater treatment efficiency was increased by 108.81%. Zero-order kinetic results showed that the reaction rate constant was the highest (2.1106 mg L −1 ·min −1 ) when the secondary flotation RC was adopted as particle electrodes. It was indicated that GFS in discrete mode played either no role or at most a minor role. Last but not least, the synergy of RC and ash was revealed from a molecular perspective. The RC exhibited hierarchical microporous/mesoporous/macroporous structure, which facilitated the entry of H 2 O 2 into the catalytic sites of ash. Abundant catalytic sites in ash accelerated adsorption and oxidation processes on RC surfaces.
研究领域:
环境科学
·
资源利用
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FUEL
·
2023
·
IF 7.4
Suqian Gu,Zhiqiang Xu,Yunxiang Dai,Yang Chen,Yangguang Ren,Yanan Tu,Le Yang,Mengyun Shi
Coal gasification wastewater (CGW) as a substitute for clean water to prepare coal water slurry, which serves as gasification/combustion feedstock, can simultaneously achieve wastewater management and resource utilization. The purpose of this work was to investigate the effects of internal components (i.e., oils, phenols, nitrogen heterocyclic compounds, and inorganic cations) in CGW on the slurryability and dispersion/aggregation behavior of lignite and their co-slurrying mechanisms through experimental and the extended DLVO (eDLVO) theoretical calculations. Results showed that compared to lignite water slurry (LWS), the maximum solids concentration ( ω max ) of coal gasification wastewater slurry (CWWS) increased by 0.80%, with a lower pseudo-plasticity. The organic compounds adsorbed competitively on the hydrophobic regions of lignite improved the slurrying capability of CWWS by decreasing the wettability, Zeta potential, roughness and pore structure of the particles. By contrast, the static stability of CWWS decreased, and its kinetic stability index ( TSI ) increased from 0.23 to 0.33. From the backscattering spectra, dodecane caused the creaming process of the slurry, while the clarification process was attributed to phenol and nitrogen heterocyclic compounds. Inorganic cations, especially NH 4 + and Ca 2+ , significantly reduced the hydrophilic and negative charges on the particle surface, which were the main unfavorable factors leading to particle aggregation and sedimentation. The eDLVO theoretical calculation results exhibited that inter-particle interaction in CWWS was determined by the hydrophobic energy ( E h ) and electrostatic energy ( E e ) and their dropped from 1.79 × 10 −16 J and 5.16 × 10 −17 J to −4.67 × 10 −16 J and 2.59 × 10 −17 J respectively.
研究领域:
环境科学
·
能源工程
✓ 已验证
DOI
高影响因子
Asia-Pacific Journal of Chemical Engineering
·
2024
·
IF 1.4
Hongzheng Zhu,Zhiqian Qin,Kun Chen,Wenliang Zhu,Qinghui Shi,Ming Yang,Chao Li,Yong Zhang
Understanding the collision between kerosene droplets and coal particles in the bubble trailing vortex region is crucial for enhancing slurry conditioning. We found the area of the bubble trailing vortex region increased as the bubble size increased via the Fluent 6.3.26 software. A kerosene droplet velocity range of 0.074–0.106 m/s and a coal particle velocity range of 0.062–0.104 m/s were obtained if a bubble had a diameter of 0.3 mm. We employed a high-speed motion acquisition system and observed the collision process, which was divided into two stages: Compression and Rebound . The critical motion distance increased as the kerosene droplet size increased, and sufficient kerosene droplet motion distance and enough kinetic energy normally resulted in a rebound phenomenon. The attenuation energy was almost positively linear to the initial energy, and the energy attenuation coefficient of the collision process was fitted to 0.626. Our results can provide valuable insight into mineral separation.
研究领域:
矿物加工工程
·
流体力学
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2024
·
IF 5.3
Chuandong Ma,Wenqi Zhang,Zhisen Li,Jida Niu,Qingbiao Wang,Zhenhua Wang,Lin Li,Xiaofang You
In this study, the slurry formation properties and multi-phase dispersion mechanism of hydrocarbon modified low-rank coal (LRC) were explored by combining experiments and simulations, aiming to provide some theoretical guidance for the slurrying of surface-modified LRC. The experimental results revealed that compared with the LRC water slurry (LRCWS), the consistency of the diesel modified low-rank coal water slurry (M−LRCWS) is decreased, the pseudo plasticity is enhanced, and the constant viscosity concentration is increased by 1.89 %. The results of XPS analysis indicated that the surface C/O of M−LRC increases from 5.67 (LRC) to 6.83, and the content of oxygen-containing groups decreases by 3.10 %, indicating that the surface non-polarity is enhanced. In molecular dynamics simulation, compared with the two dispersed systems of COAL/ Sodium poly[(naphthaleneformaldehyde) sulfonate] (MF)/H 2 O (CMW) and COAL/ Dodecane (DD)/MF/H 2 O (CDMW), the E bin of water molecules in both of systems is negative, indicating that water molecules are easy to combine with the coal surface. The absolute E bin of the CDMW system is 2612.56 kcal/mol lower than that of CMW. The adsorption force of coal molecules to water molecules is weakened, which leads to a decrease in the content of water molecules adsorbed on coal. The results show that the surface hydrophobicity of LRC modified by DD is enhanced, so the proportion of free water in the system increases, which is beneficial to increase the concentration of coal water slurry. The simulation results confirm the experimental results.
研究领域:
能源科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2025
·
IF 5.4
Jialong Bai,Jieyu Yi,Weiwang Chen,Long Kang,Zhiqiang Zhang
Frothers not only modify gas–liquid interfacial properties, but also alter coal particle surface properties, thereby influencing bubble–coal particle interactions in froth flotation processes. While previous studies have focused on frothers’ effects on gas-liquid interfaces, their impact on coal surface hydrophilicity and coal-bubble interactions remains underexplored. In this study, we measured the bubble–coal interactions using an anthracite coal sample under varying concentrations of MIBC and DF250 frothers during attachment and detachment processes of coal, in combination with surface tension measurement, XPS, FTIR, contact angle measurements, and quantum chemistry calculations. The results demonstrate that both MIBC and DF250 will adsorb on the coal surface and impart hydrophilicity onto it. Increasing frother concentration will render the coal surface more hydrophilic, which will prolong liquid drainage time (t drain ) and enhance the attachment repulsive force (F adr ) during bubble–coal particle attachment. At the same time, this also will decrease the detachment attraction force (F det ) of coal particle. In the examined concentration range, DF250 exhibits more pronounced effects than MIBC, meaning that it is less suitable for coal flotation. For both frothers and in the studied concentration range, F adr consistently exceeds F det , meaning that immediately removal of coal-bubble aggregates from the mixing zone of flotation cell seems to be desirable. In addition, regardless of the presence or absence of frother in water and the structure difference in MIBC and DF250, the contact angle of coal surface should be a good indicator of the strength of coal-bubble interactions.
研究领域:
矿物加工工程
·
界面化学
·
量子化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）