Characterization of graphitic materials prepared from different rank Pennsylvania anthracites

Nyathi, Mhlwazi S.; Clifford, Caroline Burgess; Schobert, Harold H.

doi:10.1016/j.fuel.2012.04.003

Cited by 71 publications

(47 citation statements)

References 31 publications

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“…For the products obtained in this work, this ratio was about 0.8 for coal derived and 0.7 for briquette derived products, whereas for BF coke it was about 3.0, indicating that the proportion of carbon in well-ordered graphitic structures in the products was much less than in the BF coke. The spacing, d 002 between the planes in the graphitic structure in the products, 3.7 Å A 0 , was greater than that in the BF coke, 3.48 Å A 0 or in graphite (3.35 Å A 0 ), indicating poorer crystallinity or a lower degree of graphitization [64] and the presence of some aliphatic carbon in the products. Furthermore, the 002 band for the products was broader than the corresponding band in the BF coke, again indicating a lower degree of crystalline order [47] than in the BF coke.…”

Section: X-ray Diffractionmentioning

confidence: 79%

An attempt to produce blast furnace coke from Victorian brown coal

Mollah

Jackson

Marshall

et al. 2015

Fuel

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Section: X-ray Diffractionmentioning

confidence: 79%

An attempt to produce blast furnace coke from Victorian brown coal

Mollah

Jackson

Marshall

et al. 2015

Fuel

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“…Apart from (d 002 ) being less sensitive to temperature in the process of graphitization (there is no difference between G‐WTP and G‐WTP‐t) and even inhibit the graphitization process to some extent . This inhibitory effect will be analyzed in detail later.…”

Section: Resultsmentioning

confidence: 98%

“…Therefore, the type, content and distribution of minerals in coal will inevitably affect the quality of coal‐based graphene. Some scholars believe that minerals in coal are catalysts for graphitization, but others are opposite . Although minerals in raw coal significantly limit the comprehensive utilization of coal, the effect of minerals on the quality of coal‐based graphene products is seldom reported.…”

Section: Introductionmentioning

confidence: 99%

“…Some scholars believe that minerals in coal are catalysts for graphitization, [14][15] but others are opposite. [16] Although minerals in raw coal significantly limit the comprehensive utilization of coal, [17] the effect of minerals on the quality of coal-based graphene products is seldom reported. To study the effect of minerals in anthracite on the morphology and chemical composition of graphene, in this paper, low-medium ash anthracite from the Wangtaipu Mine of Jincheng was selected as the carbon source, with raw and demineralized anthracites graphitized at high temperature and anthracite-based graphene prepared by the improved Hummers' oxidation-reduction method.…”

Section: Introductionmentioning

confidence: 99%

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Effects of Minerals in Anthracite on the Formation of Coal‐Based Graphene

et al. 2019

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The minerals in raw anthracite significantly limit the preparation of coal‐based graphene. Raw and demineralized anthracites were graphitized and coal‐based graphene was prepared by improved Hummers’ oxidation‐reduction method. The morphologies, crystal structures and spectroscopic characteristics of the products in various stages were characterized by scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy and Raman spectroscopy. The results show that demineralized or not, anthracite can be used to prepare graphene, but the minerals in anthracite physically inhibit the directional development of graphene sheets. And the residual high temperature conversion products of the minerals embedded between graphene sheets will lead to multiple irregular pore defects on the surface of graphene, which will have strongly unfavorable effects on the properties of coal‐based graphene materials. Demineralization of raw anthracite can reduce the defective pores and oxygen‐containing functional groups on the surface of coal‐based graphene and improves its morphology and properties.

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“…Lignite, the lowest rank of coal, consists of linked aromatic rings and cross‐linked aliphatic side chains with a variety of functional groups such as alicyclic groups and carboxylic acid groups [e.g., Wender , ]. Thermal evolution during diagenesis is accompanied by the breaking of weak bonds, aromatization, and structural rearrangement [ Behar and Vandenbroucke , ], and as a result, high‐rank coals (bituminous and anthracite) consist of relatively large cross‐linked pericondensed aromatic and alicyclic components [ Lazarov and Marinov , ] that ultimately form large aromatic sheets and stack the sheets [ Nyathi et al ., ]. However, the rapid heating under low‐fugacity oxygen that occurs in a slip zone during earthquake slip can pyrolyze carbonaceous materials.…”

Section: Discussionmentioning

confidence: 99%

Investigation of the records of earthquake slip in carbonaceous materials from the Taiwan Chelungpu fault by means of infrared and Raman spectroscopies

Hirono

Maekawa

Yabuta

2015

Geochem Geophys Geosyst

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To understand the mechanism of fault lubrication during the 1999 Taiwan Chi-Chi earthquake, we developed a new temperature proxy for carbonaceous materials by using infrared and Raman spectroscopies together with heating and friction experiments. We found marked anomalies in the infrared and Raman spectra of carbonaceous materials retrieved from the primary slip zone of the earthquake: the infrared spectra exhibited very weak aliphatic CH 2 and CH 3 peaks and aromatic C5C absorbance peaks, and the Raman spectra exhibited very weak disordered and graphitic bands and a high ratio of disordered band area to graphitic band area. Those weak peaks and bands and the band area ratio were reproduced by heating carbonaceous materials from the nearby host rock to 7008C. These results suggest that the frictional heat in the slip zone reached approximately 7008C. We characterized the host rock's carbonaceous materials by means of elemental analysis, pyrolysis-gas chromatography-mass spectrometry, and simultaneous thermogravimetry-differential scanning calorimetry and found that the H/C and O/C ratios were 1.29 and 0.30, respectively (which are close to the ratios for lignin) and that the volatile fraction was as high as 48 wt %. The pyrolysates obtained by heating from 100 to 4008C were dominated by phenols, fatty alcohols, and n-alkanes. When the residue from pyrolysis at 100-4008C was rapidly heated to 7008C, the resulting pyrolysate was dominated by phenols, aromatic compounds, heterocyclic compounds, and n-alkenes. This information suggests that change in the infrared and Raman spectra with increasing temperature may have been due to decomposition and aromatization reactions during pyrolysis. Rapid heating during earthquake slip may promote reactions of carbonaceous materials that are different from the reactions that occur during long-term geological metamorphism.

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Characterization of graphitic materials prepared from different rank Pennsylvania anthracites

Cited by 71 publications

References 31 publications

An attempt to produce blast furnace coke from Victorian brown coal

An attempt to produce blast furnace coke from Victorian brown coal

Effects of Minerals in Anthracite on the Formation of Coal‐Based Graphene

Investigation of the records of earthquake slip in carbonaceous materials from the Taiwan Chelungpu fault by means of infrared and Raman spectroscopies

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