Influence of Calcination and Acidification on Structural Characterization of Anyang Anthracites

Abstract

The structural parameters of six coals were determined by X-ray diffraction (XRD), scanning electron microscope (SEM), and Raman and FTIR spectroscopy. The results reveal that the derivative coals prepared by calcination and HF acidification contain much crystalline carbon like graphite structure and are improved significantly in aromaticity, coal rank, and hydroxyl concentration. The increase of hydroxyl (OH) bonds is very beneficial to the surface modification of coal crystalline layers. In addition, the derivative coals have an obvious decrease of the aliphatic C–H content and a significant increase of the aromatic C–H content in FTIR spectra compared to that for the raw coal (AY). They are consistent with the changes of aromaticity and crystalline carbon measured by XRD and Raman spectra. With the increase of coal rank, the content of defect crystalline carbon and amorphous carbon decreases gradually from AY to the coal prepared by calcination and HF acidification (AY-C-HF). The particles of AY-C-HF with about 20 nm in thickness have better dispersibility with simultaneously a lot of pore space. The process of first calcination and then acidification can help us delaminate the aromatic layers in the coals and obtain the superfine crystalline carbon materials like graphite structure.

Thermal and mechanical enhancement of styrene–butadiene rubber by filling with modified anthracite coal

“…The FTIR spectra of raw and MA are shown in Figure . We observe stretching vibrations and in‐plane vibrations of the hydroxyl bonds (OH) at the spectral peaks at 3100–3600 and 1400 cm −1 , respectively . After modification of the coal, the strength of these peaks is decreased, which corresponds to a decrease in the hydroxyl content on the coal surface; silanol formed by the hydrolysis of the silane coupling agent can react with and consume hydroxyl groups or cover their signals.…”

Influences of Coal Tar Pitch on Metallurgical Properties of Iron Carbon Agglomerates

“…A lot of amorphous carbons are in the internal of ICA due to the underdevelopment of carbon crystallites structure. It has been confirmed that the ( γ ) band around 20° is the amorphous carbon such as aliphatic side chains …”

Enhancement of low‐temperature lignite pyrolysis by recycled carbocoal for high‐quality tar in fixed‐bed reactor

“…Then, the radical polymerization reactions among the tar intermediates played a leading role, which would produce heavy tar or char fragments. Obviously, the free‐radical recombination reaction would reduce the tar yield …”