Catalytic graphitization of carbon/carbon composites by lanthanum oxide

doi:10.1016/S1002-0721(12)60008-8

Journal of Rare Earths

Volume 30, Issue 2, February 2012, Pages 128-132

https://doi.org/10.1016/S1002-0721(12)60008-8 Get rights and content

Abstract

Graphitized carbon/carbon composites were prepared by the process of catalytic graphitization with the rare-earth catalyst, lanthanum oxide (La₂O₃), in order to increase the degree of graphitization and reduce the electrical resistivity. The modified coal tar pitch and coal-based needle coke were used as carbon source, and a small amount of La₂O₃ was added to catalyze the graphitization of the disordered carbon materials. The effects of La₂O₃ catalyst on the graphitization degree and microstructure of the carbon/carbon composites were investigated by X-ray diffraction, scanning electron microscopy, and Raman spectroscopy. The results showed that La₂O₃ promoted the formation of more perfect and larger crystallites, and improved the electrical/mechanical properties of carbon/carbon composites. Carbon/carbon composites with a lower electrical resistivity (7.0 μΩ·m) could be prepared when adding 5 wt.% La₂O₃ powder with heating treatment at 2800 °C. The catalytic effect of La₂O₃ for the graphitization of carbon/carbon composites was analyzed.

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Citation Excerpt :
In a range of 1200–1800 cm−1, there are the characteristic peaks of graphitic carbon (G-band) at 1550–1650 cm−1 and defected carbon (D-band) at 1300–1400 cm−1 (Liu et al., 2013; Lucchese et al., 2010). The graphitic degree was evaluated by the relative intensity of ID/IG using peak intensities of D-band and G-band, indicating that the smaller ID/IG values are the higher graphitic degrees, that is, the higher adsorption capacities of Au(CN)2− (Zhang et al., 2012). The present DRGO from Syama mine was the more refractory and challenging to recover gold due to the higher value of ID/IG compared with the other two DRGOs (Amanya et al., 2017; Ofori-Sarpong and Osseo-Asare, 2013).
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: Foundation item: Project supported by the National High-Tech R&D Program (863 Program) of China (2009AA06Z102), the Fundamental Research Fund for the Central Universities and State Key Laboratory of Exploration Fund of China

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Catalytic graphitization of carbon/carbon composites by lanthanum oxide

Abstract

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Materials Chemistry and Physics

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Journal of Materials Science and Technology

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Composite Science and Technology

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