Authors: Jiushuai Deng Shuming Wen Xiumin Chen Yongjun Xian Dandn Wu
Publish Date: 2014/02/13
Volume: 45, Issue: 5, Pages: 2445-2452
Abstract
The ultrasoft pseudopotential plane wave method is applied to dynamic simulation of the thermal decomposition mechanism of FeS2 under vacuum The FeS2 100 111 and 210 surface relaxation and the geometric and electronic structure of the reactants and products are calculated The results indicate that FeS2 100 is the most preferred surface to dissociate and also the most common cleavage surface The thermal decomposition mechanism of FeS2 is explained by dynamic simulation on a micro stratum in general the SFe bond gradually elongated until it fractured the SS bond strengthened gradually the SFe bond was cleaved to form S the force is relatively weaker between different layers and thermal decomposition occurred easily between the layers Simultaneously the intermediate products such as Fe x S y were formed Evidence of Fe pyrolysis into Fe metal was not found and the intermediate products decomposed further The contributions of the p and d orbitals of Fe increased whereas that of the s orbital decreased The contributions of the s and p orbitals of S decreased The results obtained from FeS2 thermal decomposition experiments under vacuum and differential thermal analysis—thermogravimetry are consistent with the results of calculation and simulationThis research project was supported by the Key Program of the National Natural Science Foundation of China u0837602 KKGE201121001 Natural Science Foundation of Yunnan Province Education Department 2012J085 Excellent Doctoral Dissertation Foundation of Kunming University of Science and Technology 41118011 and the Analysis and Testing Foundation of Kunming University of Science and Technology 2011464 and the authors are grateful to Yong Deng and Yan Li The National Engineering Laboratory for Vacuum Metallurgy and Yuanyuan Zhou Honghe University for their contributions to this manuscript
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