Bao X.,Hunan Rare Earth Metal Material Research Institute |
Bao X.,Central South University |
Wang Z.,Hunan Rare Earth Metal Material Research Institute |
Su Z.,Hunan Rare Earth Metal Material Research Institute |
And 3 more authors.
Xiyou Jinshu/Chinese Journal of Rare Metals | Year: 2016
Based on our best knowledge acquired previously about separation and recovery of Sc2O3 from Bayan Obo tailings, the detail thermodynamic analyses of these chemical reactions, possibly occurred during the roasting process among CaCl2, carbon and Bayan Obo tailings, were discussed. Also, X-ray diffraction (XRD) technique was used to detect the phase transformations during roasting decomposition process. The main chemical reactions, 2CaCl2+2SiO2+O2 (g) =2CaSiO3+2Cl2 (g), CaCl2+SiO2+H2O (g) =CaSiO3+2HCl (g), were supported from the view point of thermodynamic with the existence of O2 and H2O. Moreover, with the existence of carbon, carbon-chlorination reactions were more reactive between the carbon, Bayan Obo tailings and new produced Cl2, which further broke up the original mineral compositions and activated the existing state of matter containing scandium, consequently facilitating the subsequent hydrochloric acid leaching process. © Editorial Office of Chinese Journal of Rare Metals. All right reserved. Source
Zhou X.,Central South University |
Chen F.,Central South University |
Yang J.,Central South University |
Ma L.,Hunan Rare Earth Metal Material Research Institute |
And 4 more authors.
Journal of Electroanalytical Chemistry | Year: 2015
A low-cost carbon/sulfur material has been prepared using interconnected porous carbon nanorods (PCNRs) as the framework, and self-assembled graphene sheets (GS) as the coating layer. This GS@PCNRs/S sulfur cathode exhibits excellent rate capability and cycle stability. It delivers a maximum discharge capacity of 549.9 mAh g-1 at 1 C and keeps superior cyclability over 500 cycles with an average capacity fading rate of only 0.083% per cycle. The improved electrochemical performance is primarily attributed to the wrapped, internally porous architecture of GS@PCNRs/S, which not only can offer an excellent transport of lithium ions and electrons within the electrodes, but also can inhibit polysulfide diffusion by the external chemical and physical barrier of graphene sheets. © 2015 Published by Elsevier B.V. Source