Ni H.-Y.,Guangdong Province Key Laboratory of Rare Earth Development and Application |
Ni H.-Y.,GuangZhou Research Institute of Nonferrous Metals |
Liang H.-B.,Sun Yat Sen University |
Wang L.-L.,Guangdong Province Key Laboratory of Rare Earth Development and Application |
And 3 more authors.
Rengong Jingti Xuebao/Journal of Synthetic Crystals | Year: 2015
The phosphors, Ce3+ doped with potassium gadolinium pyrosilicates K3Gd1-xCexSi2O7 were prepared through a high-temperature solid-state reaction technique. The excitation and emission spectra in range of vacuum-ultraviolet-vis, fluorescent decays and X-rays excitation luminescence (XEL) of Ce3+ in two sites both 6-fold octahedron coordination (trigonal antiprism tap) (Gd (1)3+) and 6-fold trigonal prism coordination (tp) (Gd (2)3+) were investigated, and the 5d centroid εc were calculated in view of crystal structure and an improved ligand polarization model. The results show that the emission spectra of phosphors K3Gd1-xCexSi2O7 are composed of broad band with the strongest intensity at ~518 nm and color coordination (x=0.318, y=0.473), fluorescent lifetime τ1/e and light yields are 98.1 ns and 3760 ph/MeV when Ce3+ concentration is 0.04 (mol/mol), respectively. © 2015, Chinese Ceramic Society. All right reserved.
Liu Z.,General Research Institute for Nonferrous Metals, China |
Liu Z.,Guangdong Province Key Laboratory of Rare Earth Development and Application |
Liu Z.,Kunming University of Science and Technology |
Wu Y.,Kunming University of Science and Technology |
And 7 more authors.
Zhongguo Xitu Xuebao/Journal of the Chinese Rare Earth Society | Year: 2015
Occurrence state of rare earth in pelagic clay from the Central Pacific was characterized and process of leaching rare earth by sulphuric acid was reported in this paper. Effects of process parameters on leaching ratio of rare earth element Y, including the sulphuric acid concentration, liquid-solid ratio, leaching temperature and time were investigated. The results showed that rare earth was main occurrence in apatite, and the pelagic clay was mainly composed of clay, zeolite and apatite. The best result of leaching ratio of rare earth element Y in this work was 84.38%, and leaching of the pelagic clay with sulphuric acid solution (1 mol·L-1) and liquid-solid ratio was 4/1 at 40℃ for 1 h. ©, 2015, Chinese Rare Earth Society. All right reserved.
Liu Z.-Q.,General Research Institute for Nonferrous Metals, China |
Liu Z.-Q.,Central South University |
Liu Z.-Q.,Guangdong Province Key Laboratory of Rare Earth Development and Application |
Wang W.,Central South University |
And 7 more authors.
Zhongguo Youse Jinshu Xuebao/Chinese Journal of Nonferrous Metals | Year: 2016
The process mineralogy investigation and the oxygen pressure leaching of low grade Pt-Pd concentrate with high content of magnesium were studied. Sulfuric acid pressure-oxidation leaching process was employed to achieve the selective leaching of copper, nickel, iron and enrichment of Pt-Pd. The effects of process parameters including the particle size, sulphuric acid concentration, the amount of calcium lignosulfonate, oxygen pressure, stirring speed, liquid-solid ratio, leaching temperature and time on the slag rate and leaching rates of copper, nickel and iron were investigated. The results show that leaching rates of copper and nickel are 99.27% and 98.04%, respectively, and slag rate is 37% under the leaching conditions of concentrate particle size d93< 43 μm, leaching time of 3 h, leaching temperature of 150 ℃, sulphuric acid concentration initial 4 mol/L, oxygen pressure of 0.7 MPa, stirring speed of 400 r/min, calcium lignosulfonate of 0.4% and liquid-solid ratio of 5: 1.Moreover, Pt and Pd are still not leached and the grade of Pt-Pd concentrate could be increased by 3 times after leaching process. © 2016, Central South University of Technology. All right reserved.
Xiao F.-M.,Guangdong Province Key Laboratory of Rare Earth Development and Application |
Xiao F.-M.,General Research Institute for Nonferrous Metals, China |
Peng G.-G.,Guangdong Province Key Laboratory of Rare Earth Development and Application |
Peng G.-G.,General Research Institute for Nonferrous Metals, China |
And 8 more authors.
Materials Science Forum | Year: 2016
Si/C composites were prepared by spray dying and carbonization process using silica powder, artificial graphite and glucose as raw materials. The physicochemical property and electrochemical performance of composite materials were characterized by XRD, SEM, constant current charge-discharge and cyclic voltammeter (CA)test, respectively. The results show that composite anode materials have pure phase structure with particle size of 5～20μm, and its special structure that silicon and graphite particles are constructed can exhibit good electrochemical performance. The initial discharge specific capacity of Si/C composites is 1033.2mAhg-1 at a current density of 100mAg-1.While the current density is as high as 600mAg-1, the discharge specific capacity is 584.2mAhg-1, and the first cycle coulombic efficiency is 77.3% at 100mAg-1.The mechanism of capacity fading of Si/C composites is discussed by different morphology characterization after 100 cycles. © 2016 Trans Tech Publications, Switzerland.