Vanadium trioxide（V2O3） was directly prepared by NaVO3 electrolysis in Na Cl molten salts. Electrolysis products were characterized by X-ray diffraction（XRD）, scanning electron microscopy（SEM） and energy dispers...Vanadium trioxide（V2O3） was directly prepared by NaVO3 electrolysis in Na Cl molten salts. Electrolysis products were characterized by X-ray diffraction（XRD）, scanning electron microscopy（SEM） and energy dispersive spectroscopy（EDS）. The existing state and electrochemical behavior of NaVO3 were also studied. The results indicated that V2O3 can be obtained from NaVO3. VC and C were also formed at high cell voltage, high temperature, and long electrolysis time. During electrolysis, NaVO3 was dissociated to Na＋ and VO3-in Na Cl molten salt. NaVO3 was initially electro-reduced to V2O3 on cathode and Na2O was released simultaneously. Na2CO3 was formed due to the reaction between Na2O and CO2. The production of C was ascribed to the electro-reduction of CO3（2-）. VC was produced due to the reaction between C and V2O3.展开更多
The relationships between the sulphide capacity index and the optical basicity, the mole fraction of oxygen ion and the Bell's ratio were investigated based on extensive lab scale equilibrium and industry scale qu...The relationships between the sulphide capacity index and the optical basicity, the mole fraction of oxygen ion and the Bell's ratio were investigated based on extensive lab scale equilibrium and industry scale quasi-equilibrium experimental data in the temperature range of 1300 1600℃. Although the sulphide capacity index has good relations with different representations of slag basicity. according to the data obtained under the lab scale equilibrium experimental conditions,the similar relations do not exist according to the data obtained under the industry scale quasi-equilibrium experimental conditions. So it is concluded that the sulphide capacity index, which has been considered as a measure of the slag basicity. can not be used for virtually all oxide slags of interest in the field of ironmaking and steelmaking.展开更多
In gaseous reduction of iron ore fines, alkaline earth oxides have profound effects on the precipitation behavior of fresh metal- lic iron on the particle surface. In this work, in situ observation was performed to re...In gaseous reduction of iron ore fines, alkaline earth oxides have profound effects on the precipitation behavior of fresh metal- lic iron on the particle surface. In this work, in situ observation was performed to reveal the influence of alkaline earth oxides on the precipitation morphology and micro-structure variation of fresh metallic iron from microscopic level by simulation of the gas-solid reaction condition on the surface of ore particles. Experimental results indicate that doping MgO in the particle surface can inhibit the reduction of iron oxide and however doping CaO, SrO and BaO promote; all alkaline earth oxides tested in this study can change the precipitation morphology of fresh metallic iron; minimum doping mole fraction of one oxide to inhibit iron whiskers growth （ NAO ） is related to its cation radius （ r：＋ ） and its extranuclear electronic layers（nAD ）, which can be expressed as NAO = 1.3 × 10^-5r^2AD,√nA^2.展开更多
基金supported by the National Basic Research Program of China(973 Program)(No.2013CB632606)National Natural Science Foundation of China(Nos.51474200,51422405)Youth Innovation Promotion Association,CAS(No.2015036)
文摘Vanadium trioxide（V2O3） was directly prepared by NaVO3 electrolysis in Na Cl molten salts. Electrolysis products were characterized by X-ray diffraction（XRD）, scanning electron microscopy（SEM） and energy dispersive spectroscopy（EDS）. The existing state and electrochemical behavior of NaVO3 were also studied. The results indicated that V2O3 can be obtained from NaVO3. VC and C were also formed at high cell voltage, high temperature, and long electrolysis time. During electrolysis, NaVO3 was dissociated to Na＋ and VO3-in Na Cl molten salt. NaVO3 was initially electro-reduced to V2O3 on cathode and Na2O was released simultaneously. Na2CO3 was formed due to the reaction between Na2O and CO2. The production of C was ascribed to the electro-reduction of CO3（2-）. VC was produced due to the reaction between C and V2O3.
文摘The relationships between the sulphide capacity index and the optical basicity, the mole fraction of oxygen ion and the Bell's ratio were investigated based on extensive lab scale equilibrium and industry scale quasi-equilibrium experimental data in the temperature range of 1300 1600℃. Although the sulphide capacity index has good relations with different representations of slag basicity. according to the data obtained under the lab scale equilibrium experimental conditions,the similar relations do not exist according to the data obtained under the industry scale quasi-equilibrium experimental conditions. So it is concluded that the sulphide capacity index, which has been considered as a measure of the slag basicity. can not be used for virtually all oxide slags of interest in the field of ironmaking and steelmaking.
基金supported by the National Natural Science Foundation of China and Baosteel (Grant No.50834007)the National Basic Research Program of China (973 Program) (Grant No.2012CB720401)
文摘In gaseous reduction of iron ore fines, alkaline earth oxides have profound effects on the precipitation behavior of fresh metal- lic iron on the particle surface. In this work, in situ observation was performed to reveal the influence of alkaline earth oxides on the precipitation morphology and micro-structure variation of fresh metallic iron from microscopic level by simulation of the gas-solid reaction condition on the surface of ore particles. Experimental results indicate that doping MgO in the particle surface can inhibit the reduction of iron oxide and however doping CaO, SrO and BaO promote; all alkaline earth oxides tested in this study can change the precipitation morphology of fresh metallic iron; minimum doping mole fraction of one oxide to inhibit iron whiskers growth （ NAO ） is related to its cation radius （ r：＋ ） and its extranuclear electronic layers（nAD ）, which can be expressed as NAO = 1.3 × 10^-5r^2AD,√nA^2.
