Mg-Li-Gd alloys were prepared by electrochemical codeposition from LiCl-KCl-MgCl 2 -Gd 2 O 3 melts on molybdenum electrode with constant current density at 823 and 973 K. The microstructure of the Mg-Li-Gd alloys was ...Mg-Li-Gd alloys were prepared by electrochemical codeposition from LiCl-KCl-MgCl 2 -Gd 2 O 3 melts on molybdenum electrode with constant current density at 823 and 973 K. The microstructure of the Mg-Li-Gd alloys was analyzed by X-ray diffraction （XRD）, optical microscopy （OM） and scanning electron microscopy （SEM）. The results show that magnesium and gadolinium deposit mainly in the first 30 min, and the alloy obtained contains 96.53% Mg, 0.27% Li and 3.20% Gd （mass fraction）. Then, the reduction of lithium ions occurs quickly. The composition of alloy can be adjusted by controlling electrolysis time or Gd 2 O 3 concentration in LiCl-KCl melts. With the addition of Gd into Mg-Li alloys, the corrosion resistance of the alloys is enhanced. XRD results suggest that Mg 3 Gd and Mg 2 Gd can be formed in Mg-Li-Gd alloys. The distribution of Gd element in Mg-Li-Gd alloys indicates that Gd element mainly distributes at the grain boundaries of Mg-Li-Gd alloys.展开更多
Raman spectrum of molten cryolite was recorded. Based on the new understanding of the scattering coefficients, contents of various structural entities in acidic NaF-AlF3 melts at 942-1 024 ℃ in previous research were...Raman spectrum of molten cryolite was recorded. Based on the new understanding of the scattering coefficients, contents of various structural entities in acidic NaF-AlF3 melts at 942-1 024 ℃ in previous research were reanalyzed. The new quantitative analysis results show that when cryolite ratio（CR） is less than 2, AlF4- is the dominant anion in the melts, and its mole fraction is about 0.70 for melts with CR=1.5 and 0.50 for melts with CR=2. When CR is more than 2.5, the mole fraction of AlF6^3- is relatively large, which is around 0.45 for melts with CR=2.5. Ionic structure of Na3AlF6-Al2O3 melts was investigated by UV-Raman spectroscopy. Octahedral AlF6^3- and tetrahedral AlF4- are proved to exist with possible partial replacement of F- by O^2-. Al2O2F4^2- with a large scattering coefficient also exists in the melts in which alumina concentration is more than 4% （mass fraction）. The increase of temperature causes blue-shift of the bands in the Raman spectra.展开更多
The evaporation kinetics of SnS from SnSCu2SFeS teruary system was investigated against matte grade, tetnperature and carrier gas flow rate. It was demonstrated that the evapomtion process is controlled by gas-phase m...The evaporation kinetics of SnS from SnSCu2SFeS teruary system was investigated against matte grade, tetnperature and carrier gas flow rate. It was demonstrated that the evapomtion process is controlled by gas-phase mass transport. The increases of the flow rote of carrier gas and the temperature could increase the gas-phase mass transport coefficient and the Partial pressure of SnS over the melts, respectively, and hence would appreciably promote the evaporation process. An increase of matte grade could lower the activitv coefficient of SnS in the melts, which in turn would cause the reduction of the evapomtion rate of SnS展开更多
An attempt was made to use the Wilson equation to predict the thermodynamic properties of the FeO-CaO-SiO2 melts at 1673 and 1873K. The activities of component FeO in the ternary melts at a given temperature were foun...An attempt was made to use the Wilson equation to predict the thermodynamic properties of the FeO-CaO-SiO2 melts at 1673 and 1873K. The activities of component FeO in the ternary melts at a given temperature were found to be conveniently calculated from the equation only with related binary parameters at different temperatures.The predicted values are in agreement with the ternary experimental data.展开更多
Based on Archimedes principle, the densities of Na 2WO 4 WO 3 ZnO melts at a fixed mole ratio of 3.43 of Na 2WO 4 to ZnO were measured. The results indicated that there was a linear relationship between the...Based on Archimedes principle, the densities of Na 2WO 4 WO 3 ZnO melts at a fixed mole ratio of 3.43 of Na 2WO 4 to ZnO were measured. The results indicated that there was a linear relationship between the densities and temperatures at a fixed composition. At a fixed temperature, the linear relationship between densities and compositions showed different slop within different composition regions. The reasons were explained in view of ionic composition changes.展开更多
The kinetics of SnS evaporation from SnS-Cu2S melts was investigated by a unique experimental method. It is shown that the process is controlled by the mass transport of SnS in gas phase. The evaporation rate of SnS i...The kinetics of SnS evaporation from SnS-Cu2S melts was investigated by a unique experimental method. It is shown that the process is controlled by the mass transport of SnS in gas phase. The evaporation rate of SnS is significantly enhanced by increasing tempeature and carrier gas flow rate. The apparent activation energy for the process is found to be 204.67 kJ. The evaporation rate for the present system is much smaller than that for SnS-FeS system.展开更多
The present study investigated the vaporization kinetics of MgCl_2,CaCl_2 and their binary melts in a fluidized bed at1073-1273 K,and developed a vaporization model for the binary melts to explore the possibility of a...The present study investigated the vaporization kinetics of MgCl_2,CaCl_2 and their binary melts in a fluidized bed at1073-1273 K,and developed a vaporization model for the binary melts to explore the possibility of achieving enhanced vaporization rate for the feedstock containing CaO greater than 0.2 wt%.The vaporization rate constant of MgCl_2 is more than seven times than that of CaCl_2 at 1273 K.The vaporization rate of the binary melt was significantly affected by the composition,a small quantity of CaCl_2 can remarkably deteriorate the overall vaporization rate.Experimental results coincide well with the numerical simulation by the vaporization model which regards the evolution of vaporization rate with melts composition.A correlation between the necessary operation temperature and the CaO/(CaO + MgO) of the feedstock was proposed.Predictions reveal that a similar vaporization rate for 0.2 wt%-0.4 wt%CaO content feedstock with 0.2 wt%could be achieved at lower than 1365 K.展开更多
With the application of resins in various fields, numerous waste resins that are difficult to treat have been produced. The industrial wastewater containing Cr(Ⅵ) has severely polluted soil and groundwater environmen...With the application of resins in various fields, numerous waste resins that are difficult to treat have been produced. The industrial wastewater containing Cr(Ⅵ) has severely polluted soil and groundwater environments, thereby endangering human health. Therefore, in this paper, a novel functionalized mesoporous adsorbent PPR-Z was synthesized from waste amidoxime resin for adsorbing Cr(Ⅵ). The waste amidoxime resin was first modified with H3PO4 and ZnCl_(2), and subsequently, it was carbonized through slow thermal decomposition. The static adsorption of PPR-Z conforms to the pseudo-second-order kinetic model and Langmuir isotherm, indicating that the Cr(Ⅵ) adsorption by PPR-Z is mostly chemical adsorption and exhibits single-layer adsorption. The saturated adsorption capacity of the adsorbent for Cr(Ⅵ) could reach 255.86 mg/g. The adsorbent could effectively reduce Cr(Ⅵ) to Cr(Ⅲ) and decrease the toxicity of Cr(Ⅵ) during adsorption. PPR-Z exhibited Cr(Ⅵ) selectivity in electroplating wastewater. The main mechanisms involved in the Cr(Ⅵ) adsorption are the chemical reduction of Cr(Ⅵ) into Cr(Ⅲ) and electrostatic and coordination interactions. Preparation of PPR-Z not only solves the problem of waste resin treatment but also effectively controls Cr(Ⅵ) pollution and realizes the concept of “treating waste with waste”.展开更多
基金Project(2009AA050702)supported by the National High-tech Research and Development Program of ChinaProject(GC06A212)supported by the Scientific Technology Project of Heilongjiang Province,China+2 种基金Project(50871033)supported by the National Natural Science Foundation of ChinaProject(208181)supported by the Key Project of Ministry of Education,ChinaProject(HEUCF101002)supported by the Fundamental Research Funds for the Central Universities,China
文摘Mg-Li-Gd alloys were prepared by electrochemical codeposition from LiCl-KCl-MgCl 2 -Gd 2 O 3 melts on molybdenum electrode with constant current density at 823 and 973 K. The microstructure of the Mg-Li-Gd alloys was analyzed by X-ray diffraction （XRD）, optical microscopy （OM） and scanning electron microscopy （SEM）. The results show that magnesium and gadolinium deposit mainly in the first 30 min, and the alloy obtained contains 96.53% Mg, 0.27% Li and 3.20% Gd （mass fraction）. Then, the reduction of lithium ions occurs quickly. The composition of alloy can be adjusted by controlling electrolysis time or Gd 2 O 3 concentration in LiCl-KCl melts. With the addition of Gd into Mg-Li alloys, the corrosion resistance of the alloys is enhanced. XRD results suggest that Mg 3 Gd and Mg 2 Gd can be formed in Mg-Li-Gd alloys. The distribution of Gd element in Mg-Li-Gd alloys indicates that Gd element mainly distributes at the grain boundaries of Mg-Li-Gd alloys.
基金Project (51004034) supported by the National Natural Science, ChinaProject(N090302009) supported by the Fundamental Research Funds for the Central Universities, China
文摘Raman spectrum of molten cryolite was recorded. Based on the new understanding of the scattering coefficients, contents of various structural entities in acidic NaF-AlF3 melts at 942-1 024 ℃ in previous research were reanalyzed. The new quantitative analysis results show that when cryolite ratio（CR） is less than 2, AlF4- is the dominant anion in the melts, and its mole fraction is about 0.70 for melts with CR=1.5 and 0.50 for melts with CR=2. When CR is more than 2.5, the mole fraction of AlF6^3- is relatively large, which is around 0.45 for melts with CR=2.5. Ionic structure of Na3AlF6-Al2O3 melts was investigated by UV-Raman spectroscopy. Octahedral AlF6^3- and tetrahedral AlF4- are proved to exist with possible partial replacement of F- by O^2-. Al2O2F4^2- with a large scattering coefficient also exists in the melts in which alumina concentration is more than 4% （mass fraction）. The increase of temperature causes blue-shift of the bands in the Raman spectra.
文摘The evaporation kinetics of SnS from SnSCu2SFeS teruary system was investigated against matte grade, tetnperature and carrier gas flow rate. It was demonstrated that the evapomtion process is controlled by gas-phase mass transport. The increases of the flow rote of carrier gas and the temperature could increase the gas-phase mass transport coefficient and the Partial pressure of SnS over the melts, respectively, and hence would appreciably promote the evaporation process. An increase of matte grade could lower the activitv coefficient of SnS in the melts, which in turn would cause the reduction of the evapomtion rate of SnS
文摘An attempt was made to use the Wilson equation to predict the thermodynamic properties of the FeO-CaO-SiO2 melts at 1673 and 1873K. The activities of component FeO in the ternary melts at a given temperature were found to be conveniently calculated from the equation only with related binary parameters at different temperatures.The predicted values are in agreement with the ternary experimental data.
文摘Based on Archimedes principle, the densities of Na 2WO 4 WO 3 ZnO melts at a fixed mole ratio of 3.43 of Na 2WO 4 to ZnO were measured. The results indicated that there was a linear relationship between the densities and temperatures at a fixed composition. At a fixed temperature, the linear relationship between densities and compositions showed different slop within different composition regions. The reasons were explained in view of ionic composition changes.
文摘The kinetics of SnS evaporation from SnS-Cu2S melts was investigated by a unique experimental method. It is shown that the process is controlled by the mass transport of SnS in gas phase. The evaporation rate of SnS is significantly enhanced by increasing tempeature and carrier gas flow rate. The apparent activation energy for the process is found to be 204.67 kJ. The evaporation rate for the present system is much smaller than that for SnS-FeS system.
基金Supported by the National Natural Science Foundation of China(NSFC)Distinguished Young Scholar project(No.21325628)
文摘The present study investigated the vaporization kinetics of MgCl_2,CaCl_2 and their binary melts in a fluidized bed at1073-1273 K,and developed a vaporization model for the binary melts to explore the possibility of achieving enhanced vaporization rate for the feedstock containing CaO greater than 0.2 wt%.The vaporization rate constant of MgCl_2 is more than seven times than that of CaCl_2 at 1273 K.The vaporization rate of the binary melt was significantly affected by the composition,a small quantity of CaCl_2 can remarkably deteriorate the overall vaporization rate.Experimental results coincide well with the numerical simulation by the vaporization model which regards the evolution of vaporization rate with melts composition.A correlation between the necessary operation temperature and the CaO/(CaO + MgO) of the feedstock was proposed.Predictions reveal that a similar vaporization rate for 0.2 wt%-0.4 wt%CaO content feedstock with 0.2 wt%could be achieved at lower than 1365 K.
基金supported by the National Natural Science Foundation of China (No.52364022)the Natural Science Foundation of Guangxi Province,China (Nos.2023JJA160192 and 2021GXNSFAA220096)+1 种基金the Guangxi Science and Technology Major Project,China (No.AA23073018)the Guangxi Chongzuo Science and Technology Plan,China (No.2023ZY00503).
文摘With the application of resins in various fields, numerous waste resins that are difficult to treat have been produced. The industrial wastewater containing Cr(Ⅵ) has severely polluted soil and groundwater environments, thereby endangering human health. Therefore, in this paper, a novel functionalized mesoporous adsorbent PPR-Z was synthesized from waste amidoxime resin for adsorbing Cr(Ⅵ). The waste amidoxime resin was first modified with H3PO4 and ZnCl_(2), and subsequently, it was carbonized through slow thermal decomposition. The static adsorption of PPR-Z conforms to the pseudo-second-order kinetic model and Langmuir isotherm, indicating that the Cr(Ⅵ) adsorption by PPR-Z is mostly chemical adsorption and exhibits single-layer adsorption. The saturated adsorption capacity of the adsorbent for Cr(Ⅵ) could reach 255.86 mg/g. The adsorbent could effectively reduce Cr(Ⅵ) to Cr(Ⅲ) and decrease the toxicity of Cr(Ⅵ) during adsorption. PPR-Z exhibited Cr(Ⅵ) selectivity in electroplating wastewater. The main mechanisms involved in the Cr(Ⅵ) adsorption are the chemical reduction of Cr(Ⅵ) into Cr(Ⅲ) and electrostatic and coordination interactions. Preparation of PPR-Z not only solves the problem of waste resin treatment but also effectively controls Cr(Ⅵ) pollution and realizes the concept of “treating waste with waste”.
