Metal Sm has been widely used in making Al–Sm magnet alloy materials. Conventional distillation technology to produce Sm has the disadvantages of low productivity, high costs, and pollution generation. The objective ...Metal Sm has been widely used in making Al–Sm magnet alloy materials. Conventional distillation technology to produce Sm has the disadvantages of low productivity, high costs, and pollution generation. The objective of this study was to develop a molten salt electrolyte system to produce Al–Sm alloy directly, with focus on the electrical conductivity and optimal operating conditions to minimize the energy consumption. The continuously varying cell constant(CVCC) technique was used to measure the conductivity for the Na3AlF6–AlF3–LiF–MgF2–Al2O3–Sm2O3electrolysis medium in the temperature range from 905 to 1055°C. The temperature(t) and the addition of Al2O3(W(Al2O3)), Sm2O3(W(Sm2O3)), and a combination of Al2O3and Sm2O3into the basic fluoride system were examined with respect to their effects on the conductivity(κ) and activation energy. The experimental results showed that the molten electrolyte conductivity increases with increasing temperature(t) and decreases with the addition of Al2O3or Sm2O3or both. We concluded that the optimal operation conditions for Al–Sm intermediate alloy production in the Na3AlF6–AlF3–LiF–MgF2–Al2O3–Sm2O3system are W(Al2O3) + W(Sm2O3) = 3wt%, W(Al2O3):W(Sm2O3) = 7:3, and a temperature of 965 to 995°C, which results in satisfactory conductivity, low fluoride evaporation losses, and low energy consumption.展开更多
The splat foils of Al-Sm alloys with 0.04-0.06mm in thickness were made by hammeranvil technique. The estimated cooling rute was 106K/ order of magnitude. The extended solid solubility of Sm in α-Al reached 0.5at. % ...The splat foils of Al-Sm alloys with 0.04-0.06mm in thickness were made by hammeranvil technique. The estimated cooling rute was 106K/ order of magnitude. The extended solid solubility of Sm in α-Al reached 0.5at. % Sm. The intermediate phase in the rapidlysolidified Al-Sm alloys is Al11Sm3 phase, which is stable only at temperatures above 1339K in equilibrium state and retained to ambient temperature as a metastable phase, whereas the equlibrium intermediate phase, Al3Sm, was restricted to occur.展开更多
Effect of the addition of Sm 2O 3 on CuO γ Al 2O 3 catalyst for CO oxidation reaction was investigated. The result shows that the right amount of Sm 2O 3 can promote the adsorption of the surface oxygen a...Effect of the addition of Sm 2O 3 on CuO γ Al 2O 3 catalyst for CO oxidation reaction was investigated. The result shows that the right amount of Sm 2O 3 can promote the adsorption of the surface oxygen and recovery of CuO γ Al 2O 3 catalyst. Sm 2O 3 plays an important role in change of γ Al 2O 3 phase into θ Al 2O 3 phase. In addition, the right amount of Sm 2O 3(5%) can improve the oxidation activity of the CuO γ Al 2O 3 catalyst. Whereas an excess of Sm 2O 3(10%) makes the CuO crystal in CuO γ Al 2O 3 catalyst become bigger and restrain the oxidation activity of the CuO γ Al 2O 3 catalyst.展开更多
Samarium（Sm） has been widely used in making aluminum（Al）-Sm magnet alloy materials. The research team for this study developed a molten salt electrolyte system which directly produces AI-Sm alloy to replace the en...Samarium（Sm） has been widely used in making aluminum（Al）-Sm magnet alloy materials. The research team for this study developed a molten salt electrolyte system which directly produces AI-Sm alloy to replace the energy intensive conventional distillation technology. In this study, molten melt density was measured and operation conditions were optimized to separate AI-Sm alloy product from the fluoride molten melt electrolysis media based on density differences, Archimedes＇ principle was applied to measure density for the basic molten fluoride system（BMFS： Na_3 AlF_6-AlF_3-LiF-MgF_2）electrolysis media in the temperature range from 905 to 1055 ℃.The impact of temperature（t） and the Al_2O_3 and Sm_2O_3 addition ratio（w_（（Al2O3））,w_（（Sm2O3）） in the basic fluoride system on molten melt density was examined. The fluoride molten melt density relationship was determined to be：ρ=3.11701-0.00802 w_（（Al2O3））＋0.027825 w_（（Sm2O3））-0.00117 t. The test results showed that molten density decreases with increase in temperature and Al_2O_3 addition ratio, and increases with the addition of Sm_2O_3, and/or Al_2O_3＋Sm_2O_3. The separation of Al-Sm（density 2.3 g/cm^3） product melt from the BMFS melt is achieved by controlling the BMFS density to less than 2.0 g/cm3. It is concluded that the optimal operation conditions to control the BMFS molten salt density to less than 2.0 g/cm^3 are：maintain addition of Al_2O_3＋Sm_2 O_3（w_（（Al2O3））＋w_（（Sm2O3））〈9% of Na_3AlF_6,Al_2O_3/Sm_2O_3 ratio（w_（（Al2O3））：w_（（Sm2O3）））〉 7：3, and temperature between 965 and 995 ℃.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos. 51564015 and 51674126)the Graduate Student Innovation Special Fund of Jiangxi Province (YC2015-B064)+2 种基金the Science and Technology Research Project of Jiangxi Department of Education (GJJ150664)the Outstanding Doctoral Dissertation Project Fund of JXUST (YB2016007)the Scientific Research Fund of JXUST (NSFJ2014-G09)
文摘Metal Sm has been widely used in making Al–Sm magnet alloy materials. Conventional distillation technology to produce Sm has the disadvantages of low productivity, high costs, and pollution generation. The objective of this study was to develop a molten salt electrolyte system to produce Al–Sm alloy directly, with focus on the electrical conductivity and optimal operating conditions to minimize the energy consumption. The continuously varying cell constant(CVCC) technique was used to measure the conductivity for the Na3AlF6–AlF3–LiF–MgF2–Al2O3–Sm2O3electrolysis medium in the temperature range from 905 to 1055°C. The temperature(t) and the addition of Al2O3(W(Al2O3)), Sm2O3(W(Sm2O3)), and a combination of Al2O3and Sm2O3into the basic fluoride system were examined with respect to their effects on the conductivity(κ) and activation energy. The experimental results showed that the molten electrolyte conductivity increases with increasing temperature(t) and decreases with the addition of Al2O3or Sm2O3or both. We concluded that the optimal operation conditions for Al–Sm intermediate alloy production in the Na3AlF6–AlF3–LiF–MgF2–Al2O3–Sm2O3system are W(Al2O3) + W(Sm2O3) = 3wt%, W(Al2O3):W(Sm2O3) = 7:3, and a temperature of 965 to 995°C, which results in satisfactory conductivity, low fluoride evaporation losses, and low energy consumption.
基金Project(2013AA031001)supported by the National High-tech Research and Development Program of ChinaProject(2011A080403008)supported by the Major Science and Technology Project of Guangdong Province,China
文摘The splat foils of Al-Sm alloys with 0.04-0.06mm in thickness were made by hammeranvil technique. The estimated cooling rute was 106K/ order of magnitude. The extended solid solubility of Sm in α-Al reached 0.5at. % Sm. The intermediate phase in the rapidlysolidified Al-Sm alloys is Al11Sm3 phase, which is stable only at temperatures above 1339K in equilibrium state and retained to ambient temperature as a metastable phase, whereas the equlibrium intermediate phase, Al3Sm, was restricted to occur.
文摘Effect of the addition of Sm 2O 3 on CuO γ Al 2O 3 catalyst for CO oxidation reaction was investigated. The result shows that the right amount of Sm 2O 3 can promote the adsorption of the surface oxygen and recovery of CuO γ Al 2O 3 catalyst. Sm 2O 3 plays an important role in change of γ Al 2O 3 phase into θ Al 2O 3 phase. In addition, the right amount of Sm 2O 3(5%) can improve the oxidation activity of the CuO γ Al 2O 3 catalyst. Whereas an excess of Sm 2O 3(10%) makes the CuO crystal in CuO γ Al 2O 3 catalyst become bigger and restrain the oxidation activity of the CuO γ Al 2O 3 catalyst.
基金Project supported by the National Natural Science Foundation of China(51564015,51674126)Graduate Student Innovation Special Fund of Jiangxi Province(YC2015-B064)+2 种基金Science and Technology Research Project of Jiangxi Department of Education(GJJ150664)Outstanding doctoral dissertation project fund of JXUST(YB2016007)Scientific Research Fund of JXUST(NSFJ2014-G09)
文摘Samarium（Sm） has been widely used in making aluminum（Al）-Sm magnet alloy materials. The research team for this study developed a molten salt electrolyte system which directly produces AI-Sm alloy to replace the energy intensive conventional distillation technology. In this study, molten melt density was measured and operation conditions were optimized to separate AI-Sm alloy product from the fluoride molten melt electrolysis media based on density differences, Archimedes＇ principle was applied to measure density for the basic molten fluoride system（BMFS： Na_3 AlF_6-AlF_3-LiF-MgF_2）electrolysis media in the temperature range from 905 to 1055 ℃.The impact of temperature（t） and the Al_2O_3 and Sm_2O_3 addition ratio（w_（（Al2O3））,w_（（Sm2O3）） in the basic fluoride system on molten melt density was examined. The fluoride molten melt density relationship was determined to be：ρ=3.11701-0.00802 w_（（Al2O3））＋0.027825 w_（（Sm2O3））-0.00117 t. The test results showed that molten density decreases with increase in temperature and Al_2O_3 addition ratio, and increases with the addition of Sm_2O_3, and/or Al_2O_3＋Sm_2O_3. The separation of Al-Sm（density 2.3 g/cm^3） product melt from the BMFS melt is achieved by controlling the BMFS density to less than 2.0 g/cm3. It is concluded that the optimal operation conditions to control the BMFS molten salt density to less than 2.0 g/cm^3 are：maintain addition of Al_2O_3＋Sm_2 O_3（w_（（Al2O3））＋w_（（Sm2O3））〈9% of Na_3AlF_6,Al_2O_3/Sm_2O_3 ratio（w_（（Al2O3））：w_（（Sm2O3）））〉 7：3, and temperature between 965 and 995 ℃.
