Electrical conductivity of molten LiF–DyF_3–Dy_2O_3–Cu_2O system for Dy–Cu intermediate alloy production
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摘要
Dy–Cu intermediate alloys have shown substantial potential in the field of magnetostrictive and magnetic refrigerant materials.Therefore, this study focused on investigating the electrical conductivity of molten-salt systems for the preparation of Dy–Cu alloys and on optimizing the corresponding operating parameters. The electrical conductivity of molten LiF–DyF_3–Dy_2O_3–Cu_2O systems was measured from 910 to 1030°C using the continuously varying cell constant method. The dependencies of the LiF–DyF_3–Dy_2O_3–Cu_2O system conductivity on the melt composition and temperature were examined herein. The optimal operating conditions for Dy–Cu alloy production were determined via analyses of the electrical conductivity and activation energies for conductance, which were calculated using the Arrhenius equation. The conductivity of the molten system regularly increases with increasing temperature and decreases with increasing concentration of Dy_2O_3 or Cu_2O or both. The activation energy Eκ of the LiF–DyF_3–Dy_2O_3 and LiF–DyF_3–Cu_2O molten-salt systems increases with increasing Dy_2O_3 or Cu_2O content. The regression functions of conductance as a function of temperature(t) and the addition of Dy_2O_3(W(Dy_2O_3)) and Cu_2O(W(Cu_2O)) can be expressed as κ =-2.08435 + 0.0068 t-0.18929 W(Dy_2O_3)-0.07918 W(Cu_2O). The optimal electrolysis conditions for preparing the Dy–Cu alloy in Li F–DyF_3–Dy_2O_3–Cu_2O molten salt are determined to be 2.0 wt% ≤ W(Dy_2O_3) +W(Cu_2O) ≤ 3.0 wt% and W(Dy_2O_3):W(Cu_2O) = 1:2 at 970 to 1000 °C.
Dy–Cu intermediate alloys have shown substantial potential in the field of magnetostrictive and magnetic refrigerant materials.Therefore, this study focused on investigating the electrical conductivity of molten-salt systems for the preparation of Dy–Cu alloys and on optimizing the corresponding operating parameters. The electrical conductivity of molten LiF–DyF_3–Dy_2O_3–Cu_2O systems was measured from 910 to 1030°C using the continuously varying cell constant method. The dependencies of the LiF–DyF_3–Dy_2O_3–Cu_2O system conductivity on the melt composition and temperature were examined herein. The optimal operating conditions for Dy–Cu alloy production were determined via analyses of the electrical conductivity and activation energies for conductance, which were calculated using the Arrhenius equation. The conductivity of the molten system regularly increases with increasing temperature and decreases with increasing concentration of Dy_2O_3 or Cu_2O or both. The activation energy Eκ of the LiF–DyF_3–Dy_2O_3 and LiF–DyF_3–Cu_2O molten-salt systems increases with increasing Dy_2O_3 or Cu_2O content. The regression functions of conductance as a function of temperature(t) and the addition of Dy_2O_3(W(Dy_2O_3)) and Cu_2O(W(Cu_2O)) can be expressed as κ =-2.08435 + 0.0068 t-0.18929 W(Dy_2O_3)-0.07918 W(Cu_2O). The optimal electrolysis conditions for preparing the Dy–Cu alloy in Li F–DyF_3–Dy_2O_3–Cu_2O molten salt are determined to be 2.0 wt% ≤ W(Dy_2O_3) +W(Cu_2O) ≤ 3.0 wt% and W(Dy_2O_3):W(Cu_2O) = 1:2 at 970 to 1000 °C.
Dy–Cu intermediate alloys have shown substantial potential in the field of magnetostrictive and magnetic refrigerant materials.Therefore, this study focused on investigating the electrical conductivity of molten-salt systems for the preparation of Dy–Cu alloys and on optimizing the corresponding operating parameters. The electrical conductivity of molten LiF–DyF_3–Dy_2O_3–Cu_2O systems was measured from 910 to 1030°C using the continuously varying cell constant method. The dependencies of the LiF–DyF_3–Dy_2O_3–Cu_2O system conductivity on the melt composition and temperature were examined herein. The optimal operating conditions for Dy–Cu alloy production were determined via analyses of the electrical conductivity and activation energies for conductance, which were calculated using the Arrhenius equation. The conductivity of the molten system regularly increases with increasing temperature and decreases with increasing concentration of Dy_2O_3 or Cu_2O or both. The activation energy Eκ of the LiF–DyF_3–Dy_2O_3 and LiF–DyF_3–Cu_2O molten-salt systems increases with increasing Dy_2O_3 or Cu_2O content. The regression functions of conductance as a function of temperature(t) and the addition of Dy_2O_3(W(Dy_2O_3)) and Cu_2O(W(Cu_2O)) can be expressed as κ =-2.08435 + 0.0068 t-0.18929 W(Dy_2O_3)-0.07918 W(Cu_2O). The optimal electrolysis conditions for preparing the Dy–Cu alloy in Li F–DyF_3–Dy_2O_3–Cu_2O molten salt are determined to be 2.0 wt% ≤ W(Dy_2O_3) +W(Cu_2O) ≤ 3.0 wt% and W(Dy_2O_3):W(Cu_2O) = 1:2 at 970 to 1000 °C.
引文
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[11]X.J.Lv,S.Y.Chen,Z.L.Tian,Y.Q.Lai,and J.Li,Review on the physical-chemical properties of the Na3Al F6-K3Al F6-Al F3 molten salt system,Light Met.,2013,No.8,p.29.
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[13]X.W.Hu,Z.W.Wang,B.L.Gao,and Z.N.Shi,Study on the electrical conductivity of NdF3-Li F-Nd2O3 system melts determined by CVCC technique,J.Northeastern Univ.Nat.Sci.,29(2008),No.9,p.1294.
[14]Q.S.Wu,Electrical conductivity and neodymium solubility of Nd2O3-Nd F3-Li F fusion salt system,Rare Met.Cem.Carbides,34(2006),No.1,p.52.
[15]C.F.Liao,H.Tang,X.Wang,L.S.Luo,and M.Z.Fang,Study on electrical conductivity of Na3Al F6-Al F3-Li F-Mg F2-Al2O3-Nd2O3-Cu O molten salt system,Rare Met.Cem.Carbides,44(2016),No.1,p.60.
[16]M.Bao,Z.W.Wang,B.L.Gao,Z.N.Shi,X.W.Hu,and J.Y.Yu,Electrical conductivity of Na F-Al F3-Al2O3-Ca F2-Zr O2molten salts,Trans.Nonferrous Met.Soc.China,23(2013),No.12,p.3788.
[17]C.F.Liao,Y.F.Jiao,X.Wang,B.Q.Cai,Q.C.Sun,and T.Hao,Electrical conductivity optimization of the Na3Al F6-Al2O3-Sm2O3 molten salts system for Al-Sm intermediate binary alloy production,Int.J.Miner.Metall.Mater.,24(2017),No.9,p.1034.
[18]K.Grjotheim,R.Nikolic,and H.A.?ye,Electrical conductivities of binary and ternary melts between Mg Cl2,Ca Cl2,Na Cl,and KCl,Acta Chem.Scand.,24(1970),No.2,p.489.
[19]R.Guo.Study of Al-Sc Alloy Prepared by Molten Salt Electrolysis Method[Dissertation],Northeastern University,Shenyang,2009,p.27.
[20]X.F.He,Y.G.Li,and Z.H.Li,Research on conductivity of KCl-Na Cl-Na F-Si O2 molten salt system,Hydrometall.China,29(2010),No.1,p.12.
[21]X.Guo,J.Sietsma,and Y.X.Yang,A critical evaluation of solubility of rare earth oxides in molten fluorides,[in]I.B.D.Lima,and W.L.Filho eds.,Rare Earths Industry:Technological,Economic and Environmental Implications,Elsevier,2015,p.223-234.
[22]B.L.Gao,F.G.Liu,Z.W.Wang,and Z.N.Shi,Study on electrical conductivity of the molten salts of KNO3-Na NO2-Na NO3 ternary system,J.Northeastern Univ.Nat.Sci.,31(2010),No.5,p.696.
[2]F.D.Liu,Y.Su,Y.Q.Chen,Y.F.Xiong,and X.F.Yi,Investigation and development of Nd Fe B magnets with excellent magnetic properties and stability of temperature,Met.Funct.Mater.,17(2010),No.3,p.5.
[3]L.Q.Yu,X.G.Cui,W.Luo,and M.Yan,Influence of Cu and Gd on thermal stability and magnetic properties of Nd(DyAl)FeB magnets,J.Zhejiang Univ.Eng.Sci.,39(2005),No.8,p.1251.
[4]S.M.Pang,S.H.Yan,Z.A.Li,D.H.Chen,L.H.Xu,and B.Zhao,Development on molten salt electrolytic methods and technology for preparing rare earth metals and alloys in China,Chin.J.Rare Met.,35(2011),No.3,p.440.
[5]G.K.Liu,Y.X.Tong,H.C.Hong,S.Y.Chen,and L.Gan,Studies on the preparation of Dy-Cu alloy in chloride melt by molten salt electrolysis,Acta Metall.Sinica,32(1996),No.12,p.1252.
[6]A.Sa?la,M.Gibilaro,L.Massot,P.Chamelot,P.Taxil,and A.M.Affoune,Electrochemical behavior of dysprosium(Ⅲ)in Li F-Ca F2 on Mo,Ni and Cu electrodes,J.Electroanal.Chem.,642(2010),No.2,p.150.
[7]H.Konishi,H.Ono,E.Takeuchi,T.Nohira,and T.Oishi,Electrochemical formation of RE-Cu(RE=Dy,Nd)alloys in a molten LiCl-KCl system,ECS Trans.,53(2013),No.11,p.37.
[8]K.S.Mohandas,N.Sanil,and P.Rodriguez,Development of a high temperature conductance cell and electrical conductivity measurements of MAlCl4(M=Li,Na and K)melts,Miner.Process.Extr.Metall.,115(2006),No.1,p.25.
[9]H.M.Kan,Z.W.Wang,Y.G.Ban,Z.N.Shi,and Z.X.Qiu,Electrical conductivity of Na3Al F6-Al F3-Al2O3-Ca F2-Li F(Na Cl)system electrolyte,Trans.Nonferrous Met.Soc.China,17(2007),No.1,p.181.
[10]L.Y.Chen,Research on Physical and Chemical Properties of Li F-Nd F3-Nd2O3 Molten Salt System[Dissertation],East China University of Science and Technology,Shanghai,2015,p.2.
[11]X.J.Lv,S.Y.Chen,Z.L.Tian,Y.Q.Lai,and J.Li,Review on the physical-chemical properties of the Na3Al F6-K3Al F6-Al F3 molten salt system,Light Met.,2013,No.8,p.29.
[12]V.Daněk,Physical and Chemical Analysis of Molten Electrolyte,B.L.Gao,X.W.Hu,Z.N.Shi,and Z.W.Wang,translated,Metallurgical Industry Press,Beijing,2014,p.54.
[13]X.W.Hu,Z.W.Wang,B.L.Gao,and Z.N.Shi,Study on the electrical conductivity of NdF3-Li F-Nd2O3 system melts determined by CVCC technique,J.Northeastern Univ.Nat.Sci.,29(2008),No.9,p.1294.
[14]Q.S.Wu,Electrical conductivity and neodymium solubility of Nd2O3-Nd F3-Li F fusion salt system,Rare Met.Cem.Carbides,34(2006),No.1,p.52.
[15]C.F.Liao,H.Tang,X.Wang,L.S.Luo,and M.Z.Fang,Study on electrical conductivity of Na3Al F6-Al F3-Li F-Mg F2-Al2O3-Nd2O3-Cu O molten salt system,Rare Met.Cem.Carbides,44(2016),No.1,p.60.
[16]M.Bao,Z.W.Wang,B.L.Gao,Z.N.Shi,X.W.Hu,and J.Y.Yu,Electrical conductivity of Na F-Al F3-Al2O3-Ca F2-Zr O2molten salts,Trans.Nonferrous Met.Soc.China,23(2013),No.12,p.3788.
[17]C.F.Liao,Y.F.Jiao,X.Wang,B.Q.Cai,Q.C.Sun,and T.Hao,Electrical conductivity optimization of the Na3Al F6-Al2O3-Sm2O3 molten salts system for Al-Sm intermediate binary alloy production,Int.J.Miner.Metall.Mater.,24(2017),No.9,p.1034.
[18]K.Grjotheim,R.Nikolic,and H.A.?ye,Electrical conductivities of binary and ternary melts between Mg Cl2,Ca Cl2,Na Cl,and KCl,Acta Chem.Scand.,24(1970),No.2,p.489.
[19]R.Guo.Study of Al-Sc Alloy Prepared by Molten Salt Electrolysis Method[Dissertation],Northeastern University,Shenyang,2009,p.27.
[20]X.F.He,Y.G.Li,and Z.H.Li,Research on conductivity of KCl-Na Cl-Na F-Si O2 molten salt system,Hydrometall.China,29(2010),No.1,p.12.
[21]X.Guo,J.Sietsma,and Y.X.Yang,A critical evaluation of solubility of rare earth oxides in molten fluorides,[in]I.B.D.Lima,and W.L.Filho eds.,Rare Earths Industry:Technological,Economic and Environmental Implications,Elsevier,2015,p.223-234.
[22]B.L.Gao,F.G.Liu,Z.W.Wang,and Z.N.Shi,Study on electrical conductivity of the molten salts of KNO3-Na NO2-Na NO3 ternary system,J.Northeastern Univ.Nat.Sci.,31(2010),No.5,p.696.