NdF3-LiF-Nd2O3体系粘度的研究

采用坩埚扭摆法研究了NdF3-LiF熔盐体系的粘度,讨论了NdF3含量及温度对体系粘度的影响,并考察了加入Nd2O3对体系粘度的影响。合理地解释了个别组分熔盐粘度出现异常的现象。     

NdF3-LiF-Nd2O3体系表面张力的研究

用拉筒法研究了 Nd F3- L i F体系的表面张力。采用二因子二次回归正交设计 ,得出表面张力 (σ)与Nd F3含量 (C)、温度 (t)的回归方程 ,讨论了 Nd F3含量、温度对表面张力的影响 ,并考察了加入 Nd2 O3 对体系表面张力的影响     

Nd2O3-NdF3-LiF熔盐体系中电导率及钕溶解度的测定

研究了Nd2O3-NdF3-LiF熔盐体系中电导率及钕的溶解度，并根据实验数据拟合了回归方程，分析TN度、LiF浓度、Nd2O3浓度对两种物理性质的影响。结果表明，升高温度，提高LiF浓度以及降低Nd2O3浓度可以提高熔盐体系的电导率；而降低温度，降低LiF浓度以及提高Nd2O3浓度可以减少钕在熔盐中的溶解度。所得研究结果可为电解氟盐法生产钕选择合理的电解质成分提供依据。     

NdF_3-LiF-Nd_2O_3体系熔盐电导率的研究

采用交流阻抗谱技术测定熔盐电阻,并通过CVCC法研究了在1 020～1 120℃的温度范围内NdF3-LiF-Nd2O3熔盐体系的电导率,确定了温度、Nd2O3含量与熔盐电导率之间的关系,分析了温度和Nd2O3含量之间的相互作用以及对熔盐电导率的影响。研究结果表明,温度增加、Nd2O3含量减少,则电导率增大;在温度为1 080℃,Nd2O3含量为1.5%、2%、3.5%时,熔盐电导率变化幅度小,体系较为稳定。     

Na_3AlF_6-AlF_3-LiF-MgF_2-Al_2O_3-Nd_2O_3-CuO熔盐体系电导率的研究

采用TH2810DLCR数字电桥测试仪确定熔盐电阻,通过CVCC法研究Na3AlF6-AlF3-LiF-MgF2-Al2O3-Nd2O3-CuO熔盐体系电导率,并采用最小二乘法对数据进行拟合,确定了温度、熔盐组分与熔盐电导率之间的关系式。研究结果表明,当温度升高或CuO含量增大时,熔盐电导率增大;而当Nd2O3和Al2O3含量增大时,熔盐电导率则逐渐减小;当温度一定时,同时加入相同质量比的Nd2O3和CuO,熔盐体系的电导率随Nd2O3、CuO添加量的增大而增大。     

NdF3—LiF—Nd2O3体系表面张力数学模型的研究

用拉筒法研究了低NdF3浓度下NdF3-LiF体系的表面张力,采用二因子二次回归正交设计,得出表面张力（σ）与NdF3含量（C）、温度（t) 的回归方程,讨论了NdF3含量、温度对表面张力的影响,并考察了加入Nd2O3对体系表面张力的影响。     

NdF_3-LiF-Nd_2O_3体系表面张力数学模型的研究

用拉筒法研究了低NdF3 浓度下NdF3-LiF体系的表面张力 .采用二因子二次回归正交设计 ,得出表面张力 (σ)与NdF3 含量 (C)、温度 (t)的回归方程 ,讨论了NdF3含量、温度对表面张力的影响 ,并考察了加入Nd2 O3 对体系表面张力的影响     

NdF3-LiF-Nd2O3体系表面张力的研究

用拉筒法研究了NdF3-LiF体系的表面张力。采用二因子二次回归正交设计,得出表面张力(σ)与NdF3含量(C)、温度(t)的回归方程,讨论了NdF3含量、温度对表面张力的影响,并考察了加入Nd2O3对体系表面张力的影响。     

钕铁在NdCl_3-KCl熔盐中溶解行为的研究

在用电化学方法研究了钕在NdCl_3熔盐中溶解度和溶解机理之后,本文用重差法和最大气泡压力法测定了钕和钕铁合金在NdCl_3-KCl熔盐中的溶解损失,熔盐表面张力与添加剂的关系,证实了钕铁合金的电化学和化学溶解机理:钕在熔盐中溶解损失是影响电流效率的主要因素。     

NdF3-LiF-Nd2O3系熔盐密度的研究

用阿基米德法研究了ＮｄＦ３－ＬｉＦ体系熔盐的密度。采用二因子二次回归正交设计，得出密度（ρ）与ＮｄＦ３含量（ｃ）、温度（ｔ）的回归方程，讨论了ＮｄＦ３含量及温度对熔体密度的影响，并考察了加入Ｎｄ２Ｏ３对体系密度的影响。     

钕电解相关物质理论分解电压的计算

本文计算了NdF3-LiF-Nd2O3体系各物质的理论分解电压。结果表明,采用惰性阳极,理论分解电压按Nd2O3、NdF3、LiF顺序依次增大,温度升高,理论分解电压降低;采用活性阳极(石墨)时,Nd2O3与石墨反应生成CO和CO2,其理论分解电压较小,反应较易发生,尤以生成CO的反应更易发生。但当电流密度较高或Nd2O3浓度较低时,可能生成碳氧氟化合物及氟碳化合物,并发生阳极效应,各物质的理论分解电压也随温度的升高而降低。     

钕电解阳极过电位的测定

用慢扫描示波法测定了钕电解的阳极过电位 .考察了温度、阳极电流密度、Nd2 O3添加量、电解质组成等因素对阳极过电位的影响 ,探讨了降低阳极过电位的可能途径 .结果表明 ,阳极过电位随阳极电流密度的增加而增大 ,随温度的升高而减小 ,一定范围内 ,阳极过电位与阳极电流密度的对数呈线性关系 ,满足塔菲尔方程 ;电解质中LiF和Nd2 O3浓度增加 ,阳极过电位降低 ;适当控制阳极电流密度、升高温度、增加电解质中LiF和Nd2 O3的浓度并尽可能减小极间距 ,均有利于降低阳极过电位     

NdF3—NaF—LiF熔体电导率的研究

采用三因子一次正交回归设计实验，研究了NdF3-NaF－LiF熔体的电导率，得出了该体系电导率的数学模型，分析了温度、NdF3浓度、NaF与LiF的摩尔比对电导率的影响。结果表明，提高温度、降低NdF3浓度、降低NaF与LiF的摩尔比均能提高电导率。所得研究结果可为稀土氟盐电解选择廉价电解质成分提供依据。     

Density and ionic structure of NdF3-LiF melts

NdF3-LiF melts are commonly used in the electrolysis process of metallic neodymium production. Research on the density and ionic structure of the electrolyte is important for its close connection with the electrolysis mechanism and process. In this paper, the density of LiF-NdF3 melts was studied by the Archimedes method. The results showed that the density decreased with increasing temperature and LiF contents. The changing law was discussed and explained in terms of the micro ionic structure of the melts....     

Effect of fluxes on structure and luminescence properties of Y3Al5O12：Ce^3＋ phosphors

Ce3+-activated yttrium aluminum garnet (YAG) was prepared by the solid-state reaction, in which H3BO3, LiF, NaF, KF and BaF2 were used as the fluxes. The effect of fluxes on optical properties of phosphors was studied in detail, especially the fluxes of alkali fluorides, which could enhance the emission intensity and change the wavelength of emission peaks. Among these YAG:Ce phosphors, the phosphor sintered with H3BO3 and NaF exhibited the strongest emission. The emission peaks of phosphors prepared with fluxes from LiF to KF were shifted to long wavelength. The effect of NaF concentration on the emission intensity of YAG:Ce was also investigated. The value of emis-sion intensity reached the maximum when the concentration of NaF was 0.5%.     

Study on F-F Transitions of Powdered Neodymium Compounds by Photoacoustic Spectroscopy

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Viscosity and Structure Changes of CaO-SiO2-Al2 O3-CaF2 Melts with Substituting Al2 O3 for SiO2

During the smelting process of the high Al steels,the reaction between SiO_2 in molten slag and dissolved aluminum in liquid steel always takes place.This aluminathermic reduction reaction will lead to the substitution of 1mol SiO_2 for 2/3mol Al_2O_3.Therefore,the investigations about the influence of the ratio of Al_2O_3 to SiO_2on viscosity and structure changes of mould flux during this process are very necessary.The viscosity variation of CaO-SiO_2-Al_2O_3-CaFv2 melts was studied by changing compositions considering the aluminathermic reduction reaction.It was found that viscosity increased monotonously with gradually increasing the substitution extent.According to the Raman analysis,the substitution of Al_2O_3 for SiO_2 leads to the decrease of non-bridging oxygen but the increase of bridging oxygen.Therefore,degree of polymerization and viscosity increase as the substitution extent increases.By comparing the measured viscosities with the model calculated values,it was found that both the recently developed Zhang′s model and Roboud model could describe the viscosity variation behavior of CaO-SiO_2-Al_2O_3-CaF_2 melts very well.