Abstract：The accurate determination of total rare earth content in lanthanum-nickel alloy has great significance for the effective control of production technology and product quality of lanthanum-nickel alloy. Since the content of nickel in lanthanum-nickel alloy was higher than 50% (mass fraction, similarly hereinafter), while the content of other coexisting elements was low (about 10% and 5% for cobalt and manganese), it was difficult to completely separate coexisting elements through a single separation method. The coexisting elements were separated by fluorine separation, ammonia separation and oxalic acid precipitation successively. Then the determination of total rare earth content in lanthanum-nickel alloy was discussed. The samples were dissolved with hydrochloric acid and nitric acid. The rare earths were precipitated using hydrofluoric acid, ammonia water and oxalic acid to separate and remove interference elements one by one. Under the condition of pH 1.8-2.0, the rare earths were precipitated into rare earth oxalates, which were then burned at 950℃ to form rare earth oxides (without thorium oxide). Finally the content of total metal rare earths was calculated by converting lanthanum to lanthanum oxide. The samples could be dissolved completely and smoothly using hydrochloric acid-nitric acid, and the determination result (30.42%) was consistent with the reference value (30.43%). The non-rare earth impurities including nickel, cobalt, manganese, aluminum, copper and iron were well removed by fluorine separation, ammonia separation and oxalic acid precipitation. Total content of rare earths in lanthanum-nickel alloy samples was determined according to the experimental method, and the relative standard deviations (RSD, n=11) were all less than 0.50%. The spiked recoveries were between 99% and 101%. Total content of rare earths in lanthanum-nickel alloy was determined in two laboratories according to the experimental method, and the results were consistent with the reference values.
刘显坤,刘颖,郑洲,等.Co掺杂镧镍合金及氢化物的第一性原理研究[J].稀有金属材料与工程,2010,39(8):1348-1353.LIU Xian-kun,LIU Ying,ZHENG Zhou,et al.First-principles study of Co-doped La-Ni alloy and its hydrid[J].Rare Metal Materlals and Engineering,2010,39(8):1348-1353.
[2]
许涛,王东杰,郝茜.钐钴合金中稀土总量的测定[J].稀土,2014,35(3):72-76.XU Tao,WANG Dong-jie,HAO Qian.Determination of totalrare earth contents in Sm Co alloy[J].Chinese Rare Earths,2014,35(3):72-76.
[3]
王东杰,易红宏,唐晓龙,等.稀土系贮氢合金中稀土总量的测定[J].分析试验室,2016,35(11):1353-1358.WANG Dong-jie,YI Hong-hong,TANG Xiao-long,et al.Determination of total rare earth based in rare earth system hydrogen storage alloys[J].Chinese Journal of Analysis Laboratory,2016,35(11):1353-1358.
[4]
王素梅,张慧珍,郝茜.钆镁合金中稀土总量的测定——草酸盐重量法[J].稀土,2013,34(2):65-67.WANG Su-mei,ZHANG Hui-zheng,HAO Qian.Determination of rare earth content in gadolinium magnesium alloys-oxalate gravimetric method[J].Chinese Rare Earths,2013,34(2):65-67.
[5]
王素梅,张慧珍,蒋天怡,等.氨水沉淀分离EDTA络合滴定法测定镧镍合金废渣中的镍[J].稀土,2018,39(4):119-124.WANG Su-mei,ZHANG Hui-zhen,JIANG Tian-yi,et al.Determination of nickel in waste lanthanum-nickel alloy by EDTA titrimetry after separation by precipitation with ammonia[J].Chinese Rare Earths,2018,39(4):119-124.
[6]
肖勇.氢氟酸分离-EDTA 容量法测定钕铁硼废料中稀土总量[J].江西有色金属,2007,21(1):40-41.XIAO Yong.Hydrofluoric acid separating-EDTA capacity measuring of total rare earth content in neodymium-iron-boron waste material[J].Jiangxi Nonferrous Metals,2007,21(1):40-41.
[7]
孙志峰,张志刚,张翼明,等.镝铁合金中稀土总量的测定-EDTA 容量法[J].稀土,2010,31(1):77-79.SUN Zhi-feng,ZHANG Zhi-gang,ZHANG Yi-ming,et al.Determination of total rare earth contents in Dy-Fe alloy with EDTA volume method[J].Chinese Rare Earths,2010,31(1):77-79.
孙宇红,李建华,贾建平.稀土镁合金中稀土总量的测定-草酸盐重量法测定稀土总量[J].云南大学学报,2005,27(3):400-402.SONG Yu-hong,LI Jian-hua,JIA Jian-ping.Determination of total rare earth elements in rare earth magnesium alloys-determination of total rare earth elements by oxalate gravimetric method[J].Journal of Yunnan University,2005,27(3):400-402.
