Determination of eight major rare earth oxides in light rare earth ore by X-ray fluorescence spectrometry with fusion sample preparation
YU Li-li1,2,3
1. Guangdong Institute of Resources Comprehensive Utilization, Guangzhou 510650, China; 2. State Key Laboratory for Separation and Comprehensive Utilization of Rare Metals, Guangzhou 510650, China; 3. Guangdong Key Laboratory for Development and Comprehensive Utilization of Mineral Resources, Guangzhou 510650, China
Abstract：The rare earth ore has a wide range of variety with complex composition and is usually rich in Ca, P, Fe, Ba, Si, S, Mn and Pb. During sample preparation by fusion sample preparation method, the rare earth ores containing simple substances of Fe, Mn and Pb will corrode the Pt-Au crucible.The rare earth ore sample was mixed with mixture flux [m(Li2B4O7)∶m(LiBO2)=33∶67] with mass ratio of 1∶14 (dilution ratio). Then 1mL of 500g/L NH4NO3 solution was added as oxidizer and 0.2mL of 100g/L LiBr solution was added as release reagent. The uniform glass tablet was prepared by fusion at 1050℃. Eight major rare earth oxides in light rare earth ore (including La2O3, CeO2, Pr6O11, Nd2O3, Sm2O3, Eu2O3, Gd2O3 and Y2O3) were determined by wavelength dispersive X-ray fluorescence spectrometry (WDXRF). The detection limits of rare earth oxides ranged from 5μg/g to 159μg/g. The proposed method was applied for the determination of eight rare earth oxides in two certified reference materials of rare earth ore, GSB04-3549-2019 (total rare earth content was 4.44%) and GSB04-3309-2016 (total rare earth content was 29.09%). The relative standard deviations (RSD, n=7) of determination results for rare earth oxides in low-grade rare earth ore (GSB04-3549-2019) were less than 13%, while the RSD (n=7) for high-grade rare earth ore (GSB04-3309-2016) were less than 2%. Two light rare earth ore samples (total rare earth content was 2.55% and 24.64%, respectively) were selected. The recovery test of total rare earth content was conducted according to the experimental method. The found recoveries were between 96% and 100%. The contents of La2O3, CeO2, Pr6O11, Nd2O3, Sm2O3, Eu2O3, Gd2O3 and Y2O3 in two certified reference materials of rare earth ore (GSB04-3550-2019 and GSB04-3311-2016) and two actual samples were determined according to the experimental method, and the found results were consistent with the certified values or those obtained by inductively coupled plasma atomic emission spectrometry (ICP-AES). The proposed method had relatively wide adaptability and it could meet the detection requirements of major rare earth oxides in light rare earth ores with complex composition.
李会谦,杨晓剑.稀土新材料产业的发展现状及建议[J].工程技术研究(Engineering and Technological Research),2017(1):75-76.
[3]
郭小明.稀土永磁材料的发展及应用[J].江西化工,2018(6):242-243.GUO Xiao-ming.Development and application of rare earth permanent magnet materials[J].Jiangxi Chemical Industry,2018(6):242-243.
[4]
高励珍,张立峰,崔爱端,等.草酸盐重量法测定镝铁合金中稀土总量[J].稀土,2010,31(6):61-66.GAO Li-zhen,ZHANG Li-feng,CUI Ai-duan,et al.Determination of total rare earth content in Dy-Fe alloy with oxalate gravimetric method[J].Chinese Rare Earths,2010,31(6):61-66.
[5]
宋旭东,樊小伟,陈文,等.电感耦合等离子体质谱法测定离子吸附型稀土矿中全相稀土总量[J].冶金分析,2018,38(6):19-24.SONG Xu-dong,FAN Xiao-wei,CHEN Wen,et al.Determination of total-phase rare earth content in ion-adsorption rare earth ore by inductively coupled plasma mass spectrometry[J].Metallurgical Analysis,2018,38(6):19-24.
[6]
胡珊玲,邱谨,吴志芳,等.三溴偶氮胂分光光度法测定镁合金中稀土总量[J].冶金分析,2016,36(10):85-88.HU Shan-ling,QIU Jin,WU Zhi-fang,et al.Determination of total rare earths in magnesium alloy by tribromoarsenazo spectrophotometry[J].Metallurgical Analysis,2016,36(10):85-88.
[7]
吉昂,陶光仪,卓尚军,等.X射线荧光光谱分析[M].北京:科学出版社,2003:1-7.
[8]
罗立强,詹秀春,李国会.X射线荧光光谱仪[M].北京:化学工业出版社,2008:1-5.
[9]
李小莉,张勤.粉末压片-X射线荧光光谱法测定土壤、水系沉积物和岩石样品中15种稀土元素[J].冶金分析,2013,33(7):35-40.LI Xiao-li,ZHANG Qin.Determination of fifteen rare earth elements in soil,stream sediment and rock samples by X-ray flourescence spectrometry with pressed powder pellet[J].Metallurgical Analysis,2013,33(7):35-40.
[10]
蒋天怡,吴文琪,张术杰,等.熔融制样-X射线荧光光谱法测定轻稀土精矿中稀土总量[J].冶金分析,2017,37(12):27-32.JIANG Tian-yi,WU Wen-qi,ZHANG Shu-jie,et al.Detetmination of total rare earths in light rare earth concentrate by X-ray fluorescence spectrometry with fusion sample preparation[J].Metallurgical Analysis,2017,37(12):27-32.
