DU Yejian, CAO Junjie, XUE Jianping, LI Shuping, JIANG Yujuan, WANG Binghua, GU Na
In order to meet the efficient and simultaneous determination requirements of oxide distribution in rare earth concentrates,a method for the determination of 15 rare earth element oxide distributions (La2O3,CeO2,Pr6O11,Nd2O3,Sm2O3,Eu2O3,Ga2O3,Tb4O7,Dy2O3,Ho2O3,Er2O3,Tm2O3,Yb2O3,Lu2O3 and Y2O3) in rare earth concentrate by inductively coupled plasma atomic emission spectrometry(ICP-AES) was established in this study.The sample was dissolved with hydrochloric acid and perchloric acid followed by extraction with hydrochloric acid.Dilute hydrochloric acid was selected as the medium for determination.The analytical spectral line,limit of detection and limit of quantification of rare earth element were determined through experiments.Moreover,the influences of coexisting elements,the dosage of hydrochloric acid and perchloric acid,and the amount of sample on the determination results were investigated.The results showed that rare earth element cerium(Ce) had interference with Ho 339.898 nm but had no interference with Ho 345.600 nm.Non-rare earth element titanium(Ti) had interference with Er 337.271 nm but had no interference with Er 326.478 nm.Other rare earth elements and non-rare earth elements had no interference with the analytical spectral lines selected or the interference could be ignored.0.2 g of sample could be fully dissolved with 5 mL of hydrochloric acid and 10 mL of perchloric acid.The linear correlation coefficients of tested elements were all not less than 0.999 4.The limit of detection of the method was 0.000 46%-0.035%(mass fraction,in oxide,the same below),and the limit of quantification was 0.001 5%-0.12%.The proposed method was applied for the determination of 15 rare earth element oxide distributions in 3 rare earth concentrate samples.The relative standard deviation(RSD,n=11) of determination results was between 0.41% and 2.4%.The measured results of this method were consistent with those obtained by alkali fusion-ICP-AES in GB/T 18114.8-2010,and the limit of quantification was low.The proposed method could meet the analysis and detection requirements of 15 rare earth element oxide distributions in rare earth concentrate.
