微波消解-电感耦合等离子体原子发射光谱法测定稀土合金渣中主要稀土氧化物

Determination of main rare earth oxides in rare earth alloy slag by microwave digestion-inductively coupled plasma atomic emission spectrometry

提出了微波消解-电感耦合等离子体原子发射光谱(ICP-AES)同时测定稀土合金渣中氧化镧、氧化铈、氧化镨、氧化钕、氧化钐和氧化镝等主要稀土氧化物的分析方法。考察4种不同的消解试剂体系,优化了消解参数并选择了合适的分析线。结果表明,在以下条件下样品的消解效果最好:以HNO3-HCl-HF-H2O2(V(HNO3)∶V(HCl)∶V(HF)∶V(H2O2)=4∶2∶2∶1)作为消解试剂,采用四段升温的消解程序,设定的最低温度为160℃,最低压力为1.5MPa,最高温度为225℃,最高压力为3.5MPa,每段的最大温差不超过25℃,最大压差不超过1MPa。在选定的仪器参数下,以408.671,413.765,390.843,401.255,359.260,353.171nm波长的谱线分别作为La,Ce,Pr,Nd,Sm,Dy的分析线,用稀土氧化物绘制校准曲线,ICP-AES法测定消解液中上述氧化物。测定结果的相对标准偏差在0.44%～0.98%范围,加标回收率在94%～106%之间。

An analysis method of simultaneous determination of the main rare earth oxides such as lanthanum oxide,cerium oxide,praseodymium oxide,neodymium oxide,samarium oxide and dysprosium oxide in rare earth alloy slag by microwave digestion-inductively coupled plasma atomic emission spectrometry（ICP-AES） was put forward.Four different digestion reagent systems were examined,digestion parameters were optimized and the appropriate analytical line was selected.The results showed that the digestion effect of samples was best under the following conditions： HNO3-HCl-HF-H2O2（V（HNO3）∶V（HCl）∶V（HF）∶V（H2O2）=4∶2∶2∶1） as a digestion reagent,four steps of temperature digestion process,the minimum temperature of 160℃,the minimum pressure of 1.5 MPa,the maximum temperature of 225℃,and the maximum pressure of 3.5 MPa,the maximum temperature difference of each step not exceeding 25℃,and the maximum differential pressure not more than 1 MPa.Under selected instrument parameters,using the spectral line of wavelength 408.671 nm,413.765 nm,390.843 nm,401.255 nm,359.260 nm and 353.171 nm as the analytical line of La,Ce,Pr,Nd,Sm,Dy respectively,and with rare earth oxide to prepare the calibration curve,the rare earth oxides above in digestion solution were determined by ICP-AES.The relative standard deviation of the measured results was in the range of 0.44% to 0.98%,and the recovery rate was between 94% to 106%.