电感耦合等离子体原子发射光谱法测定赤泥浸出液中稀土元素

对赤泥浸出液中稀土元素含量进行测定可以指导研发人员初步判断赤泥中的稀土总量。采用5 mol/L盐酸浸取赤泥中稀土元素镧、铈、镨、钕、钪、钇,并采用电感耦合等离子体原子发射光谱法(ICP-AES)进行了测定。以功率、辅助气流量、分析泵速和积分时间为考察因素,各元素分析谱线的发射强度为考察指标,设计了L₉(3⁴)的正交试验,确定了电感耦合等离子体原子发射光谱仪的最佳工作条件为功率950 W、辅助气流量为0.50 L/min、分析泵速为100 r/min、积分时间为10 s。使用标准加入法绘制校准曲线,消除了基体及杂质元素对待测稀土元素测定的影响。各待测元素校准曲线的线性相关系数均不小于0.999 9,方法中稀土元素镧、铈、镨、钕、钪、钇的检出限在0.002 4～0.013 mg/L之间。按照实验方法测定赤泥浸出液实际样品中稀土元素镧、铈、镨、钕、钪、钇,结果的相对标准偏差(RSD,n=6)为0.21%～1.2%,回收率为96%～114%。采用实验方法和电感耦合等离子体质谱法(ICP-MS)分别对赤泥浸出液中的稀土元素镧、铈、镨、钕、钪、钇进行测定,两种方法的测定结果基本一致。

Determination of rare earth elements in leaching solution of red mudby inductively coupled plasma atomic emission spectrometry

To determine the content of rare earth elements in leaching solution of red mud could guide researchers for preliminary assessment of the total amount of rare earth elements in red mud. After the rare earth elements including lanthanum, cerium, praseodymium, neodymium, scandium and yttrium in red mud were leached with 5 mol/L hydrochloric acid,they were determined by inductively coupled plasma atomic emission spectrometry(ICP-AES). The orthogonal experiment of L₉ (3⁴) was designed with power, auxiliary gas flow rate, analytical pump speed and integral time as the investigation factors and the emission intensity at the analytical spectral line of each element as the investigation index. Then the optimal inductively coupled plasma atomic emission spectrometer working conditions were obtained as follows: power of 950 W, auxiliary gas flow rate of 0.50 L/min, analytical pump speed of 100 r/min and integral time of 10 s. The calibration curve was prepared by standard addition method to eliminate the influence of matrix and impurity elements on the determination of rare earth elements. The linear correlation coefficients of calibration curves of test elements were all not smaller than 0.999 9. The detection limit of lanthanum, cerium, praseodymium, neodymium, scandium and yttrium in this method was between 0.002 4 and 0.013 mg/L. The content of rare earth elements (lanthanum, cerium, praseodymium, neodymium, scandium and yttrium) in leaching solution actual sample of red mud was determined according to the experimental method. The relative standard deviations (RSD, n=6) were in range of 0.21%-1.2%. The recoveries were between 96% and 114%. The content of lanthanum, cerium, praseodymium, neodymium, scandium and yttrium in leaching solution of red mud was determined by proposed method and inductively coupled plasma mass spectrometry (ICP-MS), respectively. The results were basically consistent.