稀土精矿分离出单一稀土元素的工艺过程属于连续流程制造, 多采用人工取样-ICP实验室分析测试的方法进行工艺监测与控制, 检测结果滞后于生产实际, 可能造成产品质量不稳定等后果。 实验基于能量色散X射线荧光光谱技术, 建立了一种在线测定稀土分离过程中稀土配分含量的方法。 通过对北方稀土典型元素镧、 铈、 镨、 钕的能量色散-X射线荧光光谱特征分析, 利用多元逐步回归从稀土混合料液中剥离出单一稀土元素信号。 依据相对理论偏差对滤光片、 管压、 管流等条件进行优化, 为稀土配分含量在线分析奠定了基础。 开发了XOR-50稀土配分在线分析设备和在线检测方法, 快速反映稀土分离萃取工艺状况, 提供实时的在线萃取数据, 为工艺调整提供精准可靠的数据支撑。 研究结果显示, 采用0.2 mm Al滤光片, 25 kV光管激发电压, 1 100 μA光管电流的测试条件, 同一样品的稀土元素配分含量连续11次测定的相对标准偏差小于1%; 现场分析结果与ICP-AES检测结果相符。 镧, 铈, 镨, 钕等轻稀土元素的仪器检出限小于5 μg·mL-1, 完全满足稀土配分在线监测对准确性和可靠性要求。

Separating a single rare earth element (REE) from the rare-earth concentrate is a continuous process, in which the artificial sampling - ICP laboratory analysis is usually used for process monitoring and control. The results of the test lag behind the actual production and may lead to problems such as the instability of the product quality and so on. Based on the energy dispersive X-ray fluorescence spectrometry, a method to determine the REE distribution in the process of rare earth separation was established. The X-ray fluorescence spectral signal of single rare earth element was obtained by multiple stepwise regression via analysis of typical north rare earth elements (lanthanum, cerium, praseodymium, neodymium). The experimental conditions, such as the filter, tube and tube flow, were optimized according to the relative theoretical deviation, which laid the foundation for online analysis of REE distribution. In this study, the XOR-50 analytical equipment and on-line detection method of rare earth distribution were developed, which could fast reflect the technical condition of rare earth extraction and separation, providing real-time online extraction data and offering accurate and reliable data for process adjustment. The results showed that using 0.2 mm of Al filter, 25 kV of lightpipes excitation voltage, 1 100 μA light tube current test conditions, the relative standard deviation of the REE distribution in the same sample for 11 consecutive times was less than 1%. The results of field analysis were consistent with ICP-AES test results. The detection limit of rare earth elements, such as lanthanum, cerium, praseodymium, neodymium and other light rare earth elements, was detected to be less than 5 μg·mL-1, which completely met the accuracy and reliability requirements of rare earth distribution online monitoring.