X射线荧光光谱法在线测定稀土冶炼分离过程中钬铒铥镱

我国稀土冶炼分离过程复杂,但多数稀土企业仍依靠实验室离线分析指导工艺,导致分析结果严重滞后,因此现迫切需要一种高效稳定的稀土在线分析方法。实验应用稀土配分在线分析仪,建立了一种在线测定稀土冶炼分离过程中Ho、Er、Tm、Yb配分含量的方法。将采样管置于串级萃取槽水相分隔室内,在蠕动泵作用下将样品输送至分析区域,通过X射线荧光光谱法(XRF)进行检测和数据记录。实验将XRF测试条件优化为电压40 kV、电流600 μA、测试时间60 s,模拟现场工况条件下优化蠕动泵泵速为250 r/min,并采用基本参数法消除元素间吸收增强效应。样品11次测定结果的相对标准偏差(RSD)小于0.4%,实验室模拟及现场在线测试结果与电感耦合等离子体原子发射光谱法(ICP-AES)的离线分析结果吻合较好,测试结果滞后时间短,完全能够满足稀土冶炼分离过程工艺动态控制的测定需要。

On-line determination of holmium,erbium, thulium and ytterbium in rare earth smelting separation process by X-ray fluorescence spectrometry

The smelting separation process of rare earths in China is complicated. However, most rare earth enterprises still depend on laboratory off-line analysis to guide the process, leading to serious lagging of analytical results. Therefore, it is necessary to develop a high-efficiency and stable on-line analysis method for rare earths. In this paper, a kind of on-line determination method of holmium, erbium, thulium and ytterbium content in rare earth smelting separation process was established using rare earth distribution pattern on-line analyzer. The sampling tube was located in aqueous phase compartment of cascade-stage extraction tank. The sample was transported to the analysis area by peristaltic pump for X-ray fluorescence spectrometry (XRF) analysis and data record. The XRF testing conditions were optimized: the voltage was 40 kV, the current was 600 μA, and the testing time was 60 s. The in-site conditions were simulated and the optimal peristaltic pump speed was 250 r/min. The absorption enhancement effect among elements was eliminated by fundamental parameter method. The relative standard deviation (RSD, n=11) was less than 0.4%. The laboratory simulation and in-site on-line measurement results were in good agreement with the off-line analytical results by inductively coupled plasma atomic emission spectrometry (ICP-AES). The lagging time of measurement results was short, which could meet the determination requirements of dynamic control in rare earth smelting separation process.