废弃荧光粉中Y、Eu浸出及其动力学分析

Leaching of Yttrium and Europium Elements from Waste Fluorescent Lamps and Kinetics Analysis

本文以废弃荧光粉为原料,盐酸为浸出剂,H2O2为还原剂酸浸回收稀土元素Y和Eu,探究了浸出时间、盐酸浓度、浸取温度以及固液比对稀土浸出过程的影响,并进行了浸出过程动力学分析。结果表明:在浸出时间为60 min、盐酸浓度为9 mol/L、浸出温度为80℃、液固体积比为10∶1最优条件时,Y、Eu最大浸出率分别为99.31%和88.50%。通过X射线衍射(XRD)和扫描电子显微镜(SEM)对浸出前后的材料进行表征,可以得出在浸出过程中原有的结构被破坏。采用缩心模型对浸出动力学数据进行拟合,结果显示浸出过程受扩散控制。

In order to efficiently leaching waste fluorescent powder of rare earth elements,the leaching process of rare earth elements Y and Eu was studied in the paper by direct acid leaching method from abandoned lamp with tricolor phosphors.Effect of different hydrochloric acid concentration,leaching temperature,leaching time,liquid and solid product quality on the rare earth leaching rate was determined;Furthermore,dynamic analysis was carried out to examine the leaching process.According to the experiment,the results showed that the maximum leaching rates of Y and Eu were 99.31%and 88.50%,respectively,when the leaching time was 60min,the concentration of hydrochloric acid was 9mol/L,the leaching temperature was 80℃,and the liquid-solid ratio was 10∶1.The kinetic model of acid leaching reaction shows that the leaching process is controlled by diffusion.