响应曲面法优化微波浸出废弃荧光粉中稀土元素钇和铕

Optimization of Microwave Leaching of Rare Earth Elements Yteelium and Europium in Waste Phosphors by Response Surface Methodology

某废弃荧光粉中含有49.56%的稀土氧化物,具有极大的回收利用价值。为优化该废弃荧光粉中稀土元素Y和Eu的微波浸出工艺,使用响应面法对浸出工艺进行优化,选取对浸出过程有显著影响的反应时间、微波功率和盐酸浓度三个因素作为考察因素,建立了微波功率、反应时间和盐酸浓度及三者间交互作用对稀土元素Y和Eu浸出率影响的二次多项式回归模型。研究结果表明,反应时间对稀土元素Y和Eu浸出率的影响最显著,微波功率和盐酸浓度影响次之,反应时间和盐酸浓度的交互影响对稀土元素Y和Eu的浸出率具有显著性影响。最佳优化工艺条件为:微波功率850 W、反应时间76.10 min、盐酸浓度3.58 mol/L,在此条件下,稀土元素Y和Eu浸出率的分别为97.44%和89.20%,与模型预测值十分接近,证明所用模型是可靠和准确的。

A waste phosphors contained 49.63%rare earth oxide,which had high value for recovery and utilization.In order to optimize the microwave leaching process of rare earth elements Y and Eu in the waste phosphor,the response surface method was used,and the variables that had a significant impact on the leaching process-reaction time,microwave power and hydrochloric acid concentration were selected as the factors to be investigated.A quadratic polynomial regression model of the effects of microwave power,reaction time and hydrochloric acid concentration as well as their interaction on the leaching rate of rare earth elements Y and Eu was established.The results showed that the reaction time had the most significant effect on the leaching rate of Y and Eu,followed by microwave power and hydrochloric acid concentration,and the interaction effect of reaction time and hydrochloric acid concentration had a significant effect on the leaching rate of Y and Eu.The optimal optimized process conditions were:microwave power 850 W,reaction time 76.10 min,and hydrochloric acid concentration 3.58 mol/L.Under these conditions,the leaching rates of rare earth elements Y and Eu were 97.44%and 89.20%,respectively,which were very close to the model predicted values,which proved that the model used was reliable and accurate.