纳滤浓缩稀土母液沉淀上清液的实验研究

以赣州某稀土公司浸矿所得稀土母液经NH₄HCO₃除杂沉淀后的上清液为处理对象，主要研究纳滤技术对原液中稀土离子的浓缩效率，以及对NH₃-N分离回收情况，以期能够为工业化分离应用提供借鉴.实验表明，当原液中稀土离子浓度为142.9 mg/L，氨氮浓度为346.1 mg/L时，在操作压力为0.8 MPa，进水pH值为6.49，运行温度为25 ℃的条件下，浓缩液侧稀土离子截留率达到95 %以上，Ca2+、Mg2+、Mn2+、Zn2+等杂质离子截留率能够达到75 %~90 %，透过液侧氨氮浓度为原浓度的60 %左右，有一定的浓缩效果；6.0 L的稀土母液沉淀上清液浓缩至0.6 L时，RE3+浓度升高至1 242.0 mg/L，浓缩了近8.69倍. 

Experimental study on precipitating supernatant of rare earth mother liquor by nanofiltration

The supernatant of rare earth mother solution obtained from the leaching of a rare earth company in Ganzhou is treated by the supernatant after NH₄HCO₃ removal of impurity. The concentration efficiency of rare earth ions in the raw liquid by nanofiltration and the separation and recovery of NH₃-N are mainly studied, so as to provide reference for industrial application. The experimental results showed that when the concentration of rare earth ions in the raw liquor was 142.9 mg/L and the concentration of ammonia nitrogen was 346.1 mg/L, the retention rate of rare earth ions in the concentrated liquid side reached 95 % when the operation pressure was 0.8 MPa, the influent pH was 6.49, and the running temperature was 25 degrees. The intercepting rate of impurity ions, such as Ca2+, Mg2+, Mn2+ and Zn2+, can reach 75 %~90 %. The ammonia nitrogen through the liquid side is about 60 % of the original concentration. When the supernatant of the rare earth mother solution of 6.0 L is concentrated to 0.6 L, the concentration of RE3+ is increased to 1 242.0 mg/L, and the concentration is nearly 8.69 times.