膜分离技术处理离子型稀土矿稀土开采废水

Treatment of Waste Water from Mining Process of Ionic Rare Earth with Membrane Separation Technology

对离子型稀土矿开采废水采用膜分离集成工艺进行处理,以便回收其中的稀土,降低出水的氨氮。结果表明,在经过废水的预处理后,两级反渗透膜的工艺能将废水中的氨氮降低到5.04 mg·L^(-1),低于15 mg·L^(-1)的废水排放指标。而出水中的稀土离子为0。经过反渗透浓缩回收的高浓度氨氮可循环回用于稀土的浸出过程中,而浓缩回收的稀土可通过纳滤膜进行再次回收富集。稀土回收率达到了92.98%。研究发现,稀土开采废水的预处理对氨氮的去除效果很关键。

Integrated membrane separation technology was used to treat waste water from mining process of ionic rare earth to recover rare earth and ammonia nitrogen thereof. Results shew that,after pre-treatment of the waste water,ammonia nitrogen content in the waste water could be reduced to 5. 04 mg·L^（-1） by two stages RO process,which was lower than emission standard,while the rare earth concentration was always 0. High concentration of ammonia nitrogen concentrated by RO may be recycled to be used in leaching process,meanwhile,rare earth concentrate obtained may be concentrated again by NF. The yield of total rare earth reached 92. 98%. It is discovered that pre-treatment of the waste water has great effect on ammonia nitrogen removal rate.