A set of new treatment facilities have been built to deal with the high-concentration of fluorine and ammonia-nitrogen (NH3-N) in wastewater generated from the preparation process of UO2 powder by ADU, whose concentration reaches up to 20g/L and 70g/L, respectively. Compared with various methods and summarized from vast experiences, a three-step technological process has been adopted. Firstly, fluorine is fixed by Ca(OH)2, and the product, CaF2, and other solids are filtered by centrifuge. And the teeny solids in the primary filtrate are precipitated by proper flocculants in pipe chute settling pond. Secondly, the treated wastewater with certain alkalinity is rectified by folded-plate rectifying tower. Meanwhile the ammonia is reused. Finally, adsorbed by specific adsorbent, the fluorine and NH3-N concentration of treated wastewater is further reduced. After numerous experiments and two-year running tests, the process control has been improved. Now, the wastewater treatment capability of the facility can reach 45m3/day. And the concentration of fluorine and NH3-N in the final wastewater is less than 10mg/L and 15mg/L, respectively, which can meet the state wastewater discharge standards. Besides, the concentration of the reused ammonia is raised from 5wt% to 25wt%, and the recovery can reach 99.3%.

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