钽铌冶炼过程高氟氨氮废水综合治理研究

Study on comprehensive utilization of waste water with high concentration of NH_4^+ and F^- in producing tantalum and niobium

研究综合治理钽铌冶炼过程中含有高质量浓度NH4+、F-、SO42-工业废水的技术.在蒸发过程中利用NH4HF2、(NH4)2SO4的溶解度随温度变化不同的特性,采用分步结晶法可使这两种化合物基本分离.对尚未分离的含少量NH4HF2的固体混合物,根据固体混合物组分的升华-裂化温度不同,(NH4)2SO4相对稳定,将NH4HF2(沸点240℃)蒸发,可使NH4HF2与(NH4)2SO4彻底分离.采用蒸发-分步结晶-裂化工艺,能有效地降低钽铌冶炼厂工业废水中的NH4+、F-和SO42-,制备的NH4HF2可达到国家标准.

This article introduced a technique utilizing comprehensively the waste water with high concentration NH4+,F-and SO42-.With temperature changed, there were much difference between the solubility of NH4HF and the solubility of (NH4)2SO4. As a result, NH4HF and (NH4)2SO4 could be separated. NH4HF was recovered from the solid mixture containing a little NH4F by the method of fragmentation.The concentration of NH4+,F-and SO42-in waste water is greatly reduced by evaporating, fractional crystallizing and decomposing, and NH4HF and (NH4)2SO4 achieve national standard.