离子型稀土尾矿氨氮淋洗技术研究

Study on Leaching Technology of Ammonia Nitrogen from Ion-absorbed Type Rare Earth Tailings

针对离子型稀土矿硫酸铵浸矿后尾矿残留铵盐造成持久性的氨氮污染问题,提出用淋洗法去除残留氨氮,通过室内模拟实验,探讨了水、淋洗剂A、淋洗剂B三种淋洗剂对尾矿残留氨氮的淋洗性能。结果表明,采用水淋洗尾矿水量需求大、流出液后期拖尾严重且主要淋洗的是尾矿中的水溶态铵,尾矿依然残留氨氮600.57 mg/kg矿土,尾矿残留问题未能有效解决;淋洗剂A、B淋洗尾矿后氨氮残留分别为168.8 mg/kg矿土、179.1 mg/kg矿土,均能解决尾矿氨氮残留问题,但淋洗剂B流出液峰值氨氮浓度是淋洗剂A的2倍,且淋洗剂用量低34.83%,有利于集中处理氨氮废水且缩短淋洗时间,淋洗剂B淋洗效果更佳。

Aiming at the persistent ammonia nitrogen pollution caused by residual ammonium salt of tailings after ammonium sulfate leaching of ionic rare earth ore,leaching method was proposed to remove residual ammonia nitrogen.Through laboratory simulation experiment,the leaching performance of three leaching agents,namely water,eluent A and eluent B,on residual ammonia nitrogen of tailings was discussed.The results show that the tailings with water leaching require a large amount of water,the tailing of effluent is serious in the later stage,and the main leaching is water-soluble ammonium in the tailings,and the tailings still have 600.57 mg/kg ammonia nitrogen mineral soil,and the tailings residual problem has not been effectively solved.The residual ammonia nitrogen of leaching agent A and B are 168.8 mg/kg mineral soil and 179.1 mg/kg mineral soil respectively,which can solve the residual ammonia nitrogen problem of tailings.However,the peak ammonia nitrogen concentration of leaching agent B is twice that of leaching agent A,and the dosage of leaching agent is 34.83%lower,which is conducive to the centralized treatment of ammonia nitrogen wastewater and shorten the leaching time.Leach agent B is more effective.