Abstract:

Aiming at the highly concentrated ammonia nitrogen wastewater produced in rare earth leaching,air stripping method has been used for its treatment. Through single-factor tests and orthogonal tests,the influential fac-tors of it are studied. The results show that the order of influence degrees of the main factors on the air stripping ef-fect is pH >stripping temperature >gas-liquid ratio. The optimum operation conditions are as follows:pH=11,tempe-rature 40 ℃,gas-liquid ratio 5 555.6:1,and stripping time 100 min. The NH₃ air stripped from the wastewater can be absorbed by sulfuric acid,forming(NH₄)₂SO₄ solution, which can be used as leaching solvent to be used in produc-tion again,or to be used for ammonium sulfate fertilizer production,realizing the recovery and recycling of resources. This experimental process can be used in the pretreatment of denitrification and dephosphorization second-class biological treatment or first-class enhanced treatment.

Key words: rare-earth leaching, ammonium nitrogen wastewater, air stripping

摘要：

针对稀土浸矿产生的高氨氮废水,采用吹脱法对其进行处理,通过单因素试验和正交试验对影响因素进行了研究。结果表明,各主要因素对吹脱效果的影响大小为pH >吹脱温度 >气液比;最佳操作条件:pH=11,温度为40 ℃,气液比为5 555.6:1,吹脱时间为100 min。吹脱出的NH₃用H₂SO₄吸收,形成(NH₄)₂SO₄溶液,可作为浸取剂返回生产中使用或者用于生产(NH₄)₂SO₄肥料,实现资源回收利用。该试验工艺可作为脱氮除磷二级生物处理或一级强化处理的预处理。

关键词: 稀土浸矿, 氨氮废水, 吹脱

CLC Number: 

• X703