稀土分离高铵氮废水综合回收与利用研究  

Comprehensive Recovery and Utilization of High Ammonium-nitrogen Wastewater in Rare Earth Separation Process

作　　者：周新木[1] 张丽[1] 李青强 李永绣[1] 

机构地区：[1]南昌大学化学系,江西南昌330031

出　　处：《稀土》2014年第5期7-11,共5页Chinese Rare Earths

基　　金：国家科技部支撑项目资助(2012BAE01B02)

摘　　要：稀土分离工艺中各种浓度的铵氮废水有不同的处理方法,针对其高浓度的铵氮废水,采用加硫酸并在加热及减压条件下进行回收与利用。结果表明,在一定的加酸比n(H+)∶n(NH4Cl)下,氯化铵浓度提高,其盐酸蒸出摩尔数与加入氢离子摩尔数的比值基本不变,且减压比常压高出7%左右;盐酸蒸出浓度随氯化铵含量和原料配比的增加而提高;高酸比蒸酸残留物为硫酸氢铵,低酸比则为多种铵盐;硫酸氢铵可用作稀土碳铵沉淀母液回收的pH调节剂和铵离子的补充剂,并用于南方稀土矿的稀土浸出;蒸出盐酸可用作稀土分离工艺的洗酸。高铵氮废水得以充分回收和利用。High ammonium-nitrogen wastewater from rare earth separation process was treated by reduced pressure distillation in the temperatures of 140 ℃ or 150 ℃ with sulfuric acid.The results show that when adding amount of sulfuric acid reached a certain value,mole ratio of distilled hydrochloric acid to added sulfuic acid remained unchanged with increase of concentration of ammonium chloride in samples.But the ratio obtained at reduced pressures was 7% higher than that at normal pressures.Moreover,the amount of distilled hydrochloric acid increased with the raise of ammonium chloride content and concentration of ammonium-nitrogen wastewater.The residue is ammonium bisulfate under high acid /raw material ratio.On the contrary,a variety of ammonium salts were obtained under low acid /raw material ratio.The recovered ammonium bisulfate can be used as pH adjusting agent and NH4 ＋supplement for precipitation of mother liquors of rare earth bicarbonate.It can also be used in southern rare earth ore leaching.Moreover,the distilled hydrochloric acid can be used as washing slovent in the rare earth separation process.Hence,the high ammonium-nitrogen wastewater produced in the rare earth separation process can be fully recovered and utilized.

关 键 词：稀土分离 铵氮废水 氯化铵 硫酸氢铵 综合回收 

分 类 号：TQ111.3[化学工程—无机化工]