选用柠檬酸盐作为风化壳淋积型稀土矿的浸取剂,并将柠檬酸盐对稀土的浸出效果与硫酸盐和氯化盐等浸取剂进行了对比,考察了柠檬酸铵作为浸取剂时的最佳浸取工艺。实验结果表明,柠檬酸铵作为风化壳淋积型稀土矿浸取剂时,柠檬酸根离子与稀土离子的配位作用,能促进矿石稀土离子交换,提高稀土回收率,降低浸矿剂铵盐的用量,减小氨氮废水的污染。采用柱浸回收稀土的最佳工艺条件为:柠檬酸铵浓度3 g/L,液固比2∶1,浸取剂pH 6.0-8.0,淋洗流速0.5 min/m L,稀土浸出率可达90.01%。
Ammonium citrate,sodium citrate and magnesium citrate are used as leaching reagents for weathered crust elution-deposited rare earth ore,and compared with sulfate and chloride. The result shows it can get high leaching rate with citrate,especially ammonium citrate. The best leaching condition with ammonium citrate was as following: concentration of ammonium citrate 3g/L,liquid/solid ratio 2: 1,pH 6. 0 - 8. 0 and leaching velocity 0. 5m L/min,under which rare earth leaching rate is about 90. 01%