高镁锂比盐湖卤水萃取提锂研究

以磷酸三丁酯(TBP)为萃取剂、煤油为稀释剂,在协萃剂A和共萃剂 FeCl₃存在的条件下,从高镁锂比盐湖老卤中萃取提锂。系统研究了pH值、Fe/Li摩尔比、萃取相比、萃取时间、温度等因素的影响,得出最佳工艺条件为:pH=2、Fe/Li摩尔比1.25、萃取相比(O/A)1/1、室温下萃取10 min。在优化条件下锂单级萃取率在76%以上,经过4级萃取卤水中锂萃取率可达99.44%。

Extraction of Lithium from Salt Lake Brine with High Magnesium/Lithium Ratio

With tributyl phosphate (TBP) as the extractant and kerosene as the diluent, lithium was extracted from salt lake brine with high magnesium-lithium ratio, in the presence of synergistic extractant A and co-extractant FeCl₃. After the systematical investigation of the influence of factors, such as pH value, Fe/Li molar ratio, extraction ratio, extraction time and temperature, the best process conditions were finally determined. It is found that with pH value of 2, Fe/Li molar ratio of 1.25, extraction ratio (O/A) of 1/1, the extraction test at room temperature for 10 min can result in the single-stage lithium extraction rate over 76% and the lithium extraction rate from brine after 4-stage extraction up to 99.44%.