高镁锂比盐湖卤水萃取提锂研究

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

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%。

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%.