萃取法从盐湖卤水中提取硼

Extraction of boron from salt lake brine

为加强从盐湖卤水中提取硼的研究,以青海西台吉乃尔盐湖卤水为原料,探讨了2-乙基-1,3-己二醇(EHD)/正辛醇(CA)/ExxsoLD80萃取体系对硼的分离效果。从萃取剂体积分数、酸度、萃取时间、相比、反萃取剂浓度、反萃时间等方面加以实验。确定了萃取过程的最佳实验条件:10%EHD-40%CA-50%D80,pH=2,萃取时间t=12min,相比(O/A)=1,萃取温度为室温,硼的单级萃取率为98.67%,3级逆流萃取率可达99.91%。在萃取体系中加入协萃剂,减少了萃取剂EHD的用量,在保证萃取率的同时,可改善萃取剂的乳化问题,对实现以EHD为萃取剂的萃取体系提取硼的研究具有重要意义。

In order to strengthen the study of extracting of boron from salt lake brine,the separation effect of 2-ethy-1,3-hexanediol(EHD)/n-octanol(CA)/ExxsoL D80 extraction system on boron was investigated by using salt lake brine from Qinghai Xitaijinaier.In this experiment,the extractant volum fraction,acidity,extraction time,phase ratio,stripping agent concentration,and stripping time were studied.The optimal experimental conditions for the extraction process were determined:10%EHD-40%CA-50%D80,pH=2,extraction time t=12 min,phase ratio(O/A)=1,and extraction temperature at room temperature.The single extraction rate of boron is 98.67%,and the third-stage countercurrent extraction rate can reach 99.91%under the best experimental conditions.In addition,the amount of extractant EHD was reduced by adding synergist in the extraction system.The emulsification of extractant was improved while the extraction rate was guaranteed.It is of great significance for the extraction of boron from EHD extraction system.