混合醇溶剂萃取法从平落4井深层富钾卤水中高效分离硼酸的研究

Study on effective separation of boric acid from deep underground brine in Pingluo well No.4 using mixed fatty alcohol solvent extraction method

以平落4井提溴后的卤水为原料,采用红外光谱测试了脂肪醇-硼酸萃合物的结构,探讨了脂肪醇与硼酸之间的反应机理,系统研究了钙镁盐析作用与萃取分配系数的关系以及反萃液pH值变化对反萃化学平衡的影响,确定了萃取/反萃相比、萃取温度、混合时间、萃取/反萃级数等工艺条件,建立了适用于低钙镁含量卤水的混合醇溶剂萃取硼酸的工艺路线。该工艺已应用于平落4井卤水钠、钾、硼、溴综合开发工程。

With the brine extracted from Pingluo well No. 4 as material, the structure of fatty alcohol-boric acid extracted com- plex was tested using infrared spectrum, the reaction mechanism between fatty alcohol and boric acid was explored and the relation- ship between calcium magnesium salting-out effect and extraction distribution coefficient and the impact of variation of strip liquor pH value on stripping equilibrium were studied systematically to determine extraction/back extraction phase ratio, extraction tem- perature, mixing time, extraction/back extraction stages and oth- er process conditions and to establish a process route suitable for extraction of boric acid from the brine mixed fatty alcohol solvent with low calcium-magnesium content, which has been applied in the comprehensive development project of brine sodium, potassi- um, boron and bromine in Pingluo well No. 4.