TFPB와TBP의 시너지효과를 이용한 수용액 중의 리튬이온 용매 추출

Abstract

Lithium has been used in many fields, such as the special lightweight alloy materials for aircraft, next-generation fusion fuel, batteries for mobile phones and various IT devices, etc. However, there is no land reserves of lithium in Korea, and so the lithium supply relys on imports entirely. As the price of lithium skyrocketed in recent years, researches on the solvent extraction of lithium ion from concentrated seawater from desalination facilities have been actively performed in Korea. In this study, as a preliminary study on the lithium extraction from concentrated seawater, solvent extraction of lithium ions from aqueous solution was carried out. β-diketone and neutral ligand were employed on adopted for extractants. The optimum extraction conditions were established on the kinds and purity of organic solvents, the concentration of extractant, the pH of lithium aqueous solution, the volume ratio of extraction solution to aqueous solution, the initial lithium concentration, and additional of another ions in lithium aqueous solution. It is found that kerosene is the optimum solvent of this extraction process and lithium ions in aqueous solutions of pH = 10.0 - 10.5, adjusted by ammonia aqueous solution, was most effectively extracted by the extraction solution composed of 0.02M TFPB and 0.25M TBP in kerosene. The maximum lithium extraction efficiency of lithium was 99%. The extraction efficiency decreased with the increase of initial concentration of lithium ions and the volume ratio of aqueous solution to extraction solution. And the extraction efficiency significantly decreased with the addition of other ions, such ad magnesium ion, calcium ion, sodium ion and potassium ion. Thus, a pretreatment step on procedure for the elimination of these ions is essential before lithium extraction.