Lithium extraction from carbonate-rich Salt Lake brine using HBTA/TBP system

China's salt lakes hold significant lithium reserves,yet the development of low-concentration lithium resources from the carbonate brines in Tibet is a pressing matter.Alkyl β-diketones extractants are capable of efficiently extracting lithium from alkaline solutions using an extraction method,but its optimized extraction prerequisite is an extreme alkaline solution with higher pH.This research introduces a process for the effective extraction and separation of lithium and sodium from the carbonate brine of Jieze Caka Salt Lake,utilizing trifluorinated β-biketone HB TA（4,4,4-trifluoro-1-phenyl-1,3-butanedione）-TBP（tributyl phosphate）/kerosene system.A threestage extraction yielded 98.06% of Li+ and 1.69% of Na+from the initial brine with a lower pH of 8.961 and a separation factor(βLi/Na) of 2948.The simplified process was then implemented using organic direct recycling without regeneration and scrubbing raffinate reflux for a total of 23 cycles,thereby demonstrating the exceptional effectiveness and stability of this system.The resulting lithium-rich stripping solution,with the Li/Na mass ratio amplified by 747 times,underwent further magnesium removal and precipitation using sodium carbonate to yield a high-purity lithium carbonate product of 99.50%.This study offers a novel approach and technology for the efficient separation of lithium ion directly from a partialneutral carbonate salt lake with a high Na/Li ratio and low lithium concentration.