<p>Clay-type lithium ore is an important natural lithium resource characterized by its wide distribution and large reserves. Owing to its complex composition, low-grade clay-type lithium ore contains high levels of impurities and exhibits low lithium concentrations in its leachate, necessitating the selective separation and enrichment of lithium from impurities. In this study, a synergistic solvent extraction system with Mextral®3939H and DIBK was applied for the selective extraction and separation of lithium from the leachate of low-grade clay-type lithium ore, with the objective of mitigating the imbalance between lithium supply and demand. The effects of Mextral®3939H molar fraction, equilibrium time, extraction temperature, organic-to-aqueous phase ratio (O/A), and initial aqueous pH on extraction and separation performance were systematically investigated. The optimized extraction conditions were identified as a Mextral®3939H molar fraction of 0.6, equilibrium time of 20&#xa0;min, extraction temperature of 45&#xa0;°C, O/A of 2:1, and initial aqueous pH of 7. Under these optimal conditions, the extraction efficiency of lithium reached 93.76%, while the separation coefficients between lithium and aluminum, calcium, iron, potassium, and sodium were 18.96, 797.64, 394.55, 68.38, and 313.19, respectively. The extraction equilibrium isotherm of lithium revealed that three counter-current extraction stages were required at O/A = 2:1 to reduce the lithium concentration in the raffinate to below 0.042&#xa0;mg/L, achieving an overall extraction efficiency of more than 99%. Furthermore, slope analysis suggested that the extracted lithium complex may be {Li₂⋅[A]_(o)⋅[Cl⁻] [B]_(o)⋅[HA]}. This work will provide a theoretical basis for the potential application of industrial lithium recovery from clay-type ores.</p> Graphical Abstract <p></p>