The extraction of lithium from the waste of used batteries is going to be necessary due to the limited resources of lithium. One of the most common methods to extract is liquid–liquid extraction with an organic solvent. In this study, Bis(2-ethylhexyl) phosphoric acid (D2EHPA) solvent is used for liquid–liquid extraction of lithium-ion in a T-shaped microchannel. Lithium chloride solution has been used as a dispersed phase and, D2EHPA solvent with sunflower oil has been unitized as a continuous phase. The effect of some parameters, such as the flow rate of the continuous phase and the amount of the consumed solvent on the time of slug formation process, slug length and, extraction percentage has been investigated. Results showed that the time of the slug formation decreases by increasing the flow rate of the continuous phase. Also, it found that with increasing the pH of the aqueous phase by 36% resulted in a 15% reduction in the length of the slug. With an increase of 67% of the consumed solvent, the slug length increases by about 16%. By increasing the amount of the consumed solvent, the slug length increases. In continuation, with increasing the slug length, extraction percentage increases
