RECOVERY GARAM LITHIUM PADA AIR TUA (BITTERN) DENGAN METODE PRESIPITASI

Abstract

Lithium, a silvery metal, is widely used in various industrial applications, such as the anode in rechargeable lithium ion batteries. The content of lithium in bittern has the potential to be recovered in the form of LiH(AlO₂)₂.5H₂O by precipitation method. The purposes of this study were to recover the lithium from bittern by precipitation method and determined the influence of precipitating agent concentration, pH, and reaction time on the percentage of the lithium recovery. The study was conducted with variation of the concentration of precipitating solution NaAlO₂ 250, 500, 750, mg/L Al3+, pH 11, 12, 13, and the reaction time of 1, 2, 3 hours. The response was the percent recovery of lithium in the bittern. The study was performed by mixing 250 ml of bittern and precipitating agent NaAlO₂ according to variables in a stirred reactor. The pH solution was adjusted by the addition of NaOH and the solution was stirred for a predetermined time. The precipitate that formed was filtered, washed with distilled water and dissolved with HF 0.25 N. Lithium content in the solution was determined by the gravimetric method. The result showed that concentration of NaAlO₂ as precipitating agent, pH, and reaction time gave significant influence on the percentage of the recovery lithium in bittern. The optimum conditions were obtained in the concentration of precipitating NaAlO₂ 500 mg/L Al³⁺, pH 13, and a reaction time of 3 hours, which produced 0.11 g of ion Li+ and 96.875% lithium recovery.