As the adoption of electric vehicles (EV) accelerates year after year, there is an urgent need for commercially viable solutions to recover the raw materials that make up the Lithium-Ion Batteries (LIBs). As well as lithium, other rare materials such as graphite will need to be recovered. Additionally, the fluoride materials such as Hydrogen Fluoride (HF) need to be removed from the graphite material. Fluoride can form hydrofluoric acid when dissolved in water, which is a highly toxic and corrosive substance. This research project investigated the recovery of lithium and fluoride from the spent LIBs washwater stream using hydrometallurgical approaches in three different prismatic powders (Hydro, Pyro, and Unpyro). First washing (leaching with water) resulted in 5-30% of fluoride removal and 3-30% of lithium recovery in washwater I depend on treatment conditions. This washwater I was then used to wash a new spent LIBs, which generated washwater II. This washwater II resulted in an additional 10 % of fluoride removal, but it was insignificant for lithium recovery compared to the lithium concentration in washwater I. However, there was a substantial increase in lithium recovery for Pyro powder. Washpowder I produced from the first washing was utilized in the leaching process using different leaching agents and reducing agents. It was found out that the highest sulfuric acid concentration and using sodium bisulfite as a reductant could generate the highest lithium concentration in leachate solution. Another washing using leachate cake formed in the leaching process could remove 2-6% of lithium and 0.6-9.1% of fluoride more.
Keywords: Fluoride, Hydrometallurgy, Lithium, and Spent LIBs.