Recovery of Cobalt and Lithium Values from Discarded Li-Ion Batteries

摘要

The short lifespan and massive accumulation of discarded lithium-ion batteries (LIBs) along with the significant presence of lithium and cobalt values are key facts for recycling. The discarded LIBs were ground in disc mill and sieved to separate steel case, aluminum, and copper foils from the active material. The minus 53 μm fraction was considered as an active material and XRD analysis revealed LiCoO_2 and graphite around 50% (w/w). The active material was carbothermally reduced in a muffle furnace at atmospheric conditions for a predetermined time (5-45 min) and temperature (500-900 °C) and the reduced mass was leached in distilled water for 30 min followed by wet magnetic separation. It was found that the magnetic fraction contains almost 90% cobalt values, non-magnetic majorly containing graphite and other impurities such as Mn, Cu, and Al and precipitated salt contains lithium carbonate. This study demonstrates a simple, environment friendly, and flexible process which includes indigenous carbothermal reduction of the active material, selective dissolution of lithium carbonate, and subsequently wet magnetic separation to recover cobalt values in a short time.