(84c) Recycling of Valuabe Metals From Battery Scrap Leachate by Supported Liquid Membrane Technology

In recent years the usage of Lithium Ion Batteries (LIB) has notably increased. The demand for recycling processes for the valuable components of spent Lithium ion batteries, such as Cobalt, Copper, and Lithium etc. is highly desireable.

The aim of this work was to develop a complete recycling processes for valuable metals from aqueous solutions by implementation of Supported Liquid Membrane Technology (SLMT).

In the first process step the electrode materials were separated from the non-recyclable body of the Lithium Ion Battery. The target constituents were dissolved by acid leaching with HNO₃ and H₂O₂ at elevated temperature. Leaching solutions typically contain Co²⁺, Al³⁺, Cu²⁺ Li⁺ Fe³⁺ and traces of Ni²⁺ and Mn²⁺ ions. The trivalent ions Fe³⁺ and Al³⁺ were removed by precipitation with LiOH leaving Cobalt, Copper and Lithium in solution.

The separation of Cobalt, Copper and Lithium was conducted with Supported Liquid Membrane Technology. Microporous Polyethylene membranes with a thickness of 2 mm, a pore size distribution of 7-12 µm and a porosity of 0,36 were used as membrane supports. The pertraction experiments were conducted in a lab scale unit, providing two chambers for the aqueous donor and acceptor solutions, separated by the porous membrane support with the extractants. Cobalt and Copper were separated with either DEHPA or Cyanex 272, leaving Li⁺ finally in the raffinate phase for further processing. Cobalt and Copper were separated through extraction with LIX 84. Different flux of the metal ions into the acceptor solution was applied as selectivity criterion.

Based on the experimental results the complete recycling route was validated.