Hydrometallurgical leaching and recovery of cobalt from lithium ion battery

Abstract

The main aim of this work was to test the ability of an amino acid (i.e. glycine) to leach cobalt from Li ion batteries (LiBs). The process parameters namely temperature, pulp density and concentration of glycine were optimized for maximizing the leaching efficiency of cobalt from the cathodic material. Response surface methodology (RSM) was applied for determining the experimental conditions instead of using the traditional one factor at a time (OFAT) approach in order to ascertain the interaction effects between the different factors. Thus, the optimal leaching value based on RSM and maximum cobalt leaching potential from LiBs was obtained. The optimum values for the parameters were as follows; temperature = 74 °C, pulp density = 19.9 g/L and glycine concentration = 0.936 M. Under this optimum condition, the cobalt leaching efficiency was 61.8%, while a maximum leaching of 89.7% was achieved at the following conditions: temperature = 100 °C, pulp density = 13.8 g/L and glycine concentration = 1.24 M. Oxalic acid was used for recovering cobalt from the leaching solution by varying the pH and molar ratio of oxalic acid and cobalt ions. Cobalt recovery efficiencies were ∼ 88.0% at pH 7.0 and at oxalic acid to cobalt ion molar ratio of 2.5:1.0. • Glycine in the presence of H 2 O 2 leached Co from spent Li ion batteries. • A maximum of 89% of Co was leached by glycine from LiBs. • Co was selectively recovered using oxalic acid as precipitating agent. • More than 88% of soluble Co can be recovered as Co-oxalate precipitate.