A new separation technique of nickel and cobalt in solution using a chelating resin for resource recovery from waste lithium batteries

[Display omitted] •In the case of pH 10 or higher, the column permeability rates of Ni and Co for the iminodiacetic acid type chelating resin were less than 10 % and more than 90 %, respectively.•Addition of citric acid and ammonium chloride as the complexing agent was very effective for the separation of Ni and Co. Among the minor metals contained in waste lithium-ion batteries, Ni and Co are difficult to separate in solution. Citric acid and ammonium chloride as the complexing agent, and 3.0 wt% NaCl producing a hydrochloric acid dissolved solution of waste lithium batteries, were added to the test the Ni (100 ppm) and Co (100 ppm) mixed solution. When the test solution was adjusted to a 10 or higher in pH value, the column permeability rates of Ni and Co for the iminodiacetic acid type chelating resin were less than 10 % and more than 90 %, respectively. The Ni ion formed the nickel-ammonium complex M2+-(NH3)n ion in the basic solution for adsorption on the chelating resin. We have found that this new technique is expected to easily separate Ni and Co in a hydrochloric acid dissolved solution of waste lithium batteries.