Adaptation of minerals processing operations for lithium-ion (LiBs) and nickel metal hydride (NiMH) batteries recycling: Critical review

Abstract

Production of LiBs and NiMH batteries is expected to increase rapidly due to the soaring price of oil and gas which increases interest in renewable energy as well as the introduction of hybrid vehicles (HVs), and electric vehicles (EVs) which used secondary batteries as an effective energy storage device. Development of an efficient recycling scheme to recover the valuable parts and safely dispose the harmful one at batteries end life is a necessity. The challenge, however, is how to recover all the valuable metals without sacrificing the economics of recycling process.Several LiBs and NiMH batteries recycling processes have been developed in recent years. A review of these processes and their development timeline was presented in this paper. It was found that the major drawback of these recycling processes is the losses of some of batteries valuable parts since these recycling processes are not originally developed for this type of batteries. Also, some of these processes are expensive and designed for specific types of batteries which ignore contamination of recycling stream with impurities and other type of batteries.Using minerals processing operations such as grinding, sieving, magnetic, electrostatic, and gravity separations to liberate batteries electrodal materials and concentrate valuable metals is critical step in any recycling process. This may be due to the simplicity, efficiency, flexibility, and high throughput of these separation processes. The literature showed that applying these processes reduces the volume of LiBs and NiMH scrap, liberates their valuables, reduces the need for leachate purification in hydrometallurgical process, and facilitates the decomposing of battery’s electrolyte. Based on these results a flowsheet to recycle mixed stream LiBs, and NiMH battery scrap was proposed.