First economically and environmentally viable mobile commercial metallurgical plant based on advanced hydrometallurgical and electrochemical technologies able to produce cobalt metal from spent lithium-ion batteries

Abstract

Background To counter climate change, it will be necessary to have a major transition of both energy and mobility systems. Electrification of mobility is one essential part of the solution. Nearly 65% of Cobalt is mined in Africa (e.g. Central African Republic and Democratic Republic of the Congo) and this dependency makes Europe vulnerable. It is essential to develop an efficient and robust technology capable of recycling this kind of waste. Methods Due to the risk of supply and to decrease the dependency of Europe in obtaining Cobalt, the first economically and environmentally viable mobile commercial metallurgical plant based on advanced hydrometallurgical and electrochemical technologies has been constructed (referenced as CROCODILE), which is able to produce cobalt metal from black mass from waste streams of spent batteries. The process validated on a pilot scale is made up of three different sections: leaching, liquid-liquid extraction and electrolysis. The first has the purpose of carrying out a selective leaching for cobalt, the second aims removing impurities from the lye and concentrating it into cobalt and the third concerns the recovery of metallic cobalt. During the intense demonstration campaign carried out, the optimization of the operating parameters of the whole process was carried out. Results From the experimental campaign carried out on the pilot scale, the following process yields were obtained: cobalt leaching 88.4%; maximum extraction of cobalt about equal to 60%; cobalt recovery of 63%wt in electrowinning. Conclusion A novel and innovative process for the recovery of Cobalt from black mass coming from the lithium-ion batteries has been validated at pilot scale. The Cobalt recovery rate and the purity obtained together with the low environmental impact of this process compared to conventional ones can contribute to both a greener future and make Europe independent from other markets such as that of China..