Lead acid batteries (LABs) are commonly used in automotives since their invention. LABs are also the most recycled batteries among all batteries. Currently, pyrometallurgy is the dominating recycling route of a LAB in industry. Pyrometallurgy is a process which converts metal compounds into metal at a temperature above 1000 oC. One of the main challenges in pyrometallurgy is thus the energy consumption. Another challenge is the risk of pollution of lead particulates to the environment during pyrometallurgy.
In this thesis, a solution-based recycling route was developed to minimize the environmental risk during LABs recycling. LAB waste components were recycled via a green solvent, Natural deep eutectic solvent (NADES), through a precipitation followed by calcination method.
Two types of NADESs were used, one is malic acid-based NADES, and the other is lactic acid- based NADES. The corresponding precipitates achieved by using these two NADESs were lead malate dihydrate and lead lactate, both of which were limited studied. Both precipitates were analysed and calcined at 550 oC to β-PbO.
The reaction behaviour of lead compounds from lead paste (LAB waste) in NADESs were also analysed. Results have shown that the reaction behaviour of lead compounds in NADESs were a dissolution followed by slow precipitation. This offers the possibility of the removal of impurities such as fibres or plastics in lead paste.