Nickel-cadmium batteries: waste management

Given the hazardous heavy metal content of Ni-Cd batteries, recycling is the preferred waste management option when they can no longer be recharged. Mechanical and physical methods can be used to dismantle the batteries and to separate the component materials but this yields material which is impure or heterogeneous and needs subsequent thermal or chemical treatment. Pyrometallurgical processes may be applied for the distillation of metals such as cadmium which have a low boiling point. Such processes are relatively simple and cheap but are not very versatile and are high in energy consumption. Hydrometallurgical processes, though more expensive, are more versatile, can be applied to a wider range of wastes and are more environmentally friendly. (13 references) (UK)