Lead is the heaviest stable metal. It is used mainly in lead acid batteries, (80%) of the 10 million tons produced in 2014.
Recycling of lead is very efficient and represents up to 55% of the worldwide production. If ingested, lead is poisonous to animals and humans, damaging the nervous system and causing brain disorders.
Excessive lead also causes blood disorders in mammals. Lead is a neurotoxin that accumulates both in soft tissues and the bones.
The Centers for Disease Control (US) has set the standard elevated blood lead level for adults to be 10 µg/dl of the whole blood. For children the number is set much lower at 5 µg/dl of blood as of 2012.
ELSA developed a process “MEDOX” to eliminate lead, cadmium and copper from incineration plant fumes and ash.
The process was using zinc as sacrificial metal to reduce lead, cadmium and copper from the solutions obtained after lixiviation of the fumes and ashes.
The zinc in solution subsequently recycled by electrolysis. .
The product after “MEDOX” treatment is a mixture of lead, cadmium and copper metals.
For large quantities, further separation treatments or selective cementation can be applied to recover pure metals.