Recycling of used lead acid batteries
Practical Action
Figure 2: schematic drawing of the recycling process of lead acid batteries (source:
www.campine.be)
Lead refining
As a smelting plant stops at the stage of the reduction plant, it will produce what is known as
hard or antimonial lead. If the plant wants to produce soft lead, other metals like copper,
antimony, arsenic and tin have to be removed. The refining process is applied in several steps
in kettles with addition of specific agents. After this process the soft lead can be poured into
moulds called “ingots”. These ingots are sold on the local or international market.
Pollution control measures
In the recycling plant, effective control measures need to be implemented, both to protect the
health of workers and to prevent pollution of the environment. Good plant design, with
reduction of the potential for the emission of contaminating substances, is of utmost
importance, and the newer smelting processes are inherently much cleaner than traditional
blast furnaces. Pollution abatement technologies, including the treatment of exhaust gases
and liquid effluents, need to be installed.
Those mostly exposed to releases within the plant are the workforce. Control measures such
as maintaining minimum standards of air quality within the works, medical surveillance of
employees, use of protective equipment, and provision of conditions of good hygiene in
general, is necessary to avoid occupational lead exposure.
Health and environment
While using the lead acid battery for electricity, hazards exist during refilling of the flooded
batteries. Harmful effects can occur during production and after its useful life, during
recycling. At the end of its life the battery is classified as a hazardous waste under the Basel
Convention and should be handled accordingly in order to prevent damage to human health or
to the environment (UNEP, 2003).
Health
Lead is considered as one of the most toxic heavy metals. Its use is restricted and banned in
some applications, like gasoline additives and tubes for drinking water (CE, 2000). Today, it
is known that exposure to lead can cause adverse effects on many parts of the body. The
organs potentially most affected are the brain and nervous system, kidneys, blood, and the
reproductive system of both sexes. Lead in certain forms is also considered a possible
carcinogen. Of particular concern is that relatively low levels can affect the developing foetus
and young children, impairing their mental development and causing a small but measurable
decrease in IQ. However, clinical symptoms are only found in very highly exposed individuals
(who are usually exposed at work) and this is now extremely rare in the Western World
(source: www.ila-lead.org).
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