A NEW LIFE FOR OLD CAR BATTERIES

Lead is dangerous if not handled properly,but at the same time it remains vital to our high-tech civilisation. There
is therefore a need to follow secure recycling paths in order to control the risks. But how is this achivied
at the Braubach facility of Berzelius Metall,Germanys largest lead recycler?

Starter batteries in cars currently have a service life expectancy of around 65 months before arriving at our works,
according to Gherard Goliash,Managing Director of Berzelius Metall GmbH in Braunbach,Germanys leading lear
recycler. The company operates three smelting facilities in Germany and one of its subsidiaries -BSB Recycling
GmbH- treats around 55000 tonnes of lead-containing residues each year,mostly in the form of lead accumulators
from the automotive and other industries. Feedstock also includes scrapped lead roofing sheets,lead cable jackets
and car wheel-balancing weights,as well as lead-containing residues such as ordnance sand from military shooting
ranges. At the end of a number of processing stages,these residues yield around 30000 tonnes of lead and 20000
tonnes of plastic granulate,both of which are marketed.
On arriving at the processing works,used batteries are discharged into the company''s acid tight storage bunker,
explains Mr.Goliash. From there,they are transferred to the feed cone of a hammer crusher,where rotating hammers
'shatter' them to creat fragments measuring no more than 40-50 mm.The liquid acidic fraction is collected,filtred and
then sold to customers i the electroplating and chemical industries.Mixed solids are transferred to a multi-stage
washing and separation plant where the different fractions-solid lead,lead fines,polypropylene and residual plastics-
are separated by means of a screening drum and a float-sink unit.Meanwhile,residual acid is neutralised.
The fines consisting of lead power,lead dioxide and lead sulphate are filtred off and set to Berzelius'works in Stolberg
The solid lead fraction collected from the float-sink separation unit is relatively clen and can be melted without
further treatment.
In a final step,spacer sheets are separated from the plastic fraction and consigned to thermal recovery.The
polypropylene chips contain a fairly low level of other plastic impurities and,together with other polypropylene residues
such as bottle caps,they are further downsized in a shear mill.A state-of-the-art compounding and granulation plant
thenyields a production--ready plastic material destined for injection moulding in various industrial sector,including
automotive applications.
'Sulphur would be detrimental given the type of metallurgical treatment in short rotary furnaces we use',reveals Hans-
Ulrich Steil,who is in charge of Berzelius Mettal's environmental management system.Therefore,sulphur-containing
fines are sent to Berzelius'lead smelter in Stolberg which is equipped the treatment of sulphuric primary ores.
The three short rotary furnaces operated by BSB each have a volume of 3.8m3 and are used mainly to reduce
oxides and to remove calcium,which is transformed into a slag by use of silica-containing,slag forming additions such
as broken glass or 'ordnance sand'.The company tries to achieve the highest possible silicate content in the slag in
order permanently to bind harmful ingredients and thereby minimise the risk of elutriation after deposition. This slag
is the only 'product'the company has to landfil -all of the plant's other intermediate and final products can
be fully recycled in industrial processes.
In a subsequent metallurgical step,stirring the molten lead in 100-tone crucible furnaces results in the elimination
of copper.which segregates and forms a fine powder layer covering the lead bath.Further metallurgical treatments
can be performed depending on impurity level and the type of alloy to be produced.The final products are huge
lead alloy ingots:about half of these are sent to Berzelius'Muldenhütten Recycling und Umweltechnik secondary
lead mill in Freiberg for further treatment;the remainder is alloyed to customer specification and sold to various
industrial users. Most of the reclaimed lead will end up in starter batteries once more.
'Given the environmental hazards associated with lead,all our activities have to comply with tough environmental
protection regulation and areconstantly monitored,'says Mr Goliash. Particular attention is paid to the avoidance
of any uncontrolled emissions or leakages. Water from the washing and separation plant is recycled in a closed loop
while other aqueous residues - as well as rain water- are collected and througly cleaned in a state of the art waste
water treatment system.
A huge exhaust system filters the air not only from the smelter area,but also from all the locations where lead
is stocked or treated. Even trucks leaving the site have to pass through a washing unit. The slurry from waste water
treatment and filter dust from the exhaust system are recycled into the melting ovens.
These protective measures are so efficient that,according to BSB,emission levels for dust and lead remain below
prescribed limits. The company is particularly pround of the fact that emission levels for sulphur dioxide are 90%
-plus below those seen as typical for conventional lead recycling processes.
According to Berzelius,lead remains irreplaceable not only in car starter packs but also in countless other
applications. The impact of lead on the population is on the decline thenks to legislative restrictions. And even if
metallic lead or lead compounds resistant to elutriation happened to end up in the ground,this would pose no treath
to human health since the metal would not reach the food,it argues.
Despite this,some politicians are pushing ahead with lead-banning initiatives thet,according to Mr Steil,have little
to do with true protection of the environment but are rather panic measures designed to attract votes from a scared
population.At the same time,these measures places in jeopardy not only the jobs of people employed in a variety
of industrial sectors,but also many well-established recycling routes for lead. They even threaten to undermine the
achievements of the lead recycling sector in recycling around 60% of worldwide production of metal.
Mr.Steil is particularly outraged by what he regards as the hypocrisy of politicians. The Danish government,he
notes by way of example,is at the forefront of initiatives aimed at a total ban on lead within the E.U,and yet is
prepared to allow exceptions where its own exports are concerned