Electric Arc Furnaces are commonly
used for steel production from scrap.
In Europe electric-arc furnaces produce about 86 million
tons of steel and as by-product about 20 million tons
of slag every year, the 60% of which (12 million tons)
is simply dumped with easily deducible negative impacts
for the environment; in addition, slag dumping is
a cost for the electric arc steel industry, which
has also to face frequent dump capacity problems.
Recycling of slag in road constructions is the most
interesting possible use; to this purpose slag has
to meet specific parameters, either from the mechanical,
environmental, and stability point of view. EAF slag
is not usable in the conditions as it is produced,
but only after several treatments and even after sometimes
it may still be subjected to swelling or present environmental
problems given by excessive leachate release, due
to the fact that the today established treating processes,
very long and not always environment friendly, cannot
avoid a certain level of free lime content of slag
or take under strait control all the characteristics
of the slag.
ASO Siderurgica has recently developed a new, eco-innovative
system for slag collection by means of a dry granulation
treatment, which can simplify the handling of the
slag out of the EAF and keep under control the structural
constitution of the slag thus making possible a 100%
recycling of EAF slag after only one treatment process,
completely eliminating the risk of swelling and elements
leaching to the environment. The system which has
been named SLAG-REC® is hereafter described and
its advantages highlighted.
SLAG-REC® is also the acronym of the Project n.
ECO/239025/SI2.538242 which is under development with
the financial support from the CIP-EIP-Eco-Innovation-2008
Program; the SLAG-REC® project program and its
development are as well hereafter described.