Lignite filter reduces emissions in steel plants
Cologne, Germany— Iron and
steel scrap smelting accounts for approximately 34% of steel production
worldwide, making it one of the most common iron and steel industry
processes, one that is mainly carried out in electric arc furnaces.
The thermal treatment of scrap containing paint, oil and other
organic components can produce dioxin and furan, which in some
cases necessitates additional environmental emissions reduction
The reduction of dioxin emissions
is particularly significant because in 1993 the EU Council of
Ministers set a goal of substantially reducing such emissions
by 2005, and the iron and steel industry accounts for over one
million m3/h of the relevant dioxin emissions. Irrespective of
this goal, in recent years some countries have set emissions limits
for electrosteel production plants. Luxembourg was the first country
to implement such regulations (as of January 1, 1997) which stipulates
a limit of 0.1 ngTE/m3 (0.1 nanogram toxic equivalent per cubic
meter of air).
The scope of the emissions requiring
treatment and the cost necessitate a solution that is efficient
as well as affordable. Adsorptive waste gas treatment using activated
lignite HOK in an entrained phase process is one of the simplest
and most inexpensive treatment solutions. In 1997, Luxembourg-based
Arcelor, a subsidiary of Ares S.A., upgraded the dust removal
system at their Schifflingen electrosteel plant by integrating
a pioneering adsorptive entrained phase solution that uses activated
lignite HOK. In 2001, this same system was also installed in ProfilARBED’s
Esch-Deval and Differdingen plants. Entrained phase solutions
are currently reducing PCDD/Fs at five European electrosteel plants
and are hence also substantially reducing dioxin emissions at
these facilities. According to EU estimates, this solution constitutes
one of today’s best available technologies in this realm.
Activated lignite produced from
Rhineland lignite provides outstanding separation efficiency.
The distinctive properties of
lignite from the Rhine region combined with the activation parameters
in the hearth furnace yield a type of activated coke (lignite)
that has been in use for many years as an adsorption and filter
medium for various waste gas and waste water applications.