The German metal industry is confronted with an enforcing international competition,
rising prices of energy and commodities, the increasing relevance of sustainable economy,
political demands and incentives such as emission trading. To meet these challenges it is
essential for companies to further improve resource and energy efficiency and to reduce
CO2 emissions. Usually, efforts concerning these objectives focus on new or
improved single processes. In contrast, the presented approach extends the considerations
to the inter-company perspective and considers multiple processes from ferrous and
non-ferrous metals industry which are linked by material flows. Our considerations focus
on residue flows in the iron and steel as well as the zinc industry. Steel production in
integrated steelworks or electric steel plants involves the formation of large amounts of
by-products, e.g. dusts, sludges or slags. These contain valuable substances such as iron
or zinc and can be further processed by internal re-feeding or external recycling, e.g. by
specialized companies, particularly Waelz kiln plants or the DK process. The latter
produce zinc concentrates for the zinc industry. Changes in the modes of operation of one
or more process can therefore affect the connected processes. We investigate strategies to
further reduce landfilling and to efficiently allocate by-products to internal and
external recycling options within the scope of the sketched network. We develop flowsheet
models for representative processes within the regarded industries in Germany. With an
Electric Arc Furnace (EAF), an integrated steelworks, two recycling companies, and a
hydrometallurgical zinc plant the major processes of the German iron, steel and zinc
industries are considered. We derive linear input-output functions for each of the
processes by means of multiple linear regression analysis which we apply on results of
systematically varied flowsheet simulation runs. These functions are used in a system of
linear equations, forming a material and energy flow model of the regarded network. The
model is applied to identify and assess strategies and measures to enhance resource and
energy efficiency and to reduce climate relevant CO2 emissions by scenario and
sensitivity analyses. Thus, technical and economical barriers of inter-company measures
can be overcome by identifying strategies which are technologically feasible and favorable
with regard to the named objectives.