Material efficiency and by-products

The efficiency of using materials within the Group is also continually being improved. The input per tonne of steel produced has been reduced as the recycled content has increased. Unavoidable by-products such as slag have been successfully utilised as substitute for other virgin materials. All these measures result in substantial environmental benefits.

Material efficiency is a cornerstone in Outokumpu's environmental responsibility thinking. The Group has completed many materials-related research and development projects in recent years and a number of schemes to reduce waste volumes have been implemented. One of the most important ways of reducing the quantities of waste generated in the steel industry is to modify melting shop processes so that slag is produced as a product.

Outokumpu has invested several million euros in developing slag-based products for construction and neutralising purposes.

Until the beginning of 2009, steel melting slag from the Tornio Works was processed in a grinding metal-separation process to retrieve and then reuse the valuable materials it contained. The problem was that slag treated in this way becomes a very fine powder which is difficult to utilise. During 2009, the process was modified to retrieve the metal content just as effectively but allow the slag to remain in a coarser form, making it easier to use as construction material. The new process will be launched in 2010.

Practically all significant waste streams are studied in order to reduce environmental impact. For example Outokumpu's Tornio Research coordinated following environment related research projects during 2009:

ISSF-project GRASCA – FINCON (Granulation of Slag under Controlled Atmosphere and Use of Stainless Steel Slag as Filler in Concrete)
Tests with fine steel slag as neutralising material for acidic mine waters.
Reuse of OPAR acid regeneration salts from Tornio in nickel production.
Bioleaching processes to treat metallurgical wastes to more inert and less harmful (PROBIO) and to create new, remote monitoring systems for ground and waste waters (MONIWATER).
Dust treatment study
Recover the metals from mill scale sludge, oily sludge and steel dusts.
Use of oil containing waste waters in ferrochrome sintering plant.

In the UK Alloy Steel Rod unit worked with a Thermal Recovery plant to look at the possibility of treating and reuse the mill scale. The melt shop started a project to recover metallic finds from the caster open water systems.

More than 84% of all the slag produced at the Sheffield melt shop is being used as an additive in asphalt used in road construction. Roads built using stainless steel slag are considered to be safer for drivers as the slag provides additional grip during braking (Source: MiMer 2003, Minerals and Metals recycling centre, Luleå University, Sweden and Recmix 2008 Belgium). In Avesta, a test road has been built in which slag has been used as a construction material. Avesta, Nyby and Degerfors are also engaged in a project to develop ways of reusing hydroxide flux instead of sending it to landfill.

The Sheffield melt shop is licensed by the UK Environment Agency as an accredited packaging reprocessor, an important and vital component in the UK's packaging compliance and waste reduction policies. Packaging waste from Sheffield is recycled to be used in the production of new packaging materials.