Our most important raw materials in producing stainless steel are recycled stainless and carbon steels. We have two aims when improving our resource efficiency. First, we minimize the initial use of virgin materials in our production. The second aim is to reduce the waste sent to landfilled.
Increasing the recycled content of stainless steel is the single most efficient way for Outokumpu to reduce the environmental impact which results from production processes. As recycled materials replace the virgin raw materials that would otherwise have been required, the effects cover the whole supply chain. Taking the entire product life cycle into account, achieving a 20% increase in recycled material from 60% to a level of 80% prevents 1.2 tonnes of CO2 emissions per tonne of stainless steel.
Together with metals recovered from waste products and by-products of the production process, they enable the recycled content of stainless steel produced by Outokumpu to be as much as 87%, very high if not the highest in the market. The recycled contnet of all steel production is around 30% (source: Bureau of International Recycling: Ferrous report 2017) and in stainless steel in the Western wolrd around 78% (ISSF 2015).
Closing the loop: material efficiency and by-products
Outokumpu's ultimate target is zero-waste stainless steel production. This means that all material streams from production are studied in order to find means of fully recycling, reusing or selling them as by-products on the market. Generally, all processes are developed in a way that allows valuable metals - like iron, nickel, chromium and molybdenum - to be recovered and retrieved from material streams.
Slag and dust are the main by-products of the steelmaking process. Minerals are formed as slag and hot liquid steelmaking process. Slag prevents the loss of crucial alloying elements during melting and aids in the refining stages. It is also essential in protecting the molten metal against oxidisation and heat loss. Slag is by far the biggest material side stream, and Outokumpu has invested considerable research and development in methods of retrieving valuable metals from slag and dust, to reuse the metals as raw materials in the Group's melt shops. For example our melt shop in Tornio is able to commercialize a full 100% of its slag sidestreams, selling slag products to private companies and households or reutilizing it in our own processes or construction projects. In 2017, the overall use rate (reuse, recycling and recovery) of slag was 91.1%.
Outokumpu has also developed slag-based by products for example for construction, neutralization purposes in industrial applications and agriculture. For example in road construction slag products replace virgin materials such as crushed stone aggregate and where its performance is actually better than that of its alternatives.
Dust-filtering systems at Outokumpu catch 99% of the dust generated by production operations. All of the dust generated by the company's melt shops is recycled, with collected dust fractions that have the highest metal content being recycled directly, and the remainder of the collected dust being recycled following a metal recovery process. In the Nordic region, this residue is transported to an external facility in Sweden which recovers the metals contained in the dusts. In the UK, the in-house metal-recovery facility is on site. Over the years Outokumpu has decreased dust emissions significantly.
By paying attention to waste management and segragation techniques, we have managed to maintain about 65% of waste and by-material in the circular economy. In 2017, Outokumpu was able to reduce landfill waste by more than 8% even if the production increased by 3%. Waste from our production units is sent to appropriate treatment facilities or landfill sites that are licensed to accept such materials.
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|Avesta||Sweden||Melting, hot rolling, cold rolling||Coil and sheet|
|Calvert||The United States||Melting, cold rolling||Coil and sheet|
|Dahlerbrück||Germany||Cold rolling||Precision strip|
|Degerfors||Sweden||Hot rolling||Quarto plate|
|Dillenburg||Germany||Cold rolling||Coil and sheet|
|Krefeld||Germany||Cold rolling||Coil and sheet|
|Nyby||Sweden||Cold rolling||Coil and sheet|
|Richburg||The United States||Cold rolling||Bar|
|San Luis Potosí||Mexico||Cold rolling||Coil and sheet|
|Sheffield||The United Kingdom||Melting, hot rolling, cold rolling||Wire rod, rebar|
|Tornio||Finland||Ferrochrome, melting, hot rolling, cold rolling||Ferrochrome, coil and sheet|