By-products find new life in construction materials
A leader in sustainable solutions, Outokumpu reprocesses by-products from its ferrochrome and stainless steel manufacturing operations to create high quality construction materials. Used in road construction and civil engineering projects, these products become building blocks of other products.
Sparing virgin raw materials that would otherwise be extracted, use of the by-products reduces environmental degradation and supports the circular economy, one in which process waste is redesigned into usable materials and products. Outokumpu by-products are produced at melt shops in Finland, Sweden and the U.K.
Outokumpu products available in Finland through Finnish roadworks company Destia include OKTO insulation, OKTO aggregate and Croval.
OKTO insulation is a stone by-product manufactured from molten ferrochrome slag through granulation. With better thermal insulating capacity than natural materials, as well as a high load-bearing capacity, it is especially suitable for road substructures and drainage ditches. The fraction of OKTO insulation material in standard production is 0–11 mm.
OKTO aggregate is manufactured from air-cooled ferrochrome slag by crushing. Thanks to its superior firmness, it is ideal for creating wear-resistant asphalt and concrete coatings. The fractions of aggregate in standard production are 0/5 mm, 4/8 mm, 4/11 mm, 8/11 mm, 10/16 mm and 16/22 mm.
Croval aggregate is a preferred material for heat-resistant structures in fireplaces with a melting point of 1,700 ºCelsius.
Outokumpu products available in UK through Harsco Metals & Minerals which provides environmentally sustainable solutions for co-products of steel production.
The use of stainless steel making slag in asphalt production has many great social and environmental benefits: In terms of social benefits asphalt containing stainless steel making slag increases the durability of road surface which increasing the life of the road hence reducing the need for road repairs and associated traffic delays. These asphalts surface also exhibit great properties that benefit the road user including good grip values, skid resistance, rut and deformation resistance, and reduced risk of aquaplaning.
Additionally, using slag as a substitute for a natural resource reduces the need to actively damage land by mining for virgin raw materials which also alleviate the pressure that mining can exert on communities and ecosystems in the vicinity of mines and preserves the natural beauty of the area.