STEAG is the market leader in Europe in the recycling of power plant by-products from hard coal. These products comprise fly ash, slag tap granulate or boiler sand and gypsum from the flue gas desulfurization system which remain as residues from combustion of the coal.

Every year, we recycle around five million tonnes of residues. They can mostly be used without further processing in the construction industry, the concrete industry, and by civil engineering and roadbuilding contractors, landscape architects and the mining industry.

• With our numerous subsidiaries and affiliates, we market our power plant by-products in 15 countries. 
• In intensive research and development work, we have identified a broad range of applications for our products.

Our power plant by-products

• Fly ash consists of the non-combustible host rock mined together with the coal. It is removed from the flow of flue gas by electrostatic precipitators. The fly ash is suitable for use as aggregate for cement-bound construction materials, lime-bound materials such as lime-sand bricks and aerated concrete, and for plaster and mortar.
• Slag tap granulate is the melted, non-combustible, mineral component of the coal which solidifies in a water bath. It belongs to the group of coarse-grained soils, comparable to coarse sand or fine gravel. It is used as an aggregate for concrete and concrete products, in roadbuilding, for drainage and as a blasting medium.
• Boiler sand consists of the same materials as slag tap granulate, but is more finely grained. It is used as an aggregate for concrete and mortar.
• Gypsum from flue gas desulfurization systems, like natural gypsum, requires no post-treatment. It is turned into plasterboard, plaster and filling compounds.

The power plant by-products are environmentally sound and can be used in almost all applications as construction materials without impairment of the soil or groundwater. Treatment is only necessary in special cases. In contrast to the natural resources which are becoming increasingly scarce, power plant by-products will be available in the longer term, conserving natural raw materials.