H.-J. Feuerborn — VGB PowerTech e.V., Essen, Germany
B. Müller — -MUEG – Mitteldeutsche Umwelt und Entsorgung GmbH, Braunsbedra, Germany
E. Walter— Vattenfall Europe Generation AG, Cottbus, Germany
In German lignite fired power stations about 10 million tonnes of ashes and 5 million tonnes of flue gas desulphurisation gypsum are produced every year. Most of the ashes are used for the refilling and reclamation of depleted opencast lignite mines. Furthermore, they are used in underground mining, for surface recultivation, soil beneficiation, cement production and as addition to concrete. FGD gypsum is used in the gypsum and cement industry and increasingly as fertilizer and soil conditioner.
The utilisation of the calcareous fly ash from lignite fired power plants is depending on their chemical, mineralogical and physical properties. These properties are influenced by the power plant technology, the source of coal as well as the type of coal feed. A constant product quality is of greatest importance for utilisation in hydraulic binders, cement and concrete.