Photo excavation area gray line Photos of recultivated excavations and of actual clay extraction
t Photo company HGV

demand for clay

The Lintfort and Ratingen clays extracted in the Gartroper Busch possess a wide spectrum of high-grade potential applications because of their good quality and their low water permeability.

To date and in future, the fields of application for these clays primarily involve securing the environment and ecological remediation. Worthy of mention here are the constantly expanding fields of activity in the landfill covering and landfill rehabilitation sectors, also as a consequence of the need to comply with the latest developments in technology. Waterway extension and rehabilitation, sealing canals as well as dyke construction and extension projects represent other principal marketing targets.

backfill material

Once clay extraction has been terminated, the plan is to refill the "Eichenallee" pit. Mineral materials of waste disposal class 1 (e.g. coal fly ashes, earth, slag) are used for this purpose. The areas adjacent to the excavation site, Windthrow area and Mühlenberg and also the ash deposition area have already proven to be suitable for such backfill purposes because of their geological substrata. An application will have to be filed for permission to store such materials in accordance with the German Closed Substance Cycle Waste Management Act. This contains the essential conditions to be met for surface and bottom sealing to comply with the Technical Instructions for residential waste.

Graphic: technical detail A suitably inclined deposition area surface with a gradient of at least 5 % has to be provided to allow drainage of precipitation water. Consequently, the backfill operations should also include a rise in landscape approximately 20 metres on average higher than the present morphology and thus allow the incorporation of large volumes of backfill materials. The clay excavation volumes already account for approx. 3.2 mill. m³.

Numerous coal-fired power stations are scheduled for new construction which will generate the additional requirement for waste material deposition sites, in particular for coal fly ashes, which, in turn, will ensure sufficient quantities of refill materials in the long term for the planned backfill operations.