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.
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.
