Service Communautaire d'Information sur la Recherche et le Développement - CORDIS

Mechano-chemical treatment of contaminated construction waste

The basic idea is the controlled streaming of a reagent-loaded liquid through a heap of contaminated construction waste with the aim to receive, on the one hand, a reusable material, and, on the other hand, a highly concentrated fluid waste product (precipitate or extract), in which process the regenerated effluent is led into a circuit and no sewage is produced.

Washing of contaminated construction waste in soil washing plants is not new. The construction waste usually is treated for some minutes by mechanical processes in which the surface of the construction waste material is cleaned. In buildings or parts of buildings which were exposed the attack of contaminants (eg corrosives, heavy metals or mineral hydrocarbons) for a long time the contaminants have penetrated the structure of the construction elements and can not be removed by a short time process.
The planned technological improvement is based on the innovative idea to extract the contaminants from inside the construction elements after suitable comminution in a long time process which gives the contaminants an opportunity to leave the broken construction elements in the same way as they entered.

From the technical point of view the heap leaching process may be a perspective which can be applied in precious metal mining on a large scale. Methods used in this field, however, can not be transferred directly. A research demand exists concerning: the pretreatment of the material especially to form a suitable capillary system;
the carrying-out of the heap leaching especially in respect of the physical-chemical conditions; and the removal of the dissolved contaminants from the effluent and the conditioning of the fluid circuit.

Reported by

Gesellschaft fuer Verfahrenstechnik Freiberg, FIA eV
Chemnitzer Strasse 40
09596 Freiberg
Germany
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