Other

Frank Meyer

Martin P Fischer

Hans E Mehesch

Birgit Riecks

Karlheinz Neuschaffer

Wolfgang Cornely

Rainer Machlitt

The method of cleaning soil contaminated with contaminants includes comminuting contaminated soil to form a comminuted contaminated soil; filling the comminuted contaminated soil into a countercurrent extractor from above under an inert gas atmosphere so that the comminuted contaminated soil moves as a travelling bed downward through the countercurrent extractor; feeding a solvent, advantageously acetone, into a lower portion of the countercurrent extractor so that the solvent flows upward through the travelling bed to form a decontaminated soil at the bottom of the extractor and a contaminant-charged solvent portion taken from a middle portion; supplying a conveying liquid to the lower portion of the countercurrent extractor so as to transfer the decontaminated soil from the countercurrent extractor to a filter device having a belt filter; and separating the decontaminated soil in the filter device into a cleaned soil and a reusable conveying liquid. A feeder device is provided for the filter device which avoids clogging of the moving belt filter by the soil when the soil has a high proportion of silt.

Extraction method and apparatus for cleaning contaminated soil

Hardenable foam compositions comprising oxygen-releasing foaming agents, a hardener consisting of an alkali silicate solution, a fine particle solid material which reacts with said hardener, namely an oxide mixture consisting of SiO.sub.2 and Al.sub.2 O.sub.3 extracted from a filter dust, an electrofilter ash from high-temperature power plants, and calcinated bauxite or amorphous silica, to which reaction accelerators are added, are improved, firmer, faster hardening foams. Reducing agents, in particular sulphur compounds with a reducing action are preferred. Oxidizing agents or fine particle substances such as soot or color pigments are effective.

Water-containing, hardenable foam compositions with inorganic components

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Essen, Germany

Frank Meyer