Method for cleaning fine particle fraction of separation methods and contaminated soil in the soil .

摘要

PROBLEM TO BE SOLVED: To efficiently separate fine particles 5-10 μm by chemical means.SOLUTION: Water is added to contaminated soil to form slurry, with polymeric flocculant added to the slurry for mixing and stirring. As a result, only soil particles ≥5-10 μm in the slurry are flocculated to form flocks, while fine particles 5-10 μm are dispersed in the slurry without flocculating. The slurry is then subjected to flocculation and precipitation, with the flocks precipitated, thereby separating into precipitated sludge comprising soil particles ≥5-10 μm and supernatant water containing fine particles 5-10 μm. The precipitated sludge is dehydrated to obtain recyclable cleaned soil. Also, the supernatant water is dehydrated after processed for further flocculation and precipitation, so that concentrated contaminated soil to be treated is obtained.