Cementitious encapsulation of waste materials and/or contaminated soils containing heavy metals to render them immobile

摘要

The present invention relates to the cementitious encapsulation of waste materials and/or contaminated soils containing heavy metals, to render them immobile, and particularly to the immobilization of metals, in regulated amounts, in such wastes. A waste product comprising the metals is provided. A mixture is prepared comprising the wastes and/or contaminated soils containing heavy metals, water, and a cementitious composition. The cementitious composition comprises magnesium oxide and magnesium chloride in proportions effective to produce, with said water, a magnesium oxychloride cement. The cementitious composition is present in an amount which, on setting, is effective to immobilize the metals in the waste and/or contaminated soils. The present invention is useful for the remedial treatment of landfill sites. Alternatively, introduction of a retarding agent into the cementitious composition will permit the transportation of the mixture to another site for use and deposition. The mixture can be pumped or forced into the site where it will set and harden. This application is useful in the creation of slurry wall grouting and the creation of slurry wall containment basins.