PROCESS FOR THE RECOVERY OF HEAVY METALS SUCH AS LEAD FROM METAL CONTAMINATED SOIL

摘要

A process for the decontamination of a metal contaminated soil aggregate so as to obtain a product comprising a treated soil component having a metal content lower than that of the metal contaminated soil aggregate, the metal contaminated soil aggregate comprising at least one metal selected from the group comprising Pb, Hg, Cu, Cd, Zn, Ag, Ni, Co, Ga and Cr, the contaminated soil aggregate comprising a classified soil fraction representing soil particles having a size of from 0.15 mm and smaller, comprising: providing an initial aqueous soil slurry comprising the contaminated soil aggregate, admixing at least one water soluble dialkyldithiocarbamate with the initial soil slurry so as to obtain a product aqueous soil slurry comprising one or more water insoluble metal-dialkyldithiocarbamate complexes, and separating one or more of the insoluble metal-dialkylthiocarbamate complexes from the product aqueous soil slurry so as to obtain a treated product aqueous slurry comprising a treated soil component having a metal content lower than that of the metal contaminated soil aggregate, wherein the metal moiety of the one or more water insoluble metal-dialkyldithiocarbamate complexes is a member of the group comprising Pb, Hg, Cu, Cd, Zn, Ag, Ni, Co, Ga and Cr.