Abstract: A process for the recovery of mercury from mercury-containing caustic sludge, generated from a mercury cell, chlor-alkali plant, wherein mercury is removed from the caustic sludge by treatment in a hydraulic mineral separator. The process provides a ready method for removal of mercury from caustic sludge which can allow recovery of the mercury for re-use. Alternatively, the process provides a smaller volume of mercury-contaminated material to be treated and/or land-filled.

Abstract: A process for the recovery of heavy metals, and in particular, mercury from a heavy metal-contaminated soil, or the recovery of mercury from a mercury-contaminated material, wherein the particles containing the heavy metal or mercury are separated from soil or mercury-contaminated material by a hydraulic mineral separator. The process may additionally include pre-classification of the soil particles to form a sample having essentially constant soil particle size prior to separation in the mineral separator. The process provides a ready method for removal of mercury from mercury-contaminated materials or heavy metals from heavy metal contaminated soils which process can allow recovery of the mercury or heavy metal for re-use. Alternatively, the process provides a smaller volume of mercury- or heavy metal-contaminated soil or material to be treated.