INVESTIGATION OF THE LEACHING BEHAVIOR OF INDUSTRIAL RESIDUES AND MINERAL WASTES FROM SAXONY-ANHALT (GERMANY) .1. BATCH TEST FOR EXTRACTIONAND ELUTION OF HEAVY-METALS

The reported investigation was focused on the leaching behaviour of ty pical large-tonal waste (two spoil-heap materials, two molten sands an d a flue-gas refining residue). Beside the characterization of the sol id material (via X-ray fluorescence analysis and extraction with aqua regia) and the determination of the leachability by water also a four- step extraction sequence was applied to determine the binding forms of heavy metals in the solid matrix and thus to identify their release p otential. The influence of long-term pH changes on the mobility of hea vy metals and of arsenic was simulated in agitation test at pH = 4 and pH = 11 over 24 hours. The acid and base neutralization capacities, r espectively resulting from such pH(stat) tests, provide in addition to the leached fraction of constituents a more realistic assessment of w aste material in view of an environment-protecting reuse or disposal.