Influence of combustion bed temperature on concentration and leachability of metals in slags from an incinerating plant

The present study shows that accumulation and leachability of heavy metals in slags from muncipal waste incinerating plants are dependent on the combustion bed temperature. Combustion bed temperatures of 620°C–710°C, 830°C–911°C and 830°C–970°C were measured by an IR-camera during the three incineration experiments with muncipal waste. Metals with comparatively low boiling points such as Cd, Pb and Zn predominately accumulate in the boiler ashes and filter dust when the incinerator is operated at higher grate temperature. Furthermore TOC-content is lowered significantly in slags. In contrast to this the behaviour of elution of slags from different temperature experiments investigated by DEV-S4 tests only slightly differ. Solid phase investigations indicate the formation of three evident phase components in combustion products.