SPECIATION OF METAL-IONS IN SOLID SAMPLES .2. INVESTIGATION ON FLY ASHES

Chemical speciation of 14 elements was carried out after sequential le aching experiment. Samples were collected at coal-fired electric plant s and municipal waste incinerators and 7 fractions were separated by s olvent extraction suggested for soils. The main elements (Ca, Mg, Al, Fe) were found in the mineral forms simi/ larry as they exist in the n ature. The distribution of toxic trace metals showed different pattern s among the 7 fractions depending on the origin of raw materials. The high amount of Cd (385 mg/kg) was observed in the mobile fraction of t he fly-ash sample collected in a brown coal-fired electric plant. Alon g with the total concentration of the elements, the chemical speciatio n of mobile and stable metals is of great importance.