ANALYSIS OF ELECTRICAL ARC FURNACE FLUE DUSTS BY SPARK ABLATION INDUCTIVELY-COUPLED PLASMA-ATOMIC EMISSION-SPECTROMETRY

A medium-voltage spark was used for the direct nebulization of electri c arc furnace (EAF) flue dust. In order to attain the necessary sample conductivity, powder pellets are briquetted after mixing the sample 1 + 1 with graphite. The elutriated material was excited in an argon in ductively coupled plasma (ICP). The use of cellulose as binder provide s better results in terms of reproducibility. After optimization of th e spark parameters (voltage, 500 V; repetition rate, 400 s-1; and resi stance, 2.2 OMEGA), the carrier gas flow rate (2.1 l min-1 of argon) a nd the operating power of the ICP (1.2 kW), precisions (relative stand ard deviation) for zinc, lead, cadmium and iron range from 0.8 to 2.0% . The stability of the spark sampling, during a complete spark ablatio n (SA) ICP process (almost-equal-to 90 s) was tested by plotting emiss ion intensity versus time profiles. The similarity between the amounts of analyte obtained from different pellets was proven by collecting t he spark-eroded particles and analysing their carbon contents. Five st eelmaking EAF flue dusts were selected for this study, using the two s amples with extreme contents of the elements considered, for calibrati on. The results obtained by SA-ICP matched the results obtained by ICP from nebulized solutions.