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 electric 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 inductively coupled plasma (ICP). The use of cellulose as binder provides better results in terms of reproducibility. After optimization of the spark parameters (voltage, 500 V; repetition rate, 400 s-1; and resistance, 2.2 OMEGA), the carrier gas flow rate (2.1 l min-1 of argon) and the operating power of the ICP (1.2 kW), precisions (relative standard deviation) for zinc, lead, cadmium and iron range from 0.8 to 2.0%. The stability of the spark sampling, during a complete spark ablation (SA) ICP process (almost-equal-to 90 s) was tested by plotting emission intensity versus time profiles. The similarity between the amounts of analyte obtained from different pellets was proven by collecting the spark-eroded particles and analysing their carbon contents. Five steelmaking EAF flue dusts were selected for this study, using the two samples with extreme contents of the elements considered, for calibration. The results obtained by SA-ICP matched the results obtained by ICP from nebulized solutions.