Dust formation in the arc heating of zinc-plated steel

Resumo

Dust formation in the plasma-arc heating of zinc-plated steel in argon is studied, when the current is 170–190 A, the argon flow rate is 0.06 m³/h, and the pressure in the furnace chamber is 0.1 MPa. Zinc evaporates practically completely in the first 30 s of heating. The structure of the trapped zinc-bearing dust is heterogeneous: the particles are of different shape (spherical, acicular, or membranous particles), different size, and different composition. The composition of individual dust particles is analyzed on an iCAP 6300 spectrometer (Thermo Electron, United States). On that basis, their oxide composition is estimated by means of Terra software. The dust includes particles consisting of ZnO, Fe₂O₄, carbon, and pure iron. The results indicate that, in the plasma heating of zinc-plated steel, the zinc-bearing dust may be captured separately from the other dust in the initial smelting period.