The electrocapillary motion of Cu2S and Ni3S2 droplets on the surface of fayalite-based slags under 50% Ar-CO atmosphere has been studied for the effects of droplet size, temperature, electric field strength, Cu content in Cu2S-FeS droplets, Ni content in Ni3S2-FeS droplets and slag composition. The copper matte droplets migrate to the anode (positive electrode) while the nickel matte droplets migrate to the cathode (negative electrode). Typical speeds encountered are of the order of 0.05-0.80 cm/s (Cu) and 0.16-0.62 cm/s (Ni) with droplet diameters between 0.10 and 0.28 cm, applied potentials between 0.17 and 2.0 V/cm (Cu) and 0.75 and 3.3 V/cm (Ni) and for temperatures between 1473 and 1573 K. The migration rate appears to be independent of droplet size for droplet diameters between 0.10 and 0.28 cm, but it increases with applied potential field and temperature. The effects of matte and slag contents on the migratory behavior are complex. As the Cu content in the Cu2S-FeS matte droplet increases above 40% Cu, the migration rates also increase. Below 40% Cu matte grade, the migration rates are not significantly different. As the Ni content in the Ni3S2-FeS matte droplet increases, the migration rates decrease. These migration rates are also affected by the slag composition. As the Cu and Ni matte droplets migrate in opposite directions under the influence of the electric field, electrocapillary phenomena may be used to enhance metal recovery in slag cleaning operations using electric furnaces.
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