| This dissertation provides new insights into process engineering and fundamental issues related to metal recovery from slags using DC arc furnace technology. The incentive to develop and implement new slag cleaning processes is being driven by two main forces—increasingly stringent environmental legislation, and the financial motivation to profitably process waste streams to increase overall metal recoveries. The successful commercialization of DC arc furnace technology for electric furnace steelmaking, ferrochromium production, and ilmenite smelting, has opened the door for this technology to be applied to high temperature metal recovery processes for slag treatment.; Two chemical processing issues important to metal recovery from primary lead smelter slags have been investigated and documented in Section 2 and 3. The reduction of zinc oxide from lead blast furnace slags by FeO was shown not to play a dominant role in zinc evolution (in the absence of a reductant) from these slags. The recovery of cobalt (as a co-product) could significantly contribute to the profitability of a DC arc furnace process which aimed to recover zinc (as a metal) from a Viburnum Trend lead blast furnace slag.; Several issues relating to the physics of energy, mass, and momentum transport in DC arc furnaces are poorly understood. An experimental campaign on a laboratory scale DC arc furnace investigated the influence that the plasma arc has on temperature distributions, fluid flow, reductant behavior, and solids fed through the electrode. The results are presented in Section 4 and 5. The bath temperature, measured beneath the arc attachment zone, was a strong function of applied arc power. A steep vertical temperature gradient existed beneath the arc attachment zone. The location of the anode connection strongly influenced the direction of flow in the arc attachment zone. In addition to these results, a photographic technique was developed to document the arc-bath interactions in real-time. |
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