High zinc containing steel mill dust, produced during steel making in the electric arc furnace, represents an important raw material for the production of zinc oxide. Although research and development in the last decades have focused on environmentally friendly recycling processes, only a few relevant breakthroughs have been achieved. This PhD thesis contains a detailed description of the formation mechanisms, properties, statistical data as well as current recycling processes for steel mill dust. The focus is on the process technology of the 2sDR-process, and its advantages. The 2sDR-process combines multi-metal-recycling with a zero-waste-strategy and a high ZnO product quality. The process is based on two steps which represent the main part of the technology. The first step uses a thermal treatment under oxidizing conditions to evaporate halogen compounds and other volatile components of the steel mill dust. This leads to an increased product quality in the subsequent reduction step. The second process step (reduction) is based on a metal bath containing dissolved carbon. In addition to the ZnO reduction iron oxide is reduced to metallic iron, which is collected in the metal bath together with other alloying elements present in the steel mill dust. Furthermore, an oxidic phase is formed, which is mainly represented by SiO2 and CaO and contains only small amounts of potentially environmentally harmful elements. Therefore, the 2sDR-process offers an economically attractive strategy to transfer hazardous waste (high zinc containing steel mill dust) into 100 % products. In the present work, the two process steps were transferred to pilot scale. To investigate the first process step (removal of volatile components), tests were carried out in a Thermobalance, in a Top Blown Rotary Converter and in a Short Drum Furnace. The results led to a patent which protects the technology of the first step of the 2sDR-process. Reduction tests were carried out in an Induction Furnace as well as in two different Electric Furnaces. The amount of treated steel mill dust in the tests varied from 100 g to 800 kg. The test results confirmed the feasibility of the 2sDR concept including all advantages and resulted in a detailed engineering of the process, the preparation of a plant layout and a listing of expected operational costs, earnings as well as necessary investments.