As mentioned above, the recovery of as many valuable metals as possible from secondary raw materials is becoming essential nowadays. This is important from the ecological and economical point of view, but needs a rather complex combination of metallurgical operations which should also enable the production of a high quality product. Nevertheless, today this goal is hardly realized in any process. Various residues, a focal point of the Christian Doppler Laboratory (CDL), can be taken into account for such a concept.
Especially high amounts of energy can be saved by passing the primary metal winning route. Another advantage is the conservation of primary resources and the minimization of landfilling activities. The development of such a process for different Zn and Pb-containing residues is one main goal of the CDL. The investigated basic process concept is a single step unit with different options concerning preceding and subsequent process steps.
The typical metals to recover in such residues are zinc, lead, copper, iron and tin, which should be primarily collected in a metal bath. At the same time, zinc oxide is often the main product of the recycling process and therefore its quality is the most important one concerning the feasibility of the process.