In the field of metallurgy, hydrometallurgical processes are widespread. They are used in the processing of the common metals Al, Mg, Cu and Zn but also in the winning of the rare metals such as Ge, In, Ga, Re and rare earth. Especially in the winning of metals, which are not enriched in natural mineral deposits hydrometallurgy plays a major role. By the circular flow in continuous hydrometallurgical processes the rare metals accumulate in certain mass flows. Also the treatment of residues from different metallurgical processes will be of particular importance, because of the possible selectivity of hydrometallurgical processes to extract valuable metals.
The unit operations leaching, SX and EW, reduction and refining to well-defined materials respectively are the common steps in hydrometallurgy. Concrete examples are the hydrometallurgical processing of chrome containing slags (www.chromic.eu) and the leaching and SX of rare earth (https://www.hzdr.de/db/Cms?pNid=3534) containing raw materials.