In light of the ever increasing demand for raw materials, the development of metallurgical processes for the utilization of end of life products as secondary sources becomes more important. This also applies to hard metals, and in particular, to drill heads with cutting elements made of polycrystalline diamond composite (PDC). These drill bits differ from conventional tungsten carbide cobalt hard metals in their varying and complex composition as well as their size. This master thesis deals with aspects of semi direct recycling of PDC drill heads, in which the binder alloy gets chemically dissolved and thus separated from the tungsten carbide. One of the main goals constitutes the quantification of the influence that iron has on the solubility of tungsten from various tungsten containing powders in nitric acid. In addition, different analysis methods are used and checked for their applicability to answer the research questions at hand. Furthermore, the system MODDE Pro 12 helps to generate model equations that describe the relationship between tungsten solubility and iron content in the system.