In order to develop an industrial-size recycling process for new materials, which are designed to satisfy the ever-changing demands of technological innovation, the conversion properties have to be thoroughly studied. The complex conversion of a molybdenum-tantalum alloy as well as a tungsten-rhenium alloy is fitted to two different theoretical approaches, leading to a deeper understanding of the predominant chemical mechanism in a future recycling process. The most important process parameters temperature, grainsize of the input material and oxygen content were optimized as to minimizing the impurities in the recycled product and the oxidation time.