A thermodynamic approach to the compatibility of materials combinations for recycling

For the evaluation of the compatibility of materials combinations for metallurgical recycling, a thermodynamic approach has been applied. This approach led to the construction of a decision tree model for the evaluation of the compatibility of materials combinations, the thermodynamic evaluation of materials combinations (THEMA) model. The technological and economical aspects of recycling were also mentioned, as they introduce additional constraints to the feasibility of the recycling processes. The results were structured in a matrix for materials combinations, the THEMA matrix. The decision tree and matrix are to be used as a decision support tool in product design. The objective is to minimise the recycling losses and contaminations, increasing the resource efficiency of product systems. With lower contamination levels, the recovery and recycling processes would become more profitable, as less energy and resources are required, leading to a win–win situation to the industry and environment. Some application examples are included, using a passenger vehicle as example. The major compatibility problems for the metallurgic recycling of the recovered material streams from end-of-life vehicles (ELVs) were described. From the thermodynamics perspective, special attention is required with the increasing use of lightweight metals, because they are very sensitive to contaminations.