This thesis is about REDWAVE XRF, a sensor-based sorting system for resource recycling in waste management, developed in collaboration of BT-Wolfgang Binder GmbH and Innov-X Systems. The detection for that system is based on X-ray fluorescence. The first part of this work deals with the background of X-ray fluorescence, beginning with the development by C. W. Röntgen. Furthermore, the physical process is described from excitation with different X-ray sources to interaction of X-rays with matter and finally the origin of secondary X-ray radiation. The second part gives detailed information about the assembly and function of the sorting system as well as a detailed technical description of the function of detection and factors of influence. The practical use of REDWAVE XRF is described in part three. Both an example of commercial use is given and some fields with high potential of possible successful applications are presented. Additionally, the practical use is being displayed by a detailed sorting test of scrap metal. Finally all results are summarized and reviewed and future directions are given.