For over 30 years, hydrometal has recycled nonferrous metals from complex secondary materials using hydrometallurgical processes. The tailor-made treatments developed by hydrometal contribute significantly to the development of sustainable solutions to the depletion of natural resources and fit naturally into the sustainable circular economy concept. Hydrometal’s expertise is based on a wide range of hydrometallurgical technologies that are unique in the world of the treatment of complex residues that are often considered as toxic and hazardous waste. One of these unique processes, developed recently and supported actively by Dr. Joe Ferron, is the recovery of germanium based on an innovative ion exchange process. After the leaching of complex secondary raw materials containing germanium such as zinc or iron by-products and copper cement from various industries, germanium is selectively recovered from complex solutions and concentrated 10- to 100-fold. This pure germanium concentrate can therefore be readily reintegrated into germanium refineries. This paper summarizes the methodology for developing such a process from proof-of-concept at lab scale to the evaluation of industrial performance at an industrial pilot scale.