Accelerator waste contains a number of rare isotopes that are urgently needed in various fields of scientific research. Activated components from the surroundings of high-power accelerators like the HIPA cyclotron at PSI are valuable sources for such 'isotope mining' . While the isotope production itself is practically 'for free' , because the irradiation takes place anyway, the challenge is the chemical extraction of the required isotopes from the activated matrix material. The article presents an overview on the attempts and achievements of more than 15 years research and development in the research group 'Isotope and Target Chemistry' at PSI and presents some of the highlights in scientific applications.