While the recycling of metallic scrap is nowadays state of the art, metal-containing by-products from the metallurgical industry represent a new potential secondary resource. Huge amounts of such materials are available worldwide either on dumps or continuously produced. However, their complex composition renders a detailed characterization difficult, resulting in few and weakly developed recycling concepts available to date. To realize this potential in the future more bundled competence is necessary. Montanuniversität Leoben has already developed some expertise in the field of typical by-products such as dust, slags and sludge. Due to the genesis of the primary polymetallic ores, it is especially the metallurgical processes used in the copper, lead and zinc industries that offer a high potential in their by-products. To allow an assessment of these materials a certification system similar to the ones already existing for primary resources needs to be established. This, in turn, will be of major use as a basis for investment decisions and relevant feasibility studies turning these often untouched materials into valuable resources.