Systematic selection of perspective solid waste mechanical separation technologies for material recovery

Abstract

Material recovery from waste streams is an important element of the circular economy. It relies on efficient liberation and separation of materials, which remains challenging for commingled solid waste streams. LUT University intends to research and develop new mechanical separation technologies, so an understanding of the state of the art, as well as research and development in the field in industry and academia is required. For objective review and comparison of available and emerging mechanical separation technologies, a database of a new tree-like structure was created and filled with performance figures achieved by different technologies. Custom software written in Julia parsed the database into a tabular format for easy filtering and visualization. The database allowed to describe technologies in terms of separation efficiency, suitable particle size, material categories and connections between these and other parameters. Alongside with technology performance, their underlying principles were characterized in terms of used effects, target material properties and affecting factors, that has led to insight into new possibilities for research. Considering both existing and future technologies, a feasible arsenal of techniques for separation of construction and demolition waste was proposed. Limits of direct sorting methods were identified. Ways to achieve economical multimaterial separation with sensors were discussed. The database showed potential as a decision support tool suitable for systematic selection and comparison of technologies, extendable to keep up with future technological progress.