GREENY project focuses on increasing the energy efficiency of comminution and enabling the beneficiation of difficult to process secondary raw materials. These objectives are met by upscaling new crushing and grinding processes and applying them to presently unused sources of secondary raw materials. As a use case the GREENY project takes on the efficient reuse of industry’s slag that is the sideproduct. The design and optimization methodologies, processes and equipment that are developed are applicable also to other slags and secondary raw materials. In the GREENY use case the slag contains valuable metals that can be extracted by combination of selective comminution and metal liberation from the slag. The raw slag, containing less than cost beneficially required of extractable metals, is to be used as a separate product for construction materials after comminution. During the project, emphasis is placed on improving and upscaling suitable crushing and grinding technologies for slag material to enhance the energy efficiency and performance of crushing equipment in demanding operational conditions. The processes are developed in general with difficult to refine secondary raw materials in mind, for example materials which contains both brittle and ductile phases. A novel feature of GREENY is the widespread adoption of digitalization and already previously validated modeling and simulation tools to pursue the improvements the GREENY project is commited to. Modeling activities run parallel to experimental work and interact at every step in development of new processes and applying them to the slag use case. Simultaneous use of modeling and experimentation in process and equipment development has been shown to decrease the associated R&D time and costs by a factor of at least 2 in addition to yielding typically far better outcomes. Already a very small improvement in the energy efficiency of processing equipment can yield notable economic benefits, GREENY targets a 5-10% increase in processing efficiency. Adding the competitiveness of slag reuse by improved processing enables the better utilization of this often-wasted resource, for example, the metal production of pyrometallurgical plants can be increased by 2-5% by adopting the approaches GREENY will develop.
GREENY combines the excellence of multiple disciplines. Comminution technology will be developed according to the virtual design with simulation models, which reduces the need for time consuming trial-and-error experiments. The necessary validation is performed with instrumented mineral crushing and grinding equipment at the manufacturer’s facilities. The validated simulations models allow further utilization of the simulation toolset for design purposes and testing of different scenarios. Metal separation from the slag is aimed to be optimized with modern separation techniques. In order to understand the slag behavior during crushing and achieve efficient selective comminution, the comminution process is informed by the advanced characterization of slag microstructure and its failure behavior at microscopic and macroscopic scales. Selective grinding techniques are seen as an efficient direction to seek improvements for accelerating the separation process. The effect of different processing parameters are demonstrated with the virtual and experimental setups to improve comminution process towards better overall usability of the crushed media. A suitable size distribution of the slag makes metal extraction easier and high amount of crushed slag can be effectively used.
Project results will be beneficial for mining and steel producing companies, chemical industry, construction industry, engineering and technology companies operating in these fields and material producers in general. The desired energy improvement invention in the slag crushing process are expected to be usable for crushing and comminution of rocks, further widening the market area.