Particle characterization unit
Particle characterization unit (PCU) comprising a modern laser diffraction particle size analyzer as well as sample preparation, handling and classification stations enables particle-size analysis of wet and dry ores and concentrates in the nm to mm range. The unit is especially important for the research of multicomponent mineralogy samples, as the existing apparatuses in other Aalto units are targeted merely to nanoscale or clean-room purposes.
The PCU apparatus allows hands-on education and research of improved resource efficiency for low-grade primary raw materials; in combination with the existing hydrometallurgical leaching station plus ICP and SEM equipment at Aalto, it allows valuable metal enrichment into specific fractions of side streams (e.g. waste material or ashes) so that these by-products be transformed into valuable raw material and thus, support the circular economy. This type of research is in the focus of EIT Raw Materials, and in the best case may result in national or international business initiatives. Each raw material fraction has different kinetic behavior during leaching, and the PCU allows improved definition for particle size distribution and concequently improved accuracy of kinetic models to be built.9 High Intensity Grinding (HIG) is a hot topic in minerals and metal processing. However, there is only little research about the effect of HIG milled material on leaching kinetics or process configuration.
Particle characterization unit supports the research to be carried out with small particle size fractions produced by HIG. In the best case, increased surface area can make some unit processes, such as roasting or pressure oxidation, unnecessary, and thus support Finnish business and industry in creating a truly transformational technology for e.g. gold ore processing.
Figure: PCU can provide precise information about small particle size fractions: Left: Particle-size distribution for Au concentrate leach residue. Right: Sieve fractions for different Au concentrate fractions.
