An investigation of the flow properties of rutile particles: Fluidization behaviour linked with shearing studies

The paper reports on part of an extensive experimental campaign aimed at studying the influence of operative conditions on the fluidization behaviour of industrial reactive powders. The fluidization behaviour of two different types of rutile particles, namely a synthetic and a natural rutile, was investigated at temperatures ranging from ambient up to 500 °C. Their fluidization quality was also characterised through the bed collapse test, which provides a sensitive and discriminating methodology for the assessment of the changes in the materials' responses between low and high-temperature operation. The results obtained from the fundamental fluidization tests and bed collapse technique were linked to the rheological analysis of the flow properties of the materials. The comparison underpinned the relative role of the interparticle forces and the hydrodynamic forces on the flow behaviour of the particles at process conditions.