110th Anniversary: Slurryability: What Makes a Powder Hard to Incorporate into a Slurry?

This paper investigates powder properties that are significant in determining how easily a powder may be incorporated into water to form a concentrated slurry. The slurryability of a powder is defined as the time and energy required to prepare a 50 wt % slurry as well as a threshold concentration at which 1 kJ is required to further increase the solid content by 1 wt % at the scale studied. Partial least-squares models relating powder properties to their slurryability are built on a data set of 13 powders. The most significant properties determining slurryability are the particle pore volume, powder bulk density, and the results of permeability and aeration tests on a powder rheometer. The D ₅₀ particle size and powder cohesion measurements are also relevant in the models. Through the measurement of only these six properties, the slurryability of two further powders, not included in the training data set, were predicted within ±10%.