Prilling and other spray processes have the advantage of being able to create ideal spherical particles with narrow size distributions and minimal external specific surface area in one single process step, scaleable to basically any capacity range needed.
The particle surfaces will be smooth, without edges or sharp dents and can be well sealed. All narrow-sized, spherical particle powders with a span less of than 2 and a d50 bigger than 200 microns are often recognised as dustfree and very free-flowing.
As some shrinkage is inevitable during any type of solidification, the spheres are in fact never truly ideal. Even the small changes in volume during congealing (freezing of water being an interesting exception) will result in slightly hollow spheres or spheres with a one-sided indentation due to the fact, that the droplet surface will solidify first. Turbulent, intense mixing conditions will favour hollow spheres, whereas slower and ordered flow patterns will give indentations on the back-side of the droplets, where the material stays fluid.