The melted powder particles are assuming the spherical shape under the action of surface tension of liquid state.
During the first, neck growth proceeds rapidly but powder particles remain discrete.
Water mixed into the powders can form bonds between powder particles that are strong enough to lock them together.
In this process the primary powder particles are aggregated under high pressure.
Also, if powder particles are sufficiently small, they may become suspended in the atmosphere for a very long time.
Granulation is the act or process in which primary powder particles are made to adhere to form larger, multiparticle entities called granules.
That way, powder particles bind to each other and form a solid object.
J. Smart adverts to a sufficient fluid velocity being extremely important for evacuation of removed black powder particles.
These charged powder particles then adhere to the grounded substrate.
This tell you how much liquid was replaced by the powder particles.