Abstract: An apparatus of the shot mill type includes a substantially vertical vessel, preferably cylindrical, containing shot for use as a dispersing media (also useful for deagglomerating and size-reducing material being dispersed), a bottom inlet for a mixture of particulate material to be dispersed and liquid vehicle for it, and a top outlet, a substantially vertical and axially rotatable agitator and a stationary screen in the vessel at the top thereof through which the dispersed material passes and through which the dispersing media does not pass.