Abstract: An apparatus for grinding particulate material includes a grinding chamber. Fluid sources mounted on the peripheral wall of the grinding chamber generate a stream of fluid directed along the source axis of the fluid source towards the inside of the grinding chamber. Fluid flow guides associated with fluid sources have a first aperture. Guide members associated with fluid sources have a second aperture. Each guide member co-operates with the fluid stream of the associated fluid source and the associated fluid flow guide to draw fluid towards an upstream portion of the fluid stream and to direct fluid away from a downstream portion of the fluid stream. The fluid streams from the fluid sources overlap in an empty zone of the grinding chamber. The particulate material is introduced into the fluid streams, accelerated by the fluid streams and directed towards the empty zone. Thus particles from different streams collide in the empty zone.

Abstract: A process for preparing toner compositions comprising: coinjecting into a continuously operating fluid energy mill, feed toner particles, and a liquid component; and separating the resulting comminuted toner particles.