Abstract: A method and apparatus to pulverize materials directs solid materials through a generally horizontal chamber. A rotating center element that directs the material along the chamber by basic thrust using projections such as tines, paddles, knives or blades to develop motion and resulting kinetic energy of the material. The material is directed along the axis from the material inlet toward the material outlet and reverses flow at the end of the chamber to recycle back toward the material inlet causing particles of material to collide and fracture. The rotating speed of the center element can be adjusted to affect the grinding rates and particle size distribution. The rotating center element can also be fixtured to optimize material size reduction, differences in material density and the horizontal chamber can be tilted in a declined or inclined plane to affect the grinding rates and size reduction.