Wiley mill

The Wiley mill is a laboratory-scale machine for grinding materials to a powder, and belongs to the family of cutting mills. These mills prepare materials for analysis with minimal moisture loss. Well-dried samples are preferred. In the grinding mill, the material is loaded cut into crude pieces or lumps and loaded into a hopper. From the hopper, the material drops by gravity into the path of a set of revolving hard tool steel blades driven by an electric motor. The revolving knives work against stationary knives and the resulting powder is forced through a steel screen. The powdered material then drops into a waiting collection vessel underneath.

The Wiley mill is most commonly used in agriculture and soil science laboratories but can be used on a wide variety of materials. The Wiley mill was originally designed for grinding fertilizer materials, animal hair, hoofs and other materials.