Cryogenic comminution

Ductile materials such as steel, plastics and rubber which cannot be milled easily, can be embrittled by lowering the temperature of the material. Once embrittled the material will lend itself more easily to comminution by conventional methods, usually with the use of a hammer mill. Liquid nitrogen is a gas used for this purpose. The process is expensive due to the cost of the gas but is used for some specialised applications.