Investigation of the material transport behaviour of tube- and trough-vibration mills by radioactive indicators

Vibration mills are used for grinding granular materials into powders with very small particle sizes (some μm). Grinding process is carried out with dry materials or with materials suspended in water. The mills are partially filled with grinding bodies, normally with steel or ceramic balls or cylpebs. By labelling the solid material or the aqueous phase with radionuclides, the residence time distribution of material in tube and trough mills was determined under various working parameters. Conclusions concerning the material transport behaviour in different mills were drawn: Whereas tube-vibration mills show nearly a plug flow, trough-vibration mills represent more or less a mixing vessel. Connections were found between material transport behaviour and working parameters, application recommendations are given. (author)