Method for treating particles of a bulk material and method for controlling a roll mill

摘要

An apparatus for sorting particles of a bulk material moving on a transport ribbon (38) comprises an electro optical monitoring unit (101) above transport ribbon (38) for detecting the particles to be sorted out. Jet nozzles (45, 46) are controlled by a signal emitted by this electro optical monitoring unit (40), the jet nozzles being provided at the side opposite the bulk material of transport ribbon (38), which consists of an air permeable material. By means of the gas jet passing through transport ribbon (38), the particles to be sorted out are lifted off from the transport ribbon and are thrown into storage containers (47, 48). The bulk material is passed through a gap between rollers or grinding elements to provide flake-shaped particles which are then observed to provide first and second measurements which are subtracted from each other.