Method and apparatus for fine distribution of particles of coarse crushed coal, ores, industrial minerals and rocks

摘要

Coarse-crushed particles of coal, ore, industrial minerals or rock are finely graded by passing them through a feed unit 14 into a cycle 19, 22, 38, 39,41 comprising a cryogenic liquid, for example liquid carbon dioxide, and passing this cryogenic flow with the mineral particles contained to a fine grader 17 through a zone therein with mechanically induced high-frequency vibration, ideally ultrasound. The fine grader 17 may be multistage and provided with units so as to be able to return oversize mineral particles, the cryogenic flow 38, after having left the fine grader 17, being fed to a separator 18 in order to separate the finely graded particles and to return the cryogenic flow to the feed unit 14. The low temperature in the cryogenic liquid is maintained in a refrigeration unit 16, and losses of liquid are replaced by means of additional liquid that is added to the flow. IMAGE