| 摘要 |
Diamond particles 26 are sorted from rock particles 28 by cooling the particles using liquid nitrogen to below the freezing point of water and feeding the cooled particles onto the inner surface of a perforated drum conveyor 12 of fine mesh. The conveyor is passed through water bath 22 so that the rock particles become secured to the conveyor as a result of a body of frozen water extending on both sides of the mesh. Diamond particles, having a higher thermal diffusivity, warm up and are not secured to the conveyor. The diamond particles are deposited in receiver 44 using scraper 34 and the rock particles are separately recovered, using hot water sprays 29, in receiver 30. <IMAGE> |
