| 摘要 |
In a method of sorting small particles, typically diamond (10) and gangue (12) particles having a size of 3mm or less, on the basis of differences in their thermal diffusivity the particles are firstly cooled e.g. in liquid nitrogen bath (14) to a low temperature below the freezing point of a liquid. Thereafter the particles are introduced into a body of the liquid such as water (18), the surface tension of the liquid previously having been adjusted such that particles (12) with relatively low thermal diffusivity cause freezing of the liquid with which they are in contact and are accordingly caused to float. Particles (10) with relatively high thermal diffusivity lose heat too rapidly to freeze the liquid and accordingly sink in the liquid. The floating and sunken particles are then recovered separately, in bins (24) and (26). |
