The number and quality prediction scheme of spiral separator and TBS is the same as that of heavy medium, but the specific gravity medium is larger. Generally, ep0.1-0.2 is taken. In the design specification of coal preparation plant, the I value is taken, which is 0.2-0.25, so the method is the same as jigging. In fact, they are almost the same. The particle size of spiral separator is not as sensitive as TBS, but it is very sensitive to density. The higher the density, the better. Therefore, spiral separator is suitable for gangue discharge.