Spiral separator is a kind of separation equipment that realizes the separation of minerals with different densities under the action of gravity and centrifugal force depending on the characteristics of liquid flow. The feed is fed from the upper end of the spiral sorter and rotates downward along the spiral groove. During the movement of the material flow in the spiral groove, along the inner side to the outer side of the groove, the thickness of the water layer gradually increases, heavy mineral particles such as gangue gradually move to the lower layer, and light minerals such as coal float on the upper layer of the material flow, forming a lower flow layer dominated by heavy products and an upper flow layer dominated by light products.

After the particle group is stratified, because the heavy product is located in the lower layer, in contact with the tank and under the pressure of the upper liquid flow, the movement resistance increases and forms a velocity difference with the light product. The light products move towards the outer edge of the groove under the action of spiral material flow, the heavy products move towards the inner edge of the groove under the action of gravity, hydrodynamic pressure, friction and inertial centrifugal force, and the intermediate density materials occupy the middle zone of the groove, that is, the light and heavy particles are basically divided according to density on the cross section.

At the bottom of the spiral separator, the product chute is used to collect these materials respectively, so as to realize the separation of light and heavy products.