The influence of magnetic field frequency on eddy current separation

Solid waste contains a large amount of non-ferrous metal resources. Eddy current separation can separate and enrich them. Increasing the eddy current force of is the key to improving efficient separation. The alternating magnetic field frequency plays an important role in regulating the eddy current force. It includes the magnetic roller speed and pole pair configuration. In this study, based on electromagnetic field theory and COMSOL Multiphysics simulation, the influences of the magnetic roller speed and pole pair configuration on the eddy current force of particles with different radii are investigated. And eddy current mechanism and magnetic field mechanism are revealed to explain the relationship between the magnetic roller speed, the pole pair configuration and eddy current force, respectively. Study shows that the optimal magnetic roller speed decreases as the particle size increases and the optimal pole pair configuration is 6 pairs for separating particles with the radii of 2 ~ 16 mm. The results are beneficial for the magnetic roller design and production cost reduction, which will be used to separate larger size range materials. And they also can guide the setting of optimal operating parameters according to the particle sizes.