The magnetic system is the main part of the magnetic separator, magnetic separator performance is not only related to magnetic materials and magnetic characteristics, but also with the structure of the magnetic system has a great relationship.

弱磁場磁選機一般都設計為開放的磁系。它是由永磁磁塊粘結迭合而成的磁極和底板以及磁矩組成。這是一個三極磁系，由于空氣的磁阻較大，所以形成的磁場屬于弱磁場。

Weak magnetic separators are generally designed to open the magnetic system. The magnetic pole and the base plate and the magnetic moment formed by the permanent magnet block are bonded together. This is a three pole magnetic system, due to the large magnetic resistance of the air, so the formation of the magnetic field is weak.

閉合磁系由于磁極間的空氣隙小，容易產生強磁場。所以選別弱磁性礦物的強磁場磁選機都設計為閉合的磁系。為了進一步提高閉合磁系的磁場力，可以縮小空氣隙，以此減小磁阻。但是這樣做會使選別空間減小，使設備處理能力降低，所以目前多從改進磁極對的形式和它的幾何尺寸，以及在兩磁間放置導磁系數很高的聚磁介質來提高磁場力。如在兩原磁極間放置一個整體的具有一定形狀的感應介質（轉輥、轉錐或轉盤）構成磁路，還可在原磁極之間放置多個具有一定形狀的感應介質（齒板、球、柱或網等）構成磁路。

The closed magnetic system is easy to generate strong magnetic field due to the small air gap between the magnetic poles. So the strong magnetic field magnetic separation of the weak magnetic minerals is designed as a closed magnetic system. In order to further improve the magnetic field force of the closed magnetic system, the air gap can be reduced, thereby reducing the magnetic field of the magnetic field. But it will make the separation space decreases, reducing the equipment processing capacity, so the improvement of the magnetic pole from the form and its size, and placed in the two magnetic permeability between high magnetic media to improve magnetic force. Such as a whole has a certain shape of the induction medium in the two original pole (roller, cone or disc) constitute a magnetic circuit, can also be placed with a plurality of induction medium with a certain shape in the original pole (tooth plate, spherical and cylindrical or net) constitute a magnetic circuit.