According to the sorting medium, it can be divided into:
Dry magnetic separators: Separate in the air, mainly used to separate large, coarse-grained strong magnetic ore and fine-grained weak magnetic ore. At present, it is also trying to be used to sort fine-grained strong magnetic ore.
Liquid magnetic separators: sorting in water or magnetic liquid. Mainly used to separate fine-grained strong magnetic ore and fine-grained weak magnetic ore.
In addition, liquid magnetic separator can be classified according to the way the magnetic ore particles are selected, the direction of movement of the feed material, the method of discharging and sorting products from the selected zone, and the structural characteristics of the discharged magnetic products.
The closed loop through which magnetic flux intensively passes is called a magnetic circuit. The magnetic system of the magnetic separator needs to generate a certain strength magnetic field, and most of the magnetic flux in the magnetic field is required to concentrate through the separation space. The height, width, radius and number of poles of the magnetic system, the magnetic potential difference between adjacent magnetic poles, the pole pitch, the ratio of the pole face width and the pole gap width, the shape of the magnetic pole and the magnetic end face, and the distance from the magnetic end face to the arrangement center have a big influence on magnetic field characteristics.
Taking the manual drawer type magnetic separator as an example, the magnetic circuit part adopts a five-pole magnetic system, and each magnetic pole is made of ferrite and a neodymium iron boron permanent magnet block, which is fixed to the magnetic guide plate with a screw through the central hole of the magnetic block on the upper side. The magnetic guide plate is fixed on the shaft of the cylinder through the bracket, the magnetic system is fixed, and the cylinder can rotate. The polarities of the magnetic poles are arranged alternately along the circumference, with the same polarity along the axial direction. The outside of the magnetic system is a roller made of stainless steel non-magnetic material. The non-magnetic material is used to prevent the magnetic line of force from entering the selected area through the cylinder and forming a magnetic short circuit with the cylinder. Non-magnetic materials should also be used for the part of the tank near the magnetic system, and ordinary steel plates or hard plastic plates for the rest.
The permanent magnet is the most important part of the magnetic separator, and the quality of the permanent magnet determines its performance characteristics. Permanent magnets of magnetic separators are generally made of a certain size, so they are customarily called permanent magnet blocks or magnet blocks for short. The permanent magnet materials that can be used as the magnetic system of the magnetic separator include permanent magnet ferrite, alnico, iron chromium cobalt and manganese aluminum iron, samarium cobalt permanent magnet materials, and neodymium iron boron permanent magnet materials. At present, the mainstream permanent magnet materials used in magnetic separation equipment are mainly permanent magnet ferrite (strontium ferrite and barium ferrite), followed by neodymium iron boron permanent magnet materials.
