Magnetic Separator is one of the most widely used and highly versatile models in mineral processing, and is suitable for the separation of materials with magnetic differences. Magnetic separators are widely used in mining, wood, kiln, chemical, food and other industries. For the mining industry, the magnetic separator is suitable for wet or dry magnetic separation of manganese ore, magnetite, pyrrhotite, roasted ore, ilmenite, hematite and other materials with a particle size of less than 50mm. It is used for iron removal of coal, non-metallic minerals, building materials and other materials. Magnetic separators are divided into two categories. The magnetic system of permanent magnetic separators is mostly made of high-quality ferrite materials or composited with rare earth magnetic steel. Earlier, the average magnetic induction intensity on the surface of the magnetic cylinder of the magnetic separator was 80- 400mT. With the continuous development of technology, after the magnetic separator can be made into a roll shape, the magnetic field intensity is also increased to 1650mT, which is the highest magnetic field intensity currently measured.
Application range of magnetic separator
Magnetic separators are widely used in resource recovery, wood industry, mining, kiln industry, chemical, food and other factories. It is also used for iron removal of coal, non-metallic minerals, building materials and other materials. It is one of the most widely used and highly versatile models in the industry.
The structure of the magnetic separator
Wet permanent magnet drum magnetic separator is mainly composed of cylinder, roller, brush roller, magnetic system, tank body and transmission part [1]. The cylinder is made of 2-3mm stainless steel plate and welded into a cylinder, and the end cover is a cast aluminum part or a workpiece, which is connected to the cylinder with stainless steel screws. The motor drives the cylinder, the magnetic roller and the brush roller to rotate through the reducer or directly with the stepless speed regulating motor. The magnetic system is an open magnetic system, which is installed in the cylinder and exposed to the full magnetism. The magnetic block is mounted on the bottom plate of the magnetic yoke with stainless steel bolts, the shaft of the magnetic yoke extends out of the cylinder, and the shaft end is fixed with a crank arm. The declination of the magnetic system can be adjusted by turning the crank arm, and it can be fixed with a pull rod after proper adjustment. The working area of the tank body is made of stainless steel plate, and the frame and other parts of the tank body are welded with ordinary steel.
The working principle of magnetic separator
After the ore slurry flows into the tank body through the ore feeding box, under the action of the water flow of the ore feeding water spray pipe, the ore particles enter the ore feeding area of the tank body in a loose state. Under the action of the magnetic field, the magnetic ore particles are magnetically aggregated to form a "magnetic cluster" or "magnetic chain". . Since the polarities of the magnetic poles are alternately arranged along the rotation direction of the cylinder and are fixed during operation, when the "magnetic group" or "magnetic chain" rotates with the cylinder, a magnetic stirring phenomenon occurs due to the alternation of the magnetic poles and is mixed with The non-magnetic minerals such as gangue in the "magnetic cluster" or "magnetic chain" fall off during the tumbling, and the "magnetic group" or "magnetic chain" that is finally attracted to the surface of the cylinder is the concentrate. The concentrate moves with the cylinder to the edge of the magnetic system where the magnetic force is the weakest, and is discharged into the concentrate tank under the action of the flushing water flow from the discharge pipe. Non-magnetic or weakly magnetic minerals are left in the pulp and discharged out of the tank with the pulp, that is, tailings.
The technical advantages of magnetic separator
- 1. The permanent magnetic drum type magnetic separator adopts the rare earth composite magnetic system, and the surface layer of the magnetic system is reinforced with a stainless steel belt structure. Gaskets and sealants are added on both sides of the cylinder section to ensure no water seepage; excellent technical and reasonable configuration. After a unique design scheme, the distribution of magnetic induction intensity is more effective, and the actual effect of screening is more significant.
- 2. The body has undergone a unique design scheme, which is not easy to block and run out of materials. The tank body is semi-reverse flow.
- 3. There are two types of driving methods: left transmission system and right transmission system.
- 4. The vulcanized rubber on the surface of the drum adopts the immediate vulcanized rubber method instead of the bonding method. The vulcanized rubber layer adopts the high wear resistance and high strength, the thickness is 4mm, the service life is 2-3 years, and the bonding compressive strength is 3.5Mpa.
- 5. The field compressive strength is large, the electromagnetic field depth is large, and the solution work ability is large.
- 6. The structure is simple and the output is large; the actual operation is simple and easy to maintain.
- 7. The design scheme of the ore feeding box has a relative structure that causes the inflow of effective ore pulp, so that the utilization rate of the magnetic minerals is further improved.
Classification of magnetic separators
- According to the type of magnet, it can be divided into: permanent magnetic separator and electromagnetic iron remover
- According to the dryness and wetness of the mine, it can be divided into: dry iron remover, wet iron remover
- According to the magnetic system, it can be divided into: drum magnetic separator, roller magnetic separator, drum magnetic separator and flat magnetic separator.
- According to the number of magnetic systems, it can be divided into: single-cylinder magnetic separator, double-cylinder magnetic separator and combined multi-cylinder magnetic separator.
- According to the ore feeding method, it can be divided into: the upper ore feeding magnetic separator and the lower ore feeding magnetic separator.
- According to the classification of magnetic field strength, it can be divided into: weak magnetic separator, medium magnetic separator and strong magnetic separator.
- According to the classification of the magnetic system, it can be divided into: open magnetic circuit magnetic separator, closed magnetic circuit magnetic separator.
How to choose a magnetic separator
Wet permanent magnet drum magnetic separator is a kind of magnetic separator commonly used in iron ore processing plants, it is suitable for separating strong magnetic minerals. According to the different structure of the tank, the magnetic separator is divided into three types: co-current, counter-current and semi-counter-current. The selected particle sizes of the magnetic separators of three different tank types are as follows: the downstream tank body is ≤6mm, the countercurrent tank body is ≤1.5mm, and the semi-countercurrent tank body is ≤0.5mm.
The downstream magnetic separator has a large processing capacity and is suitable for the rough selection and selection of relatively coarse-grained strong magnetic materials, and can also work with multiple units in series. When the feed volume of the downstream magnetic separator is large, the magnetic ore particles are easily lost to the tailings, so the operation management should be strengthened to control the lower pulp level.
Counter-current magnetic separator is suitable for roughing and sweeping of fine-grained strong magnetic minerals, with high recovery rate but low concentrate grade. Because the coarse-grained materials are easy to deposit and block the separation space, the counter-current magnetic separator is not suitable for the processing of coarse-grained materials.
The semi-countercurrent magnetic separator can obtain high-quality iron ore concentrate, and at the same time can obtain a better recovery rate, so the semi-countercurrent magnetic separator is widely used in production practice. It is suitable for roughing and selection of ore particles below 0.5mm, and can also be connected in series and parallel to achieve multiple sweeping and selection.
