What is the basic principle of magnetic separation?Magnetic separator is mainly used for separating various minerals such as ferrous metals, non-ferrous metals, precious metals, non-metals.
Magnetic separator also can separate non-metal ores
When the magnetic separator is doing the separation work, the strong magnetic field will absorb the minerals with stronger magnetism to the effective separating surface or magnetic matrices. At the same time, non-magnetic mineral composition, not being affected by a magnetic field, discharges from the discharge port along another trajectory.
Classification of magnetic separator
According to different properties of materials, the magnetic separator is divided into the dry magnetic separator and wet magnetic separator.
The two types of magnetic separators both can effectively process various minerals
- Dry magnetic separating machine can effectively implement the separating process without mixing with water.
- The wet magnetic separator must be mixed with water or other media to form a slurry for magnetic separation.
- Ore material is sent not by a slurry tank but a vibrating feeder to the dry magnetic separator which is installed the dustproof device.
- As for wet magnetic separators, it needs tanks to keep the fluidity of ore slurry and pumps to feed material.
Permanent magnetic drum dry separator
Dry magnetic separators are mainly for separating dry magnetic minerals, and the most commonly used is permanent magnetic drum dry separator.
What mixtures can be separated by permanent magnetic drum dry separator?
Dry magnetic separator mainly used to separate large and coarse particles of strong magnetic ore.
It is widely used for beneficiating weakly magnetic minerals with less than 2-3 mm of weak and reselecting of rare metal ores.
It needs to be used together with Raymond mill, crushers and ball mill.
Machine materials and structures
It mainly consists of a permanent magnet system, a rotating drum (with single and double drum), a magnetic separator mine-separating box, a feed tank, and a flushing pipe.
The rotary drum is made of 2mm thick fiberglass, and its surfaces reinforced a layer of wear-resistant rubber. Adopting fiberglass is to prevent the over-heat of the rotary drum and the increase of the motor power caused by the vortex effect.
The permanent magnet system of the dry magnetic separator is made of high-quality ferrite or composite including ferrite material and rare earth magnetic steel. The average magnetic induction intensity of the drum surface is at the range of 100~600mt.
The magnetic separator mine-separating box is sealed with foam plastic. A pipe is installed on the top of the separating box which is connected with the dust collector so that the box can work in a negative pressure state.
The separating process of the Permanent magnetic drum dry separator
First, the electric vibration feeder sends the finely ground ore particles to the upper roller for coarse separation.
Then, the magnetic particles are sucked on the roller surface, brought to the electrodeless area, discharged from the concentrated area.
Non-magnetic ore particles are thrown away from the roller surface due to the combined action of gravity and centrifugal force and enter the lower roller for further selection.
Finally, the non-magnetic ore particles enter the tailings tank, while the magnetic ore particles re-selected enter the concentrate ore trough.
Advantages of the magnetic dry separator
Permanent magnetic drum dry separator working site
- 1Reasonable magnetic field distribution, no demagnetization for long-term use
- 2The tank body adopts computer simulation fluid design, which effectively prevents the slurry from settling and clogging
- 3Dry magnetic separator has the advantages of large enrichment ratio, strong adaptability to ore feeding particle size, concentration, and grade fluctuation
- 4It produces products with high concentrate grade and high recovery rate
Permanent magnetic drum wet separator
What materials can be processed by wet magnetic separator?
The permanent magnetic drum wet separator is suitable for the ores like magnetic pyrite, roasted ore, ilmenite, and other materials with a particle size of less than 3mm. It is also used to remove iron from coal, non-metallic ores, and building materials.
permanent magnetic drum made of high-quality material
Machine materials and structures
Just like a dry magnetic separator, the wet magnetic separator is also made of ferrite or composite including ferrite material and rare earth magnetic steel. The average magnetic induction intensity of the drum surface is at the range of 100~600mt.
How to separate ores by permanent magnetic drum wet separator?
It can be divided into three types according to the various tanks:
This method is generally used for coarse selection of strong magnetic minerals with 0-6mm, presenting a high recovery rate and high grade.
Countercurrent-slurry feed direction is opposite to the drum rotating direction. the magnetic concentrate is discharged on one side of the feed opening while the tailings are discharged on the other side.
It is generally used for coarse separating and scavenging the material with 0.6-0mm, and keeping the high recycling rate.
Semi-countercurrent: the slurry feed direction is half the same and half opposite of the drum rotating direction, and the difference with the cocurrent type is that the ore slurry turns a circle in the tank.
The slurry is washed completely by the water, which can prevent inclusions. The movement direction of the slurry is consistent with the direction of the magnetic force, which is conducive to further recycling. semi-countercurrent method also benefits for getting high-grade magnetic concentrate from strong magnetic ore with 0.5-10mm by coarse separation and scavenging, keeping stable slurry surface and operation.
Advantages of the magnetic wet separator
- 1Full magnetic design shows large contact area between the pulp and the effective working surface
- 2The adsorption area is close to the brush unloading device, which can effectively prevent the adsorption
- 3The diameter of the raw ore can reach 16mm
- 4The magnetic content of tailings is significantly reduced, which is 1-3% lower than that of ordinary magnetic separation equipment
- 5The separating process is lengthened to make concentrate grade increase by 2-4%
Fote wet magnetic separators have brought Indian customers huge profit
This Indian customer wants to separate vanadium titanium magnetite tailings：
To reduce production costs, Fote Company provides the Indian client the method which comprises the following steps:
Step1Concentrating the magnetic tailings, and sending it into a spiral chute to obtain a spiral ore concentrate and a helical mine tailing;
Step 2Sieving the helical ore concentrate, collecting the part with the graininess of 0.6-0.074 mm;
Step3Drying, enriching the titanium ores to make a further dry magnetic separation, thereby obtaining titanium ore concentrate and ilmenite.
The solution for separating titanium ore concentrate not only ensures the quality but increases the recovery rate by 10-25 percentage points. The annual output of titanium concentrate of our customers has increased from 50 thousand tons to 500 thousand tons.
Facts have proved that Fote magnetic separator can improve the classification efficiency, especially increase the concentration of underflow, and reduce the phenomenon of overflow and roughness. It has significantly raised the recovery rate and product quality and greatly improved the comprehensive utilization rate of resources.