Magnetic separator

Magnetic separator is a core equipment that utilizes the magnetic difference of materials to separate magnetic and non-magnetic substances in a magnetic field. It is widely used in mining, metallurgy, environmental protection, building materials, food and other fields.

1、 Core working principle
● Materials (ore/slurry/powder) passing through the magnetic field zone:
● Magnetic particles: Adsorbed by magnetic force, they fall off (concentrate) after being carried out of the magnetic field zone by the drum/medium.
● Non magnetic particles: Only subject to gravity/centrifugal force, falling directly (tailings).
● Sorting key: magnetic field strength, magnetic field gradient, material particle size/humidity.

2、 Main classification (by 4 dimensions)
1. According to the magnetic field source (most commonly used)
Permanent magnet magnetic separator
○ Magnetic source: neodymium iron boron, ferrite permanent magnet.
○ Advantages: Energy saving, simple structure, long lifespan, and maintenance free.
○ Applicable: Strong magnetic minerals (magnetite), iron removal.
Electromagnetic magnetic separator
○ Magnetic source: An energized coil generates a magnetic field.
Advantages: Adjustable magnetic field strength and high intensity.
○ Applicable: Weak magnetic minerals (hematite, manganese ore), high gradient sorting.
2. Sort by medium (dry and wet)
Wet magnetic separator
○ Medium: Water (slurry).
○ Advantages: High sorting accuracy, good fine particle effect, dust-proof.
○ Applicable: Fine grained iron ore and non-metallic ore below 3mm for iron removal
Magnetic separator
○ Medium: Air (dry material).
○ Advantages: No need for water, simple process, suitable for arid areas.
○ Applicable: Coarse particles below 50mm, water shortage scenarios, and iron removal from coal/scrap steel.
3. According to the magnetic field strength (determining the sorting object)

Table

4. According to the structural form
● Cylinder type (CT series): the most mainstream, divided into downstream, upstream, and semi upstream slots.
● Roller type: strong magnetic/high gradient, fine particle, non-metallic purification.
● Disc/ring type: high-precision selection, rare metal recycling.
● Belt type: sorting of large materials, scrap steel, and garbage.

3、 Core structure (taking cylindrical as an example)
1. Magnetic system: permanent magnet/electromagnetic, generating a magnetic field (core).
2. Drum: Made of stainless steel/wear-resistant material, it rotates to drive the material.
3. Tank body: filled with slurry/guide material, divided into forward/reverse/semi reverse flow.
4. Feeding/discharging: uniform feeding of ore, separation and collection of concentrate and tailings.
5. Transmission: The drum is driven by a motor and a reducer.

4、 Main application scenarios
● Mining: iron ore selection, manganese/titanium ore enrichment, non-metallic ore (quartz, feldspar, kaolin) iron removal and purification.
● Coal: Remove magnetic impurities such as pyrite, reduce ash and sulfur content.
● Environmental protection/recycling: Recycling iron metals from steel slag, scrap steel, garbage, and electronic waste.
● Building materials/ceramics: Raw materials remove iron, improve whiteness, and prevent black spots during firing.
● Food/Medicine: Remove iron impurities from flour, sugar, and medicine to ensure safety.

5、 Advantages and disadvantages
● Advantages
○ Efficient, low-cost, and high recovery rate (iron ore can reach 95%+).
○ Simple structure, easy maintenance, and high degree of automation.
○ Environmental Protection: Wet dust prevention, dry water pollution free.
○ Strong adaptability: particle size of 0-50mm, suitable for both dry and wet materials.
● Disadvantages
○ Only magnetic/non-magnetic, non-magnetic minerals cannot be sorted.
○ Strong magnetic field/high gradient models have high prices and energy consumption.
○ Fine grained sticky and wet materials are prone to clogging, leading to a decrease in sorting efficiency.