Permanent magnetic drum separators are commonly used in mineral processing plants, primarily for separating weakly magnetic minerals (such as hematite, manganese ore, and ilmenite) or strongly magnetic minerals (such as magnetite). Their core structure consists of a permanent magnet system and a trough, the design of which directly influences the separation effect. Based on the relative relationship between the slurry flow direction and the magnetic drum rotation direction, they can be divided into the following three types:
Three type magnetic separator
1. Co-current Magnetic Separator Structural Features: Slurry flow direction: The same as the direction of rotation of the magnetic drum (co-current). Feeding location: Slurry is fed from above the magnetic drum, and tailings are discharged from below. Concentrate discharge method: The rotating magnetic drum carries the concentrate to the discharge area, where it is stripped by scrapers or flushing water. Operation: Slurry enters the trough from the feed box and flows in the direction of rotation of the magnetic drum. Magnetic minerals are attracted to the surface of the magnetic drum and fall off as the drum rotates to the discharge area. Non-magnetic minerals (tailings) are discharged directly from the bottom of the trough.
Advantages and Disadvantages
Advantages: Simple structure and easy maintenance. Suitable for coarse-grained minerals (>0.5mm), fast slurry flow rate, and large processing capacity.
Disadvantages: Low recovery rate of magnetic minerals (easily carried away by the slurry), low concentrate grade (inclusion of non-magnetic particles).
Poor separation effect on fine-grained minerals.
Applicable Scenarios Roughing operations: where recovery rates are not high. Preliminary enrichment of strongly magnetic minerals (such as magnetite).
2. Counter-current Magnetic Separator Structural Features: Slurry flow direction: Countercurrent to the direction of magnetic drum rotation. Feeding location: Slurry is fed from the bottom of the trough, with tailings overflowing from above. Concentrate discharge method: The magnetic drum absorbs magnetic minerals and then rotates to the unloading area for stripping.
During operation, the slurry flows upward from the bottom of the tank, in the opposite direction of the magnetic drum's rotation. Magnetic minerals are attracted to the drum's surface, while tailings overflow from the top. The concentrate falls off as the drum rotates to a non-magnetic field.
Advantages and Disadvantages
Advantages: High recovery rate (long contact time between slurry and magnetic drum), suitable for fine-grained minerals (<0.1mm), small processing capacity, and good performance for weakly magnetic minerals (such as hematite).
Disadvantages: Low concentrate grade (gangue inclusions), slow slurry flow rate, prone to clogging, and requires regular cleaning.
Applicable Scenarios: Sweeping and separation operations: Improving the recovery rate of magnetic minerals in tailings. Separation of fine-grained weakly magnetic minerals (such as hematite and manganese ore).
3. Semi-Countercurrent Magnetic Separator Structural Features: Slurry Flow Direction: Countercurrent at the bottom, Cocurrent at the top (combining the characteristics of both cocurrent and countercurrent flow). Feeding Location: Slurry is fed from the lower center of the trough, with tailings overflowing from the top. Concentrate Discharge Method: Magnetic minerals are adsorbed and then rotated to the unloading area for stripping. During operation, slurry is fed from the lower center. The lower countercurrent area improves recovery, while the upper cocurrent area increases concentrate grade. Magnetic minerals are adsorbed, while non-magnetic minerals overflow and are discharged from the top. The concentrate is collected in the unloading area using flushing water or scrapers.
Advantages and Disadvantages
Advantages: High recovery and high concentrate grade, suitable for medium- and fine-grained minerals (0.1-0.5mm), moderate processing capacity, and wide adaptability.
Disadvantages: Complex structure, slightly higher maintenance costs, and high feed concentration and particle size requirements.
Applicable Scenarios: Selection operations where high concentrate grade and recovery rate are required. Sorting of common minerals such as magnetite and ilmenite.
Wet magnetic separator
Three rollls magnetic separator
