JXSC Mineral

How to Optimize the Dry Magnetic Separator Effect

The dry magnetic separator is a magnetic beneficiation machine for the separation of dry magnetic minerals, especially suitable for the magnetic separation of magnetite, pyrrhotite, roasted ore, ilmenite and other materials with a particle size below 3mm. It is used for iron removal of coal, non-metallic minerals, building materials and other materials. Three main points to ensure that the dry magnetic separator can achieve good magnetic separation effect: the thickness of feed layer, the vibration speed of vibration tank, the magnetic field strength and the working gap.

Dry High Intensity Magnetic Separator

Application of Magnetic Separation:  removal of miscellaneous stones, improve the grade, achieve sales. 

Advantages of simple structure, large treatment capacity, convenient operation and easy maintenance.

According to user needs, we can provide downstream, semi-countercurrent, counter-current type, such as a variety of strong magnetic separation table.

I. Thickness of feeding layer

The thickness of the feed layer is related to the particle size of the raw material to be processed and the content of magnetic minerals. Coarse-grained raw materials are generally thicker than fine-grained feed layers.When dealing with coarse grades, the thickness of the feed should not exceed about 1.5 times the maximum particle size.When dealing with medium grades, the thickness of the feed layer can reach about 4 times of the maximum particle size, and the thickness of fine grades can reach about 10 times. When the content of magnetic minerals in the raw material is not much, the feeding layer should be thinner. If it is too thick, the magnetic ore particles in the lowermost layer will not only receive less magnetic force, but also be subjected to the pressure of the non-magnetic ore particles above in addition to their own weight, reducing the recovery rate of magnetic products. When the content of magnetic minerals is large, the feeding layer can be appropriately thicker.

II. Vibration speed of vibration tank

The vibration speed of the vibrating tank determines the time that the ore particles stay in the magnetic field and the size of the mechanical force. The greater the product of the vibration frequency and the amplitude of the vibrating tank, the greater the vibration speed and the shorter the residence time of the ore particles in the magnetic field.The mechanical force acting on the ore particles is mainly gravity and inertial force. Gravity is a constant, and the inertial force increases or decreases in proportion to the square of the speed.The magnetic force of weak magnetic minerals in the magnetic field does not exceed the gravity. Therefore, if the speed of the vibrating tank exceeds a certain limit, the magnetic force will not be enough to attract them well due to the sharp increase of the inertial force. Therefore, the moving speed of weak magnetic minerals in the magnetic field of the magnetic separator should be lower than that of strong magnetic minerals.

Generally speaking,when separating concentrate,there are many monomer minerals in the raw materials, their magnetic properties are stronger, and the vibration speed of the vibration tank can be higher. During trough separation,the raw materials contain more conjoined organisms, and the magnetic properties of the conjoined organisms are weak. In order to improve the recovery rate, the speed of the vibrating tank should be lower.hen dealing with fine-grained raw materials, the frequency of the vibrating tank should be slightly higher (in favor of loosening the ore particles), and the amplitude should be smaller.For coarse-grained materials, the frequency should be slightly lower and the amplitude should be larger. Appropriate operating conditions should be determined through practice according to the nature of the raw materials and the requirements for separation.

III. Magnetic field strength and working gap

The strength of the magnetic field and the working gap are closely related to the particle size, magnetism and operation requirements of the raw materials to be processed. When the working gap is fixed, the magnetic field strength between the two magnetic poles is determined by the ampere turns of the coil, and the number of turns is not adjustable, so the magnetic field strength is adjusted by changing the magnitude of the current. The strength of the magnetic field depends on the magnetic properties of the raw materials to be processed and the operating requirements. Weak magnetic field strengths should be used for processing minerals with stronger magnetic properties and selection operations. When dealing with minerals with weak magnetic properties and roughing operations, a stronger magnetic field strength should be used.

When the current is constant, changing the size of the working gap can make the magnetic field strength and magnetic field gradient change at the same time. The size of the working gap depends on the particle size of the raw materials to be processed and the operation requirements. Larger when dealing with coarse levels and smaller when dealing with finer levels. During rough separation, the working gap should be adjusted to a minimum to improve the recovery rate. When separating concentrate, it is best to increase the working gap to reduce the non-uniformity of the magnetic field distribution between the two poles, and then increase the distance from the magnetic ore particles to the tip of the disk teeth. In order to increase the selectivity of separation and improve the grade of magnetic products, but at the same time, the current should be appropriately increased to compensate for the magnetic field strength reduced by increasing the working gap.

In addition, the following points should be paid attention to during the use of the dry magnetic separator:

  • The wear of the cylinder wall of the permanent magnet cylinder. If it is found that the glue is seriously worn after the glue has fallen off, it should be dealt with in time or the glue should be re-applied.
  • Is there any sundries such as iron lumps in the box, it should be removed immediately after being found.
  • For the overheating of the motor, the continuously variable transmission and the permanent magnet cylindrical bearing, the temperature rise of the bearing shall not exceed 35°C in general, and the highest shall not exceed 65°C.
  • The tension of the transmission belt should be appropriate.
  • The wear of the belt is found to be seriously worn, and the belts of the same length should be replaced in groups.
  • Whether there is enough lubricating grease at each lubricating point, and whether the oil level of the continuously variable transmission is normal, if it is found to be insufficient, it should be replenished in time.

The daily optimization and maintenance of the dry magnetic separator will directly affect the operation rate and service life of the permanent magnet dry magnetic separator. In order to discover defects and diseases in time and eliminate hidden dangers, it is also necessary to stop work regularly for maintenance, make careful inspections of important components such as cylinder walls, boxes, transmission belts, etc. It makes detailed records to avoid potential safety hazards and ensure smooth production.