Magnetite is one of the important minerals for obtaining iron resources. Its iron content is high and its magnetism is strong. It is an important material for steel production. In order to obtain magnetite concentrate, different beneficiation processes need to be adopted, and the process can not be separated from magnetic separation equipment. What are the common magnetic separation equipment for magnetite?
At present, the common magnetic separation equipment in concentrators are magnetic drum, cylindrical magnetic separator, magnetic separation column, magnetic screen, magnetic desliming tank, demagnetizer and other types.
Magnetic drum is one of the commonly used equipment in magnetite ore dressing plant, also known as magnetic pulley, which is commonly used in the separation of rich magnetite ore and the tail throwing operation of rough separation.
During magnetic separation, the upper limit of the selected particle size of this type of magnetic separation equipment is 100mm, and the lower limit of the selected particle size is 10mm. The processing capacity of a single machine depends on the feed selected particle size, and the upper limit of the processing capacity is 250t/(h • m).
There are two types of cylindrical magnetic separators: dry type and wet type. The selection depends on the beneficiation environment.
Dry cylindrical magnetic separator: it is a magnetic separation equipment with open magnetic system structure and multi pole radial magnetic pole arrangement. It is mainly used for dry tailing of fine magnetite ore or dry separation in water shortage areas. The upper limit of particle size is 30mm, and the lower limit of particle size is - 200 mesh (- 0.074mm), with content ≤ 40%. The processing capacity of a single machine also depends on the particle size of the feed, and the upper limit of the processing capacity is 20t/(h • m).
Wet cylindrical magnetic separator: it is also a magnetic separation equipment with open magnetic system structure and multi pole radial arrangement. For different operations such as roughing, concentration or scavenging, the distribution of magnetic field on the surface of the separation area and the peak magnetic field intensity change accordingly, and different types of separation grooves (downstream, countercurrent and semi countercurrent) can be selected. The upper limit of the selected particle size is 10mm, and the lower limit of the selected particle size is - 200 mesh (-0.074mm), with the content of ≤ 90%. The processing capacity of a single machine depends on the feed selected particle size and the type of separation tank. The upper limit of the processing capacity is 60t/(h • m).
Magnetic separation column is a kind of magnetic gravity separation equipment which combines the magnetic system of electromagnetic weak magnetic field with separation column. The magnetic field of multistage alternating solenoid makes the fine strong magnetic mineral particles alternately produce magnetic aggregation and looseness, while the rising water will effectively remove the single gangue or poor intergrowth particles with small proportion from the feed. This equipment is mainly used for the cleaning operation of fine particle magnetite to improve concentrate grade and cleaning separation efficiency. At present, due to the limitation of equipment structure, the single machine processing capacity is low.
The magnetic screen is also a kind of magnetic gravity combined separation equipment. After the effective agglomeration of magnetite in the weak magnetic field, the special screen installed in the magnetic field is used to discharge the magnetic substances from the screen, and gangue and poor intergrowth are discharged from the screen, so as to achieve effective separation. This equipment is mainly used for the cleaning operation of magnetite to improve concentrate grade and cleaning separation efficiency. Due to the limitation of the structure, the single machine processing capacity of the device is small.
Magnetic desliming tank is a kind of separation equipment with magnetic gravity combined action, which is widely used in magnetite concentrators. It is mainly used to remove fine gangue and slime, and sometimes also used for dehydration of magnetite, so it is also called magnetic dewatering tank. The magnetic system structure of the magnetic desalting tank mainly includes the lower permanent magnetic system, the upper permanent magnetic system and the upper electromagnetic magnetic system. The magnetic field distribution of the magnetic desalting tank of the upper permanent magnetic system and the electromagnetic magnetic system is basically the same, and its water supply mode is different from the magnetic desalting tank of the lower magnetic system.
The demagnetizer uses alternating magnetic field to make the magnetized magnetite particles lose remanence and improve the separation accuracy of the next separation operation. Generally, the demagnetization of the coarse concentrate of magnetite primary magnetic separation is carried out before the coarse concentrate enters the secondary grinding or secondary concentration.
The above six types of magnetic separation equipment are widely used in the magnetite concentrator. The specific equipment selection should be based on the nature of magnetite ore. Only by selecting suitable equipment can the magnetite concentrate products be greatly improved. In addition, the above equipment can also be used for the separation of other magnetic minerals or the removal of iron from minerals.
