Dry or Wet Magnetic Separator? How to Choose the Type of Magnetic Separator?
As a common beneficiation process, magnetic separation process separate minerals based on their magnetic difference, which widely used in the separation of black metals, non-ferrous metals and rare metal ores and the removal of iron impurities from other minerals, such as magnetite, titanomagnetite, hematite, limonite, siderite, ferrochrome ore and manganese ore, etc. While the common types of magnetic separation equipment can be classified into dry magnetic separator and wet magnetic separator depending on the material to be processed.
The dry magnetic separator is the mainstream magnetic separation equipment and it was also used for industrial weak magnetic separation as the earliest magnetic separation equipment. It is suitable for dry and water-deficient areas and mainly used to select bulk, coarse-grained ferromagnetism and finer particles of weak magnetic ore, which has a simple Process flow. Common dry magnetic separation equipment includes dry weak magnetic separator (iron remover, magnetic pulley), dry strong magnetic separator (induction roller magnetic separator, dry electromagnetic disc strong magnetic separator, Dry roll-to-roll magnetic separator).
The magnetic pulley is used for the pre-selection of block ferromagnetic ore. It is generally used after the crushing of the raw ore coarse grain or before the final broken product into the grinding machine, during which the waste rock can be removed and the ore grade can be improved, thereby reducing the grinding cost.
The induction roller magnetic separator consists of an electromagnetic system, a sorting system and a transmission system. It can be used to recover ilmenite in coastal sand mines, or to sort mixed concentrates such as chromite, monazite, wolframite and iron ore.
Dry electromagnetic disc type strong magnetic separator is mostly used for the selection of rare metal coarse concentrate. It is used to separate the weak magnetic ore with magnetization coefficient greater than 5.0*10-7m^3/kg and particle size less than 2mm.
The dry-type roller type strong magnetic separator has two magnetic roller relative arrangements, which constitutes a closed magnetic circuit and is driven by a turbine speed reduction mechanism. It can be used for sorting materials containing a plurality of different magnetic minerals with the particle size of 3 mm or less.
Dry magnetic separation has higher requirements to the material. The material to be sorted must be dry and in an independent free form, otherwise the magnetic separation effect will be affected. In addition, the beneficiation efficiency of the dry magnetic separator is mainly limited by three factors, the speed of the drum, the position of the baffle and the amount of ore included.
The wet magnetic separator is a magnetic separator commonly used in iron ore dressing plants. It can be used not only for sorting operations, but also for replacing the magnetic dewatering tank as a concentration device before filtration. The process is more complicated, and it is necessary to rely on water as the medium for sorting. Common wet magnetic separation equipment includes wet weak magnetic separation equipment (magnetic dewatering tank, permanent magnet cylindrical magnetic separator), wet strong magnetic separation equipment (wet induction roller type strong magnetic separator, Jones type strong magnetic separator, Flat ring magnetic separator). According to the structure of the tank, the wet magnetic separator can be divided into three types, namely, forward flow type, reverse flow type and semi-reverse flow type.
The wet energy-saving magnetic separator can effectively process extremely poor iron ore and improve the quality of the final iron concentrate, generally used for fine-grained ferromagnetic and weak magnetic ore and iron powder selection. Two commonly used wet magnetic separators are downstream magnetic separator and semi-reverse magnetic separator.
The downstream magnetic separator refers to the moving direction of the slurry is the same as the cylinder moving direction or the product moving direction. The slurry enters the cylinder magnetic system from the feed box directly, and the non-magnetic and weak magnetic particles are discharged from the gap below the cylinder. While the magnetic ore particles are attracted to the surface of the cylinder and rotate with the cylinder to the weak magnetic field at the edge of the magnetic system, and then unloads from the unloading water pipe to the concentrate tank. The downstream magnetic separator has large processing capacity and can be used in series. It is suitable for rough selection and selection of coarse-grained strong magnetic ore with a dressing size of 0~6mm, and can also be used for recovering magnetic heavy medium.
The semi-reverse flow magnetic separator has high concentrate quality and metal recovery. The ore slurry is loosely suspended from the tank below the separation space. The direction of the slurry movement is basically the same as the direction of the magnetic field force. Therefore, the ore particles can reach the surface of the cylinder with high magnetic force, and the tailings are discharged from the tailing hole on the bottom plate. The overflow surface height maintains the level of slurry in the tank. The semi-reverse flow magnetic separator is widely used for roughing and selecting operations of fine magnetic ore (less than 0.2mm), and can be used in combination to improve the concentrate grade.
The selection of magnetic separator is a comprehensive problem that needs to be considered in many aspects. If you want to know exactly which magnetic separator should be used, you need to go through a series of processes such as mineral processing test or consult a professional manufacturer. Then choose the suitable one according to the specific conditions of different mines.
评论
发表评论