The magnetic field gradient of the magnetic separator, how to evaluate the magnetic separation effec

The main condition for the separation of minerals by magnetic separation method is magnetic force, and the magnitude of magnetic force is related to both the magnetic properties of the minerals and the magnetic field characteristics of the magnetic separator. The characteristics of magnetic field mainly refer to the variation law of magnetic field intensity and magnetic field gradient in magnetic field space and their influence on the magnitude and distribution of magnetic force.

Magnetic fields are divided into uniform and non-uniform magnetic fields. In a uniform magnetic field, the magnetic field strength and direction of each point are the same, so the gravitational force and repulsion of the magnetic ore particles located in it are equal in magnitude, and they are only rotated by the action of torque, and stop when they turn to be consistent with the direction of the magnetic field, and the ore particles do not move, that is, they are not attracted by any magnetic pole.

In the inhomogeneous magnetic field, the magnitude and direction of the magnetic field strength change point by point, and the magnetic ore particles are not only affected by the torque, but also by the magnetic force, so that the ore particles move from the place with low magnetic field strength to the place with high magnetic field strength. In the magnetic separator, magnetic ore particles are attracted by magnetic force, so as to achieve the purpose of separating magnetic minerals from non-magnetic minerals. Therefore, only inhomogeneous magnetic fields are used in magnetic separators, because the more inhomogeneous the magnetic field, the greater the magnetic force acting on the magnetic particles.

The non-uniformity of the magnetic field strength is expressed in terms of the magnetic field gradient. The magnetic field gradient is the amount of change in the strength of the magnetic field along the direction of the normal of the magnetic poleDenoted by DH dx (or gradh). In the inhomogeneous magnetic field, the magnitude and direction of the magnetic field strength at each point are different, that is, the larger the ≠ of DH dx, the greater the inhomogeneity of the magnetic field. Conversely, the less inhomogeneous the magnetic field.

Knowledge Expansion] The specific magnetic force acting on the magnetic ore particles is directly proportional to the specific magnetic susceptibility k of the ore particles, that is, the stronger the magnetic force of the ore particles; The greater the magnetic force experienced. The specific magnetic force is proportional to the product of the magnetic field strength and the magnetic field gradient (i.e., the magnetic field magnetic force), that is, the greater the magnetic field strength and the greater the magnetic field gradient, the greater the magnetic force experienced by the ore particles. The magnetic properties of the ore particles themselves are the main basis for whether magnetic separation can be carried out.

If the magnetic properties of the ore particles are very weak, the magnetic force in the magnetic field of the magnetic separator is very small, and the ore particles are difficult to separate. The magnetic field strength and magnetic field gradient are the main indicators of the magnetic field performance of the magnetic separator. When designing the magnetic separator, we should strive to increase the magnetic field magnetic force, so as to expand the variety of sorting minerals and improve the production capacity of the equipment.

Guote equipment permanent magnet high gradient plate magnetic separator has good magnetic separation effect, high magnetic field, field strength up to 15000gs, and good iron removal effect!

The high-gradient magnetic separator is a kind of equipment that uses a high-intensity magnetic field to separate mineral particles, and its magnetic separation effect can be evaluated by the following indicators: Magnetic separation index: The magnetic separation index is one of the important indicators to measure the magnetic separation effect of the high-gradient magnetic separator.

It indicates the degree of magnetization of magnetic minerals in the slurry under a certain magnetic induction intensity, which is generally expressed by the magnetic body line density per unit length. The higher the magnetic separation index, the higher the separation efficiency of the high-gradient magnetic separator. Selection rate:

The selection rate indicates the ability of a high-gradient magnetic separator to separate mineral particles, i.e., the proportion of concentrate needed to separate from the original mineral. The higher the selection rate, the better the sorting effect of the high-gradient magnetic separator. Magnetic field strength:

The magnetic field strength is one of the key factors affecting the magnetic separation effect of the high gradient magnetic separator. The greater the magnetic field strength, the better the magnetic separation effect of the high-gradient magnetic separator, but it will also increase the cost of equipment and energy consumption. Processing power:

The processing capacity of the high-gradient magnetic separator refers to the number of mineral particles processed per unit time, and it is also one of the important indicators to evaluate the effect of the magnetic separator. On the premise of maintaining a certain level of lapping indicators such as magnetic field strength and selection rate, the greater the processing capacity, the higher the production efficiency of the equipment. The above indicators can be considered comprehensively, and the magnetic separation effect of the high-gradient magnetic separator can be evaluated.

It is necessary to select the appropriate high-gradient magnetic separator according to the actual use and specific ore type to achieve the best magnetic separation effect.

The structure of the periodic high-gradient magnetic separator is mainly composed of iron armored solenoid magnet, stainless steel gross medium, sorting box, slurry outlet, inlet valve and other components. The solenoid is wound by hollow flat copper wire or hollow copper wire, which is excited with low voltage and high current and cooled by water to achieve sufficient field strength. The iron armor and magnetic pole head are made of pure iron, and their function is to form a closed loop with the solenoid, and the magnetic field lines are completely enclosed in the iron shell of the square frame, which improves the field strength of the inner cavity of the tube.

Because the machine is often used for materials with weak magnetism, low content and fine particle size (5 10 m), the slurry generally passes through the medium at a slow speed under the background magnetic field of 1 2 t. Therefore, the diameter of the inlet and outlet slurry pipeline is small, the pipe can pass through the sample pole head, and the medium is longer 30 50cm.

The sorting box is made of non-magnetic material (stainless steel or copper), and there are slurry outlets and slurry inlets at the top and bottom, and the sorting medium steel wool is installed in the box (or cylinder). The background field strength of the machine can reach 1600 kA m (2 104 oE).

Magnetic field characteristics. The magnetic field of the high gradient magnetic separator is often expressed by the strength of the background magnetic field, the background magnetic field refers to the magnetic field when the medium is not filled, in the magnetic field change curve of the background magnetic field of the iron solenoid magnet along its axis, the background magnetic field of the solenoid magnet is weak at both ends, and the rest is basically uniform.

After the steel wool is magnetized in the magnetic field, the gradient generated is directly proportional to its magnetization J, which is inversely proportional to the radius of the steel wool, generally in the magnetic field of 7000gs (10-4t), the magnetization is gradually close to the magnetic saturation. The magnetization of fine steel wool is about 1040 kA m (1300 OE), at which point the highest saturation magnetization is reached. Therefore, a steel wool with a radius of 10 m can produce a magnetic field gradient of 107 oe cm (105 t m).

If the height of the solenoid coil is equal to the height of the sorting box, it is called "** circle", and the height of the solenoid is 50% higher than the sorting box 100% is called "long coil". Compared with the first circle, the average diameter of the long coil is smaller, so the long coil is less than the number of turns of the first circle, and the amount of wire is less, which can save copper wire and reduce energy consumption, which greatly reduces the cost.

1. Ferrous metals: pseudo-hematite, hematite, limonite, siderite, chromite, ilmenite, manganese, etc.;

2. Non-ferrous metals: tungsten-containing quartz veins with fine grains embedded in wolframite stove high ore, separation of pyrrhotite in cassiterite polymetallic sulfide ore, separation of cassiterite and wolframite, separation of limonite and other minerals, separation of scheelite and wolframite, garnet and other minerals, etc.;

3. Rare metals: tantalum-niobium, iron lepidolite, monazite, etc.

4. Non-metallic aspects: the purification of quartz, feldspar, and Gaozu Lingling, the raw materials of glass pottery Zhaoshan porcelain, the deironization of high-temperature refractory materials sillimanite, andalusite, orchid crystal, and harmful impurities such as amphibole, mica, tourmaline, garnet, etc.;

5. Other aspects: weak magnetic tailings**; iron beneficiation of hematite sludge in alumina plant; wastewater treatment in steel mills and power plants; Cleaning of chemical raw materials contaminated with catalysts, etc.

High gradient magnetic separator refers to the magnetic separation equipment with a fine or micron diameter of the polymagnetic medium adsorbed by magnetic minerals in the working magnetic field, which can produce a large magnetic field adsorption force on fine magnetic minerals, so as to ensure the best effect of magnetic separation.

The high-gradient strong magnetic separator is suitable for the characteristics of hematite fine grain inlay, and its magnetic field strength can reach more than 10,000 gauss.

The strong magnetic separator is a kind of magnetic separation equipment that is different from the conventional weak magnetic separator, and the Qingzhou Chenguang beneficiation laboratory is usually used to separate the weak magnetic ore, such as hematite, limonite, ilmenite; and non-metallic minerals to remove impurities. It can continuously improve the grade of ore and obtain a higher rate.

The high-gradient strong magnetic separator adopts the vertical rotation and backflush concentrate of the rotating ring Bijingqing, and is equipped with a high-regret front-frequency vibration mechanism, which fundamentally solves the worldwide technical problem that the magnetic medium of the flat-ring strong magnetic separator and the flat-ring high-gradient magnetic separator are easy to block. It has the advantages of large enrichment ratio, strong adaptability to the fluctuation of feed material, concentration and products, reliable work, and convenient operation and maintenance. Front.