Magnetic medium box device and method for analyzing high-gradient magnetic separation capture mechanism

Abstract

The invention relates to a magnetic medium box device and method for analyzing a high-gradient magnetic separation capture mechanism, and belongs to the technical field of high-gradient magnetic separation process mechanism research. The magnetic medium box device comprises a cooling chamber and a magnetic medium stack, the magnetic medium stack is formed by vertically stacking a plurality of freely detachable magnetic medium units, the cooling chamber is a hollow annular cavity, and a liquid nitrogen inlet and a liquid nitrogen outlet are formed in the top of the cooling chamber. When the magnetic medium box device is used for analyzing a high-gradient magnetic separation capturing mechanism, firstly, a plurality of magnetic medium rods and positioning pieces on the two sides of the magnetic medium rods form magnetic medium units, and after a plurality of magnetic medium units are placed into an inner ring space of a cooling chamber, the magnetic medium box device is assembled; putting the magnetic medium box device into a high-gradient magnetic separator, starting a magnetic separation test, after the test is finished, keeping a magnetic field unchanged, introducing a proper amount of liquid nitrogen into the cooling chamber through a liquid nitrogen inlet, disconnecting the magnetic field after particles captured on the surface of the magnetic medium are completely frozen, taking out the magnetic medium box device, and sequentially disassembling the magnetic medium units, and the particles captured on each magnetic medium rod are independently washed with clear water, collected, detected and analyzed. By means of the indirect heat transfer effect of the liquid nitrogen cooling chamber, rapid freezing and accurate collection of particles on the magnetic medium are achieved, and the device and method which are easy to operate are provided for high-gradient magnetic separation capture mechanism analysis experiments.

Description

Technical Field

[0001] The invention relates to a magnetic medium box device and a method for analyzing a high gradient magnetic separation capture mechanism, belonging to the technical field of high gradient magnetic separation process mechanism research. Background Art

[0002] High gradient magnetic separation is an important method for separating weakly magnetic materials. It is widely used in the field of mineral processing for the separation of weakly magnetic minerals and the purification of non-metallic minerals. Magnetic media are the carriers for capturing magnetic minerals in high gradient magnetic separators. Studying the capture mechanism of particles on magnetic media is an important part of the theoretical research on high gradient magnetic separation. However, for a long time, the research on the capture mechanism of high gradient magnetic separation has mainly adopted mathematical analytical modeling or simulation methods, and experimental research has provided little evidence. In the few existing experimental studies, the main research object is a single magnetic medium rod, while the actual magnetic medium box contains a large number of magnetic medium rods, and the capture characteristics of particles by magnetic medium rods at different positions are significantly different. Therefore, there is an urgent need for an experimental device and method suitable for analyzing the capture mechanism of particles on multiple magnetic media.

[0003] The Chinese patent with publication number CN105701309A discloses a method for analyzing and detecting the capture characteristics of magnetic media. After the ore feeding of the high-gradient magnetic separation test is completed, the method maintains the magnetic field, then lowers the liquid level to slowly expose the magnetic media in the separation zone from the fluid, and at the same time, introduces cold air at -10 to -15°C into the magnetic media to cool and fix the magnetic particles accumulated on the surface of the exposed medium filaments; after the magnetic media are completely exposed from the fluid and completely cooled, the magnetic field is removed, the magnetic media is taken out, and the unit medium module is removed in a low temperature environment of -5 to 0°C to obtain the medium monofilament, which is placed in a cold preservation device. However, in actual operation, the cold air in this method has a poor freezing effect on the magnetic particles, and the cold air needs to be introduced for more than 1 hour continuously to completely freeze the particles; the high-speed cold air introduced directly contacts the particles, which easily causes some particles to fall off or shift; in addition, after the particles are frozen, the magnetic medium unit needs to be removed in a low temperature environment, which is difficult to operate. Summary of the invention

[0004] In view of the problems and shortcomings of the above-mentioned prior art, the present invention provides a magnetic medium box device and method for analyzing the high gradient magnetic separation capture mechanism. The present invention is implemented through the following technical solutions.

[0005] A magnetic medium box device for analyzing the capture mechanism of high gradient magnetic separation, the magnetic medium box device comprises a cooling chamber 2 and a magnetic medium stack, wherein the magnetic medium stack is composed of a plurality of magnetic medium units 3 which can be freely detached and stacked up and down, the cooling chamber 2 is a hollow annular cavity, and a liquid nitrogen inlet 6 and a liquid nitrogen outlet 7 are respectively arranged on the top thereof; a plurality of magnetic medium rods 3-2 and positioning pieces 3-1 on both sides thereof form a detachable magnetic medium unit 3, a plurality of groups of magnetic medium units 3 are placed up and down through the positioning pieces 3-1 on both sides to form a magnetic medium stack, and the magnetic medium stack is placed in the inner annular space of the cooling chamber 2 to complete the assembly of the magnetic medium box device.

[0006] A method for analyzing a magnetic medium box device of a high gradient magnetic separation capture mechanism, the steps of which include: placing the magnetic medium box device in a separation chamber of a high gradient magnetic separator, starting a magnetic separation test, and after the experiment, keeping the magnetic field unchanged, introducing liquid nitrogen into a cooling chamber 2 through a liquid nitrogen inlet 6, disconnecting the magnetic field after particles captured on the surface of the magnetic medium are completely frozen, taking out the magnetic medium box device, disassembling a plurality of magnetic medium units 3 in turn, and washing, collecting, detecting and analyzing the particles captured on each magnetic medium rod 3-2 with clean water.

[0007] Liquid nitrogen is used as a coolant to quickly supercool the captured particles on the magnetic medium to -30°C or even lower temperature. When the operator removes the magnetic medium unit 3 in a room temperature environment, the particles can still remain in a frozen state.

[0008] The coolant in the cooling chamber 2 cools down the magnetic medium unit 3 by indirect heat transfer, thereby avoiding the problem of particle falling or displacement caused by direct contact between the coolant and the magnetic medium unit 3 .

[0009] The positioning plates 3 - 1 on both sides of the magnetic medium and the cooling chamber 2 are made of materials with good thermal conductivity, thereby achieving higher heat transfer efficiency.

[0010] The magnetic medium rod 3-2 in the magnetic medium box device is made of magnetic stainless steel material, and the positioning piece 3-1 and the cooling chamber 2 are made of non-magnetic material with good thermal conductivity, preferably, made of aluminum alloy.

[0011] The detection and analysis means mainly include microscopic analysis, chemical analysis, laser particle size analysis, etc., to determine the yield, grade, metal distribution rate and particle size distribution of particles captured by the magnetic medium at different positions.

[0012] The beneficial effects of the present invention are:

[0013] (1) In the magnetic medium box device provided by the present invention, the magnetic medium unit is easy to assemble and disassemble, and can realize the separate collection and analysis of captured particles on each magnetic medium in each magnetic medium unit.

[0014] (2) The present invention uses liquid nitrogen with a boiling point of -196°C as the cooling medium, and the positioning plate and the cooling chamber are made of materials with good thermal conductivity, so the cooling efficiency is higher.

[0015] (3) The present invention adopts indirect heat transfer cooling, which avoids problems such as particle falling or displacement caused by direct contact between the coolant and the magnetic medium unit.

[0016] (4) The liquid nitrogen indirect cooling method adopted by the present invention can supercool the captured particles on the magnetic medium to -30°C or even lower temperature, and the particles can remain in a frozen state for a long time. Therefore, the operator can remove the magnetic medium unit at room temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a configuration diagram of a specific magnetic medium box device of the present invention placed in a periodic high gradient magnetic separator;

[0018] Figure 2 It is a schematic diagram of the structure of a magnetic medium box device specific to the present invention;

[0019] Figure 3 It is a schematic diagram of the structure of a specific magnetic medium unit of the present invention;

[0020] Figure 4 is a diagram showing the position of each layer of magnetic medium units in the magnetic medium box and their corresponding numbers in Example 1 of the present invention;

[0021] Figure 5 It is a schematic diagram of the structure of the magnetic medium box used in this comparative example 1.

[0022] In the figure: 1-excitation coil, 2-liquid nitrogen cooling chamber, 3-magnetic medium unit, 3-1 is positioning plate, 3-2 is magnetic medium rod, 4-upper magnetic pole head, 5-feed hopper, 6-liquid nitrogen inlet, 7-liquid nitrogen outlet, 8-lower magnetic pole head. DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods.

[0024] Example 1

[0025] With a particle size of -200 mesh accounting for 65%, TiO 2 50g of ilmenite ore with a grade of 8.92% was used as raw material, and the magnetic medium box device and method for analyzing the high-gradient magnetic separation capture mechanism of the present invention were used to carry out experiments, and the magnetic particles captured by the magnetic medium at different positions were collected separately, dried and weighed. The specific implementation steps are as follows:

[0026] (1) Produce by 3D printing technology Figure 2The device shown has an annular cooling chamber 2, and a liquid nitrogen inlet 6 and a liquid nitrogen outlet 7 are respectively provided at the top of the cooling chamber 2. The volume of the cooling chamber 2 is about 50 mL, and the material of the cooling chamber 2 is non-magnetic 316L stainless steel;

[0027] (2) A magnetic medium rod 3-2 with a diameter of 3 mm and the positioning pieces 3-1 on both sides thereof are connected by glue to form a magnetic medium unit 3. Ten groups of magnetic medium units 3 are pressed Figure 2 In the manner shown, the magnetic medium box device is assembled by placing the two side positioning pieces 3-1 up and down in the inner ring space of the cooling chamber. The material of the two side positioning pieces 3-1 is aluminum alloy. Among them, the 1, 3, 5, 7, 9 magnetic medium units contain three magnetic medium rods, and the 2, 4, 6, 8, 10 magnetic medium units contain four magnetic medium rods. The number and position of each magnetic medium rod are as shown in FIG. Figure 4 As shown, the horizontal spacing between the centers of adjacent magnetic medium rods is 6 mm, and the vertical spacing is 5.2 mm.

[0028] (3) Place the magnetic medium box device into the separation chamber of the high gradient magnetic separator, cover the upper magnetic pole head 4 and the feed hopper 5, turn on the magnetic field, feed the slurry from the feed hopper 5, start the magnetic separation test, and complete the capture and separation process of the particles by the magnetic medium under the specified operating conditions (magnetic field intensity 0.8T, pulsation frequency 300r / min, pulsation stroke 10mm);

[0029] (4) After the experiment, the magnetic field was kept unchanged and 50 mL of liquid nitrogen was introduced into the cooling chamber 2. After the particles captured on the surface of the magnetic medium were completely frozen, the magnetic field was disconnected, the magnetic medium box was taken out, and the magnetic medium unit modules were disassembled one by one. The particles captured on each magnetic medium rod were rinsed and collected separately with clean water. After drying and weighing, the weight of the particles captured on each magnetic medium rod is shown in Table 1.

[0030] Table 1

[0031] serial number N11 N12 N13 N21 N22 N23 N24 Weight / g 0.71 0.72 0.72 0.57 0.59 0.60 0.58 serial number N31 N32 N33 N41 N42 N43 N44 Weight / g 0.50 0.53 0.52 0.47 0.48 0.46 0.45 serial number N51 N52 N53 N61 N62 N63 N64 Weight / g 0.41 0.39 0.41 0.36 0.38 0.37 0.35 serial number N71 N72 N73 N81 N82 N83 N84 Weight / g 0.31 0.32 0.30 0.25 0.25 0.24 0.23 serial number N91 N92 N93 N101 N102 N103 N104 Weight / g 0.20 0.21 0.18 0.28 0.29 0.30 0.29

[0032] In this embodiment, liquid nitrogen is introduced for indirect cooling, and the magnetic particles can be completely frozen directly in just 5 minutes. Compared with introducing cold air at -10 to -15°C for more than 1 hour, the present invention significantly reduces the freezing time.

[0033] Comparative Example 1

[0034] The Chinese invention patent with publication number CN106093813A discloses a method for testing and analyzing the capture of magnetic medium monofilaments. The magnetic medium stack used in the method is as follows: Figure 5 shown.

[0035] According to the arrangement shown in 4, use Figure 5A magnetic medium stack was made in the manner shown, wherein the 1st, 3rd, 5th, 7th, and 9th rows contained three magnetic medium rods, and the 2nd, 4th, 6th, 8th, and 10th rows contained four magnetic medium rods. The horizontal spacing between the centers of adjacent magnetic medium rods was also 6 mm, and the vertical spacing was also 5.2 mm. The magnetic medium stack was used to replace the detachable magnetic medium in Example 1, and the high gradient magnetic separation experiment was carried out using the same raw materials and steps. The results show that Figure 5 In the magnetic medium stack shown, when a single magnetic medium rod is pulled out from the perforation, the frozen accumulation will fall off, so this method cannot achieve the collection and analysis of a single magnetic medium captured particle in a true sense.

[0036] Comparative Example 2

[0037] In this comparative example 2, the same magnetic medium box device and the same implementation steps (1) to (3) as those in Example 1 are used, except that the cooling method in implementation step (4) is changed. In Example 1, liquid nitrogen is introduced into the cooling chamber from the inlet 6, and the particles on the magnetic medium unit are frozen by indirect heat transfer; in this comparative example 2, about 200 ml of liquid nitrogen is directly poured into the cooling chamber from the feed hopper 5, and the particles on the magnetic medium unit are frozen by direct contact with the liquid nitrogen. Similarly, the particles captured on each magnetic medium rod are collected separately, and after drying and weighing, the particle weight distribution is shown in Table 2.

[0038] In this comparative example 2, liquid nitrogen is directly introduced, and the magnetic particles can be completely frozen directly in only 2 minutes, which is shorter than the cooling time in Example 1. However, by comparing the data in Table 1 and Table 2, it can be seen that directly introducing liquid nitrogen will cause the weight of the accumulated particles on some magnetic medium rods to decrease, especially the particles on the first and second rows of magnetic medium rods. In comparison, the magnetic medium box device and method for analyzing the capture mechanism of high gradient magnetic separation provided by the present invention can avoid problems such as falling or displacement caused by direct contact between the coolant and the particles.

[0039] Table 2

[0040] serial number N11 N12 N13 N21 N22 N23 N24 Weight / g 0.60 0.62 0.61 0.60 0.50 0.49 0.48 serial number N31 N32 N33 N41 N42 N43 N44 Weight / g 0.45 0.44 0.47 0.43 0.45 0.45 0.44 serial number N51 N52 N53 N61 N62 N63 N64 Weight / g 0.42 0.40 0.39 0.35 0.36 0.35 0.35 serial number N71 N72 N73 N81 N82 N83 N84 Weight / g 0.29 0.31 0.31 0.26 0.25 0.25 0.24 serial number N91 N92 N93 N101 N102 N103 N104 Weight / g 0.20 0.19 0.21 0.27 0.30 0.29 0.28

[0041] The specific implementation modes of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above implementation modes, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A magnetic medium cartridge device for analyzing the capture mechanism of high gradient magnetic separation, characterized in that: The magnetic medium box device comprises a cooling chamber (2) and a magnetic medium stack, wherein the magnetic medium stack is composed of a plurality of magnetic medium units (3) which can be freely detached and stacked up and down, and the cooling chamber (2) is a hollow annular cavity, and a liquid nitrogen inlet (6) and a liquid nitrogen outlet (7) are respectively provided on the top thereof; a plurality of magnetic medium rods (3-2) and positioning pieces (3-1) on both sides thereof form a detachable magnetic medium unit (3), a plurality of groups of magnetic medium units (3) are placed up and down through the positioning pieces (3-1) on both sides to form a magnetic medium stack, and the magnetic medium stack is placed in the inner annular space of the cooling chamber (2), thereby completing the assembly of the magnetic medium box device.

2. A method for analyzing the magnetic medium cartridge device of high gradient magnetic separation capture mechanism according to claim 1, characterized in that the steps include: The magnetic medium box device is placed in the separation chamber of the high gradient magnetic separator to start the magnetic separation test. After the experiment is over, the magnetic field is kept unchanged and liquid nitrogen is introduced into the cooling chamber (2) through the liquid nitrogen inlet (6). After the particles captured on the surface of the magnetic medium are completely frozen, the magnetic field is disconnected, the magnetic medium box device is taken out, and several magnetic medium units (3) are disassembled in turn. The particles captured on each magnetic medium rod (3-2) are rinsed with clean water, collected, and tested and analyzed.

3. The method for analyzing the magnetic medium cartridge device of high gradient magnetic separation capture mechanism according to claim 2, characterized in that: Liquid nitrogen is used as a coolant to quickly supercool the captured particles on the magnetic medium to -30°C or even a lower temperature. When an operator removes the magnetic medium unit (3) in a room temperature environment, the particles can still remain in a frozen state.

4. The method for analyzing the magnetic medium cartridge device of high gradient magnetic separation capture mechanism according to claim 2, characterized in that: The coolant in the cooling chamber (2) cools the magnetic medium unit (3) in an indirect heat transfer manner, thereby avoiding the problem of particle falling or displacement caused by direct contact between the coolant and the magnetic medium unit (3).

5. The method for analyzing the magnetic medium cartridge device of high gradient magnetic separation capture mechanism according to claim 2, characterized in that: The positioning plates (3-1) on both sides of the magnetic medium and the cooling chamber (2) are both made of materials with good heat conduction effects, thereby achieving higher heat transfer efficiency.

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