Compared with the constant-conducting magnetic separator, the magnetic separator with superconducting magnet as the magnetic source has the following outstanding advantages: (1) high field strength, the magnetic field strength of the magnet made of Nb-Ti superconducting material can reach 5 tex; 2) Small volume and light weight, the current density of the superconducting material is two orders of magnitude higher than that of the copper wire, thus greatly reducing the volume and weight of the magnet; (3) low energy consumption, 90% energy saving than the normal conducting magnet; (4) high magnetic field The high magnetic force brought about greatly improved the processing capacity of the magnetic separator. Consulting company developed CryofosGLF low linear-type superconducting magnet for magnetic separator mineral apatite-containing solder stone South Africa. Test of iron refractory bauxite is used as the starting material (dry) show, when ore containing Fe 2 O 3 2.4%, again by sorting the amount of processing 80 tons / • m, the non-magnetic product The Fe 2 O 3 was reduced to 1.27% (required to drop to 1.4%) and the aluminum recovery rate was 69%. The British Low Temperature Consulting Company has developed a vertical string-can reciprocating superconducting magnetic separator with a diameter of 266 mm, a length of 500 mm, a center field strength of 5 tex, and a capacity of 6 ton per hour for processing the Georgian kaolin in the United States. . The advanced nature of this superconducting high-gradient magnetic separator designed by Eliz is the fast switching characteristics of the magnet. At rated voltage, the magnetic field rises from zero to the highest field strength of 5 ties in just 36 seconds; down to zero. The time is 27 seconds. In 1986, an industrial high gradient superconducting magnetic separator developed by Eliz was installed at the Wren Kaolin Plant in Hubtr, Georgia. The machine has a diameter of 2140 mm and a height of 500 mm; the background field strength is 2 tex; the outer dimensions are 3962×3962×2134 mm; and the machine weighs 209 tons. Compared with the same size of the guide machine, it saves space by 34%, reduces the weight by 47%, and saves energy costs by $150,000 per year. The aircraft is worth more than 2 million US dollars and is similar to the regular guide. Since the magnetic and demagnetization time is shortened, the effective operation rate is improved, and the processing capacity of the device is also improved as compared with the conventional guide. pmls pmls ZSL MED , https://www.zslmed.com
In view of the above advantages of superconducting magnets, since the 1970s, China, the United Kingdom, the United States, West Germany, France, Finland, Austria, the Czech Republic and the Soviet Union have successively carried out research and development of superconducting magnetic separators and made considerable progress. Nowadays superconducting magnetic separators have been developed into the industrial application stage.
First, open gradient superconducting magnetic separator
1. Dry Offset Superconducting Magnetic Separator The British Low Temperature Consulting Company (CCL) has cooperated with relevant units to develop two types of dry offset superconducting magnetic separators. The structural principle of the cylindrical magnet superconducting magnetic separator is shown in Fig. 1. Unlike other magnetic separators of the same type, it has a ramp shifter that prevents magnetic particles from sticking to the wall. This structural magnetic separator has two fatal disadvantages: the separator is difficult to adjust and the magnet utilization is low.
The cryogenic consulting company developed a production type (processing capacity of 60 tons / hour) linear magnet magnetic separator, which overcomes the above two shortcomings. The magnetic separator divider is easy to configure and adjust and has two sorting faces. The cross-sectional structure of the magnet is shown in Figure 2.
The magnet consists of four “runway†coils that are fastened and bonded together (see Figure 2) with a total number of turns of 9810åŒ. The superconducting wire is a NbTi wire having a copper ratio of 1.4 and a diameter of 0.4 and 0.5 mm. The rated operating current is 60% of the critical current. The superconducting magnet weighs 60 kg and the magnet has a size of 3000 x 67 x 122 mm. The magnetic field of the sorting area is 3 tex. 
Figure 1 Open gradient superconducting magnetic separator with slope shifter
Figure 2 Magnet structure of linear open gradient superconducting magnetic separator [next]
2. Cylinder superconducting magnetic separator The industrial DESCOS cartridge superconducting magnetic separator developed by Humboldt has been introduced to the market as a commodity. The magnetic separator has a diameter of 1216 mm and a length of 1500 mm; the surface magnetic field of the cylinder can reach 3.2 tex. The magnetic system can be rotated around the axis and can be used both wet and dry. When processing materials with low magnetic content, the treatment capacity can reach 100 tons/hour.
The DESCOS magnetic separator consists of three parts: a superconducting magnetic system, a refrigeration system and a drum separator. The magnetic structure is shown in Figure 3. The magnetic field distribution of the magnetic system is shown in Figure 4. In order to increase the field strength of the drum surface, the distance between the superconducting coil and the outer surface of the drum should be shortened as much as possible. This distance of the DESCOS machine is 30 mm.
Figure 3 DESCOS cartridge superconducting magnetic separator magnetic system
1. superconducting coil; 2. radiant screen; 3. vacuum tank; 4. cylinder;
5. Sliding bearing; 6. Supply line; 7. Vacuum line; 8. Power supply line
Figure 4 Magnetic flux density distribution of DESCOS superconducting magnetic separator
a. along the circumference of the cylinder; b. along the cylinder axis
In fact, the drum magnetic separator and the magnetic system do not need to be looked after at all. The service intervals for the refrigeration system (including the compressor) are approximately 5,000 hours and have reached industrial availability.
Second, high gradient superconducting magnetic separator
Open gradient superconducting magnetic separators cannot sort fine materials. Replacing a high-consumption superconducting magnetic separator with a high-gradient magnetic permeability machine with high energy consumption due to reduced energy consumption, reduced investment, and increased processing capacity (background field strength can reach 5 tex) The benefits have been greatly improved.
1. String-can reciprocating magnetic separator In view of the technical difficulty of superconducting magnets for magnetic and demagnetization frequently, a tandem reciprocating superconducting magnetic separator has been developed. Two or more sorting tanks are strung together. When one tank is working in a magnetic field, the other tank is pushed out of the magnet to flush out the sorbed magnetic material. After the canister in the magnet absorbs the magnetic material, it is pushed out of the magnet, and the empty canister re-enters the magnet to work. This reciprocating action allows the magnet to never demagnetize and complete the periodic sorting operation. [next]
There are two types of series-type superconducting magnetic separators: vertical and horizontal. They are shown in Figures 5 and 6, respectively.
Figure 5 Schematic diagram of a series of tank reciprocating high gradient superconducting magnetic separator
Figure 6 Horizontal string tank reciprocating high gradient superconducting magnetic separator
The Czech Republic has developed a horizontal collet reciprocating superconducting magnetic separator. The coil consists of 8 partial coils wound with a Cu/NbTi composite wire. The low temperature container has a room temperature space of 560 mm and a length of 1,320 mm. The maximum field strength of the magnet is 5 tex. The amount of kaolin treated is 5 tons per hour. The machine has been applied in a kaolin mine in the Czech Republic.
2. Fast-switching superconducting high-gradient magnetic separator The fast-switching superconducting magnetic separator developed by Eliz is a new achievement of superconducting magnet technology. The structure of a laboratory machine with a field strength of 5 tex is shown in Fig. 7. The outer iron yoke solenoid magnet is 940 mm high, 864 mm in diameter and weighs 2,721 kg. The room temperature hole diameter is 152 mm and the sleeve is 508 mm. A sorting tank with a diameter of 102 mm and a length of 508 mm with steel wool can be installed. The magnetic field can be continuously changed by the voltage divider during operation.
Figure 7 Schematic diagram of the Eliz 5 ultra-high gradient superconducting magnetic separator
Superconducting magnetic separator