CN104399580B - A laboratory magnetic separator suitable for the separation of fine-grained strong magnetic materials - Google Patents

Abstract

The present invention relates to a kind of laboratory magnetic separator being suitable to the sorting of particulate strongly magnetic material.A kind of laboratory magnetic separator being suitable to the sorting of particulate strongly magnetic material, it is characterised in that it includes frame, sorting under casing, concentrate hopper, unloads ore deposit sensing roller, sorting rotary drum, central hollow bearing, actuating device, excitation wire bag, iron core；Sorting under casing is adjusted device and is fixed in frame, and sorting under casing is positioned at the lower section of sorting rotary drum；Being provided with multiple iron core and multiple excitation wire bag in the cavity of sorting rotary drum, be provided with circulating cooling guide hole in each iron core, circulating cooling guide hole is sequentially connected in series by conduit and communicates, and connects with outside cooling aqueous phase through central hollow bearing；One end of sorting rotary drum is connected with frequency conversion speed-down driving means by actuating device；The end of multi-pole coils group connects with the control set for adjusting sorted outside rotary drum；Unload the ore deposit sensing rubbed outer rim plastic contact taking turns and sorting rotary drum of roller.It is high that this magnetic separator has sorting magnetic field intensity, sorting magnetic field and sorting rotary drum rotating speed continuously adjustabe, operates safe and reliable, adapts to the Comprehensive Characteristics continuously run, it is adaptable to the sorting of the materials such as particulate strongly magnetic material and similar artificial magnet ore deposit.

Description

A laboratory magnetic separator suitable for the separation of fine-grained strong magnetic materials

technical field

The invention relates to a laboratory magnetic separator suitable for separating fine-grained strong magnetic materials.

Background technique

In the process of mineral processing and material separation, the magnetic characteristics of the material are used to separate and recover the magnetic minerals in it with a magnetic separator. At present, the separation of strong magnetic materials is mainly carried out with a weak magnetic separator. The magnetic separator in the laboratory is due to the strength of the magnetic field. Low, the magnetic field strength is generally only 150 mT ~ 250 mT.

As the particle size of the materials to be selected becomes finer, and the magnetic properties of some materials to be selected are lower, that is, the specific magnetic susceptibility coefficient is lower, such as: some artificial magnetic materials. At present, the weak magnetic separator in the laboratory cannot effectively separate the current fine-grained strong magnetic materials due to the low magnetic field strength and some structural problems; Overheating will cause a further decrease in magnetic field strength and loss of stability, seriously affecting the separation process; at the same time, some magnetic separators are likely to cause safety hazards to operators because they do not have ore unloading devices or there are potential safety hazards in unloading devices. affect the experimental process.

The present invention draws lessons from the characteristics of the original laboratory weak magnetic separator equipment, and adopts the combination of the iron core with the circulating cooling guide hole and the excitation coil package, which can increase the excitation current and improve the magnetic field intensity; the imported circulating cooling water improves the combination The stability of the magnetic poles, and the effective matching of the designed sorting bottom box and the sorting drum, thereby reducing the particle size of the strong magnetic material sorting. The use of unloading induction rollers and friction transmission makes the operation of the equipment safe and reliable, which is conducive to ensuring the safety of the operator, and provides a suitable and reliable new experimental equipment for the separation of fine-grained strong magnetic materials.

Contents of the invention

The object of the present invention is to provide a laboratory magnetic separator suitable for the separation of fine-grained strong magnetic materials. The magnetic separator is used for the separation of fine-grained strong magnetic materials. It has continuously adjustable magnetic field and drum, and is safe to operate. Features of reliable and continuous operation.

In order to achieve the above object, the technical solution of the present invention is: a laboratory magnetic separator suitable for the separation of fine-grained strong magnetic materials, characterized in that it includes a frame 1, a sorting bottom box 2, a concentrate tank 3, Unloading induction roller 4, sorting drum 5, central hollow bearing 6, transmission device 7, excitation wire package 8, iron core 9;

The upper end of the sorting bottom box 2 is provided with an ore supply fixing hole 17, and the sorting bottom box 2 is fixed on the frame 1 through an adjustment device. The inside of the sorting bottom box 2 is a cavity, and the bottom of the sorting bottom box 2 is an arc. Shape, the lower end side of sorting bottom box 2 is provided with non-magnetic material discharge port 22, and discharge port 22 is provided with control valve, and the same side of sorting bottom case 2 lower end side discharge port is provided with overflow port 11; The sorting bottom box 2 is located below the sorting drum 5;

The sorting drum 5 is cylindrical; the cavity of the sorting drum 5 is provided with a plurality of iron cores 9 and a plurality of excitation wire packages 8, and the iron core 9 is provided with circulating cooling guide holes 10, and the iron cores of all levels The circulating cooling guide hole in the pipe is connected in series by the conduits 15 to form a circulating water channel. The inlet of the circulating water channel passes through the central hollow bearing 6 through the water inlet end of the first connecting conduit 16 and communicates with the external cooling water. The outlet of the circulating water channel is connected by the first The water outlet ends of the two connecting conduits pass through the central hollow bearing 6 and communicate with the concentrate flushing water pipe; the two ends of the sorting drum 5 are respectively connected with the frame 1 by the central hollow bearing 6 (the central hollow bearing 6 passes through the sorting rotor drum 5), one end of the sorting drum 5 is connected with the frequency conversion deceleration drive device 20 by the transmission device 7; Two excitation wire packages 8 are connected end to end to form a multi-level coil group, and the ends of the multi-level coil group communicate with the adjustment control device 18 outside the sorting drum 5 through the central hollow bearing 6;

The ore unloading induction roller 4 is in plastic contact with the outer edge of the sorting drum 5 through the friction wheel 13, and the two ends of the ore unloading induction roller 4 are respectively connected with the frame 1 by bearings, and the inside of the ore unloading induction roller 4 is equipped with a magnetic material ; The ore discharge induction roller 4 is arranged in the concentrate tank 3, and the front end bottom of the concentrate tank 3 is provided with a magnetic material discharge port 12; there is concentrate washing water above the separation drum 5 and the ore discharge induction roller 4 exit 14.

The frame is provided with wheels for walking.

The diameter of the sorting drum 5 is 300mm-2000mm.

The number of stages of the multi-stage coil group is 3-6, and its magnetic field strength can be adjusted by adjusting the current connection of the control device 18, and the magnetic field strength can reach 350 mT-450 mT.

The multistage coil groups are arranged axially, and the magnetic wrap angle is 90°-180°.

The circulating cooling guide holes 10 of the iron core 9 are distributed in a grid shape, and the axial grids are 1 to 5.

The circulating cooling guide holes 10 are connected through connecting conduits 16, such as welding, and the conduits at all levels are connected end to end, and the first and last ends pass through the central hollow bearing 6 to communicate with the external cooling water.

The outer edge of the sorting drum 5 and the sorting bottom box 2 are partially concentric circles, and the gap between the outer edge of the sorting drum 5 and the sorting bottom box 2 is continuously adjustable through the adjusting device. The distance between the outer edge of the drum 5 and the sorting bottom box 2 is 3 mm to 60 mm.

The ore unloading induction roller 4 is in plastic contact with the outer edge of the sorting drum 5 through the friction wheel 13 , and the friction wheel 13 is plastically connected with the ore unloading induction roller 4 .

The beneficial effects of the present invention are:

1. The laboratory magnetic separator of the present invention utilizes the iron core of the circulating cooling guide hole and the multi-level magnetic pole group composed of the excitation wire package, which can obtain a higher magnetic field strength, and the magnetic field strength can reach 350 mT to 450 mT, which is suitable for fine grain particle sorting.

2. The iron core of the laboratory magnetic separator of the present invention is provided with circulating cooling guide holes, and the excitation wire package is forcibly cooled by cooling water, so that the strength of the sorting magnetic field is stable, and it is suitable for long-term continuous operation.

3. The laboratory magnetic separator of the present invention utilizes the ore unloading induction roller, and the friction wheel is in plastic contact with the sorting drum, so there is no potential safety hazard, and the operation process is safe.

4. The laboratory magnetic separator of the present invention utilizes the concentric circles of the sorting drum and the sorting bottom box, and the distance between the sorting drum and the sorting bottom box is continuously adjustable, so that the magnetic particles in the material are fully adsorbed , the separation effect is remarkable, and it is suitable for a wide range of separation particle sizes.

5. The non-magnetic material outlet at the lower end of the sorting bottom box of the laboratory magnetic separator of the present invention is on the side and on the same side as the overflow port, which facilitates the collection of non-magnetic tailings products and makes the test results accurate and reliable.

6. The test shows that: when the concentration of the material to be treated is 10 wt% to 35 wt%, and the particle size of the material -0.045 mm accounts for 55% to 95%, after separation by the laboratory magnetic separator of the present invention, the tailings Non-magnetic materials can be reduced by 5% to 25%. The laboratory magnetic separator operates for a long time, and the temperature rise of the excitation wire package does not exceed 3 ℃. When the material particle size -0.030 mm accounts for more than 95%, it can still be effectively sorted, and the sorting effect is good.

Description of drawings

Fig. 1 is a schematic structural view of the present invention.

Fig. 2a is a cross-sectional view of the iron core with circulating cooling guide holes of the present invention.

Figure 2b is a right side view of Figure 2a.

Fig. 3a is a schematic diagram of the ore unloading induction roller and the friction wheel of the present invention.

Figure 3b is a right side view of Figure 3a.

Fig. 4a is a schematic diagram of the sorting bottom box of the present invention.

Figure 4b is a right side view of Figure 4a.

In the figure: 1-frame, 2-sorting bottom box, 3-concentrate tank, 4-unloading induction roller, 5-sorting drum, 6-central hollow bearing, 7-transmission device, 8-excitation wire package, 9-iron core, 10-circulating cooling guide hole, 11-overflow port, 12-magnetic material outlet, 13-friction wheel, 14-concentrate flushing water outlet, 15-conduit (with circulating cooling The connecting duct between the inside of the iron core of the pilot hole), 16-the first connecting duct (the duct connecting the iron core of the pilot hole and the outside for circulating cooling), 17-the ore feeding fixing hole, 18-regulating control device, 19 -transmission hinge, 20-variable frequency reduction driving device, 21-stop pulley, 22-non-magnetic object ore outlet.

detailed description

As shown in Figure 1, Figure 2 (a, b), Figure 3 (a, b) and Figure 4 (a, b), a laboratory magnetic separator suitable for the separation of fine-grained strong magnetic materials, it includes Frame 1, sorting bottom box 2, concentrate tank 3, ore unloading induction roller 4, sorting drum 5, central hollow bearing 6, transmission device 7, excitation wire package 8, iron core 9, adjustment control device 18 and Frequency conversion deceleration drive device 20;

The upper end of the sorting bottom box 2 is provided with an ore feeding fixing hole 17, and the sorting bottom box 2 is fixed on the frame 1 through an adjustment device (the frame is provided with wheels for walking, and the wheels can stop the pulley 21). The inside of the box 2 is a cavity, and the bottom of the sorting bottom box 2 is arc-shaped (or partly cylindrical). There is a control valve (the control valve is threaded to the end of the discharge port 22), and an overflow port 11 is provided on the same side as the discharge port at the lower end of the sorting bottom box 2; the sorting bottom box 2 is located at the bottom of the sorting drum 5 Bottom (the gap between the sorting bottom box and the sorting drum is adjustable up and down and adjusted by the adjusting device);

The sorting drum 5 is cylindrical (the diameter of the sorting drum 5 is 300 mm to 2000 mm); the cavity of the sorting drum 5 is provided with multiple (multi-stage) iron cores 9 and multiple Each excitation wire package 8 (the adjustable magnetic pole composed of a plurality of iron cores 9 and the excitation wire package 8 is located inside the sorting drum 5 and can be continuously adjusted), and the iron core 9 is provided with a circulating cooling guide hole 10, and the iron cores at all levels The circulating cooling guide hole in the pipe is connected in series by conduits 15 to form a circulating water channel (pipelines at all levels are connected end to end, and the first and last ends pass through the central hollow bearing 6 to communicate with the external cooling water). The inlet of the circulating water channel passes through the first connecting conduit The water inlet end of 16 passes through the central hollow bearing 6 and communicates with the external cooling water, and the outlet of the circulating water channel passes through the central hollow bearing 6 and the concentrate through the outlet end of the second connecting conduit (that is, there are 2 "connecting conduits"). The flushing water pipes are connected (the outlet of the circulating cooling water can be connected with the inlet of the concentrate flushing water to save energy and water); the two ends of the sorting drum 5 are respectively connected to the frame 1 by the central hollow bearing 6 (to adjust The angle of the coil group; the sorting drum 5 is rotatable and driven by the transmission device 7), one end of the sorting drum 5 is connected with the frequency conversion deceleration drive device 20 by the transmission device 7; the iron core 9 is fixedly connected with the central hollow bearing 6 (The central hollow bearing 6 passes through the sorting drum 5), the middle and lower part (outside) of the iron core 9 is wound by a coil to form an excitation wire package 8, and a plurality of excitation wire packages 8 are connected end to end to form a multi-level coil group, and the multi-level coil group The end communicates with the adjustment control device 18 outside the sorting drum 5 through the central hollow bearing 6;

The ore unloading induction roller 4 is in plastic contact with the outer edge of the sorting drum 5 through the friction wheel (elastic friction wheel) 13 (the friction wheel 13 is plastically connected with the ore unloading induction roller 4, and the ore unloading induction roller is in contact with the sorting drum through the elastic friction wheel) The drums are connected and driven, and the two friction wheels 13 are respectively set on the two ends of the ore unloading induction roller 4). The inside of the ore unloading induction roller 4 is provided with a magnetic material; the concentrate tank 3 is provided with an ore unloading induction roll 4, and the bottom of the front end of the concentrate tank 3 (see Figure 1, which means the bottom right of the concentrate tank) is provided with a magnetic Material outlet 12; there is a concentrate flushing water outlet 14 above between the sorting drum 5 and the ore discharging induction roller 4 (that is, the outlet of the concentrate flushing water pipe is located between the sorting drum 5 and the ore discharging induction roller 4 above).

The adjustment device is the connection and adjustment between the sorting bottom box 2 and the frame 1, which is fixedly connected by bolts, and the gap between the bottom box 2 and the sorting drum 5 is adjusted with the double nuts of the bolts [frame 1 is vertically set The upper and lower adjustment slots, the bolts with double nuts pass through the upper and lower adjustment slots to connect with the sorting bottom box 2, the loose nuts move the bolts to adjust the height of the sorting bottom box, adjust the position of the double nuts, and adjust the sorting bottom box 2 Clearance from Rack 1]. The adjusting device can also adopt other devices that can adjust the up and down, left and right positions.

The transmission device is a transmission structure of gears and transmission hinges (racks). At one end of the sorting drum 5, a large gear plate is fixedly connected with the sorting drum 5, such as multi-point clamping or welding; One end of the reduction drive device 20 is a smaller gear plate; the two gear plates are connected and driven by a transmission hinge (rack) 19 .

The variable frequency deceleration driving device 20 is composed of a variable frequency regulator and a variable frequency drive motor, which can be connected to adjust the motor speed within a certain range, so as to achieve the goal of adjusting the speed of the sorting drum.

Described regulating control device 18 is made of frequency conversion controller, excitation current regulator (for regulating the electric current of magnetic separator magnetic field), rectifier, digital display meter, adjusting knob etc.; The rotating speed of sorting drum 5 is controlled by frequency conversion The controller adjusts and controls the speed of its rotating speed, and the magnetic field intensity of the magnetic separator is realized by controlling the current of the excitation wire package 8 by the excitation current regulator.

The iron core is located at the middle and lower part of the sorting drum 5 (within the circumference of 90°-180°, that is, "the multi-stage coil groups are arranged axially, and the magnetic wrap angle is 90°-180°.").

The iron core 9 is arranged inside the sorting drum 5, see Fig. 2b, there is a slight gap between the two ends of the iron core 9 and the sorting drum 5, so the length is a little shorter than the length of the sorting drum, and the center The hollow bearing 6 is a connected bearing, and only the two ends are connected with the frame 1 through rolling bearings.

The number of stages of the multi-stage coil group is 3-6, and its magnetic field strength can be adjusted by adjusting the current connection of the control device 18, and the magnetic field strength can reach 350 mT-450 mT.

The multistage coil groups are arranged axially, and the magnetic wrap angle is 90°-180°.

The circulating cooling guide holes 10 of the iron core 9 are distributed in a grid shape, and the axial grids are 1 to 5.

The outer edge of the sorting drum 5 and the sorting bottom box 2 are partially concentric circles, and the gap between the outer edge of the sorting drum 5 and the sorting bottom box 2 can be continuously adjusted by fixing the adjusting device on the frame 1. Adjustment, the distance between the outer edge of the sorting drum 5 and the sorting bottom box 2 is 3 mm to 60 mm.

Tests have shown that: when the concentration of the material to be treated is 10 wt% to 35 wt%, and the material particle size -0.045 mm accounts for 55% to 95%, after being separated by the laboratory magnetic separator of the present invention, the nonmagnetic can be reduced by 5% to 25%. The laboratory magnetic separator operates for a long time, and the temperature rise of the excitation wire package does not exceed 3 ℃. When the material particle size -0.030 mm accounts for more than 95%, it can still be effectively sorted, and the sorting effect is good.

work process:

1. According to the particle size of the material to be sorted, or the magnetic strength of the material, or the expected concentrate grade, determine the distance between the sorting drum 5 and the sorting bottom box 2, and adjust the sorting drum and the sorting bottom box spacing;

2. Turn the valve of the non-magnetic material outlet 22 to a position with a smaller opening;

3. Inject a certain amount of water into the sorting bottom box 2, so that the water level in the sorting bottom box 2 reaches the overflow port, and a small amount of water can be discharged from the overflow port;

4. Start the corresponding button in the adjustment control device to make the sorting drum 5 run, and adjust the speed of the sorting drum 5 by adjusting the speed of the frequency conversion deceleration drive device;

5. Open the valve of the concentrate flushing water, and the circulating cooling water in the iron core will start immediately;

6. According to the particle size of the material to be sorted, or the magnetic strength of the material, or the expected concentrate grade, determine the different sorting magnetic field strength; start the corresponding button in the adjustment control device (note: before opening this button , it is necessary to confirm that the current adjustment knob is in the minimum or small position, so as not to burn the coil when starting), adjust the current value of the required magnetic field strength;

7. Feed the slurry of the material to be selected from the ore feeding pipe (connected to the outlet of the mixing tank in addition), and the ore feeding pipe can be inserted into the ore feeding fixing hole 17 to fix it. Due to the difference in magnetic force, the magnetic particle material Adsorbed on the surface of the sorting drum 5, along with the rotary motion of the sorting drum 5, it is brought to this end of the ore unloading induction roller 4, and is sucked to the induction roller by the induction of the ore unloading induction roller 4, and then passed through The operation of the unloading induction roller loses its magnetic attraction, and after being washed by the concentrate flushing water, it falls to the concentrate tank 3 and is discharged, and is collected as a magnetic material.

8. The non-magnetic particles in the material enter the lower end of the sorting bottom box 2 through the flow of the slurry, and are discharged through the non-magnetic material discharge port 22. If the slurry fluctuates, they can pass through the same side of the non-magnetic material discharge port 22 The overflow port 11 is discharged, and both slurries are collected as non-magnetic materials.

working principle:

1. The separation of magnetic materials is inseparable from magnetic separation equipment. The magnetic field strength of conventional laboratory magnetic separation equipment is only 150 mT ~ 250 mT, and the magnetic field strength decreases with the increase of the temperature of the excitation wire package during long-term operation. This device uses the circulating cooling guide hole in the iron core, and connects with the external cooling water through the central hollow bearing through the connecting conduit, so as to keep the temperature of the iron core from rising and ensure the stability of the magnetic field strength generated by the iron core and the excitation wire package. At the same time, thicker wires can be wound around the coil, and a larger excitation current can be provided to achieve the purpose of increasing the magnetic field strength, which is beneficial to the separation of fine-grained magnetic materials, and also beneficial to the separation of artificial magnetic materials with lower magnetic susceptibility coefficients. select.

2. According to the combination of the iron core and the excitation wire package, a multi-level coil group is formed. The multi-level coil group is arranged axially, which can form fluctuations in different magnetic field strengths, and form strong tumbling on magnetic materials, which is beneficial to reduce magnetic inclusions and improve magnetic materials. sorting efficiency;

3. The ore unloading induction roller is in plastic contact with the outer edge of the sorting drum through the friction wheel, so that only the sorting drum needs to be driven, reducing the number of transmission devices, and more importantly, improving the safety of operation and eliminating potential safety hazards ;

4. The outer edge of the sorting drum and the sorting bottom box are partially concentric circles, and the gap between the outer edge of the sorting drum and the sorting bottom box is continuously adjustable, which is beneficial to the separation of materials with different particle sizes;

5. The non-magnetic material discharge port at the lower end of the sorting bottom box is on the side and on the same side as the overflow port, which is beneficial to the collection of non-magnetic materials.

Claims (7)

1. the laboratory magnetic separator being suitable to the sorting of particulate strongly magnetic material, it is characterised in that it includes frame (1), sorting under casing (2), concentrate hopper (3), unloads ore deposit sensing roller (4), sorting rotary drum (5), central hollow bearing (6), actuating device (7), excitation wire bag (8), iron core (9)；

The upper end of sorting under casing (2) is provided with to ore deposit fixing hole (17), sorting under casing (2) is adjusted device and is fixed in frame (1), it is cavity in sorting under casing (2), bottom in sorting under casing (2) is arc, the lower end side of sorting under casing (2) is provided with nonmagnetics discharging opening (22), nonmagnetics discharging opening (22) place is provided with control valve, and the homonymy of sorting under casing (2) lower end side nonmagnetics discharging opening is provided with overfall (11)；Sorting under casing (2) is positioned at the lower section of sorting rotary drum (5)；

Sorting rotary drum (5) is cylindric；It is provided with multiple iron core (9) and multiple excitation wire bag (8) in the cavity of sorting rotary drum (5), iron core (9) is provided with circulating cooling guide hole (10), circulating cooling guide hole in iron cores at different levels is sequentially connected in series to communicate by conduit (15) and constitutes cyclic water channel, the import of cyclic water channel connects with outside cooling aqueous phase through central hollow bearing (6) through the water inlet end of first connection conduit (16), and the outlet of cyclic water channel is connected with concentrate wash tub pipe through central hollow bearing (6) by the water side of second connection conduit；The both ends of sorting rotary drum (5) are connected with frame (1) by central hollow bearing (6) respectively, and one end of sorting rotary drum (5) is connected with frequency conversion speed-down driving means (20) by actuating device (7)；Iron core (9) is fixing with central hollow bearing (6) to be connected, the middle and lower part of iron core (9) is wound excitation wire bag (8) by coil, multiple excitation wire bags (8) join end to end and constitute multi-pole coils group, and the end of multi-pole coils group connects with sorting rotary drum (5) control set for adjusting (18) outward through central hollow bearing (6)；

Unloading the rubbed outer rim plastic contact taking turns (13) and sorting rotary drum (5) in ore deposit sensing roller (4), the two ends unloading ore deposit sensing roller (4) are connected with frame (1) by bearing respectively, and the inside unloading ore deposit sensing roller (4) is provided with permeability magnetic material；Being provided with in concentrate hopper (3) and unload ore deposit sensing roller (4), the front bottom end of concentrate hopper (3) is provided with Magnetic Materials discharging opening (12)；Sorting rotary drum (5) and the top unloaded between ore deposit sensing roller (4) have concentrate flushing water to export (14).

A kind of laboratory magnetic separator being suitable to the sorting of particulate strongly magnetic material the most according to claim 1, it is characterised in that: described frame is provided with the wheel for walking.

A kind of laboratory magnetic separator being suitable to the sorting of particulate strongly magnetic material the most according to claim 1, it is characterised in that: a diameter of 300 mm～2000 mm of described sorting rotary drum (5).

A kind of laboratory magnetic separator being suitable to the sorting of particulate strongly magnetic material the most according to claim 1, it is characterized in that: the progression of described multi-pole coils group is 3～6 grades, its magnetic field intensity is adjusted the electric current of control device (18) and connects adjustable, and magnetic field intensity is up to 350 mT～450 mT.

A kind of laboratory magnetic separator being suitable to the sorting of particulate strongly magnetic material the most according to claim 1, it is characterised in that: described multi-pole coils group axially arranges, and disk pack angle is 90 °～180 °.

A kind of laboratory magnetic separator being suitable to the sorting of particulate strongly magnetic material the most according to claim 1, it is characterised in that: the circulating cooling guide hole (10) of described iron core (9), it is distributed in grill-shaped, axial grid is 1～5.

A kind of laboratory magnetic separator being suitable to the sorting of particulate strongly magnetic material the most according to claim 1, it is characterized in that: the outer rim of described sorting rotary drum (5) and sorting under casing (2) are in partial concentric circles, and sort the outer rim of rotary drum (5) and the gap of sorting under casing (2), being adjusted device continuously adjustabe, the outer rim of sorting rotary drum (5) is 3 mm～60 mm with the spacing of sorting under casing (2).