CN107116030A - The piece-rate system and separation method of solid mixture - Google Patents

Abstract

The invention relates to the technical field of material separation, and discloses a separation method and a separation system for a solid mixture, wherein the separation system includes: a screening separation device, including a plurality of material collection bins, and the screening separation device includes a plurality of sieve apertures For different screens, multiple material collection bins correspond to multiple screens respectively, so as to collect mixtures with different particle diameter ranges; the winnowing separation device is connected to at least one material collection bin among the multiple material collection bins, so that the material The material in the collection bin can be sent to the corresponding wind separation device for separation through the conveying device. The separation system of the solid mixture of the present invention can separate the mixture according to the particle size and density of the solid mixture particles. Through the above technical scheme, it can be applied to the separation of the mixture of complex materials according to actual needs. Based on the characteristics of the material itself and the process itself, for Strong performance, which solves the problem of poor separation effect of the existing single separation method.

Description

Separation system and separation method for solid mixture

technical field

The invention relates to the technical field of material separation, in particular to a separation system and method for a solid mixture.

Background technique

In the material treatment process, it is often necessary to separate the solid particle mixture in order to achieve the purpose of classification and reuse. Commonly used separation methods for solid particle mixtures include screening, flotation, air selection, etc. The principle is to separate particles by utilizing the differences in particle size, density and other physical properties between materials. When the density difference of the mixture particles is not large, or the particle size distribution is partially overlapped, it is often difficult to separate using the existing single separation method or device.

Contents of the invention

The object of the present invention is to provide a separation system for a solid mixture, which can continuously separate the mixture according to the particle diameter and specific gravity of the material in the mixture.

In order to achieve the above object, the present invention provides a separation system for a solid mixture, wherein the separation system includes a screening separation device and a winnowing separation device, wherein,

The screening and separation device includes a plurality of material collection bins, the screening and separation device includes a plurality of screens with different sieve apertures, and the plurality of material collection bins are respectively corresponding to a plurality of screens to collect different particles mixture of diameter ranges,

The material collection bin of at least one of the plurality of material collection bins is connected to the wind separation separation device, so that the materials in the material collection bin can be sent to the corresponding wind separation separation device through the conveying device for separation .

Preferably, the screening and separation device includes a roller sieve, which includes N+1 material collection bins and N layers of screens that are set in sequence and rotate around the axis of rotation, and the meshes of the N layers of screens are Apertures gradually decrease from the inside to the outside, the first end of the N-layer screen is arranged obliquely higher than the second end, the respective first ends of the N-layer screen are aligned with each other and the length of the N-layer screen is It gradually increases from the outer layer to the inner layer, the outermost screen is the first layer, and the N+1 material collection bins are arranged in sequence under the N layers of screens, wherein the i-th material The collection bin is directly opposite to the side wall of the i-th screen and arranged under the i-th screen, and the second end of the i-th layer of screen extends to be opposite to the i+1-th material collection bin, i= 1,2,...,N.

Preferably, the solid mixture collected in the jth material collection bin is transported to the wind separation device through a lifter, wherein j=1, 2, ..., N+1.

Preferably, the winnowing separation device includes a hopper, a riser and a gas material separator, the pipe wall of the riser is provided with a feed hole and a fluidization air hole, and the fluidization air hole is located below the feed hole, The hopper communicates with the feeding hole of the riser through the conveying pipe, and the fluidizing air hole is connected with a fluidizing air pipe, and the fluidizing air pipe communicates with the rising pipe and can pass into the rising pipe upwards. Flowing fluidized gas flow, the upper end nozzle of the riser communicates with the gas material separator.

Preferably, the delivery pipe is provided with a star valve.

Preferably, the conveying pipe includes a guide part, which extends obliquely downward from the feed hole to the inside of the riser pipe, and the guide part is provided with air holes,

The tube wall of the riser is also provided with a loose air hole, which is adjacent to the feed hole and is located below the feed hole, the loose air hole is connected with a loose air pipe, and the loose air pipe can be connected with the The ventilation holes on the guide part correspondingly let in loose air flow.

Preferably, the side wall of the riser includes a first part, the first part is located below the feeding hole and corresponds to the guide part, the first part and the guide part enclose a closed space, the Loose trachea can communicate with this closed space.

Preferably, an air flow distribution member is provided in the riser, and the air flow distribution member includes a plurality of branch pipes communicating with the fluidization air holes, and the part of the side wall of the branch pipe facing downward is provided with a split hole, and the plurality of branch pipes Arranged along the radial direction of the riser to form dendrites or wells.

Another object of the present invention provides a kind of separation method of solid mixture, wherein, this separation method comprises:

Step 1: Preliminary separation of the mixture according to the particle diameter of each material in the mixture, so as to preliminarily separate the mixture into a plurality of groups

Step 2: Further separate the mixture after preliminary separation according to the specific gravity of each material in the mixture of each group.

Preferably, in said step one, a sieving separation device is used to sieve and separate said mixture,

The step 1 further includes: setting the mesh aperture of the screening and separating device according to the particle diameter of each material in the mixture, so as to preliminarily separate the mixture into multiple groups.

Preferably, in said step 2, a wind separation device is used to further separate the mixture after the primary separation,

The step 2 also includes: setting the wind speed in the winnowing separation device according to the specific gravity of each material in the mixture after preliminary separation.

The separation system of the solid mixture of the present invention can separate the mixture according to the particle size and density of the solid mixture particles. Through the above technical scheme, it can be applied to the separation of the mixture of complex materials according to actual needs. Based on the characteristics of the material itself and the process itself, for Strong performance, which solves the problem of poor separation effect of the existing single separation method.

Other features and advantages of the present invention will be described in detail in the detailed description that follows.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the description, together with the following specific embodiments, are used to explain the present invention, but do not constitute a limitation to the present invention. In the attached picture:

Figure 1 is a schematic diagram of a separation system according to a preferred embodiment of the present invention

Fig. 2 is a schematic diagram of an air distribution member according to a preferred embodiment of the present invention.

Explanation of reference signs

10 Roller sieve; 11 1st sieve; 12 2nd sieve; 13 Rotary shaft; 14 1st material collection bin; 15 2nd material collection bin; 16 3rd material collection bin; 20 Elevator ; 30 wind separation device; 31 hopper; 32 riser; 33 gas material separator; 34 conveying pipe; 35 fluidizing gas pipe; 36 star valve;

detailed description

Specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described here are only used to illustrate and explain the present invention, and are not intended to limit the present invention.

In the present invention, unless otherwise stated, the used orientation words should be properly understood in conjunction with the directions described in the specification and the directions in the drawings.

In order to illustrate the principle of the technical solution of the present invention more clearly, the separation method of the solid mixture provided by the present invention is first described below, and the separation system of the solid mixture provided by the present invention is a specific application of this method.

Specifically, the present invention provides a method for separating a solid mixture, wherein the method for separating comprises:

Step 1: Preliminary separation of the mixture according to the particle diameter of each material in the mixture, so as to preliminarily separate the mixture into a plurality of groups

Step 2: Further separate the mixture after preliminary separation according to the specific gravity of each material in the mixture of each group.

It should be noted that, according to the concept of the present invention, in the process of separating the solid mixture, the method of separating according to the particle size and the method of separating according to the specific gravity can be combined and applied in a corresponding order according to needs, and each separation The method can be applied multiple times by changing the specific parameters of the operation, which is not limited in the present invention.

The technical scheme of the present invention utilizes the properties of each material in the mixture to carry out the separation operation. Specifically, the mixture is firstly separated according to the particle diameter (ie particle size) of the material. For example, different materials often have different particle size ranges, and in some cases, sieving according to particle size can separate mixtures. However, for more cases, the particle size range between different materials usually overlaps, such as the mixture of particle A and particle B, wherein the particle size of particle A is 0-13mm, and the particle size of particle B is 6mm. Therefore, a single The preliminary separation of the mixture according to the particle size can separate the particle A with a particle size much smaller than 6mm and the particle size much larger than 6mm, while the particle A and particle B with a particle size close to 6mm are difficult to separate according to the particle size.

Preferably, in the step 1, a sieving separation device is used to sieve and separate the mixture, and in the step 1, it also includes: setting the sieving separation device according to the particle diameter of each material in the mixture Mesh aperture of the device to initially separate the mixture into groups.

That is to say, the mixture can be preliminarily separated into multiple groups of different particle size ranges by selecting an appropriate screen according to the particle size of each material in the mixture.

Then, for materials whose particle size is within the same range and therefore cannot be separated by particle size, further separation is carried out according to the density of the material.

Preferably, in the step 2, the air separation device 30 is used to further separate the mixture after the primary separation, and the step 2 also includes: setting the air separation according to the specific gravity of each material in the mixture after the preliminary separation. Wind speed in the separation unit.

Among them, the principle of separating the materials by the air separation device 30 is based on the specific gravity of the materials themselves. For example, the air flow of the horizontal air separation device is usually perpendicular to the direction in which the materials fall, so that materials with different specific gravity have different moving distances in the horizontal direction. , the horizontal distance after the fall of the material with a larger specific gravity is smaller, while the horizontal distance after the fall of the material with a smaller specific gravity is larger, so that the materials with different specific gravity in the mixture can be separated from each other. Or, preferably adopt vertical winnowing separation device 30 among the present invention, in vertical winnowing separation device 30, the direction of airflow is basically opposite to the direction that material falls, that is to say, airflow is to basically flow along the vertical upward direction, And the flow velocity of the air flow is set to enable at least one material in the mixture to move upward along the riser of the vertical wind separation device 30, while at least one other material in the mixture can move up along the vertical wind separation device 30 under the action of gravity. Select the riser of the separation device 30 to fall.

That is to say, the air separation device 30 can further separate the mixture according to the specific gravity of the material. For example, in combination with the above example, in the mixture of particle A and particle B, the particle size of particle A is 0-13mm, the particle size of particle B is 6mm, and the specific gravity of the particle frame is 1100kg/m ³ , and the specific gravity of particle B is 2300kg/m ³ , therefore, the preliminary separation of the mixture according to the particle size can separate the particle A with a particle size much smaller than 6mm and the particle size much larger than 6mm, and then separate the particle A and particle B with a particle size of about 6mm according to the specific gravity.

It should be noted that the key point of the inventive concept of the present invention is the comprehensive application of various material separation principles. According to the properties of various materials in the mixture, appropriate separation devices are used in an appropriate order to separate the mixture multiple times, thereby Finally, the desired single substance is obtained. In the various intermediate steps of separation, it is not necessarily possible to obtain a single substance directly. For example, after sieving and separating according to the particle size, the solid particles in a certain particle size range are still a mixture of various substances, but in another particle size range The solid particles may be a single substance, and then according to the actual needs, the mixture obtained by the preliminary separation is again selected according to other properties of each material in the mixture and then separated by an appropriate separation method.

Among them, the method of separating according to the particle size and the method of separating according to the specific gravity can be applied multiple times in any applicable order. For example, after the mixture is initially separated according to the particle size, for a mixture of a certain particle size range, another The sieve of the pore size is used for further separation. Similarly, after preliminary separation of the mixture according to the specific gravity, for the mixture of a certain specific gravity range, another flow rate of the air flow can be selected for air separation again.

The separation method and separation system of the solid mixture of the present invention can separate the mixture according to the particle size and density of the solid mixture particles. Through the above technical scheme, it can be applied to the separation of the mixture of complex materials according to actual needs, based on the characteristics and process of the material itself The method itself has strong pertinence and solves the problem of poor separation effect of the existing single separation method.

Corresponding to the above-mentioned separation direction of the solid mixture of the present invention, the present invention also provides a separation system for the solid mixture, wherein the separation system includes a screening separation device and a winnowing separation device 30, wherein,

The screening and separation device includes a plurality of material collection bins, the screening and separation device includes a plurality of screens with different sieve apertures, and the plurality of material collection bins are respectively corresponding to a plurality of screens to collect different particles mixture of diameter ranges,

At least one material collection bin in the plurality of material collection bins is connected to the wind separation device 30, so that the material in the material collection bin can be sent to the corresponding wind separation device 30 through a conveying device to separate.

According to the concept of the present invention, in the process of separating the solid mixture, the screening separation device and the winnowing separation device 30 can be combined and applied in a corresponding sequence according to needs, and each separation device can change, for example, the sieve aperture or flow rate. It can be applied multiple times based on specific parameters such as wind speed, which is not limited by the present invention.

Based on the above description of the separation method, the principle and effect of the separation system of the present invention will not be repeated here, and the specific structure of the separation system will be described in detail below in conjunction with a preferred embodiment of the separation system.

In practical applications, the mixture is usually screened and separated first. Wherein, the screening and separating device can select a screen with a corresponding sieve aperture according to needs, and the number of screens in the screening and separating device can also be set according to actual needs. The screening and separating device can be any suitable device in the prior art, such as a vibrating screen or a roller sieve. For the vibrating screen, the sieve aperture of the screen gradually decreases from top to bottom, that is to say, the particle size of the material retained on the upper screen is larger than that of the material retained on the lower screen.

After the particles of the mixture are divided into multiple groups of mixtures according to the particle size range by using the sieve, the mixture of each particle size range is stored in the material collection bin of the screening and separation device. Then, the mixture within one or more particle size ranges can be further sieved, or further separation can be carried out by using a wind separation device according to the different specific gravity of the material.

Preferably, the screening and separation device includes a roller sieve 10, the roller sieve 10 includes N+1 material collection bins and N layers of screens that are set in sequence and rotate around the rotation axis 13, and the N layers of screens The sieve hole diameter gradually decreases from the inside to the outside, the first end of the N-layer screen is arranged obliquely higher than the second end, the respective first ends of the N-layer screen are aligned with each other and the N-layer screen The length of the net gradually increases from the outer layer to the inner layer, the outermost screen is the first layer, and the N+1 material collection bins are arranged in sequence under the N layers of screens, wherein the first The i-th material collection bin is directly opposite to the side wall of the i-th sieve and arranged under the i-th sieve, and the second end of the i-th layer of sieve extends to be opposite to the i+1-th material collection bin , i=1,2,...,N.

The circular drum screen usually includes a plurality of screens arranged with a common rotation axis 13, and the angle between the plurality of screens and their common rotation axis 13 is preferably 2-20 degrees with the horizontal plane, and the first of each screen The end is sloped higher than the second end. In this way, the material enters the circular roller screen from the first end and is discharged from the second end, so the i-th material collection bin opposite to the i-th layer of screen is set under the i-th layer of screen, and the i-th layer of screen The second end extends to the i+1 material collection bin, and the particles passing through the sieve holes of the i-th layer of sieve fall into the i-th material collection bin, and on the i-th layer of sieve (that is, the particles that cannot pass through the i-th layer of sieve) sieve) particles slide along the sieve to the second end under the action of gravity and fall into the i+1th material collection bin. That is to say, the particle size range of the materials collected in the first material collection bin is the smallest, and then increases sequentially. The mesh of the screen is preferably rectangular to prevent material from being stuck.

For example, in the mixture of particle A and particle B, the particle size of particle B is concentrated in the vicinity of d, the particle size range of particle A is wide, and d is in the middle of the particle size range of particle A, so two layers of sieves are preferably used The circular roller sieve, the sieve size of the first layer of sieve 11 is d-(1～2)mm, the sieve size of the second layer of sieve 12 is d+(1～2)mm, therefore, the particle size is smaller than d - (1 ~ 2) mm particle A falls into the first material collection bin 14, particle size greater than d + (1 ~ 2) mm particle A falls into the third material collection bin 16, and the particle size is greater than or equal to d- (1～2)mm and less than d+(1～2)mm The mixture of particle A and particle B falls into the second material collection bin 15 .

In order to separate the mixture of particle A and particle B with the same particle size range in the second material collection bin 15, a further separation operation needs to be carried out according to the properties of particle A and particle B except particle size.

Preferably, the solid mixture collected in the jth material collection bin is transported to the winnowing separation device 30 through the elevator 20, where j=1, 2, . . . , N+1.

Preferably, the winnowing separation device 30 includes a hopper 31, a riser 32 and a gas material separator 33, the pipe wall of the riser 32 is provided with feed holes and fluidization air holes, and the fluidization air holes are located at the inlet Below the feed hole, the hopper 31 communicates with the feeding hole of the riser 32 through the delivery pipe 34, and the fluidization air hole is connected with a fluidization air pipe 35, and the fluidization air pipe 35 communicates with the riser 32 In addition, an upwardly flowing fluidizing airflow can be introduced into the riser 32 , and the upper end nozzle of the riser 32 communicates with the gas material separator 33 .

In this preferred embodiment, the riser 32 is generally arranged vertically, and a feed hole and a fluidization air hole are arranged on the riser 32. The fluidization air hole is arranged below the feed hole, and the fluidization air pipe 35 passes through the flow The gasification holes deliver fluidization gas to the riser 32 , and the fluidization gas flows in the riser 32 from bottom to top. And, the material that enters the riser 32 of the winnowing separation device 30 from the material collection bin through the hoist falls under the action of gravity, and the fluidization gas flows upward after entering the riser 32 from the fluidization air hole. The flow rate of the fluidizing gas, so that the fluidizing gas can overcome the gravity of the less dense particles when passing through the particles, so that the less dense particles move upward, and the denser particles continue to move downward under the action of gravity , so that the particles of two different densities are separated from each other. Specifically, the flow rate of the fluidization gas is set between the minimum fluidization velocities of the two particles.

Wherein, the gas-material separator 33 is preferably a cyclone separator. When the fluidization gas enters the gas-material separator 33 from the upper end of the riser 32 upwards, the gas-material separator 33 can separate the material in the fluidization airflow. Particles separate out.

In addition, in order to prevent the fluidizing gas from blowing the particles back into the delivery pipe 34 , the delivery pipe 34 is provided with a star valve 36 . The star valve 36 is set on the conveying pipe 34 closer to the side of the riser 32, so that the material can enter the riser 32 from the hopper 31 along the conveying pipe 34, and can prevent the material from flowing back through the star along with the fluidizing gas. type valve 36 into the hopper 31.

And, the length of the delivery pipe 34 above the star valve 36 can be set to a relatively slender shape, in addition, the hopper 31 can also be set to a slender shape with a smaller cross-sectional area, so that the hopper 31 and the star valve The height of the material in the conveying pipe 34 above 36 is relatively high, so as to increase the pressure exerted on the star valve 36 by the material, thereby improving the sealing strength of the star valve 36 .

Preferably, the conveying pipe 34 includes a guide portion 37, which extends obliquely downward from the feed hole to the inside of the riser pipe 32, and the guide portion 37 is provided with air holes,

The tube wall of the riser 32 is also provided with a loose air hole, which is adjacent to the feed hole and is located below the feed hole, the loose air hole is connected with a loose air pipe 38, and the loose air pipe 38 can lead to loose airflow corresponding to the air holes on the guide part 37 .

That is to say, a guide 37 is provided below the feed hole, and when the material enters the riser 32 from the feed hole, it can fall near the center of the riser 32 along the guide 37, so that the material can be evenly distributed. By the role of fluidizing gas.

Moreover, the diameter of the vent hole on the guide part 37 is set to be smaller than the minimum particle diameter of the material particles, so as to prevent the material from blocking the vent hole. The loose air pipe 38 can be arranged to pass through the loose air hole and extend into the riser pipe 32. In order to make the loose air flow introduced from the loose air pipe 38 fully act on the ventilation hole of the guide part 37, the loose air pipe 38 can preferably be arranged For the nozzle toward the guide.

The loose air pipe 38 leads a loose air flow through the air holes to disturb the material conveyed through the guide part 37, so that the particles of the material can be fully dispersed and separated by the subsequent fluidizing air flow.

Preferably, the side wall of the riser 32 includes a first part, the first part is located below the feed hole and corresponds to the guide part 37, and the first part and the guide part 37 enclose a closed space , the loose air hole is provided on the first part, and the loose air pipe 38 can communicate with the closed space.

It should be noted that the above-mentioned closed space can be set accordingly according to needs. Preferably, the closed space is surrounded by the guide part 37 and surrounding structures, and the loose air tube 38 can be set to be inserted into the closed space through the side wall. In the closed space, it can also be set that the loose air hole is arranged on the first part of the side wall of the riser 32, so that the loose air pipe 38 directly extends into the closed space.

The enclosed space can make the loose air flow more concentratedly applied to the air holes of the guide part 37, so as to ensure the flow velocity and intensity of the loose air flow and improve the effect of loose materials.

Preferably, the riser 32 is provided with an airflow distribution member 39, the airflow distribution member 39 includes a plurality of branch pipes communicating with the fluidization air holes, and the part of the sidewall of the branch pipes facing downward is provided with a distribution hole.

In order to enable the fluidizing air flow to evenly blow the particles over the entire cross-section of the riser 32, it is preferably realized by evenly distributing a plurality of branch pipes of the air distribution member 39 on the cross-section of the riser 32, and in order to avoid falling Particles block the split hole on the branch pipe, and the split hole opening on the branch pipe is set downwards, and the airflow blown from the split hole returns upward after contacting the material accumulated at the bottom of the riser 32.

Another advantage of arranging the opening of the orifice facing downward is that the clogging of the orifice is prevented. During normal use, it is usually necessary to stop feeding materials to the riser 32 first, and stop the input of the fluidizing airflow after all the materials in the riser 32 have been separated, so as to prevent the material in the riser 32 from disintegrating after the fluidizing airflow stops. It falls under the action of gravity and blocks the shunt hole. However, in the case of an emergency shutdown of the equipment, the fluidizing air flow stops conveying at this time, but the material continues to be conveyed into the riser 32. At this time, since the opening of the split hole is set downward, even in this case, it will not cause the material Clogged orifice. When the device is restarted, the device can resume normal operation without additional cleaning of the shunt hole.

The plurality of branch pipes in the air distribution member 39 can be arranged in any suitable structure. Preferably, a plurality of branch pipes are arranged along the radial direction of the riser 32 to form a branch shape or a well lattice shape.

For example, in the separation of the mixture of particle A and particle B, the particle size of particle A is 0-13mm, the particle size of particle B is 6m, the mass mixing ratio of A and B is 1:5, and the density of particle A is 1100km/m ³ , the density of particle B is 2300kg/m ³ .

Separation system comprises circular roller sieve and winnowing separation device 30, and this circular roller sieve comprises double-layer grate bar screen cloth, and the grate bar pitch of the first layer of screen cloth 11 is 5mm, and the second layer of screen cloth 12 grate bar pitch is 7mm, therefore Collect granule A of 0-5mm in the first material collection bin 14, collect the mixture of granule A and particle B of 5-7mm in the second material collection bin 15, collect the granule of 7-13mm in the third material collection bin 16 First. Wherein, the second material collection bin 15 is transported to the winnowing separation device 30 by a bucket elevator or a belt conveyor. The air separation device 30 adopts a vertical fluidized air separation device.

Wherein, the minimum fluidization velocity of particle A and particle B with a particle diameter of 5-7mm is 12m/s and 17m/s respectively, so the flow velocity of the fluidization gas is set to 13m/s, and the diameter of the riser 32 is set to 200mm, The flow rate of the fluidizing gas is 1470m ³ /h, and the gas flow distribution part includes 6 branch pipes arranged in a branch shape along the horizontal direction. The diameter of each branch pipe is 15mm, and the diameter of the distribution hole on each branch pipe is 4mm. The fluidizing gas pipe 35 has a diameter of 50 mm.

In addition, it should be noted that in the case of canceling the pre-dispersed air supply, the mass fraction of particle A contained in the material collected in the lower part of the vertical fluidized riser is 2.3%, and the material collected in the cyclone separator contains 0.5% Particle B. At this time, if the separation effect is to be improved, it is necessary to appropriately increase the lifting gas volume and increase the height of the riser, thereby increasing the operating energy consumption and the height of the equipment.

The preferred embodiment of the present invention has been described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the specific details of the above embodiment, within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, These simple modifications all belong to the protection scope of the present invention.

In addition, it should be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way if there is no contradiction. The combination method will not be described separately.

In addition, various combinations of different embodiments of the present invention can also be combined arbitrarily, as long as they do not violate the idea of the present invention, they should also be regarded as the disclosed content of the present invention.

Claims (11)

1. a separation system of solid mixture, it is characterized in that, this separation system comprises screening separation device and winnowing separation device (30), wherein, The screening and separation device includes a plurality of material collection bins, the screening and separation device includes a plurality of screens with different sieve apertures, and the plurality of material collection bins are respectively corresponding to a plurality of screens to collect different particles mixture of diameter ranges, At least one of the plurality of material collection bins is connected to the air separation device (30), so that the material in the material collection bin can be sent to the corresponding air separation device (30) through a conveying device to separate. 2. The separation system according to claim 1, characterized in that, the screening and separation device comprises a roller sieve (10), and the roller sieve (10) includes N+1 material collection bins and successively set and N layers of screens rotating around the rotation axis (13), the apertures of the N layers of screens gradually decrease from inside to outside, and the first end of the N layers of screens is obliquely arranged higher than the second end, The respective first ends of the N layers of screens are aligned with each other and the length of the N layers of screens gradually increases from the outer layer to the inner layer, the outermost screen is the first layer, and the N+1 materials The collection bins are arranged sequentially under the N layers of screens, wherein the i-th material collection bin is directly opposite to the side wall of the i-th screen and is arranged under the i-th screen, and the i-th The second end of the layer of screen extends to be opposite to the i+1th material collection bin, i=1, 2, . . . , N. 3. separation system according to claim 2, is characterized in that, the solid mixture collected in the jth material collection bin is transported to the air separation device (30) by a hoist (20), Wherein, j=1, 2, . . . , N+1. 4. separation system according to claim 1, is characterized in that, described winnowing separation device (30) comprises hopper (31), riser (32) and gas material separator (33), and this riser (32) Feeding holes and fluidizing air holes are arranged on the pipe wall, and the fluidizing air holes are located below the feeding holes. The material hole is connected, and the fluidizing air hole is connected with a fluidizing air pipe (35), and the fluidizing air pipe (35) is communicated with the riser (32) and can lead to an upward flow in the riser (32). The fluidizing airflow of the riser (32) is communicated with the gas material separator (33). 5. The separation system according to claim 4, characterized in that a star valve (36) is arranged on the delivery pipe (34). 6. Separation system according to claim 4, characterized in that the conveying pipe (34) comprises a guide (37) extending obliquely downwards from the feed hole to the Inside the riser (32), the guide (37) is provided with air holes, The pipe wall of the riser (32) is also provided with loose air holes, which are adjacent to the feed hole and located below the feed hole, and the loose air hole is connected with a loose air pipe (38), The loose air duct (38) can lead in loose airflow corresponding to the air holes on the guide part (37). 7. The separation system of claim 6, wherein: The side wall of the riser (32) includes a first part, which is located below the feed hole and corresponds to the guide part (37), and the first part surrounds the guide part (37). into a closed space, and the loose trachea (38) can communicate with the closed space. 8. The separation system according to claim 4, characterized in that, the riser (32) is provided with an airflow distribution part (39), and the airflow distribution part (39) includes a plurality of air holes communicating with the fluidization air holes. A branch pipe, the part of the side wall facing downwards of the branch pipe is provided with a split hole, A plurality of branch pipes are arranged along the radial direction of the riser (32) to form dendrites or wells. 9. A separation method for a solid mixture, characterized in that the separation method comprises: Step 1: Preliminary separation of the mixture according to the particle diameter of each material in the mixture, so as to preliminarily separate the mixture into a plurality of groups Step 2: Further separate the mixture after preliminary separation according to the specific gravity of each material in the mixture of each group. 10. separation method according to claim 9 is characterized in that, in described step one, adopts screening separation device to carry out screening separation to described mixture, The step 1 further includes: setting the mesh aperture of the screening and separating device according to the particle diameter of each material in the mixture, so as to preliminarily separate the mixture into multiple groups. 11. separation method according to claim 9 is characterized in that, in described step 2, adopt air separation device to further separate the mixture after preliminary separation, The step 2 also includes: setting the wind speed in the winnowing separation device according to the specific gravity of each material in the mixture after preliminary separation.