Gradient refined separation method and system for gasified slag

Abstract

The invention discloses a stepped refined separation method and system for gasified slag, and belongs to the technical field of industrial bulk solid waste treatment. Comprising an iron removal device, a size mixing device, a screening device and a sorting device which are sequentially communicated, the sorting device comprises an overflow flotation bin and an underflow flotation bin which are vertically separated, the overflow flotation bin is provided with an upper overflow opening and an upper underflow opening, and the underflow flotation bin is internally provided with a lower overflow opening and a lower underflow opening. According to the system, the multi-stage separation device is combined with the flotation technology, step-by-step separation of components with different particle sizes and densities is achieved, four types of products are obtained, new solid waste cannot be generated, the problems that the fine particle separation efficiency is low and resources are wasted are effectively solved, comprehensive utilization of all components of the gasified slag is achieved, and the comprehensive utilization rate of the gasified slag is improved. The method has the advantages that the separation efficiency is improved, and accurate separation of carbon components and inorganic mineral substances and multi-component gradient recovery are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of industrial bulk solid waste treatment, and in particular relates to a gasification slag step-by-step fine sorting method and system. Background Art

[0002] Fumed slag is the solid residue left after coal combustion and gasification. It is divided into coarse slag and fine slag. Coarse slag is the water-containing slag discharged from the bottom of the gasifier after the coal undergoes melting, quenching, and condensation in the gasifier. Fine slag is the water-containing slag carried out by the crude coal gas flow and obtained through preliminary washing, purification, and precipitation. Both coarse and fine slag contain rich inorganic minerals. Due to incomplete gasification, both contain some residual carbon. The residual carbon content depends on factors such as the feed coal type, gasification process, and operating conditions. Generally speaking, fumed slag is mainly composed of Al2O3, SiO2, CaO, Fe2O3, and residual carbon. The particle size is less than 5mm, and the residual carbon content ranges from 20% to 40%.

[0003] At present, the main treatment methods for coal gasification slag are still mainly storage and landfill, and the comprehensive utilization rate is low. This treatment method not only occupies a large amount of land resources, but also causes serious environmental pollution and ecological damage. Although some technologies have attempted to utilize gasification slag as a resource, such as using multi-stage screening, cyclone separation and other processes for treatment, these methods generally have problems such as complex process flow, high energy consumption of equipment, and low sorting efficiency. In particular, for fine-particle gasification slag with a particle size of less than 0.2 mm, it is difficult for existing technologies to achieve accurate separation of carbon components and inorganic minerals, resulting in the purity of the final product being unable to meet industrial application requirements. In addition, traditional sorting processes can often only obtain a single type of product, and cannot achieve the cascade recycling of multiple valuable components in gasification slag, resulting in a waste of resources. In view of the above problems, the existing technology is in urgent need of improvement. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a gasification slag step-by-step fine sorting method and system to solve the problem in the prior art that the gasification slag sorting process is complicated and the purity of the final product is difficult to use directly.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A gasification slag step-by-step fine sorting system comprises a deironing device, a slurry mixing device and a screening device connected in sequence, wherein the screening device is provided with an oversize outlet and an undersize outlet, the oversize outlet being used to output gasification slag with a particle size of ≥0.2 mm, the undersize outlet being used to output gasification slag with a particle size of <0.2 mm, and the undersize outlet being connected to the sorting device; The sorting device includes an overflow flotation bin and an underflow flotation bin separated from each other in upper and lower parts. The underflow flotation bin is provided with a cyclone. The upper end of the cyclone is connected to an overflow discharge pipe. The upper end outlet of the overflow discharge pipe is in the overflow flotation bin. The overflow flotation bin is provided with an overflow air inlet pipe and a flotation reagent. The overflow flotation bin is provided with an upper overflow port and an upper underflow port. The underflow discharge pipe of the cyclone is in the underflow flotation bin. The underflow air inlet pipe and a flotation reagent are provided in the underflow flotation bin. The underflow flotation bin is provided with a lower overflow port and a lower underflow port. The material output from the upper overflow port is processed to obtain high-precision carbon powder, the material output from the lower overflow port is processed to obtain coarse carbon powder, the material output from the upper bottom flow port is processed to obtain inorganic filler, and the material output from the lower bottom flow port is processed to obtain aluminum silicate.

[0006] A further improvement of the present invention is: Preferably, the overflow flotation bin and the underflow flotation bin are separated by an isolation plate, and the isolation plate and the bottom plate of the underflow flotation bin are both inverted cone-shaped; The overflow discharge pipe passes through the center of the isolation plate.

[0007] Preferably, the upper bottom flow port is provided at the bottom of the isolation plate, and the upper overflow port is provided at the upper portion of the side wall of the overflow flotation bin; The lower overflow port is arranged at the upper part of the side wall of the underflow flotation bin, and the lower underflow port is arranged at the center of the bottom plate of the underflow flotation bin.

[0008] Preferably, the overflow air inlet pipes are evenly arranged on a disc, the disc is fixed in the overflow flotation bin, and the underflow air inlet pipes are evenly distributed on the bottom plate of the underflow flotation bin.

[0009] Preferably, an upper distributor is provided at the upper end of the overflow discharge pipe, and a lower distributor is provided at the lower end of the bottom flow discharge pipe.

[0010] Preferably, the oversize material outlet is sequentially connected to a first dehydration device and a first decarbonization device; The lower bottom flow port is communicated with the inlet of the first dehydration device.

[0011] Preferably, the upper and lower flow ports are sequentially connected to the fourth dehydration device, the second decarbonization device and the air separation device, and one outlet of the air separation device is connected to the outlet of the first decarbonization device.

[0012] Preferably, the upper overflow port is connected to a second dehydration device, and the lower overflow port is connected to a third dehydration device.

[0013] A sorting method of the above-mentioned gasified slag step-by-step fine sorting system comprises the following steps: S1, the gasified slag enters the iron removal device for iron removal, and then enters the slurry mixing device to be mixed with water to obtain slurry; S2, the slurry is screened by a screening device into fumed slag with a particle size of ≥0.2 mm and fumed slag with a particle size of <0.2 mm according to the particle size, and the fumed slag with a particle size of ≥0.2 mm is processed to form aluminum silicate; S3, the gasified slag with particle size less than 0.2mm enters the sorting device and is processed by the cyclone to be divided into particles with density less than 2g / cm 3 Slurry and density> 2g / cm 3 of slurry; S4, density <2g / cm 3 The slurry is separated into material 1 and material 3 in the overflow flotation bin under the action of flotation reagents and gas. Material 1 is discharged through the upper overflow port and becomes high-precision carbon powder, while material 3 is discharged through the upper bottom flow port and becomes inorganic filler. Density>2g / cm 3 The slurry is separated into material 2 and material 4 in the underflow flotation bin under the action of flotation reagent and gas. Material 2 is discharged through the lower overflow port and becomes coarse carbon powder, and material 4 is discharged through the lower underflow port and becomes aluminum silicate.

[0014] Preferably, the material one and the material two are subjected to dehydration treatment, and the material three and the material four are subjected to dehydration, decarbonization and air separation treatment.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention discloses a gasification slag step-by-step fine sorting system. The system realizes the step-by-step separation of components with different particle sizes and densities through a multi-stage sorting device combined with a flotation process, obtains four types of products, and does not generate new solid waste. It effectively solves the problems of low efficiency in fine particle sorting and waste of resources, and realizes the comprehensive utilization of all components of the gasification slag. It has the advantages of improving sorting efficiency, realizing precise separation of carbon components and inorganic minerals, and multi-component step-by-step recovery. The system has the characteristics of simple structure, low cost, easy operation, and continuous operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of a gasification slag step-by-step fine separation process and system according to the present invention; Figure 2 It is a structural schematic diagram of the sorting device of the present invention; Among them: 1. Iron removal device; 2. Slurry mixing device; 3. Screening device; 4. Sorting device; 5. First dehydration device; 6. First decarbonization device; 7. Second dehydration device; 8. Third dehydration device; 9. Fourth dehydration device; 10. Second decarbonization device; 11. Air separation device; 401. Feed pipe; 402. Cyclone; 403. Overflow flotation bin; 404. Underflow flotation bin; 405. Overflow air inlet pipe; 406. Overflow discharge pipe; 407. Underflow discharge pipe; 408. Upper distributor; 409. Lower distributor; 410. Underflow air inlet pipe; 411. Upper overflow port; 412. Upper underflow port; 413. Lower overflow port; 414. Lower underflow port; 415. Isolation plate. DETAILED DESCRIPTION

[0017] The present invention is described in further detail below with reference to the accompanying drawings: To facilitate understanding of the features and effects of the present invention by those skilled in the art, the following provides a general description and definition of the terms and expressions used in the specification and claims. Unless otherwise indicated, all technical and scientific terms used herein have the ordinary meanings as understood by those skilled in the art regarding the present invention. In the event of conflict, the definitions in this specification shall prevail.

[0018] In this document, unless otherwise specified, “include,” “including,” “contains,” “has” or similar terms cover the meanings of “consisting of” and “mainly consisting of,” for example, “A includes a” covers the meanings of “A includes a and other” and “A only includes a.”

[0019] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0020] The following examples were prepared using conventional instruments and equipment in the art. Experimental methods in the following examples, where specific conditions are not specified, were generally performed under conventional conditions or according to the conditions recommended by the manufacturer. The various raw materials used in the following examples, unless otherwise specified, were conventional commercially available products, with specifications conventional in the art. In the present specification and the following examples, unless otherwise specified, "%" indicates percentage by weight, "part" indicates parts by weight, and "ratio" indicates weight ratio.

[0021] Analysis of the particle size distribution of gasified slag revealed that fine slag with a particle size of less than 0.2 mm accounts for over 65% of the total, and residual carbon is primarily concentrated in this particle size. Based on this, the present invention proposes combining physical screening with density separation, integrating cyclone separation and dual-stage flotation within a single separation device. This allows for differentiated processing of materials of varying densities by optimizing the flotation bin structure.

[0022] The present invention discloses a gasification slag step-by-step fine sorting system, comprising an iron removal device 1, a slurry mixing device 2, a screening device 3, a sorting device 4, a first dehydration device 5, a first decarbonization device 6, a second dehydration device 7, a third dehydration device 8, a fourth dehydration device 9, a second decarbonization device 10 and an air separation device 11.

[0023] Among them, the sorting device 4 includes a feed pipe 401, a cyclone 402, an overflow flotation bin 403, an underflow flotation bin 404, an overflow air inlet pipe 405, an overflow discharge pipe 406, an underflow discharge pipe 407, an upper distributor 408, a lower distributor 409 and an underflow air inlet pipe 410.

[0024] The feed port of the iron removal device 1 is connected to the outlet of the gasified slag, the discharge port is connected to the inlet of the slurry mixing device 2, the outlet of the slurry mixing device 2 is connected to the screening device 3, the screening device 3 is provided with two outlets, namely, the undersize outlet and the oversize outlet, the undersize outlet is connected to the sorting device 4, the oversize outlet is connected to the first dehydration device 5, the outlet of the first dehydration device 5 is connected to the first decarbonization device 6, the outlet of the first decarbonization device 6 outputs product four, and the undersize outlet is connected to the sorting device 4.

[0025] The sorting device 4 is divided into an overflow flotation bin 403 and an underflow flotation bin 404 separated by an isolation plate 415. The overflow flotation bin 403 is provided with an overflow discharge pipe 406, an overflow air inlet pipe 405 and an upper distributor 408; the underflow flotation bin 404 is provided with a cyclone 402, an underflow discharge pipe 407, a lower distributor 409 and an underflow air inlet pipe 410.

[0026] The bottom of the overflow flotation bin 403 is an isolation plate 415, which is an inverted cone. The lower end of the overflow discharge pipe 406 passes through the center of the isolation plate 415 and is connected to the upper part of the cyclone 402. The upper end of the overflow discharge pipe 406 is connected to the inverted cone-shaped upper distributor 408. The upper distributor 408 is upwardly dispersed, and the pulp residue is dispersed upward from the upper distributor 408 into the overflow flotation bin 403. There are multiple overflow air inlet pipes 405, which are fixed on a disc. The disc is fixed in the overflow flotation bin 403 for installing the overflow air inlet pipe 405. The overflow air inlet pipe 405 sprays gas upward. The upper overflow port 411 is provided on the upper part of the side wall of the overflow flotation bin 403, and the upper bottom flow port 412 is provided at the bottom of the isolation plate 415 near the overflow discharge pipe 406.

[0027] The cyclone 402 is fixedly arranged in the bottom flow flotation bin 404. The upper end of the cyclone 402 is connected to the overflow discharge pipe 406. The cyclone 402 is connected to the feed pipe 401 of the sorting device 4. Further, the feed pipe 401 is connected to the upper part of the side wall of the cyclone 402, so that the material can fully enter the cyclone 402. The lower end of the cyclone 402 is connected to the bottom flow discharge pipe 407. The bottom flow discharge pipe 407 is connected to the lower distributor 409. The lower distributor 409 is in an inverted cone shape. A gap exists between the feed pipe 407 and the lower distributor 409, allowing the slurry output from the underflow discharge pipe 407 to be dispersed upward by the lower distributor 409, reacting with the flotation reagent in the underflow flotation tank 404. The underflow air inlet pipes 410 are evenly distributed in layers of rings on the bottom plate of the underflow flotation tank 404, and their outlets produce vertically upward bubbles. The bottom plate of the underflow flotation tank 404 is frustum-shaped, with the center portion connected to the lower underflow port 414, allowing the reacted slurry to converge and be discharged from the lower underflow port 414. The lower overflow port 413 is located on the upper side wall of the underflow flotation tank 404, allowing Material 2 to be discharged from the lower overflow port 413.

[0028] The oversize material outlet is connected to the first dehydration device 5 and the first decarbonization device 6 in sequence. The inlet of the first dehydration device 5 is also connected to the lower bottom flow port 414. The logistics 4 output from the lower bottom flow port 414 and the material output from the oversize material outlet enter the first dehydration device 5 for processing at the same time.

[0029] The upper bottom flow outlet 412 is sequentially connected to the fourth dehydration unit 9, the second decarbonization unit 10, and the air separation unit 11. The air separation unit 11 has two outlets: one outlet outputs product three, and the other outlet is connected to the outlet of the first decarbonization unit 6 and is then fed into product four. The air separation unit uses airflow gravity separation (such as an air separator): light materials are carried away by the airflow, while heavy materials fall. One outlet is used to output light materials with small particle size and low weight, which can be used in products such as paint and rubber. The other outlet outputs heavy materials, mainly manufactured sand, which is then fed into product four.

[0030] The upper overflow port 411 is connected to the second dehydration device 7 , and the lower overflow port 413 is connected to the third dehydration device 8 .

[0031] Traditional processes require separate equipment such as cyclones, flotation machines, and dewatering screens. This application integrates cyclone separation and two-stage flotation into a single device through structural innovation of the sorting device. This application addresses the problems of low flotation efficiency and insufficient product purity caused by uneven material distribution during the sorting process, effectively separating high-precision carbon powder from inorganic fillers, while also reducing residual carbon impurities in the aluminum silicate product and avoiding cross-contamination between different products.

[0032] In the overflow flotation bin, the lower-density carbonaceous foam is quickly discharged through the overflow port on the upper sidewall, preventing it from mixing with the inorganic filler settling at the bottom. The upper underflow port at the bottom of the isolation plate collects the settled inorganic filler through a tapered slope, forming a one-way discharge channel. In the underflow flotation bin, the denser materials separated by the cyclone move toward the bin wall under centrifugal force. Coarse carbon powder is discharged laterally through the lower overflow port on the upper sidewall, while the densest aluminum silicate falls vertically into the lower underflow port at the center of the bottom plate under the influence of gravity. This spatial layout prioritizes the horizontal discharge of light materials and separates heavy materials along a vertical path, effectively isolating the movement paths of materials of different densities.

[0033] In a specific example, the inverted conical structure of the isolation plate 415 and the bottom plate of the underflow flotation bin means that the bottom plate is tapered with a low center and high edges, guiding the denser particles to settle and discharge along the inclined surface. By providing the isolation plate 415, the present invention can provide an effective isolation structure, prevent interference between particles of different densities, optimize particle motion trajectories through fluid dynamics, and reduce energy loss during the sorting process.

[0034] In a specific example, the overflow air inlet pipes arranged evenly along the circumference of the disk form an annular air flow diffusion layer, and the gas enters the flotation chamber in a radial path through the outlet of the annular array, so that the flotation reagent and the density are less than 2g / cm 3 The annular pore array on the bottom plate of the underflow flotation bin sprays gas vertically upward from the bottom, which can fully contact the slurry and avoid the phenomenon of carbon powder and inorganic matter being carried away due to the concentration of air flow in local areas. 3 The slurry is uniformly disturbed, strengthening the separation boundary between aluminum silicate and coarse carbon powder while preventing flotation reaction interruption caused by bottom material sedimentation. The dual gas distribution structure of the disc and bottom plate forms a spatial complement. Through the synergistic effect of the upper radial airflow and the lower vertical airflow, the three-dimensional mixing efficiency of gas, solid and liquid is improved.

[0035] In a specific example, this solution establishes a graded processing path, combining the oversize and underflow products during the dehydration stage. This simplifies equipment layout and leverages the complementary properties of the materials to improve dehydration efficiency. Prior art methods for co-processing oversize and underflow products have not been disclosed, limiting product purity during the sorting stage. This solution, however, further removes residual carbon through a decarbonization process, ensuring that the final product meets requirements for direct utilization.

[0036] In a specific example, the iron removal device 1 is an electromagnetic iron remover or a permanent magnetic iron remover, which is used to remove metal impurities in the gasified slag to prevent subsequent equipment wear; further, it can be a suspended iron remover, a drum iron remover, a flat iron remover or a pipeline iron remover.

[0037] In a specific example, the slurry mixing device 2 uses gasified slag and water as raw materials to adjust the slurry concentration to 500~1200g / L. The slurry mixing device has a built-in ultrasonic generator to generate ultrasonic waves to activate the slurry and disperse the encapsulated carbon in the slurry.

[0038] In a specific example, the screening device 3 is composed of a cyclone screen, a vibrating screen or an interference bed, and is used to sort out the gasified slag with a particle size of less than 0.2 mm according to the particle size.

[0039] In a specific example, the first decarbonization device 6, the second dehydration device 7, the third dehydration device 8 and the fourth dehydration device 9 are all rotary dryers, plate and frame filter presses, vacuum belt conveyors or centrifugal dryers.

[0040] In a specific example, the first decarbonization device 6 and the second decarbonization device 10 are both rotary kilns, pusher kilns or tunnel kilns.

[0041] In a specific example, the air separation device 11 is an air separator, the principle of which is to separate particles of different sizes and densities in the material by controlling the air flow speed and direction.

[0042] In a specific example, the upper distributor 408 and the lower distributor 409 are in a bell-mouth shape or an inverted cone shape to change the fluid motion trajectory to cause overflowing materials so that the materials can be evenly dispersed.

[0043] In a specific example, the iron removal device 1, the slurry mixing device 2, the screening device 3, the sorting device 4, the first dehydration device 5, the first decarbonization device 6, the second dehydration device 7, the third dehydration device 8, the fourth dehydration device 9, the second decarbonization device 10 and the air separation device 11 are connected by pipelines or belts.

[0044] In a specific example, flotation agents are added to the overflow flotation bin 403 of the sorting device 4. When the slurry is captured by bubbles and flotation agents, the slurry with low density overflows from the upper overflow port 411 at the top and becomes material one; the slurry with high density flows out from the bottom and becomes material three.

[0045] In a specific example, flotation reagents are added to the underflow flotation bin 404, and the air-water mixture can be transported into the underflow flotation bin 404 through the underflow air inlet pipe 410. Bubbles are generated in the slurry and captured by the bubbles and reagents. The material with lower density and larger surface area overflows from the lower overflow port 413 at the top, which is material two, and the slurry of the material with higher density and smaller surface area flows out from the lower underflow port 414 at the bottom, which is material four.

[0046] The flotation reagents are diesel, kerosene, octanediol, octanol, surfactant, terpineol, etc. It should be understood that the materials floated in the overflow flotation bin 403 and the underflow flotation bin 404 are different, and the flotation reagents can be different.

[0047] A second aspect of the present invention discloses a separation method based on the above-mentioned gasified slag step-by-step fine separation system, comprising the following steps: S1, the gasified slag enters the iron removal device for iron removal, and then enters the slurry mixing device to be mixed with water to obtain slurry; S2, the slurry is screened by a screening device into fumed slag with a particle size of ≥0.2 mm and fumed slag with a particle size of <0.2 mm according to the particle size, and the fumed slag with a particle size of ≥0.2 mm is processed to form aluminum silicate; S3, the gasified slag with particle size less than 0.2mm enters the sorting device and is processed by the cyclone to be divided into particles with density less than 2g / cm 3 Slurry and density ≥2g / cm 3 The higher the content of high-density matter in the gasified slag, the higher the content of inorganic minerals and the stronger the overall hydrophilicity of the sample; the study found that 86.10% of the particles in the gasified slag had a density greater than 2.0 g / cm 3 Among them, 13.90% of the low-density materials have a particle density of less than 2.0 g / cm 3 , so 2.0 is selected as the density judgment point.

[0048] S4, density <2g / cm 3 The slurry reacts with flotation reagents and gas in the overflow flotation tank and is divided into material 1 and material 3. Material 1 is discharged through the upper overflow port and processed to become high-precision carbon powder as product 1. Material 3 is discharged through the upper bottom flow port and processed to become inorganic filler. The main component is SiO2, which also includes Al2O3 and unremoved Fe2O3. SiO2+Al2O3+Fe2O3>70%. Product 3 has a density of ≥2g / cm 3 The slurry reacts with the flotation reagent and gas in the underflow flotation bin and is divided into material 2 and material 4. Material 2 is discharged through the lower overflow port and processed to become coarse carbon powder as product 2. Material 4 is discharged through the lower underflow port and processed to become aluminum silicate as product 4.

[0049] In this process, after iron removal, the fumed slag enters a slurry mixing unit to form a uniform slurry. A screening unit separates the coarse particles for direct aluminum silicate production. The fine particle slurry enters the cyclone of the sorting unit, where it is separated by density into a light overflow and a heavy underflow. The overflow enters the upper flotation chamber, where microbubbles act to form a foam layer of carbon particles, which is collected by scrapers as high-precision carbon powder. The sinking inorganic minerals are discharged through the underflow outlet to be used as filler. The underflow enters the lower flotation chamber, where the contact between the bubbles and the heavy particles is enhanced. The floating coarse carbon powder and the sinking aluminum silicate are discharged through their respective outlets.

[0050] In a specific example, the gasified slag passes through the iron removal device 1 to remove the iron slag in the gasified slag, and enters the slurry preparation device 2. In the slurry preparation device 2, the gasified slag is adjusted to 500-1200g / L slurry by adding water. The slurry is pumped into the screening device 3. After screening, the gasified slag with a particle size greater than 0.2mm is retained on the screen as the oversize material, the main components of which are impurities such as SiO2 and Al2O3; the gasified slag with a particle size less than 0.2mm is pumped into the sorting device 4 along with the slurry. After sorting, four products are produced, namely product 1, product 2, product 3 and product 4. In a specific example, the gasified slag flows through the feed pipe 401 along the tangent line into the cyclone 402 at a certain flow rate. Under the action of centrifugal force, the density is less than 2g / cm 3 The slurry flows from the overflow discharge pipe 406, is evenly distributed through the upper distributor 408, and then enters the overflow flotation bin 403; under the action of centrifugal force, the density is greater than 2g / cm 3 The slurry flows from the underflow discharge pipe 407 , is evenly distributed through the lower distributor 409 , and then enters the underflow flotation bin 404 .

[0051] Specifically, material one overflows through the upper overflow port 411 and enters the second dehydration device 7 for dehydration to obtain high-precision carbon powder with a fixed carbon content of >85%; material two overflows through the lower overflow port 413 and enters the third dehydration device 8 for dehydration and drying to obtain product two, which is coarse carbon powder and can be used as an adsorbent or reducing carbon powder; material three flows out through the upper bottom flow port 412 and is successively processed by the fourth dehydration device 9, the second decarbonization device 10 and the air separation device 11 to obtain an inorganic filler, the main component of which is SiO2, and the carbon content in the inorganic filler is <1%; material four flows out from the lower bottom flow port 414 and is successively processed by the first dehydration device 5 and the first decarbonization device 6 to obtain product four, which is aluminum silicate. Product four also includes the residual material output by the air separation device 11, which is mainly machine-made sand.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A gasification slag step-by-step fine separation system, characterized in that: The invention comprises an iron removal device (1), a slurry mixing device (2) and a screening device (3) which are connected in sequence, wherein the screening device (3) is provided with an oversize outlet and an undersize outlet, wherein the oversize outlet is used to output gasified slag with a particle size of ≥0.2 mm, and the undersize outlet is used to output gasified slag with a particle size of <0.2 mm, and the undersize outlet is connected to a sorting device (4); The separation device (4) comprises an overflow flotation bin (403) and an underflow flotation bin (404) separated from each other. A cyclone (402) is provided in the underflow flotation bin (404). The upper end of the cyclone (402) is connected to an overflow discharge pipe (406). The upper end outlet of the overflow discharge pipe (406) is in the overflow flotation bin (403). An overflow air inlet pipe (405) is provided in the overflow flotation bin (403). ) and flotation reagents, the overflow flotation bin (403) is provided with an upper overflow port (411) and an upper underflow port (412); the underflow discharge pipe (407) of the cyclone (402) is in the underflow flotation bin (404), the underflow flotation bin (404) is provided with an underflow air inlet pipe (410) and flotation reagents, and the underflow flotation bin (404) is provided with a lower overflow port (413) and a lower underflow port (414); The material output from the upper overflow port (411) is processed to obtain high-precision carbon powder, the material output from the lower overflow port (413) is processed to obtain coarse carbon powder, the material output from the upper bottom flow port (412) is processed to obtain inorganic filler, and the material output from the lower bottom flow port (414) is processed to obtain aluminum silicate.

2. The gasification slag step-by-step fine separation system according to claim 1 is characterized in that: The overflow flotation bin (403) and the underflow flotation bin (404) are separated by an isolation plate (415), and both the isolation plate (415) and the bottom plate of the underflow flotation bin (404) are inverted cone-shaped; The overflow discharge pipe (406) passes through the center of the isolation plate (415).

3. The gasification slag step-by-step fine separation system according to claim 2, characterized in that: The upper bottom flow port (412) is provided at the bottom of the isolation plate (415), and the upper overflow port (411) is provided at the upper portion of the side wall of the overflow flotation bin (403); The lower overflow port (413) is arranged at the upper portion of the side wall of the underflow flotation bin (404), and the lower underflow port (414) is arranged at the center of the bottom plate of the underflow flotation bin (404).

4. The gasification slag step-by-step fine separation system according to claim 1, characterized in that: The overflow air inlet pipe (405) is evenly arranged on a disc, and the disc is fixed in the overflow flotation bin (403). The underflow air inlet pipe (410) is evenly distributed on the bottom plate of the underflow flotation bin (404).

5. The gasification slag step-by-step fine separation system according to claim 1, characterized in that: An upper distributor (408) is provided at the upper end of the overflow discharge pipe (406), and a lower distributor (409) is provided at the lower end of the bottom flow discharge pipe (407).

6. The gasification slag step-by-step fine separation system according to claim 1, characterized in that: The oversize material outlet is sequentially connected to a first dehydration device (5) and a first decarbonization device (6); The lower bottom flow outlet (414) is connected to the inlet of the first dehydration device (5).

7. The gasification slag step-by-step fine separation system according to claim 6, characterized in that: The upper and lower flow outlets (412) are sequentially connected to the fourth dehydration device (9), the second decarbonization device (10) and the air separation device (11), and one outlet of the air separation device (11) is connected to the outlet of the first decarbonization device (6).

8. The gasification slag step-by-step fine separation system according to claim 1, characterized in that: The upper overflow port (411) is connected to the second dehydration device (7), and the lower overflow port (413) is connected to the third dehydration device (8).

9. A sorting method based on the gasified slag step-by-step fine sorting system according to claim 1, characterized in that: The following steps are involved: S1, the gasified slag enters the iron removal device (1) for iron removal, and then enters the slurry mixing device (2) to be mixed with water to obtain slurry; S2, the slurry is screened by a screening device (3) according to particle size into gasified slag with a particle size of ≥0.2 mm and gasified slag with a particle size of <0.2 mm, and the gasified slag with a particle size of ≥0.2 mm is processed to form aluminum silicate; S3, the gasified slag with a particle size of less than 0.2 mm enters the separation device (4), is processed by the cyclone (402), and is divided into particles with a density of less than 2 g / cm 3 Slurry and density> 2g / cm 3 of slurry; S4, density <2g / cm 3 The slurry is separated into material 1 and material 3 in the overflow flotation bin (403) under the action of flotation reagent and gas. Material 1 is discharged through the upper overflow port (411) and processed to become high-precision carbon powder. Material 3 is discharged through the upper bottom flow port (412) and processed to become inorganic filler. Density>2g / cm 3 The slurry is separated into material 2 and material 4 in the underflow flotation bin (404) under the action of flotation reagents and gas. Material 2 is discharged through the lower overflow port (413) and processed to become coarse carbon powder, and material 4 is discharged through the lower underflow port (414) and processed to become aluminum silicate.

10. The method according to claim 9, characterized in that The material one and the material two are subjected to dehydration treatment, and the material three and the material four are subjected to dehydration, decarbonization and air separation treatment.

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