Gasification fine slag separation system
By combining equipment such as coarse screens, countercurrent classifiers, classifying hydrocyclones, and stacked fine screens, the problem of separating ultrafine particles of gasification ash slag has been solved, achieving efficient separation and maximizing the recovery of fixed carbon, thus improving the economic benefits of the separation system.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- WEIHAI HAIWANG TECH CO LTD
- Filing Date
- 2025-04-25
- Publication Date
- 2026-04-28
AI Technical Summary
Existing technologies are ineffective in processing ultrafine particles in gasification ash, resulting in low fixed carbon recovery rates, low economic value, and insufficient sorting efficiency and precision.
The system employs a combination of equipment including a coarse screen, a countercurrent classifier, a classifying hydrocyclone unit, a spiral separator, and a stacked fine screen. By classifying and separating materials of different particle sizes, and combining this with a spray water-enhanced classification and concentration system, it achieves efficient separation of gasified fine slag.
It significantly improves the sorting accuracy and efficiency of gasification slag, maximizes the recovery of fixed carbon, reduces resource waste, and enhances economic benefits.
Smart Images
Figure CN224167672U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of gasification ash and slag resource utilization technology, and in particular to a gasification fine slag sorting system. Background Technology
[0002] Gasification ash is a solid waste generated during the gasification process of raw materials such as coal and biomass, mainly consisting of coarse and fine ash. Fine gasification ash (particle size <0.5mm) constitutes a high proportion, with a fixed carbon content of 30%-50%, and possesses high resource recovery value. However, ultrafine particles (<0.074mm) typically account for over 50% of the fine gasification ash, and in some cases even exceed 70%, making it difficult for traditional sorting technologies to effectively process.
[0003] In existing technologies, the separation of gasification ash mainly employs the spiral separation method. This method utilizes the forces of gravity, centrifugal force, and water flow within the spiral channel to achieve separation based on differences in particle size and density. While suitable for processing ash with a relatively wide particle size range (0.1-5 mm), this method suffers from low precision, particularly in separating ultrafine ash (particle size < 0.074 mm). This results in limited fixed carbon recovery, and the economic value of ultrafine ash (ash content > 80%) is low, making effective physical separation difficult. The method suffers from significant classification challenges and low classification efficiency. In addition, fluidized bed separation technology is also used. Fluidized bed separation technology has high precision and is simple to operate, but the separation particle size is narrow. The biggest problem with gasification fine slag is that the proportion of particles with a diameter <0.074mm generally exceeds 50%, and in some cases even exceeds 70%. Physical separation is basically ineffective for particles with a diameter <0.074mm. Moreover, this part of the material has a low carbon content and is mostly high ash material with an ash content of more than 80%, which has very low economic value and separation value.
[0004] Therefore, in the separation process, in addition to effective separation, it is still necessary to strengthen the efficient desliming process. There is an urgent need to provide a separation system that is highly efficient, low in energy consumption, and maximizes the recovery of fixed carbon in gasification ash residue, so as to increase economic benefits, reduce resource waste, and conform to the green, environmentally friendly and sustainable energy path. Utility Model Content
[0005] The purpose of this invention is to provide a gasification fine slag separation system that solves the problems of high separation difficulty, low separation efficiency, poor separation effect, and resource waste in the existing technology.
[0006] The embodiments of this utility model can be implemented through the following technical solutions:
[0007] A gasification fine slag separation system includes a coarse screen, wherein the outlet of the undersize material of the coarse screen is connected to the inlet of a mixing tank, and the outlet of the mixing tank is connected to the inlet of a countercurrent classifier.
[0008] The underflow port of the countercurrent classifier is connected to the feed inlet of the classifying hydrocyclone unit, and the underflow port of the classifying hydrocyclone unit is connected to the screw tail high-frequency screen and the stacked fine screen respectively through the separator.
[0009] Furthermore, the feed inlet of the coarse screen is connected to the mixing tank via a raw material feeding pump, and the coarse screen is equipped with spray water to enhance classification.
[0010] Furthermore, the mixing tank is connected to the countercurrent classifier via a countercurrent classifier feed pump. The mixing tank remixes the undersize material from the coarse screen and feeds the mixed slurry into the countercurrent classifier via the countercurrent classifier feed pump.
[0011] Furthermore, the underflow port of the countercurrent classifier is connected to the inlet of the classifying hydrocyclone unit via a spiral feed barrel, and the spiral feed barrel is connected to the inlet of the classifying hydrocyclone unit via a spiral feeding pump.
[0012] Furthermore, the overflow port of the grading hydrocyclone unit is connected to the feed inlet of the thickener, and the underflow port of the grading hydrocyclone unit is connected to the spiral separator.
[0013] Furthermore, the tailings outlet of the spiral separator is connected to the spiral tail high-frequency screen, and the concentrate outlet of the spiral separator is connected to the stacked fine screen.
[0014] Furthermore, the oversize material outlet of the stacked fine screen is connected to a centrifuge, which is used to dewater the oversize material of the stacked fine screen.
[0015] Furthermore, the overflow slurry of the countercurrent classifier, the overflow slurry of the classifying hydrocyclone unit, the undersize material of the screw tail high-frequency screen, and the undersize material of the stacked fine screen are respectively discharged by gravity or introduced into the thickening tank for treatment.
[0016] Furthermore, the overflow port of the grading hydrocyclone unit and / or the under-screen discharge port of the screw tail high-frequency screen and / or the under-screen discharge port of the stacked fine screen are connected to the thickener via a tailings bucket and a tailings pump.
[0017] Furthermore, the overflow outlet of the thickening tank is connected to the circulating water tank, and the underflow outlet of the thickening tank is connected to the filter press via a filter press feed pump.
[0018] The gasification fine slag separation system provided in this embodiment of the utility model has at least the following beneficial effects:
[0019] The separation system of this application fully utilizes the different advantages of various fine-particle material grading and separation equipment. Specifically, the coarse screen controls the coarse material entering the separation equipment, removing large particles of high-ash products (φ1mm and above). The counter-current classifier controls the fine material entering the separation equipment, while discharging most of the high-ash fine mud material (φ0.074mm and below). A subsequent classifying hydrocyclone controls the fine mud content and feed concentration, and a spiral separator discharges as much high-ash, high-density material as possible. This achieves separation of materials with a particle size of 1mm-0.074mm. A stacked fine screen further enhances the removal of high-ash fine mud from the concentrate. The thickening system controls the circulating water quality to ensure smooth system operation. By using different grading and separation combinations, the advantages and characteristics of each are fully utilized, maximizing the benefits of gasification fine slag separation and significantly improving separation accuracy, efficiency, and value. It boasts advantages such as simple process and strong practicality. Attached Figure Description
[0020] Figure 1 This is a process flow diagram of a gasification fine slag separation system according to this application.
[0021] Numbers in the diagram
[0022] 1-Agitator, 2-Raw material feed pump, 3-Coarse screen, 4-Blending tank, 5-Countercurrent classifier feed pump, 6-Countercurrent classifier, 7-Spiral feed tank, 8-Spiral feed pump, 9-Classifying hydrocyclone unit, 10-Spiral separator, 11-Spiral tail high-frequency screen, 12-Layer fine screen, 13-Centrifuge, 14-Tailings tank, 15-Tailings pump, 16-Thickening tank, 17-Filter press feed pump, 18-Filter press, 19-Circulating water tank, 20-Circulating water pump. Detailed Implementation
[0023] The present invention will now be further described based on preferred embodiments and with reference to the accompanying drawings.
[0024] In addition, for ease of understanding, various components on the drawings have been enlarged (thickened) or reduced (thinned), but this is not intended to limit the scope of protection of this utility model.
[0025] Singular forms of words also include plural meanings, and vice versa.
[0026] In the description of the embodiments of this utility model, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use. These are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the utility model. Furthermore, in the description of this utility model, the terms "first," "second," etc., are used to distinguish different units, but these are not limited by the manufacturing order, nor should they be construed as indicating or implying relative importance. Their names may differ in the detailed description and claims of the utility model.
[0027] The terminology used in this specification is for illustrative purposes and is not intended to limit the scope of the invention. It should also be noted that, unless otherwise explicitly stated and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, a direct connection, or an indirect connection via an intermediate medium; or they can refer to the internal communication between two components. Those skilled in the art will readily understand the specific meanings of the terms within the context of this invention.
[0028] Figure 1 This is a process flow diagram of a gasification fine slag separation system according to this application, as shown below. Figure 1 As shown, a gasification fine slag separation system includes a coarse screen 3, a mixing tank 4, a countercurrent classifier 6, a spiral feed tank 7, a classifying hydrocyclone unit 9, a spiral separator 10, a high-frequency screw screen 11, a stacked fine screen 12, a centrifuge 13, and a thickener 16. The outlet of the coarse screen 3 is connected to the inlet of the mixing tank 4, and the outlet of the mixing tank 4 is connected to the inlet of the countercurrent classifier 6. The overflow port of the countercurrent classifier 6 can be connected to the inlet of the thickener 16. The large particles larger than 1mm on the coarse screen 3 are high-ash products. The washable material is directly discharged as tailings. The material undersized by the coarse screen 3 enters the mixing tank 4 for mixing. The mixed material is then fed into the countercurrent classifier 6. The countercurrent classifier 6 is used to discharge most of the high-ash fine mud (materials below φ0.074mm) in advance. The material below φ0.074mm has high ash content and poor selectivity. It can be directly fed into the thickener 16 through the overflow port of the countercurrent classifier 6. By adopting the above scheme, materials with a particle size in the range of 1-0.1mm can be obtained. Materials in this particle size range have high fixed carbon content and have certain selectivity.
[0029] Furthermore, the underflow port of the countercurrent classifier 6 is connected to the feed inlet of the classifying hydrocyclone unit 9. The underflow port of the classifying hydrocyclone unit 9 is connected to the screw tail high-frequency screen 11 and the stacked fine screen 12 through the separator. The screw tail high-frequency screen 11 is used to dewater the tailings product after separation by the separator and transfer it to the tailings site. The stacked fine screen 12 is used to perform efficient and fine classification of the fine ore with fine particles remaining after separation by the separator. Its main function is to discharge the fine particles in the concentrate.
[0030] Specifically, the feed inlet of the coarse screen 3 is connected to the mixing tank 1 via the raw material feeding pump 2. The coarse screen 3 is equipped with spray water for enhanced classification. The gasified fine slag is transferred into the mixing tank 1. The slurry concentration is adjusted by adding water, and then fed into the coarse screen 3 via the raw material feeding pump 2 for 1mm coarsening. Through the spray water enhanced classification on the coarse screen 3, the material on the screen is mostly φ1mm or larger with high ash content, ranging from 90-99%. It has poor selectivity and low carbon content, so it is discharged as tailings.
[0031] In some preferred embodiments, the undersize material from the coarse screen 3 enters the mixing tank 4 for remixing. The mixing tank 4 is connected to the countercurrent classifier 6 via a countercurrent classifier feed pump 5. The mixing tank 4 feeds the prepared slurry, adjusted to about 40%, into the countercurrent classifier 6 via the countercurrent classifier feed pump 5 for classification. The countercurrent classifier 6 is used to discharge most of the high-ash fine mud in advance.
[0032] In some preferred embodiments, the underflow port of the countercurrent classifier 6 is connected to the inlet of the classifying hydrocyclone unit 9 via a spiral feed tank 7. The spiral feed tank 7 is connected to the inlet of the classifying hydrocyclone unit 9 via a spiral feed pump 8. The underflow of the countercurrent classifier 6 consists of coarse particles, which flow by gravity to the spiral feed tank 7. Water is added to the spiral feed tank 7 to adjust the slurry to 80 g / l - 120 g / l, and then the spiral feed pump 8 feeds it into the classifying hydrocyclone unit 9 for classification. The main function of the classifying hydrocyclone unit 9 is to discharge the high-ash fine particles (below φ0.074mm) remaining in the underflow of the countercurrent classifier 6 into the classification system in advance, optimize the classification conditions of the downstream spiral separator 10, and control the feed concentration entering the spiral separator 10 to be between 15-25%.
[0033] The overflow port of the grading hydrocyclone unit 9 is connected to the inlet of the thickener 16. The slurry flowing out of the overflow port of the grading hydrocyclone unit 9 flows by gravity to the thickener 16. The underflow port of the grading hydrocyclone unit 9 is connected to the spiral separator 10. The underflow material of the grading hydrocyclone unit 9 flows by gravity into the distributor of the spiral separator 10, and then enters the spiral separator 10 for separation. Since the spiral separator 10 has a wide separation particle size range, it is mainly used for separating materials in the range of φ1-φ0.074mm. In the gasification fine slag, the material in the range of φ1-φ0.1mm has strong selectivity. Therefore, using the spiral separator 10 for separation can significantly improve the separation efficiency.
[0034] In some preferred embodiments, the tailings outlet of the spiral separator 10 is connected to the spiral tail high-frequency screen 11, and the concentrate outlet of the spiral separator 10 is connected to the stacked fine screen 12. During the separation process, high-ash and high-density products, due to their high specific gravity and slow flow velocity, move towards the inner circle of the spiral separator 10, forming tailings products. The tailings products are dewatered by the spiral tail high-frequency screen 11 after passing through the tailings outlet of the spiral separator 10 and transferred to the tailings site. Meanwhile, the concentrate and fine-grained materials, due to their lighter mass, gradually move towards the outer circle, eventually becoming spiral concentrate products discharged from the outer circle. Therefore, after being classified by the countercurrent classifier 6 and the classifying hydrocyclone 9, the remaining fine particles are enriched into the spiral concentrate products through the spiral. The concentrate outlet of the spiral separator 10 is connected to the stacked fine screen 12, and the classification efficiency of the stacked fine screen 12 can reach up to 85% or more, which can efficiently classify the material at the concentrate outlet of the spiral separator 10.
[0035] It should be added that the main function of the stacked fine screen 12 is to discharge fine-grained materials from the concentrate. Due to the separation principle of the spiral separator 10, during the separation process, except for materials with lighter specific gravity that enter the concentrate, most materials below the separation lower limit will enter the concentrate product with the water flow. For fine-grained materials below the separation lower limit of the separator, there will be a enrichment effect. At the same time, after the separator removes most of the high specific gravity and high ash content materials, the proportion of fine-grained materials in the overflow product will increase. Therefore, it is necessary to strengthen desliming.
[0036] In some preferred embodiments, the oversize material outlet of the stacked fine screen 12 is connected to the centrifuge 13. The oversize concentrate enters the centrifuge 13 for dewatering. After dewatering, the concentrate is sun-dried or dried and can then be sold or used as a high-quality concentrate.
[0037] The overflow slurry of the grading hydrocyclone unit 9, the material under the screw high-frequency screen 11, and the material under the stacked fine screen 12 are all fine-grained high-ash products, which can be either gravity-flowed or enter the thickening tank 16 for thickening operations according to the actual site layout.
[0038] In some preferred embodiments, the overflow port of the grading hydrocyclone unit 9 and / or the under-screen discharge port of the screw tail high-frequency screen 11 and / or the under-screen discharge port of the stacked fine screen 12 are connected to the thickener 16 through the tailings bucket 14 and the tailings pump 15 for thickening operations.
[0039] In some preferred embodiments, the overflow port of the thickening tank 16 is connected to the circulating water tank 19, and the circulating water tank 19 is connected to the circulating water pump 20, so that the overflow of the thickening tank 16 enters the circulating water tank 19 as circulating water, and is then supplied to the whole plant by the circulating water pump 20.
[0040] In some preferred embodiments, the underflow outlet of the thickening tank 16 is connected to the filter press 18 via the filter press feed pump 17. The underflow is pumped into the filter press 18 via the filter press feed pump 17 for filtration. The product of the filter press 18 is transferred to the tailings site as tailings, and the filtrate of the filter press 18 is returned to the thickening tank for thickening.
[0041] To facilitate understanding of the process flow of the gasification fine slag separation system of this application, the following detailed explanation is provided in conjunction with specific process steps:
[0042] S1. Gasification fine slag often contains a small amount of coarse particles larger than 1mm, with an ash content of over 90%, which have no sorting value. Therefore, the gasification fine slag is transported to mixing tank 1, and water is added to adjust the slurry to a suitable concentration. Then, it is fed into coarse screen 3 through raw material feeding pump 2 for classification. The large particles larger than 1mm on the coarse screen 3 are high-ash products and are directly discharged as tailings. The undersize material of the coarse screen 3 enters the slurry mixing tank 4 for slurry mixing and is used as feed for the countercurrent classifier.
[0043] S2. Among the remaining gasification fine slag, materials <0.074mm account for more than 50%, and in some cases, the proportion exceeds 70%, with high ash content. It is recommended to screen them out. However, the classification effect of conventional vibrating screens and hydrocyclones is generally not good. Therefore, the gasification fine slag slurry in the mixing tank 4 is fed into the countercurrent classifier 6 by the countercurrent classifier feed pump 5 for classification. The classification efficiency of the countercurrent classifier 6 is higher than that of conventional vibrating screens and hydrocyclones. The overflow of the countercurrent classifier is the slurry of materials <0.074mm, which directly enters the thickening system. The underflow material of the countercurrent classifier 6 flows by gravity into the feed tank 7 as the feed for the classifying hydrocyclone.
[0044] S3. The underflow slurry in the spiral feed tank 7 is mixed with water and adjusted to 80-120g / l. It is then fed into the classifying hydrocyclone unit 9 by the spiral feed pump 8 for classification and concentration. The material with a particle size of less than 0.074mm in the slurry is further discharged. At the same time, the feed concentration entering the spiral separator 10 is controlled. The underflow flows by gravity to the distributor of the spiral separator 10.
[0045] S4. The spiral separator 10 performs material separation. The concentrate from the spiral separator 10 flows by gravity to the stacked fine screen 12 for further desliming. After desliming by the aforementioned classifying hydrocyclone unit 9 and countercurrent classifier 6, a small amount of material with a particle size smaller than 0.074mm will be enriched in the spiral concentrate after spiral separation. Therefore, the stacked fine screen 12 is needed to enhance the concentrate desliming operation. The tailings from the spiral separator 10 enter the spiral tail high-frequency screen 11 for dewatering and are discharged as tailings products.
[0046] S5. The stacked fine screen 12 performs efficient desliming of the spiral concentrate. The concentrate on the stacked fine screen 12 flows by gravity to the centrifuge 13 for dewatering and is used as the concentrate product. The slurry under the stacked fine screen 12 flows by gravity or is transferred to the thickening system.
[0047] The overflow from S6, the underflow from the grading hydrocyclone unit 9, the underflow from the stacked fine screen 12, and the underflow from the screw high-frequency screen 11 all enter the thickener 16 for thickening. The overflow from the thickener 16 is used as circulating water, and the underflow from the thickener 16 is pumped into the filter press 18 for filtration and then treated separately as tailings.
[0048] The specific embodiments of this application have been described in detail above. For those skilled in the art, several improvements and modifications can be made to this application without departing from the principle of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.
Claims
1. A gasification fine slag separation system, characterized in that: Includes a coarse screen (3), the outlet of the undersize material of the coarse screen (3) is connected to the inlet of the mixing tank (4), and the outlet of the mixing tank (4) is connected to the inlet of the countercurrent classifier (6). The underflow port of the countercurrent classifier (6) is connected to the feed inlet of the classifier hydrocyclone unit (9), and the underflow port of the classifier hydrocyclone unit (9) is connected to the screw tail high-frequency screen (11) and the stacked fine screen (12) respectively through the separator.
2. The gasification fine slag separation system according to claim 1, characterized in that: The feed inlet of the coarse screen (3) is connected to the mixing tank (1) through the raw material feeding pump (2), and the coarse screen (3) is equipped with spray water to enhance classification.
3. The gasification fine slag separation system according to claim 1, characterized in that: The mixing tank (4) is connected to the countercurrent classifier (6) via the countercurrent classifier feed pump (5). The mixing tank (4) re-mixes the material undersize from the coarse screen (3) and feeds the mixed slurry into the countercurrent classifier (6) via the countercurrent classifier feed pump (5).
4. The gasification fine slag separation system according to claim 1, characterized in that: The underflow port of the countercurrent classifier (6) is connected to the inlet of the classifying hydrocyclone unit (9) through a spiral feed barrel (7), and the spiral feed barrel (7) is connected to the inlet of the classifying hydrocyclone unit (9) through a spiral feed pump (8).
5. The gasification fine slag separation system according to claim 1, characterized in that: The overflow port of the grading hydrocyclone unit (9) is connected to the feed port of the thickener (16), and the underflow port of the grading hydrocyclone unit (9) is connected to the spiral separator (10).
6. The gasification fine slag separation system according to claim 5, characterized in that: The tailings outlet of the spiral separator (10) is connected to the spiral tail high-frequency screen (11), and the concentrate outlet of the spiral separator (10) is connected to the stacked fine screen (12).
7. The gasification fine slag separation system according to claim 6, characterized in that: The material outlet of the stacked fine screen (12) is connected to a centrifuge (13), which is used to dewater the material on the stacked fine screen (12).
8. The gasification fine slag separation system according to claim 1, characterized in that: The overflow slurry of the countercurrent classifier (6), the overflow slurry of the classifier hydrocyclone unit (9), the material under the screw high-frequency screen (11), and the material under the stacked fine screen (12) are respectively discharged by gravity or introduced into the thickener (16) for treatment.
9. The gasification fine slag separation system according to claim 1, characterized in that: The overflow port of the grading hydrocyclone unit (9) and / or the under-screen discharge port of the screw tail high-frequency screen (11) and / or the under-screen discharge port of the stacked fine screen (12) are connected to the thickener (16) through the tailings bucket (14) and the tailings pump (15).
10. The gasification fine slag separation system according to claim 5, 8, or 9, characterized in that: The overflow port of the thickening tank (16) is connected to the circulating water tank (19), and the underflow outlet of the thickening tank (16) is connected to the filter press (18) through the filter press feed pump (17).