Coal gasification fine slag grading flotation recovery system and method

Abstract

According to the grading flotation recovery system and method for the fine coal gasification slag, according to the particle size composition characteristics of the fine coal gasification slag, the fine coal gasification slag is divided into a coarse fraction part with a large specific surface area and multiple reaction active sites and a fine fraction part with a small specific surface area and small reaction active sites through a cyclone; then, fine flotation is conducted on the coarse fraction part and the fine fraction part by adopting the optimal reagent dosage, flotation can be conducted on the coarse fraction part by adopting a large reagent dosage, and flotation is conducted on the fine fraction part by adopting a small reagent dosage; the problem that when the coal gasification fine slag is directly floated, flotation needs to be conducted according to a large dosage of agents in a unified mode, and consequently the agent consumption is large is solved. Therefore, the problems that coal gasification fine slag flotation is difficult, the reagent dosage is large, and the concentrate yield is low are solved through graded flotation.

Description

Technical Field

[0001] The invention belongs to the technical field of solid waste resource utilization, and specifically relates to a system and method for recovering coal gasification fine slag by graded flotation. Background Art

[0002] Coal gasification slag is a kind of solid waste that is difficult to separate. The high residual carbon content seriously affects the treatment and application of coal gasification slag. In order to improve the reuse rate of coal gasification slag resources, make it meet national standards and industry standards, and realize the value-added utilization and cleanness of coal chemical industry, it is necessary to efficiently separate the different components of coal gasification slag. Flotation of coal gasification slag is an effective separation method. After effective sorting of coal gasification slag, the carbon-rich components can be used as secondary gasification raw materials, high calorific value fuels and even raw materials for the preparation of carbon materials; the glass phase aluminosilicate inorganic components are highly active and can be used to prepare building materials, mesoporous materials, aluminosilicate ceramics and even zeolites, water purifiers, etc. Flotation of coal gasification slag can achieve partial or even complete conversion of coal gasification slag, avoid the damage to the environment caused by landfill of coal gasification slag, and turn waste into treasure through resource conversion, bringing huge environmental benefits, economic benefits and safety benefits to society.

[0003] Many experts and scholars have conducted flotation tests on coal gasification slag. They found that the flotation of coal gasification slag requires a large amount of flotation reagents, and its concentrate yield and tailings ash content cannot meet the resource utilization standards. Summary of the invention

[0004] In order to solve the above problems of the prior art, the present invention provides a coal gasification fine slag classification flotation recovery system and method, which can reduce the dosage of reagents and reduce the ash content of concentrate.

[0005] The present invention is achieved through the following technical solutions: A coal gasification fine slag classification flotation recovery system, comprising: a cyclone, a first slurry agitator, a second slurry agitator, a flotation machine and a flotation column; The cyclone is used to sort the water-coal slurry formed by coal gasification fine slag and water; the overflow outlet of the cyclone is connected to the first inlet of the first slurry agitator, and the first slurry agitator also has a second inlet for adding reagents; the outlet of the first slurry agitator is connected to the inlet of the flotation machine; the underflow outlet of the cyclone is connected to the first inlet of the second slurry agitator, and the second slurry agitator also has a second inlet for adding reagents; the outlet of the second slurry agitator is connected to the inlet of the flotation column.

[0006] Preferably, it also includes: a flotation concentrate concentrator, a flotation ore concentrate concentrator and a flotation tailings concentrator; the flotation concentrate outlet of the flotation machine is connected to the inlet of the flotation concentrate concentrator, the flotation tailings outlet of the flotation machine is connected to the inlet of the flotation tailings concentrator, the flotation ore concentrate outlet of the flotation column is connected to the inlet of the flotation ore concentrate concentrator, and the flotation tailings outlet of the flotation column is connected to the inlet of the flotation tailings concentrator.

[0007] Furthermore, it also includes: a concentrate filter press, a middling filter press and a tailings filter press; the underflow outlet of the flotation concentrate concentrator is connected to the inlet of the concentrate filter press, the underflow outlet of the flotation middling concentrator is connected to the inlet of the middling filter press, and the underflow outlet of the flotation tailings concentrator is connected to the inlet of the tailings filter press.

[0008] Furthermore, it also includes: a concentrate bin, a middling bin, and a tailings bin; the concentrate outlet of the concentrate filter press is connected to the concentrate bin, the middling outlet of the middling filter press is connected to the middling bin, and the tailings outlet of the tailings filter press is connected to the tailings bin.

[0009] Furthermore, it also includes: a circulating water pool; the overflow outlets of the flotation concentrate concentrator, the flotation mide concentrator and the flotation tailings concentrator, and the filtrate outlets of the concentrate filter press, the mide filter press and the tailings filter press are all connected to the circulating water pool; the outlet of the circulating water pool is connected to the third inlet of the first slurry agitator and the second slurry agitator.

[0010] Furthermore, it also includes a stirring barrel, a first reagent mixing barrel, and a second reagent mixing barrel; the outlet of the stirring barrel is connected to the inlet of the cyclone through the first slurry pump, the outlet of the first reagent mixing barrel is connected to the second inlet of the first slurry agitator, and the outlet of the second reagent mixing barrel is connected to the second inlet of the second slurry agitator.

[0011] Preferably, the mesh size of the cyclone is 0.1 mm.

[0012] A method for recovering coal gasification fine slag by graded flotation, comprising: Mixing coal gasification fine slag with water to obtain coal-water slurry; The water-coal slurry is separated by a cyclone to obtain an overflow and an underflow; The overflow is stirred and mixed with the first reagent and water, and then flotation is performed to obtain flotation concentrate and flotation tailings; The bottom flow is stirred and mixed with the second reagent and water, and then flotation is performed to obtain flotation ore and flotation tailings.

[0013] Preferably, in the coal gasification fine slag classification flotation recovery method, the volume ratio of the first reagent to the overflow is (1-2):1.

[0014] Preferably, in the coal gasification fine slag classification flotation recovery method, the volume ratio of the second reagent to the underflow is (3-4):1.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The coal gasification fine slag classification flotation recovery system of the present invention, according to the particle size composition characteristics of the coal gasification fine slag, uses a cyclone to divide the coal gasification fine slag into a coarse particle part with a large specific surface area and many reactive sites and a fine particle part with a small specific surface area and small reactive sites, and then uses the most suitable reagent dosage to respectively carry out fine flotation on the coarse particle part and the fine particle part, and a larger dose of reagent can be used for flotation on the coarse particle part, and a smaller dose of reagent can be used for flotation on the fine particle part, thereby avoiding the problem of large reagent consumption caused by the need to uniformly use a larger dose of reagent for flotation when the coal gasification fine slag is directly floated. At the same time, a flotation machine is used for flotation on the coarse particle part, and the flotation machine is more suitable for coarse-grained ore pulp, while a flotation column is used for flotation on the fine particle part, and the flotation column can better float fine ore particles, and the bubbles generated are fine and dense, which is conducive to the flotation of fine ore particles. Therefore, the present invention solves the problems of difficult flotation of coal gasification fine slag, large dosage of reagents and low concentrate output through graded flotation, thereby finding a suitable utilization method for coal gasification fine slag solid waste and laying the foundation for further graded and refined coal gasification fine slag, which not only efficiently recovers carbon resources but also contributes to environmental protection.

[0016] The coal gasification fine slag classification flotation recovery method of the present invention first divides the coal gasification fine slag into a coarse particle part with a large specific surface area and many reactive sites and a fine particle part with a small specific surface area and small reactive sites, and then uses the most suitable reagent dosage to respectively carry out fine flotation on the coarse particle part and the fine particle part, and a larger dosage of reagent can be used for flotation on the coarse particle part, and a smaller dosage of reagent can be used for flotation on the fine particle part. Compared with the traditional full-particle-grade one-time flotation process, the method of the present invention has a small amount of reagent, low cost, high sorting efficiency, and a large recovery rate of available resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 The present invention is a flow chart of the coal gasification fine slag classification flotation recovery method.

[0019] Figure 2 It is a schematic diagram of the coal gasification fine slag classification flotation recovery system of the present invention.

[0020] Attached Figure 2 Description of the mark: 1. Mixing barrel; 2. Cyclone; 3. First reagent preparation barrel; 4. Second reagent preparation barrel; 5. First slurry agitator; 6. Second slurry agitator; 7. Flotation machine; 8. Flotation column; 9. Flotation concentrate concentrator; 10. Flotation middling concentrator; 11. Flotation tailings concentrator; 12. Concentrate filter press; 13. Middling filter press; 14. Tailings filter press; 15. Concentrate bin; 16. Middling bin; 17. Tailings bin; 18. First slurry pump; 19. Second slurry pump; 20. Third slurry pump; 21. Fourth slurry pump; 22. Fifth slurry pump; 23. Sixth slurry pump; 24. Seventh slurry pump; 25. Circulating water tank. DETAILED DESCRIPTION

[0021] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0022] It should be noted that the process equipment or devices not specifically specified in the following embodiments are all conventional equipment or devices in the art.

[0023] It should be noted that the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices. Moreover, unless otherwise specified, the numbering of each method step is only a convenient tool for identifying each method step, and is not intended to limit the order of arrangement of each method step or to define the scope of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the present invention without substantially changing the technical content.

[0024] In addition, it should be noted that the terms "first", "second", etc. of the present invention are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. The orientation or position relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention; in addition, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two elements.

[0025] Since coal gasification is an incomplete oxidation process, and after high-temperature activation by water vapor, the residual carbon particles in the coal gasification fine slag have the characteristics of larger specific surface area, more reactive sites than conventional coal, and a large difference in the zero potential of the mineral from conventional coal. Moreover, these residual carbon particles are mostly concentrated in the coarse-grained part of the coal gasification fine slag. Because the pores of these coarse-grained parts are relatively developed, a large amount of reagents are required during flotation. The fine-grained part of the coal gasification fine slag has the characteristics of small specific surface area and few reactive sites. This part requires a smaller dose of reagents to achieve good flotation. If the coal gasification fine slag is directly floated, because of the presence of the coarse-grained part, the reagent dosage needs to be prepared according to the coarse-grained part, resulting in a large overall reagent dosage. If the reagent dosage is insufficient, it will lead to insufficient flotation.

[0026] Therefore, in order to solve the problem of excessive consumption of direct flotation reagents, the present invention divides the coal gasification fine slag into a coarse particle size fraction with a large specific surface area and many reaction active sites and a fine particle size fraction with a small specific surface area and small reaction active sites according to the particle size composition characteristics of the coal gasification fine slag, and then flotation is performed separately to achieve separation and enrichment of organic carbon and inorganic matter, so as to achieve the purpose of reducing the amount of reagents used and reducing the ash content of the concentrate.

[0027] Based on the above ideas, see Figure 2 The coal gasification fine slag classification flotation recovery system of the present invention comprises: a cyclone 2, a first slurry agitator 5, a second slurry agitator 6, a flotation machine 7 and a flotation column 8; The cyclone 2 is used to sort the water-coal slurry formed by coal gasification fine slag and water; the overflow outlet of the cyclone 2 is connected to the first inlet of the first slurry agitator 5, and the first slurry agitator 5 also has a second inlet for adding reagents; the outlet of the first slurry agitator 5 is connected to the inlet of the flotation machine 7; the underflow outlet of the cyclone 2 is connected to the first inlet of the second slurry agitator 6, and the second slurry agitator 6 also has a second inlet for adding reagents; the outlet of the second slurry agitator 6 is connected to the inlet of the flotation column 8.

[0028] The coal gasification fine slag classification flotation recovery system of the present invention first uses a cyclone 2 to classify the coal gasification fine slag into two particle sizes, and then uses the most suitable reagents and reagent dosages to perform fine flotation on the two particle sizes, which can greatly improve the problems of difficult flotation of coal gasification fine slag, large reagent dosage and low concentrate yield.

[0029] As a preferred embodiment, the coal gasification fine slag classification flotation recovery system of the present invention also includes: a flotation concentrate concentrator 9, a flotation middling concentrator 10 and a flotation tailings concentrator 11; the flotation concentrate outlet of the flotation machine 7 is connected to the inlet of the flotation concentrate concentrator 9, the flotation tailings outlet of the flotation machine 7 is connected to the inlet of the flotation tailings concentrator 11, the flotation middling outlet of the flotation column 8 is connected to the inlet of the flotation middling concentrator 10, and the flotation tailings outlet of the flotation column 8 is connected to the inlet of the flotation tailings concentrator 11.

[0030] In a further solution, the coal gasification fine slag classification flotation recovery system also includes: a concentrate filter press 12, a middling filter press 13 and a tailings filter press 14; the underflow outlet of the flotation concentrate concentrator 9 is connected to the inlet of the concentrate filter press 12, the underflow outlet of the flotation middling concentrator 10 is connected to the inlet of the middling filter press 13, and the underflow outlet of the flotation tailings concentrator 11 is connected to the inlet of the tailings filter press 14.

[0031] In addition, in order to further improve production efficiency, the coal gasification fine slag classification flotation recovery system of the present invention can also include: a concentrate bin 15, a middling bin 16, and a tailings bin 17; the concentrate outlet of the concentrate filter press 12 is connected to the concentrate bin 15, the middling outlet of the middling filter press 13 is connected to the middling bin 16, and the tailings outlet of the tailings filter press 14 is connected to the tailings bin 17.

[0032] The present invention uses a flotation concentrate concentrator 9, a flotation ore concentrate concentrator 10 and a flotation tailings concentrator 11 to sediment and concentrate the flotation concentrate, flotation ore and flotation tailings obtained from the flotation machine 7 and the flotation column 8, respectively, to obtain high-concentration flotation concentrate, flotation ore and flotation tailings, and further uses a concentrate filter press 12, a middling filter press 13 and a tailings filter press 14 to filter to obtain final concentrate, middling and tailings products, which are respectively stored in a concentrate bin 15, a middling bin 16 and a tailings bin 17.

[0033] In order to improve the utilization rate of water, the coal gasification fine slag classification flotation recovery system of the present invention also includes: a circulating water pool 25; the overflow outlets of the flotation concentrate concentrator 9, the flotation middling concentrator 10 and the flotation tailings concentrator 11 and the filtrate outlets of the concentrate filter press 12, the middling filter press 13 and the tailings filter press 14 are all connected to the circulating water pool 25, so that water can be recycled, thereby improving the utilization rate of water and reducing costs.

[0034] The coal gasification fine slag classification flotation recovery system of the present invention also includes a stirring barrel 1, a first reagent mixing barrel 3, and a second reagent mixing barrel 4; the outlet of the stirring barrel 1 is connected to the inlet of the cyclone 2 through the first slurry pump 18, the outlet of the first reagent mixing barrel 3 is connected to the second inlet of the first slurry agitator 5, and the outlet of the second reagent mixing barrel 4 is connected to the second inlet of the second slurry agitator 6.

[0035] The concentrate filter press of the present invention is an integrated machine for filtration, filtration pressing and steam drying; the medium ore filter press is an ultra-high pressure filter press, model 1500.

[0036] The present invention recycles the obtained flotation tailings without landfilling and storage, thereby reducing pollution to the environment.

[0037] The sieve hole diameter of the cyclone 2 used in the present invention is 0.1 mm.

[0038] See also Figure 1 The coal gasification fine slag classification flotation recovery method of the present invention comprises the following steps: Mixing coal gasification fine slag with water to obtain coal-water slurry; The water-coal slurry is separated by a cyclone 2 to obtain an overflow and an underflow; The overflow is stirred and mixed with the first reagent, and then flotation is performed to obtain flotation concentrate and flotation tailings; The underflow is stirred and mixed with the second reagent, and then flotation is performed to obtain flotation ore and flotation tailings.

[0039] The coal gasification fine slag classification flotation recovery method of the present invention first uses a cyclone 2 to classify the coal gasification fine slag into a coarse particle size and a fine particle size, and then uses the most appropriate amount of reagent to perform fine flotation on the coarse particle size and the fine particle size of the coal gasification fine slag.

[0040] For coarse-grained coal gasification fine slag, a larger reagent dosage can be used for flotation. Specifically, the volume ratio of the first reagent to the underflow is preferably (3-4):1.

[0041] For fine-grained coal gasification slag, a smaller reagent dosage is used for flotation. Specifically, the volume ratio of the second reagent to the overflow is preferably (1-2):1.

[0042] Example The coal gasification fine slag classification flotation recovery system of the present embodiment includes: a mixing barrel 1, a cyclone 2, a first slurry agitator 5, a second slurry agitator 6, a flotation machine 7, a flotation column 8, a flotation concentrate concentrator 9, a flotation middling concentrator 10, a flotation tailings concentrator 11, a concentrate filter press 12, a middling filter press 13, a tailings filter press 14, a concentrate bin 15, a middling bin 16, a tailings bin 17, a circulating water pool 25, a first slurry pump 18, a second slurry pump 19, a third slurry pump 20, a fourth slurry pump 21, a fifth slurry pump 22, a sixth slurry pump 23, and a seventh slurry pump 24.

[0043] The mixing barrel 1 is used to mix coal gasification fine slag with water to form water-coal slurry; the water-coal slurry outlet of the mixing barrel 1 is connected to the inlet of the cyclone 2 through the first slurry pump 18, the overflow outlet of the cyclone 2 is connected to the first inlet of the first slurry agitator 5, the outlet of the first reagent preparation barrel 3 is connected to the second inlet of the first slurry agitator 5, and the outlet of the first slurry agitator 5 is connected to the inlet of the flotation machine 7 through the second slurry pump 19.

[0044] The flotation concentrate outlet of the flotation machine 7 is connected to the inlet of the flotation concentrate thickener 9, the underflow outlet of the flotation concentrate thickener 9 is connected to the inlet of the concentrate filter press 12, the concentrate outlet of the concentrate filter press 12 is connected to the concentrate bin 15, and the overflow outlet of the flotation concentrate thickener 9 and the filtrate outlet of the concentrate filter press 12 are connected to the circulating water tank 25. The flotation tailings outlet of the flotation machine 7 is connected to the inlet of the flotation tailings thickener 11.

[0045] The underflow outlet of the cyclone 2 is connected to the first inlet of the second slurry agitator 6, the outlet of the second reagent preparation barrel 4 is connected to the second inlet of the second slurry agitator 6, and the outlet of the second slurry agitator 6 is connected to the inlet of the flotation column 8 through the third slurry pump 20. The flotation ore outlet of the flotation column 8 is connected to the inlet of the flotation ore thickener 10, the underflow outlet of the flotation ore thickener 10 is connected to the inlet of the medium ore filter press 13 through the fourth slurry pump 21, the medium ore outlet of the medium ore filter press 13 is connected to the medium ore bin 16, and the overflow outlet of the flotation ore thickener 10 and the filtrate outlet of the medium ore filter press 13 are both connected to the circulating water tank 25. The flotation tailings outlet of the flotation column 8 is connected to the inlet of the flotation tailings thickener 11.

[0046] The underflow outlet of the flotation tailings thickener 11 is connected to the inlet of the tailings filter press 14 through the fifth slurry pump 22, the tailings outlet of the tailings filter press 14 is connected to the tailings bin 17, and the overflow outlet of the flotation tailings thickener 11 and the filtrate outlet of the tailings filter press 14 are both connected to the circulating water pool 25. The outlet of the circulating water pool 25 is connected to the third inlet of the first slurry agitator 5 and the second slurry agitator 6 through the seventh slurry pump 24.

[0047] The cyclone 2 used in this embodiment is a composite water-medium cyclone with a sieve hole diameter of 0.1 mm. The composite water-medium cyclone can classify materials according to density while classifying them according to particle size, and can achieve higher precision classification.

[0048] Based on the coal gasification fine slag classification flotation recovery system and the coal gasification fine slag classification flotation recovery method of this embodiment, the specific steps are as follows: The coal gasification fine slag is mixed with water x from the clean water tank by using a mixing barrel 1 to obtain water-coal slurry a.

[0049] The obtained water-coal slurry a is inputted into the Φ0.1 mm compound cyclone 2 by the first slurry pump 18 for classification treatment to obtain the underflow b with a particle size greater than 0.1 mm and the overflow c with a particle size less than 0.1 mm.

[0050] After classification by the Φ0.1mm compound cyclone 2, the underflow b enters the first pulp agitator 5 for flotation pretreatment; and after classification by the Φ0.1mm compound cyclone 2, the overflow c enters the second pulp agitator 6 for flotation pretreatment.

[0051] The underflow b enters the first slurry agitator 5, is mixed with the reagent from the first reagent preparation barrel 3 and the water y from the circulating water pool 25, and then is fed into the flotation machine 7 by the second slurry pump 19 for flotation. After flotation, flotation concentrate d and flotation tailings e are obtained, wherein the flotation concentrate d is fed into the flotation concentrate concentrator 9 for sedimentation, and the flotation tailings e is fed into the flotation tailings concentrator 11 for sedimentation; after the flotation concentrate d is settled by the flotation concentrate concentrator 9, the underflow i is discharged through the outlet at the bottom of the flotation concentrate concentrator 9, and is transported by the fourth slurry pump 21 to the concentrate filter press 12 for dehydration, and then the concentrate n and the filtrate o are discharged respectively; the concentrate obtained by the concentrate filter press 12 The ore n is discharged into the concentrate bin 15, the filtrate o of the concentrate filter press 12 is discharged into the circulating water pool 25, and the overflow h of the flotation concentrate thickener 9 is discharged from the outlet above the flotation tailings thickener 9 and fed into the circulating water pool 25; after the flotation tailings e is settled through the flotation tailings thickener 11, the underflow k discharged through the outlet at the bottom of the flotation tailings thickener 11 is transported by the sixth slurry pump 23 to the tailings filter press 14 for dehydration, and then the tailings p and the filtrate q are discharged respectively; the tailings p obtained by the tailings filter press 14 is discharged into the tailings bin 17, the filtrate q of the tailings filter press 14 is discharged into the circulating water pool 25, and the overflow j discharged from the outlet above the flotation tailings thickener 11 is fed into the circulating water pool 25.

[0052] Overflow c enters the second slurry agitator 6, is mixed with the reagent from the second reagent preparation tank 4 and the water z from the circulating water pool 25, and then is fed into the flotation column 8 by the third slurry pump 20 for flotation. After flotation, flotation ore f and flotation tailings g are obtained. Among them, flotation ore d is fed into the flotation ore concentrator 10 for sedimentation, and the flotation tailings g is mixed with the flotation tailings e for treatment together; after the flotation ore f is settled by the flotation ore concentrator 10, the flotation ore f is sent to the flotation ore concentrator 10 for sedimentation. The underflow m discharged from the outlet at the bottom of the concentrator 10 is transported to the middling filter press 13 through the fifth slurry pump 22 for dehydration, and then the middling r and the filtrate s are discharged respectively; the middling r obtained by the middling filter press 13 is discharged to the middling bin 16, and the filtrate s of the middling filter press 13 is discharged into the circulating water pool 25, and the overflow l discharged from the outlet above the flotation middling concentrator 10 is fed into the circulating water pool 25; the flotation tailings p are recycled and not landfilled, thereby reducing pollution to the environment.

[0053] The invention classifies the coal gasification fine slag into coarse and fine grades, and respectively uses the most suitable dosage of reagents to perform fine flotation on the coarse and fine grades of the coal gasification fine slag. The coal gasification fine slag classification flotation recovery method of the invention can greatly improve the problems of difficult flotation of coal gasification fine slag, large dosage of reagents and low concentrate yield.

[0054] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural transformation made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A coal gasification fine slag classification flotation recovery system, characterized in that: include: A cyclone (2), a first slurry agitator (5), a second slurry agitator (6), a flotation machine (7) and a flotation column (8); The cyclone (2) is used to separate the water-coal slurry formed by coal gasification fine slag and water; the overflow outlet of the cyclone (2) is connected to the first inlet of the first slurry agitator (5), and the first slurry agitator (5) also has a second inlet for adding reagents; the outlet of the first slurry agitator (5) is connected to the inlet of the flotation machine (7); the underflow outlet of the cyclone (2) is connected to the first inlet of the second slurry agitator (6), and the second slurry agitator (6) also has a second inlet for adding reagents; the outlet of the second slurry agitator (6) is connected to the inlet of the flotation column (8).

2. The coal gasification fine slag classification flotation recovery system according to claim 1, characterized in that: Also includes: A flotation concentrate thickener (9), a flotation ore concentrate thickener (10) and a flotation tailings thickener (11); the flotation concentrate outlet of the flotation machine (7) is connected to the inlet of the flotation concentrate thickener (9), the flotation tailings outlet of the flotation machine (7) is connected to the inlet of the flotation tailings thickener (11), the flotation ore concentrate outlet of the flotation column (8) is connected to the inlet of the flotation ore concentrate thickener (10), and the flotation tailings outlet of the flotation column (8) is connected to the inlet of the flotation tailings thickener (11).

3. The coal gasification fine slag classification flotation recovery system according to claim 2, characterized in that: Also includes: A concentrate filter press (12), a middling filter press (13) and a tailings filter press (14); the underflow outlet of the flotation concentrate concentrator (9) is connected to the inlet of the concentrate filter press (12), the underflow outlet of the flotation middling concentrator (10) is connected to the inlet of the middling filter press (13), and the underflow outlet of the flotation tailings concentrator (11) is connected to the inlet of the tailings filter press (14).

4. The coal gasification fine slag classification flotation recovery system according to claim 3, characterized in that: Also includes: A concentrate bin (15), a middling bin (16), and a tailings bin (17); the concentrate outlet of the concentrate filter press (12) is connected to the concentrate bin (15), the middling outlet of the middling filter press (13) is connected to the middling bin (16), and the tailings outlet of the tailings filter press (14) is connected to the tailings bin (17).

5. The coal gasification fine slag classification flotation recovery system according to claim 3, characterized in that: Also includes: A circulating water pool (25); overflow outlets of the flotation concentrate thickener (9), the flotation middling thickener (10) and the flotation tailings thickener (11) and filtrate outlets of the concentrate filter press (12), the middling filter press (13) and the tailings filter press (14) are all connected to the circulating water pool (25); the outlet of the circulating water pool (25) is connected to the third inlet of the first slurry agitator (5) and the second slurry agitator (6).

6. The coal gasification fine slag classification flotation recovery system according to claim 4, characterized in that: It also comprises a stirring barrel (1), a first reagent preparation barrel (3), and a second reagent preparation barrel (4); the outlet of the stirring barrel (1) is connected to the inlet of the cyclone (2) via a first slurry pump (18), the outlet of the first reagent preparation barrel (3) is connected to the second inlet of the first slurry agitator (5), and the outlet of the second reagent preparation barrel (4) is connected to the second inlet of the second slurry agitator (6).

7. The coal gasification fine slag classification flotation recovery system according to claim 1, characterized in that: The sieve hole diameter of the cyclone is 0.1 mm.

8. A method for recovering coal gasification fine slag by graded flotation, characterized in that: include: Mixing coal gasification fine slag with water to obtain coal-water slurry; The water-coal slurry is separated by a cyclone to obtain an overflow and an underflow; The overflow is stirred and mixed with the first reagent and water, and then flotation is performed to obtain flotation concentrate and flotation tailings; The bottom flow is stirred and mixed with the second reagent and water, and then flotation is performed to obtain flotation ore and flotation tailings.

9. The method for recovering coal gasification fine slag by graded flotation according to claim 8, characterized in that: The volume ratio of the first agent to the overflow is (1-2):

1.

10. The method for recovering coal gasification fine slag by graded flotation according to claim 8, characterized in that: The volume ratio of the second reagent to the bottom flow is (3-4):1.

Images