A method and complete set of equipment for classifying flotation of coal gasification slag based on gas-liquid-solid three-phase system

Abstract

The invention discloses a coal gasification slag classification flotation method and complete equipment based on a gas-liquid-solid three-phase system, which mainly comprises a flotation component, a classification component, a discharge component and a bubble generating component, wherein the flotation component comprises a slurry feeding pipe, a reagent feeding pipe and a flotation tank; the classification component is mainly a screening plate; the discharge component comprises a discharge plate, a clean coal discharge tank, a tailings discharge pipe and an electric valve; and the bubble generating component comprises a bubble generator and a gas inlet. In the actual operation process, the pretreated gasification slag slurry enters the flotation tank through the feed port, and the gasification slag of different particle sizes is formed in the four flotation tanks through the grading action of the primary, secondary and tertiary screening plates. The refined carbon particles in the gasification slag are combined with the microbubbles generated by the bubble generator under the action of the flotation agent to form mineralized bubbles, and are discharged from the primary, secondary, tertiary and quaternary clean coal discharge tanks respectively to form four kinds of concentrate products with different ash contents, while the tailings at the bottom are discharged through the primary and secondary tailings discharge pipes. The device has a simple structure, is easy to disassemble, convenient to maintain and easy to operate, and can be used for integrated continuous operation of graded flotation of gasification slag.

Description

Technical Field

[0001] The present invention relates to the technical field of comprehensive treatment and resource utilization of coal-based solid waste, and in particular to a method and complete set of equipment for graded flotation of coal gasification slag based on a gas-liquid-solid three-phase system. Background Art

[0002] Coal gasification is an industrial technology for clean utilization of coal. It is used to produce synthesis gas without harmful elements and support the sustainable development of coal chemical industry. However, in the process of coal gasification, the residual carbon formed by incomplete coal gasification is closely embedded in the slag and quenched in a water bath, generating a large amount of coal gasification slag. Every year, coal gasification produces hundreds of millions of tons of coal gasification slag, which is one of the coal-based wastes and easily causes pollution of surrounding soil and water quality. Therefore, it is of great significance to utilize coal gasification slag as a resource to minimize environmental pollution. Since the residual carbon component of coal gasification slag has the potential to be used as fuel and carbon material, recycling the residual carbon component of coal gasification slag is an important way to utilize coal gasification slag as a resource. At present, the commonly used ways to recover residual carbon mainly include flotation, gravity separation and special separation processes. Among them, flotation has good development potential due to the high grade of concentrate products. However, due to the porous structure of the residual carbon in the gasification slag, its specific surface area is increased, and the collector that improves the hydrophobicity of the carbon particle surface is mostly filled in the pores, thereby increasing the amount of flotation reagents used, resulting in the final flotation cost being too high and difficult to achieve scale. Considering that the residual carbon content of the gasification slag increases with the increase of particle size, it is currently a more feasible process to use a grading method to perform preliminary grading treatment on the gasification slag to reduce the subsequent flotation feed amount. However, traditional grading and flotation are two different processes. When used for the recovery of residual carbon in the gasification slag, the two processes and equipment need to be combined, which can easily cause the process flow to be cumbersome and the equipment layout to be more, which is not conducive to the compression of production costs and the simplification of operation methods. Based on this, the present invention has developed a gasification slag grading flotation method and complete set of equipment based on the gas-liquid-solid three-phase system on the basis of traditional grading and flotation processes and equipment, which can realize the integration of grading flotation operations of gasification slag, simplify the process flow, reduce production costs, and easily realize the scale of resource utilization of gasification slag. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a coal gasification slag classification flotation method and complete set of equipment based on a gas-liquid-solid three-phase system which has simple device, convenient operation, high sorting accuracy and can be used for resource utilization of coal gasification slag.

[0004] To achieve the above object, the present invention is implemented according to the following technical solutions:

[0005] 1. A method and complete set of equipment for graded flotation of coal gasification slag based on a gas-liquid-solid three-phase system, characterized in that the main structure is composed of a primary flotation cell, a secondary flotation cell, a tertiary flotation cell and a quaternary flotation cell, and is blocked by a primary screening plate, a secondary screening plate and a tertiary screening plate respectively; a slurry feed pipe and a flotation reagent feed pipe are installed on the side of the primary flotation cell to facilitate the entry of coal gasification slag slurry and reagents, a primary clean coal discharge trough is mainly installed on the upper right end, and a primary unloading plate is installed on the lower right end, wherein a primary bubble generator and a primary gas inlet are arranged inside, so as to facilitate the generation of bubbles in the primary flotation cell; the secondary flotation cell and the primary flotation cell are separated by a primary screening plate, and the external configuration The secondary clean coal discharge trough and the secondary unloading plate are provided with a secondary bubble generator inside, and the secondary bubble generator is connected to the secondary gas inlet; the tertiary flotation cell is associated with the secondary flotation cell through the secondary screening plate, the tertiary clean coal discharge trough is arranged at the upper right end, and the right lower end is connected to the third-level unloading plate, and the tertiary bubble generator is installed inside, and the third-level bubble generator is connected to the tertiary gas inlet; the fourth-level flotation cell is at the very end of the main structure, the fourth-level clean coal discharge trough is installed at the upper end of the side, and the first-level tailings discharge pipe and the second-level tailings discharge pipe are arranged at the lower end of the side, the first-level tailings discharge pipe is equipped with a first-level electric valve, and the second-level tailings discharge pipe is equipped with a second-level electric valve.

[0006] As a further optimization solution of the present invention, the main structure is a rectangular parallelepiped structure with a length of 12000 mm, a width of 4000 mm, a height of 3000 mm, and a side thickness of 200 mm.

[0007] As a further optimization scheme of the present invention, the cross-section of the primary flotation cell is trapezoidal, with an upper width of 3000mm and a lower width of 6000mm; the cross-section of the secondary flotation cell is a parallelogram, with a width of 3000mm and a length of 5000mm; the cross-section of the tertiary flotation cell is a parallelogram, with a width of 3000mm and a length of 5000mm; the cross-section of the quaternary flotation cell is a triangle, with a wide side of 3000mm, a long side of 4000mm and a hypotenuse of 5000mm.

[0008] As a further optimization scheme of the present invention, the aperture of the first-stage screen plate is 1 mm, and the opening rate is 10%; the aperture of the second-stage screen plate is 0.5 mm, and the opening rate is 10%; the aperture of the third-stage screen plate is 0.1 mm, and the opening rate is 15%.

[0009] As a further optimization scheme of the present invention, the first-stage bubble generator, the second-stage bubble generator and the third-stage bubble generator all have a spiral structure with a large lower diameter and a small upper diameter. The diameter of the lower ring is 4000mm, the diameter of the upper ring is 100mm, and the height is 3000mm. The spiral tube is a hollow tube with an outer diameter of 300mm and an inner diameter of 250mm. The difference is that the first-stage bubble generator is evenly arranged with 0.5mm air holes on the top, and the wind speed of the first-stage gas inlet connected to it is 2m / s; the second-stage bubble generator is evenly arranged with 0.2mm air holes on the top, and the wind speed of the first-stage gas inlet connected to it is 3m / s; the third-stage bubble generator is evenly arranged with 0.1mm air holes on the top, and the wind speed of the first-stage gas inlet connected to it is 4m / s.

[0010] As a further optimization scheme of the present invention, the slurry feed pipe and the flotation reagent feed pipe are both hollow tubes with an outer diameter of 200 mm and an inner diameter of 180 mm.

[0011] As a further optimization scheme of the present invention, the first-level tailings discharge pipe and the second-level tailings discharge pipe are both hollow pipes with an outer diameter of 200 mm and an inner diameter of 180 mm; the first-level tailings discharge pipe is equipped with a first-level electric valve with an adjustable switching frequency and a control range of 2-10 seconds / time; the second-level tailings discharge pipe is equipped with a second-level electric valve and a first-level electric valve with an adjustable switching frequency and a control range of 2-10 seconds / time.

[0012] As a further optimization scheme of the present invention, the first-stage unloading plate, the second-stage unloading plate and the third-stage unloading plate are all rectangular, 500 mm long, 500 mm wide, and 200 mm thick. The four corners are fixed to the bottom of the first-stage flotation tank, the second-stage flotation tank and the third-stage flotation tank by four bolts respectively.

[0013] As a further optimization scheme of the present invention, the first-level clean coal discharge trough, the second-level clean coal discharge trough and the third-level clean coal discharge trough are respectively parallel to the first-level screening plate, the second-level screening plate and the third-level screening plate, and are 500mm wide, 800mm long and 200mm high.

[0014] As a further optimization solution of the present invention, the four-stage clean coal discharge chute is located on the right side of the main structure, with a width of 4000 mm, a length of 800 mm, and a height of 200 mm.

[0015] In addition, the present invention also provides a gas-liquid-solid three-phase system coal gasification slag classification flotation method, using the above-mentioned coal gasification slag classification flotation complete set of equipment to carry out the residual carbon recovery operation of coal gasification slag, the specific steps are as follows:

[0016] Step 1: After pretreatment, coal gasification slag slurry with a certain concentration enters the main structure through the slurry inlet pipe, and is mixed with the flotation reagent (including frother and collector) entering through the flotation reagent inlet pipe to form a coal gasification slag mixture;

[0017] Step 2: The coal gasification slag mixture entering the main structure passes through the primary screening plate, the secondary screening plate and the tertiary screening plate in turn, forming a coal gasification slag mixture of >1mm in the primary flotation tank, a coal gasification slag mixture of 1-0.5mm in the secondary flotation tank, a coal gasification slag mixture of 0.5-0.1mm in the tertiary flotation tank, and a coal gasification slag mixture of <0.1mm in the quaternary flotation tank.

[0018] Step 3: External gas passes through the primary gas inlet and the primary bubble generator to generate flotation bubbles in the primary flotation tank. At this time, the refined carbon particles in the coal gas slag in the tank combine with the flotation bubbles to form mineralized bubbles and float to the liquid surface, flow along the first screening plate to the primary clean coal discharge tank, and then be discharged to form a primary concentrate; under the same operation, the secondary concentrate is floated out in the secondary flotation tank, the tertiary concentrate is floated out in the tertiary flotation tank, and the quaternary concentrate is floated out in the quaternary flotation tank. Finally, the tailings in the fourth-stage flotation tank are discharged through the primary tailings discharge pipe and the secondary tailings discharge pipe;

[0019] Step 4: According to the quality of the flotation concentrate (the main indicator is ash content), reasonably adjust the switching frequency of the first-level electric valve and the second-level electric valve to control the residence time of the gasification slag mixture in the flotation tank to promote the full flotation of the gasification slag.

[0020] Step 5: When a certain amount of flotation tailings are deposited in the primary flotation tank, the secondary flotation tank and the tertiary flotation tank, the primary discharge plate, the secondary discharge plate and the tertiary discharge plate are opened to discharge the flotation tailings, thereby completing the entire graded flotation operation.

[0021] Step 6: Collect the concentrate and tailings products from the entire graded flotation process. After subsequent dehydration operations, five products of different grades, namely, primary concentrate, secondary concentrate, tertiary concentrate, quaternary concentrate and tailings, can be obtained to meet the product needs of different users.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1) This device innovatively adopts the integrated process of classification and flotation, which can classify the coal gasification slag and flotate at the same time, which can simplify the process flow, facilitate practical operation, and effectively reduce the flotation cost;

[0024] 2) This device adopts a four-stage flotation method, combined with the grading effect of the screening plate, it can achieve product diversification (i.e. four fines and one tailing) and improve product competitiveness.

[0025] 3) According to the floatability characteristics of each particle size of gasification slag, this device adopts bubble generators with different exhaust apertures, which can realize a gas-liquid-solid three-phase system of large bubbles with coarse particles and small bubbles with fine particles for gasification slag of different particle sizes, greatly improving the flotation accuracy.

[0026] 4) This device uses a spiral bubbler device for the first time, which can easily form multiple foam layers in the flotation tank, effectively increase the contact frequency between bubbles and refined carbon particles in the gasification slag, reduce the amount of foaming agent used, and improve the problem of small bubble volume and large amount of reagent used in traditional flotation equipment.

[0027] 5) This device uses a controllable valve to adjust the flow rate of the coal gasification slag slurry in the flotation tank. According to the grade and quality of the flotation product, the slurry flow rate can be reasonably adjusted to control the flotation time, which can easily improve the yield and grade of the flotation product.

[0028] 6) The device has no movable mechanical parts, simple structure, and adopts gravity feeding and discharging method, which reduces the energy consumption of flotation equipment and improves the wide applicability of flotation equipment, which is conducive to industrial promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the device structure of the present invention.

[0030] Figure 2 yes Figure 1 Top view of the .

[0031] Figure 3 yes Figure 1 Front view of.

[0032] Figure 4 yes Figure 1 Rear view of.

[0033] In the figure: 1. main structure; 2. ore pulp feeding pipe; 3. flotation reagent feeding pipe; 4. primary flotation tank; 5. primary screening plate; 6. secondary flotation tank; 7. secondary screening plate; 8. tertiary flotation tank; 9. tertiary screening plate; 10. quaternary flotation tank; 11. primary bubble generator; 12. secondary bubble generator; 13. tertiary bubble generator; 14. primary discharge plate; 15. secondary discharge plate; 16. tertiary discharge plate; 17. primary tailings discharge pipe; 17-1. primary electric valve; 18. secondary tailings discharge pipe; 18-1. secondary electric valve; 19. quaternary clean coal discharge trough; 20. primary gas inlet; 21. secondary gas inlet; 22. tertiary gas inlet; 23. primary clean coal discharge trough; 24. secondary clean coal discharge trough; 25. tertiary clean coal discharge trough. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments. The specific embodiments described herein are only used to explain the present invention and are not used to limit the invention.

[0035] like Figure 1 , 2 As shown, the present embodiment is a complete set of equipment for grading flotation of coal gasification slag based on a gas-liquid-solid three-phase system, the main structure 1 is a rectangular parallelepiped structure, 12000mm long, 4000mm wide, 3000mm high, 200mm thick, mainly composed of flotation components, grading components, bubble generating components and discharge components, etc. The flotation components are composed of a primary flotation cell 4, a secondary flotation cell 6, a tertiary flotation cell 8 and a quaternary flotation cell 10. The cross section of the primary flotation cell 4 is trapezoidal, with an upper width of 3000mm and a lower width of 6000mm. A slurry feeding pipe 2 and a flotation reagent feeding pipe 3 (both are hollow pipes with an outer diameter of 200mm and an inner diameter of 180mm) are installed on the side to facilitate the entry of gasification slag slurry and reagents; the cross section of the secondary flotation cell 6 is a parallelogram, with a width of 3000mm and a length of 5000mm; the cross section of the tertiary flotation cell 8 is a parallelogram, with a width of 3000mm and a length of 5000mm; the cross section of the quaternary flotation cell 10 is a triangle, with a wide side of 3000mm, a long side of 4000mm and a hypotenuse of 5000mm. The grading components mainly include a primary screening plate 5 (aperture of 1 mm, porosity of 10%, located between the primary flotation cell 4 and the secondary flotation cell 6), a secondary screening plate 7 (aperture of 0.5 mm, porosity of 10%, located between the secondary flotation cell 6 and the tertiary flotation cell 8) and a tertiary screening plate 9 (aperture of 0.1 mm, porosity of 15%, located between the tertiary flotation cell 8 and the quaternary flotation cell 10). According to the four-stage flotation mode of the flotation cell in the flotation component, combined with the grading function of the screening plate of the grading component, the grading and flotation integration process can be realized, and the flotation can be carried out while the gasification slag is graded, which can simplify the process flow, facilitate practical operation, effectively reduce the flotation cost, realize product diversification (i.e., four refineries and one tail), and improve product competitiveness;

[0036] In some embodiments, Figure 3 , 4As shown, a complete set of gasification slag classification flotation equipment based on a gas-liquid-solid three-phase system adopts a spiral bubbler device for the first time as a bubble generating component, namely a primary bubble generator 11, a secondary bubble generator 12 and a tertiary bubble generator 13. The primary bubble generator 11 is in the primary flotation tank 4, the secondary bubble generator 12 is in the secondary flotation tank 6, and the tertiary bubble generator 13 is in the tertiary flotation tank 8. The three bubble generators all have a spiral structure with a large lower diameter and a small upper diameter. The diameter of the lower ring is 4000mm, the diameter of the upper ring is 100mm, and the height is 3000mm. The spiral tube is a hollow tube with an outer diameter of 300mm and an inner diameter of 250mm. The difference is that the primary bubble generator 11 is evenly arranged with 0.5mm pores on the top, and the wind speed of the primary gas inlet connected thereto is 2m / s; the secondary bubble generator 12 is evenly arranged with 0.2mm pores on the top, and the wind speed of the primary gas inlet connected thereto is 3m / s; the tertiary bubble generator 13 is evenly arranged with 0.1mm pores on the top, and the wind speed of the primary gas inlet connected thereto is 4m / s. The above three bubble generators with different exhaust apertures can realize a gas-liquid-solid three-phase system of large bubbles with coarse particles and small bubbles with fine particles for gasification slag of different particle sizes. At the same time, multiple foam layers can be easily formed in different flotation tanks, which can effectively increase the contact frequency between bubbles and refined carbon particles in the gasification slag, reduce the amount of frother used, and improve the problem of small bubble volume and large amount of reagent used in traditional flotation equipment.In addition, in order to realize the discharge of coal gasification slag flotation products, the discharge components are mainly composed of a primary discharge plate 14, a secondary discharge plate 15, a tertiary discharge plate 16, a primary clean coal discharge trough 23, a secondary clean coal discharge trough 24, a tertiary clean coal discharge trough 25, a fourth clean coal discharge trough 19, a primary tailings discharge pipe 17, a secondary tailings discharge pipe 18, a primary electric valve 17-1 and a secondary electric valve 18-1; the primary discharge plate 14, the secondary discharge plate 15 and the tertiary discharge plate 16 are all rectangular, 500mm long, 500mm wide, 200mm thick, and the four corners are fixed by four bolts on the bottom of the primary flotation tank 4, the secondary flotation tank 6 and the tertiary flotation tank 8; the primary clean coal discharge trough 23, the secondary clean coal discharge trough 24 and the tertiary clean coal discharge trough 25 are respectively connected to the primary screening plate 5, the secondary screening plate 6 and the tertiary screening plate 8. The dividing plate 7 and the three-stage screening plate 9 are parallel, with a width of 500mm, a length of 800mm and a height of 200mm; the first-level tailings discharge pipe 17 and the second-level tailings discharge pipe 18 are both hollow pipes with an outer diameter of 200mm and an inner diameter of 180mm; the first-level tailings discharge pipe 17 is equipped with a first-level electric valve 17-1, the switching frequency of which is adjustable, and the control range is 2-10 seconds / time; the second-level tailings discharge pipe 18 is equipped with a second-level electric valve 18-1, the switching frequency of which is adjustable, and the control range is also 2-10 seconds / time. The flow velocity of the gasification slag slurry in the flotation tank can be adjusted by the first-level electric valve 17-1 and the second-level electric valve 18-1, and then according to the grade of the flotation product (i.e., yield and ash content), the slurry flow rate is reasonably adjusted to control the flotation time, which is easy to improve the yield and grade of the flotation product.

[0037] In actual use, the gasification slag classification flotation complete set based on the gas-liquid-solid three-phase system of the present embodiment has no movable mechanical parts and a simple structure. Through the slurry feeding pipe (2), the first-level clean coal discharge trough 23, the second-level clean coal discharge trough 24, the third-level clean coal discharge trough 25, the fourth-level clean coal discharge trough 19, the first-level tailings discharge pipe 17, the second-level tailings discharge pipe 18 and other components, a gravity-flow feeding and discharging method can be realized, which reduces the energy consumption of the flotation equipment and improves the wide applicability of the flotation equipment, which is conducive to industrial promotion.

[0038] It should be noted that the first-stage electric valve 17-1 and the second-stage electric valve 18-1 in this embodiment can be directly purchased on the market for installation and use, and the specific installation structure is common knowledge in the field, so this embodiment will not be repeated. In addition, the first-stage electric valve 17-1 and the second-stage electric valve 18-1 in this embodiment can be controlled by a separate controller, and the control and adjustment method is a conventional operation in the field and this embodiment will not be repeated.

[0039] It should be further explained that the main components of the complete set of gasification slag classification flotation equipment based on the gas-liquid-solid three-phase system in this embodiment are connected as a whole by integral welding. In particular, the first-stage discharge plate 14, the second-stage discharge plate 15 and the third-stage discharge plate 16 are respectively fixed to the bottom of the first-stage flotation tank 4, the second-stage flotation tank 6 and the third-stage flotation tank 8 through side flanges combined with sealing rings, nuts and bolts. The installation method is a conventional operation in the field and will not be repeated in this embodiment.

[0040] The coal gasification slag classification flotation complete set device based on the gas-liquid-solid three-phase system of this embodiment can be used to carry out efficient carbon extraction operation of coal gasification slag, and the specific steps are as follows:

[0041] Step 1: After pretreatment, coal gasification slag slurry with a certain concentration enters the main structure 1 through the slurry inlet pipe 2, and is mixed with the flotation reagent (including frother and collector) entering through the flotation reagent inlet pipe 3 to form a coal gasification slag mixture;

[0042] Step 2: The coal gasification slag mixture entering the main structure 1 passes through the primary screening plate 5, the secondary screening plate 7 and the tertiary screening plate 9 in sequence, forming a coal gasification slag mixture of >1 mm in the primary flotation tank 4, a coal gasification slag mixture of 1-0.5 mm in the secondary flotation tank 6, a coal gasification slag mixture of 0.5-0.1 mm in the tertiary flotation tank 8, and a coal gasification slag mixture of <0.1 mm in the quaternary flotation tank 10.

[0043] Step 3: External gas passes through the primary gas inlet 20 and the primary bubble generator 11 to generate flotation bubbles in the primary flotation tank 4. At this time, the refined carbon particles in the coal gas slag in the tank combine with the flotation bubbles to form mineralized bubbles and float to the liquid surface, flow along the first screening plate 19 to the primary clean coal discharge tank 23, and then are discharged to form a primary concentrate; under the same operation, the secondary concentrate is floated out in the secondary flotation tank 6, the tertiary concentrate is floated out in the tertiary flotation tank 8, and the quaternary concentrate is floated out in the quaternary flotation tank 10. Finally, the tailings in the quaternary flotation tank 10 are discharged through the primary tailings discharge pipe 17 and the secondary tailings discharge pipe 18;

[0044] Step 4: According to the quality of the flotation concentrate (the main indicator is ash content), the switching frequency of the first-level electric valve 17-1 and the second-level electric valve 18-1 is reasonably adjusted to control the residence time of the gasification slag mixture in the flotation tank to promote the full flotation of the gasification slag.

[0045] Step 5: When a certain amount of flotation tailings are deposited in the primary flotation cell 4, the secondary flotation cell 6 and the tertiary flotation cell 8, the primary discharge plate 14, the secondary discharge plate 15 and the tertiary discharge plate 16 are opened to discharge the flotation tailings, thereby completing the entire graded flotation operation.

[0046] Step 6: Collect the concentrate and tailings products from the entire graded flotation process. After subsequent dehydration operations, five products of different grades, namely, primary concentrate, secondary concentrate, tertiary concentrate, quaternary concentrate and tailings, can be obtained to meet the product needs of different users.

[0047] The above embodiments of the present invention are applicable to coal gasification slag with different ash contents, and can obtain relatively satisfactory coal gasification flotation products. Two specific application embodiments are provided below:

[0048] Application Example 1

[0049] The integrated operation of graded flotation is carried out on the coal gasification slag with ash content of 50%. The switching frequency of the first-level electric valve 17-1 and the second-level electric valve 18-1 is adjusted to 6 seconds / time, and the following results can be obtained:

[0050] Table 1 Ash content and yield of flotation products

[0051] product Ash Yield use Primary concentrate 8％ 8％ Carbon Materials Secondary concentrate 13％ 12％ Clean coal for power generation Tertiary Concentrate 39％ 20％ Clean coal for power generation Grade 4 Concentrate 50％ 34％ Medium coal for power Tailings 87％ 26％ Building Materials total 50％ 100％

[0052] Application Example 2

[0053] The coal gasification slag with an ash content of 62% was subjected to integrated flotation classification operation. The switching frequency of the first-stage electric valve 17-1 and the second-stage electric valve 18-1 was adjusted to 8 seconds / time. The grade data of the flotation products are shown in Table 2:

[0054] Table 2 Ash content and yield of flotation products

[0055] product Ash Yield use Primary Concentrate 9％ 5％ Carbon Materials Secondary concentrate 23％ 15％ Clean coal for power generation Tertiary Concentrate 49％ 10％ Clean coal for power generation Grade 4 Concentrate 55％ 34％ Medium coal for power Tailings 97％ 36％ Building Materials total 62％ 100％

[0056] Application Example 3

[0057] The coal gasification slag with an ash content of 42% was subjected to integrated flotation classification operation. The switching frequency of the first-stage electric valve 17-1 and the second-stage electric valve 18-1 was adjusted to 3 seconds / time. The grade data of the flotation products are shown in Table 3:

[0058] Table 3 Ash content and yield of flotation products

[0059] product Ash Yield use Primary Concentrate 6％ 12％ Carbon Materials Secondary concentrate 13％ 23％ Clean coal for power generation Tertiary Concentrate 29％ 20％ Clean coal for power generation Grade 4 Concentrate 56％ 24％ Medium coal for power Tailings 90％ 21％ Building Materials total 42％ 100％

[0060] In summary, the present invention aims at the environmental pollution problem caused by the increasing amount of coal gasification slag year by year, combines the physical / chemical characteristics of coal gasification slag itself, and innovatively proposes a coal gasification slag classification flotation method and complete set of equipment based on a gas-liquid-solid three-phase system by modifying the spiral bubbler component, installing a gravity discharge component, and adding a classification component. The integrated operation of classification flotation of coal gasification slag is realized in the gas-liquid-solid three-phase system composed of gas phase (bubbles), liquid phase (water flow) and solid phase (coal gasification slag particles), which effectively improves the flotation operation accuracy and reduces the flotation operation cost. At the same time, the overall structure has no transmission components, and the operation is simple and reliable, which improves the wide applicability of the device and is conducive to the industrial application of the device, thereby providing a feasible solution for the comprehensive treatment and resource utilization of coal gasification slag.

[0061] The technical solution of the present invention is not limited to the above-mentioned specific embodiments. All technical variations made according to the technical solution of the present invention fall within the protection scope of the present invention.

Claims

1. A complete set of equipment for classifying and flotation of coal gasification slag based on a gas-liquid-solid three-phase system, characterized in that The main structure (1) is composed of a primary flotation tank (4), a secondary flotation tank (6), a tertiary flotation tank (8) and a quaternary flotation tank (10), which are blocked by a primary screening plate (5), a secondary screening plate (7) and a tertiary screening plate (9) respectively; the primary flotation tank (4) is provided with a slurry feed pipe (2) and a flotation reagent feed pipe (3) on the side thereof to facilitate the entry of coal gasification slag slurry and reagents; a primary clean coal discharge trough (23) is mainly provided on the upper right end thereof; a primary discharge plate (14) is provided on the lower right end thereof; a primary bubble generator (11) and a primary gas inlet (20) are arranged inside the secondary flotation tank (6) to facilitate the generation of bubbles in the primary flotation tank (4); the secondary flotation tank (6) is separated from the primary flotation tank (4) by a primary screening plate (5); a secondary clean coal discharge trough (24) and a secondary discharge plate (15) are arranged outside the secondary flotation tank (6); a secondary gas inlet (20) and a secondary gas inlet (21) are arranged inside the secondary flotation tank (6) The third-stage flotation tank (8) is connected to the second-stage flotation tank (6) through the second-stage screening plate (7), the third-stage clean coal discharge trough (25) is arranged at the upper right end, and the third-stage discharge plate (16) is connected at the lower right end, and the third-stage bubble generator (13) is installed inside, and the third-stage bubble generator (13) is connected to the third-stage gas inlet (22); the fourth-stage flotation tank (10) is located at the end of the main structure (1), the fourth-stage clean coal discharge trough (19) is installed at the upper side end, and the first-stage tailings discharge pipe (17) and the second-stage tailings discharge pipe (18) are arranged at the lower side end, the first-stage tailings discharge pipe (17) is equipped with a first-stage electric valve (17-1), and the second-stage tailings discharge pipe (18) is equipped with a second-stage electric valve (18-1).

2. A complete set of equipment for classifying and flotation of coal gasification slag based on a gas-liquid-solid three-phase system according to claim 1, characterized in that: The main structure (1) is a rectangular parallelepiped structure with a length of 12000 mm, a width of 4000 mm, a height of 3000 mm, and a side thickness of 200 mm.

3. The complete set of coal gasification slag classification flotation equipment based on gas-liquid-solid three-phase system according to claim 1, characterized in that: The cross section of the primary flotation cell (4) is trapezoidal, with an upper width of 3000 mm and a lower width of 6000 mm; the cross section of the secondary flotation cell (6) is a parallelogram, with a width of 3000 mm and a length of 5000 mm; the cross section of the tertiary flotation cell (8) is a parallelogram, with a width of 3000 mm and a length of 5000 mm; the cross section of the quaternary flotation cell (10) is a triangle, with a wide side of 3000 mm, a long side of 4000 mm and a hypotenuse of 5000 mm.

4. The complete set of coal gasification slag classification flotation equipment based on gas-liquid-solid three-phase system according to claim 1, characterized in that: The aperture of the first-stage screening plate (5) is 1 mm, and the opening rate is 10%; the aperture of the second-stage screening plate (7) is 0.5 mm, and the opening rate is 10%; the aperture of the third-stage screening plate (9) is 0.1 mm, and the opening rate is 15%.

5. The complete set of coal gasification slag classification flotation equipment based on gas-liquid-solid three-phase system according to claim 1, characterized in that: The first-stage bubble generator (11), the second-stage bubble generator (12) and the third-stage bubble generator (13) all present a spiral structure with a larger lower diameter and a smaller upper diameter, the lower ring diameter is 4000 mm, the upper ring diameter is 100 mm, the height is 3000 mm, and the spiral tube is a hollow tube with an outer diameter of 300 mm and an inner diameter of 250 mm; the difference is that the first-stage bubble generator (11) is evenly arranged with 0.5 mm air holes on the top, and the wind speed of the first-stage gas inlet connected thereto is 2 m / s; the second-stage bubble generator (12) is evenly arranged with 0.2 mm air holes on the top, and the wind speed of the first-stage gas inlet connected thereto is 3 m / s; the third-stage bubble generator (13) is evenly arranged with 0.1 mm air holes on the top, and the wind speed of the first-stage gas inlet connected thereto is 4 m / s.

6. The complete set of equipment for classifying and flotation of coal gasification slag based on a gas-liquid-solid three-phase system according to claim 1, characterized in that: The slurry feed pipe (2) and the flotation reagent feed pipe (3) are both hollow tubes with an outer diameter of 200 mm and an inner diameter of 180 mm.

7. The complete set of equipment for classifying and flotation of coal gasification slag based on a gas-liquid-solid three-phase system according to claim 1, characterized in that: The first-level tailings discharge pipe (17) and the second-level tailings discharge pipe (18) are both hollow pipes with an outer diameter of 200 mm and an inner diameter of 180 mm; the first-level tailings discharge pipe (17) is equipped with a first-level electric valve (17-1), the switching frequency of which is adjustable within a range of 2-10 seconds per time; the second-level tailings discharge pipe (18) is equipped with a second-level electric valve (18-1) and a first-level electric valve (17-1), the switching frequency of which is adjustable within a range of 2-10 seconds per time.

8. The complete set of equipment for classifying and flotation of coal gasification slag based on a gas-liquid-solid three-phase system according to claim 1, characterized in that: The first-stage unloading plate (14), the second-stage unloading plate (15) and the third-stage unloading plate (16) are all rectangular parallelepiped, 500 mm long, 500 mm wide and 200 mm thick, and the four corners are fixed to the bottom of the first-stage flotation tank (4), the second-stage flotation tank (6) and the third-stage flotation tank (8) by four bolts.

9. The complete set of equipment for classifying and flotation of coal gasification slag based on a gas-liquid-solid three-phase system according to claim 1, characterized in that: The first clean coal discharge trough (23), the second clean coal discharge trough (24) and the third clean coal discharge trough (25) are respectively parallel to the first screening plate (5), the second screening plate (7) and the third screening plate (9), and have a width of 500 mm, a length of 800 mm and a height of 200 mm.

10. The complete set of coal gasification slag classification flotation equipment based on gas-liquid-solid three-phase system according to claim 1, characterized in that: The fourth-level clean coal discharge chute (19) is located on the right side of the main structure (1), and has a width of 4000 mm, a length of 800 mm, and a height of 200 mm.

11. A gas-liquid-solid three-phase system coal gasification slag classification flotation method, characterized in that: The integrated operation of gasification slag classification flotation is carried out using a complete set of coal gasification slag classification flotation equipment based on a gas-liquid-solid three-phase system as described in any one of claims 1 to 10, and the specific steps are as follows: Step 1: After pretreatment, coal gasification slag slurry with a certain concentration enters the main structure (1) through the slurry inlet pipe (2) and is mixed with the flotation reagent entering through the flotation reagent inlet pipe (3) to form a coal gasification slag mixture; Step 2: The coal gasification slag mixture entering the main structure (1) passes through the primary screening plate (5), the secondary screening plate (7) and the tertiary screening plate (9) in sequence, forming a coal gasification slag mixture with a diameter of >1 mm in the primary flotation tank (4), a coal gasification slag mixture with a diameter of 1-0.5 mm in the secondary flotation tank (6), a coal gasification slag mixture with a diameter of 0.5-0.1 mm in the tertiary flotation tank (8), and a coal gasification slag mixture with a diameter of <0.1 mm in the quaternary flotation tank (10); Step 3: External gas is introduced into the primary flotation tank (4) through the primary gas inlet (20) and the primary bubble generator (11). At this time, the refined carbon particles in the coal gas slag in the tank are combined with the flotation bubbles to form mineralized bubbles and float to the liquid surface, flow along the primary screening plate (5) to the primary clean coal discharge tank (23), and then discharged to form a primary concentrate; under the same operation, a secondary concentrate is floated out in the secondary flotation tank (6), a tertiary concentrate is floated out in the tertiary flotation tank (8), and a quaternary concentrate is floated out in the fourth flotation tank (10); finally, the tailings in the fourth flotation tank (10) are discharged through the primary tailings discharge pipe (17) and the secondary tailings discharge pipe (18); Step 4: According to the quality of the flotation concentrate, the switching frequency of the first-stage electric valve (17-1) and the second-stage electric valve (18-1) is reasonably adjusted to control the residence time of the coal gasification slag mixture in the flotation tank, so as to promote the full flotation of the coal gasification slag; Step 5: When a certain amount of flotation tailings are deposited in the primary flotation tank (4), the secondary flotation tank (6) and the tertiary flotation tank (8), the primary discharge plate (14), the secondary discharge plate (15) and the tertiary discharge plate (16) are opened to discharge the flotation tailings, thereby completing the entire graded flotation operation; Step 6: Collect the concentrate and tailings products from the entire graded flotation process. After subsequent dehydration operations, five products of different grades, namely, primary concentrate, secondary concentrate, tertiary concentrate, quaternary concentrate and tailings, can be obtained to meet the product needs of different users.

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