Separation system and method for high-ash components of coal gasification slag

Abstract

The invention discloses a separation system and method for coal gasification slag high-ash components in the technical field of coal chemical industry solid waste resource utilization, and the separation system comprises a linear screen screening part which is used for receiving coal gasification slag and then screening the coal gasification slag, grinding oversize products to obtain high-ash components, and conveying undersize products to a size mixing part; the size mixing part is used for carrying out size mixing, mixing and stirring on the undersize product, and then conveying slag slurry to the spiral sorting part; the spiral separation part is used for carrying out spiral separation on the slag slurry to obtain concentrate, middling and tailings, the concentrate is subjected to slag-water separation to extract clean coal, the middling flows back to the slurry mixing part to be separated again, and the tailings are subjected to slag-water separation and precipitation to obtain high-ash components. The method has the characteristics of simplicity in operation, low cost and good separation effect, and has important significance on resource recycling of high-ash components and residual carbon in the coal gasification slag.

Description

Technical Field

[0001] The invention relates to a system and method for separating high-ash components of coal gasification slag, belonging to the technical field of resource utilization of coal chemical solid waste. Background Art

[0002] In modern industrial production, coal gasification is an important clean energy technology. This technology produces synthesis gas by reacting coal with oxygen or steam at high temperature, and has been widely used in chemical raw materials and energy production. However, the byproduct gasification slag produced in the coal gasification process contains residual carbon and high ash components. If it is not separated and treated, it will not only increase environmental risks, but also the high-value residual carbon in the gasification slag cannot be effectively recycled, which is a great waste of resources. The current storage method of coal chemical enterprises requires large space and is unsustainable, with high environmental safety risks and low resource utilization. Therefore, it is urgent to develop low-cost and high-efficiency methods for the resource utilization of gasification ash.

[0003] Traditional delamination grouting filling technology generally uses fine-grained fillers such as mud, fine sand, and fly ash to prepare slurry. In recent years, studies have shown that using high-ash components of coal gasification slag instead of fine sand, fly ash, etc. to prepare delamination grouting slurry is a potential way to utilize resources. This technology has the potential to consume a large amount of coal gasification ash. According to the provisions of the Inner Mongolia Autonomous Region Local Standard "Technical Specifications for the Use of General Industrial Solid Wastes for Mine Backfill and Ecological Restoration", the organic matter content in solid waste should be less than 2%, and the total amount of water-soluble salts should be less than 2%. If the coal gasification slag with a high ash component of more than 80%-85% can be separated, and the high ash component of the coal gasification slag and the clean coal component can be effectively sorted and enriched, the resource recovery of the high ash component of the coal gasification slag and the residual carbon can be achieved at the same time.

[0004] Traditional methods for treating coal gasification slag mainly include physical sorting and chemical treatment. Physical sorting methods, such as gravity sorting and magnetic separation, are simple to operate and low in cost, but the sorting accuracy and efficiency are usually not high, and it is difficult to meet the separation requirements of high-ash components. Chemical treatment methods, such as chemical leaching, can effectively improve the carbon recovery rate, but the operation is complicated, the cost is high, and secondary pollution may occur. Spiral separators are widely used in mineral processing and waste recycling due to their simple structure, relatively low cost, convenient operation and environmental protection. Spiral separators use the difference in specific gravity of materials in the rotating fluid force field for sorting, and have shown high separation efficiency and accuracy in many fields. However, direct application in the separation of high-ash components of coal gasification slag still faces some technical challenges, such as insufficient sorting accuracy, limited processing capacity, and low separation efficiency of high-ash components. The existing spiral sorting technology for treating coal gasification slag is mainly used to sort clean coal components, and there is a research gap in the separation and enrichment of high-ash components. It is urgent to propose a system and method that can efficiently separate the high-ash components of coal gasification slag, laying a technical foundation for the configuration of delamination grouting slurry for the high-ash components of coal gasification slag. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a separation system and method for high-ash components of coal gasification slag. The large-size coal gasification slag is screened out by a linear screen to obtain some high-ash components, which are then separated by a spiral separator, which significantly improves the efficiency of separating high-ash components in coal gasification slag and provides a new solution for the efficient and clean utilization of coal resources. The method can not only effectively separate the high-ash components of coal gasification slag, but also improve the recovery rate of residual carbon, reduce the energy consumption and cost of the operation process, and has a good prospect for promotion and application.

[0006] To achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0007] In a first aspect, the present invention provides a system for separating high-ash components of coal gasification slag, comprising:

[0008] Linear screen screening section: after receiving the coal gasification slag, it will be screened, wherein the product on the screen is ground to obtain the high ash component, and the product under the screen is transported to the slurry mixing section;

[0009] Slurry preparation section: after slurry preparation and mixing of the under-screen product, the slurry is transported to the spiral separation section;

[0010] Spiral separation section: The slag slurry is spirally separated to obtain three products: concentrate, middlings and tailings. The concentrate is separated from the slag water to extract clean coal, the middlings are returned to the slurry mixing section for re-sorting, and the tailings are separated from the slag water and precipitated to obtain high ash components.

[0011] Furthermore, the linear screen screening section includes a linear screen, an outlet of the linear screen for the product on the screen is connected to a ball mill, an outlet of the ball mill is connected to a high-ash component storage tank, and an outlet of the linear screen for the product under the screen is connected to a slurry mixing section.

[0012] Furthermore, the mesh size of the linear sieve is 1-2 mm.

[0013] Furthermore, the slurry mixing section includes a slurry mixing tank with a built-in stirrer, the inlet of the slurry mixing tank is connected to the under-screen product outlet of the linear screen, and the outlet of the slurry mixing tank is connected to the spiral sorting section through a pipeline with a valve and a slurry pump.

[0014] Furthermore, the slurry concentration in the slurry mixing pool is 10% to 20%.

[0015] Furthermore, the spiral sorting part includes a spiral sorter, the inlet of the spiral sorter is connected to the outlet of the slurry mixing tank, the spiral sorter is provided with a concentrate outlet, a middling outlet and a tailings outlet, the tailings outlet is connected to a first slag-water separator, the overflow of the first slag-water separator is connected to a sedimentation tank, the slag discharge port of the first slag-water separator is connected to a high-ash component collecting tank, the overflow of the sedimentation tank is connected to the slurry mixing tank via a pipeline with a reflux pump, the slag discharge port of the sedimentation tank is connected to the high-ash component collecting tank, the middling outlet is connected to the slurry mixing tank via a pipeline with a reflux pump, the concentrate outlet is connected to a second slag-water separator, the overflow of the second slag-water separator is connected to the slurry mixing tank via a pipeline with a reflux pump, and the slag discharge port of the second slag-water separator is connected to a clean coal storage tank.

[0016] Furthermore, the inner diameter of the spiral separator is 1.00m, 1.20m or 1.50m.

[0017] Furthermore, the separation apertures of the first slag-water separator and the second slag-water separator are 0.15 mm.

[0018] Furthermore, the sedimentation tank is a horizontal flow or vertical flow sedimentation tank.

[0019] In a second aspect, the present invention provides a method for separating high-ash components of coal gasification slag, comprising:

[0020] The linear screen screening part receives the coal gasification slag and screens it, wherein the product on the screen is ground to obtain a high-ash component, and the product under the screen is transported to the slurry mixing tank;

[0021] The slurry is mixed and stirred by the slurry mixing section, and then the slurry is transported to the spiral separation section;

[0022] The spiral separation section is used to spirally separate the slag slurry to obtain three products: concentrate, middlings and tailings. The concentrate is separated from the slag water to extract clean coal, the middlings are returned to the slurry mixing section for re-sorting, and the tailings are separated from the slag water and precipitated to obtain high ash components.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The present invention can effectively separate high-ash components of raw materials through a linear screen, thereby increasing the carbon content of the feed of the spiral separator, and then using the spiral separator for separation, which can effectively improve the efficiency of the spiral separator in separating high-ash components of coal gasification slag;

[0025] Second, the present invention is particularly suitable for separating coal gasification slag with an ash content of more than 80%-85%, and can effectively separate and enrich the high-ash component and clean coal component of the coal gasification slag. The combined device of a linear screen, a spiral separator with a specific inner diameter and a sedimentation tank is used. The obtained high-ash component can be used as a separation layer grouting filler, and the clean coal component can be used for coal blending;

[0026] 3. The present invention optimizes the inner diameter and operating parameters of the spiral separator, adjusts the separation and reflux order of concentrate, middlings and tailings, realizes the simultaneous separation of high-ash components in the gasification slag and the enrichment of clean coal components, and the design of the sedimentation tank realizes the complete collection of high-ash components in the wastewater;

[0027] Fourth, the present invention does not use biological or chemical separation methods. Water is used as the separation medium in the whole process. The wastewater discharged by the spiral separator can be completely reused after treatment. While achieving the separation of high-ash components, the environmental impact is reduced;

[0028] 5. The present invention avoids the use of chemical reagents, greatly reduces the processing cost, and at the same time the separated residual carbon has a certain combustibility and can be recycled as a resource, thereby increasing the economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0030] Figure 1 A schematic diagram of a processing flow of a system and method for separating high-ash components of coal gasification slag provided in Embodiment 1 of the present invention;

[0031] Figure 2 This is an overall system schematic diagram of a system and method for separating high-ash components of coal gasification slag provided in Example 1 of the present invention;

[0032] Figure 3The present invention provides a schematic diagram of an overall system block diagram of a system and method for separating high-ash components of coal gasification slag according to a first embodiment of the present invention.

[0033] Among them: 1. Linear screen; 2. Slurry mixing tank; 3. Mixer; 4. Slurry pump; 5. Spiral separator; 6. First slag-water separator; 7. High ash component collecting tank; 8. Sedimentation tank; 9. Second slag-water separator; 10. Clean coal storage tank; 11. Ball mill; 12. High ash component storage tank; 13. Reflux pump. DETAILED DESCRIPTION

[0034] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0035] The following detailed description is an exemplary description, which is intended to provide further detailed description of the present invention. Unless otherwise specified, all technical terms used in the present invention have the same meaning as those generally understood by those skilled in the art to which the present invention belongs. The terms used in the present invention are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present invention.

[0036] Embodiment 1:

[0037] A system and method for separating high-ash components of coal gasification slag, firstly, a linear screen is used to screen out large-size coal gasification slag to obtain part of the high-ash components, and then the small-size coal gasification slag is subjected to spiral sorting. The spiral sorter uses the difference in specific gravity of coal gasification slag in a rotating fluid force field for sorting. By optimizing the design and operating parameters of the spiral sorter, the separation and reflux sequence of concentrate, middlings and tailings is adjusted to achieve efficient sorting and enrichment of high-ash components and clean coal components in coal gasification slag, wherein the high-ash components meet the standard requirement that the organic matter content in solid waste should be less than 2%, and can be used as a delamination grouting filler, and the clean coal components can be used for coal blending.

[0038] Refer to the attached Figure 1 , the specific implementation of the present invention includes the following key steps:

[0039] (1) Linear sieve screening: The coal gasification slag is graded at 2.0 mm using a linear sieve, and the product on the sieve is ground by a ball mill to obtain a high ash component; (2) Spiral separation: The product under the sieve enters a slurry mixing tank, where it is slurried at a concentration of 10% to 20% and mixed and stirred. The slurry is pumped into a spiral separator by a slurry pump to obtain three products: concentrate, middlings and tailings. The middlings are returned to the front end of the spiral separator, the concentrate is separated from the slag and water, and graded at 0.15 mm. The solid phase larger than 0.15 mm is the clean coal product, and the portion smaller than 0.15 mm is returned to the front end of the spiral separator together with the supernatant; the middlings are returned to the front end of the spiral separator, the tailings are separated from the slag and water, and graded at 0.15 mm. The portion smaller than 0.15 mm is entered into a sedimentation tank together with the supernatant, and the overflow is returned to the slurry mixing tank. The precipitated sludge and the portion larger than 0.15 mm are the tailings product; (3) Separation and collection of high ash components: The separated tailings product and the coal gasification slag on the 2 mm sieve are collected as high ash components.

[0040] Refer to the attached Figure 2In this embodiment, a separation system for high-ash components of coal gasification slag is provided, including a linear screen 1, a slurry mixing tank 2, a mixer 3, a slurry pump 4, a spiral separator 5, a first slag-water separator 6, a high-ash component collecting tank 7, a sedimentation tank 8, a second slag-water separator 9, a clean coal storage tank 10, a ball mill 11, a high-ash component storage tank 12 and a reflux pump 13. The outlet of the above-screen product of the linear screen 1 is connected to the ball mill 11, the outlet of the ball mill 11 is connected to the high-ash component storage tank 12, the outlet of the below-screen product of the linear screen 1 is connected to the inlet of the slurry mixing tank 2, the outlet of the slurry mixing tank 2 is connected to the inlet of the spiral separator 5, the spiral separator 5 includes a concentrate outlet, a middling outlet and a tailings outlet, the concentrate outlet is connected to the second slag-water separator 9, the second slag-water separator 9 includes an overflow port and a slag discharge port, the overflow port is connected to the slurry mixing tank 2 through a reflux pump 13, the slag discharge port is connected to the clean coal storage tank 10, the middling outlet is connected to the slurry mixing tank 2 through a reflux pump 13, the tailings outlet is connected to the first slag-water separator 6, the first slag-water separator 6 includes an overflow port and a slag discharge port, the overflow port is connected to the sedimentation tank 8, the slag discharge port is connected to the high-ash component collecting tank 7, the sedimentation tank 8 includes an overflow port and a slag discharge port, the overflow port is connected to the slurry mixing tank 2 through a reflux pump 13, the slag discharge port is connected to the high-ash component collecting tank 7 The specific connection method can be: the mixer 3 runs in the slurry mixing tank 2, the outlet of the slurry mixing tank 2 is connected to the spiral separator 5 through a valve, a pipeline, and a slurry pump 4, and the connection and closing of the inlet of the spiral separator 5 are controlled by a valve. The concentrate outlet of the spiral separator 5 is connected to the second slag-water separator 9 through a valve and a pipeline, and the connection and closing of the inlet of the second slag-water separator 9 are controlled by a valve. The overflow port of the second slag-water separator 9 is connected to the slurry mixing tank 2 through a valve and a pipeline, and the connection and closing of the reflux inlet are controlled by a valve. The intermediate ore outlet of the spiral separator 5 is connected to the slurry mixing tank 2 through a valve and a pipeline, and the connection and closing of the intermediate ore reflux inlet are controlled by a valve. The intermediate ore is repeatedly sorted in the spiral separator 5, and the valve is switched manually or automatically according to the number of sorting times or sorting time of the intermediate ore in the spiral separator 5, so that all the tailings are finally separated, and the high ash components are processed separately.

[0041] During operation, the coal gasification slag is directly sent to the linear screen 1 for screening. The aperture of the linear screen 1 is 1-2 mm. In this embodiment, the gasification slag larger than 2 mm flows out through the screen product outlet and is input into the ball mill 11 for grinding and crushing. After crushing, the gasification slag smaller than 0.2 mm is input into the high ash component storage tank 12 for temporary storage to be processed later. The gasification slag smaller than 2 mm flows out through the screen product outlet and is input into the slurry mixing tank 2. The mixer 3 operates in the slurry mixing tank 2 to make the coal gasification slag The gasified slag is mixed with water evenly, and the mixed coal gasification slag slurry flows out from the outlet of the slurry mixing tank 2 and is input into the spiral separator 5 through the slurry pump 4. The operating parameters of the spiral separator 5 include the spiral speed, the feed rate and the water flow rate, which should be selected according to the physical and chemical properties of the coal gasification slag and the final sorting ash requirements. The spiral separator 5 sorts the coal gasification slag and separates the coal gasification slag into three kinds of minerals: concentrate, middlings and tailings. The concentrate is input into the second slag-water separator 9 through the concentrate outlet for slag-water separation, and the slag-water separation is 0. 15mm classification, thereby extracting clean coal, the clean coal is input into the clean coal storage tank 10 through the slag discharge port of the second slag-water separator 9 for temporary storage, and is to be recycled later. The part less than 0.15mm passes through the overflow port of the second slag-water separator 9 together with the supernatant, and is input into the slurry mixing tank 2 through the reflux pump 13. The middlings pass through the middling outlet and are input into the front end of the slurry mixing tank 2 through the reflux pump 13 for repeated sorting. The tailings are input into the first slag-water separator 6 through the tailings outlet for slag-water separation, and the tailings are divided into 0.15mm and 0.15mm. The high-ash component is extracted through the slag discharge port of the first slag-water separator 6 and input into the high-ash component collecting tank 7 for temporary storage for subsequent processing. The part smaller than 0.15 mm and the supernatant are input into the sedimentation tank 8 through the overflow port of the first slag-water separator 6. The sedimentation tank 8 can adopt a horizontal flow or vertical flow sedimentation tank. The sedimentation tank 8 obtains sedimentation sludge and supernatant through sedimentation. The sedimentation sludge is input into the high-ash component collecting tank 7 through the slag discharge port, and the supernatant is refluxed to the slurry mixing tank through the reflux pump 13.

[0042] Embodiment 2:

[0043] The coal gasification slag produced by a coal chemical plant was screened by a linear screen, and the gasification slag less than 2 mm was transported to spiral separators with inner diameters of 1 m, 1.2 m, and 1.5 m for sorting. The ash content of the high-ash component obtained by combining the linear screen oversize and tailings was determined in accordance with the "Industrial Analysis Methods for Coal" (GB / T 30732-2014). The results are shown in Table 1.

[0044]

[0045] Table 1 Ash content ratio of products separated by spiral separators with different inner diameters in Example 2

[0046] The experimental results show that after being treated by the separation system and method of the high ash component of the coal gasification slag, the ash content of the tailings is significantly increased. Among them, the coal gasification slag screened by the linear screen has an ash content of 98.35% for the product above the sieve of 2mm or more, and the coal gasification slag below the sieve is sorted by a spiral separator with an inner diameter of 1.2m. After sedimentation and separation, the ash content of the concentrate product is 30.97%, and the ash content of the medium ore is 44.38%. The ash content of the separated high ash component product can reach 99.29%. The experimental results prove that the method of the present invention is effective in separating the high ash component of the coal gasification slag. The high ash component product with an ash content of more than 98% can meet the ash content requirements of the disposal methods such as delamination grouting fillers, and the clean coal component can be used as coal blending.

[0047] It is known from common technical knowledge that the present invention can be implemented by other embodiments that do not deviate from its spirit or essential features. Therefore, the above disclosed embodiments are only illustrative in all respects and are not exclusive. All changes within the scope of the present invention or within the scope equivalent to the present invention are included in the present invention.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A system for separating high-ash components from coal gasification slag, characterized in that: include: Linear screen screening section: after receiving the coal gasification slag, it will be screened, wherein the product on the screen is ground to obtain the high ash component, and the product under the screen is transported to the slurry mixing section; Slurry preparation section: after slurry preparation and mixing of the under-screen product, the slurry is transported to the spiral separation section; Spiral separation section: The slag slurry is spirally separated to obtain three products: concentrate, middlings and tailings. The concentrate is separated from the slag water to extract clean coal, the middlings are returned to the slurry mixing section for re-sorting, and the tailings are separated from the slag water and precipitated to obtain high ash components.

2. The separation system of high-ash components of coal gasification slag according to claim 1 is characterized in that: The linear screen screening section comprises a linear screen (1), an outlet of the linear screen (1) for the product on the screen is connected to a ball mill (11), an outlet of the ball mill (11) is connected to a high-ash component storage tank (12), and an outlet of the linear screen (1) for the product under the screen is connected to a slurry preparation section.

3. The separation system of high ash components of coal gasification slag according to claim 2 is characterized in that: The mesh size of the linear sieve (1) is 1-2 mm.

4. The separation system of high ash components of coal gasification slag according to claim 2 is characterized in that: The slurry mixing section comprises a slurry mixing tank (2) with a built-in stirrer (3), the inlet of the slurry mixing tank (2) is connected to the under-screen product outlet of the linear screen (1), and the outlet of the slurry mixing tank (2) is connected to the spiral separation section via a pipeline with a valve and a slurry pump (4).

5. The separation system of high-ash components of coal gasification slag according to claim 4 is characterized in that: The slurry concentration of the slurry adjustment pool (2) is 10% to 20%.

6. The separation system of high-ash components of coal gasification slag according to claim 4 is characterized in that: The spiral separation section comprises a spiral separator (5), the inlet of the spiral separator (5) is connected to the outlet of the slurry mixing tank (2), the spiral separator (5) is provided with a concentrate outlet, a middling outlet and a tailings outlet, the tailings outlet is connected to a first slag-water separator (6), the overflow port of the first slag-water separator (6) is connected to a sedimentation tank (8), the slag discharge port of the first slag-water separator (6) is connected to a high-ash component collection tank (7), the overflow port of the sedimentation tank (8) is connected to a belt A pipeline with a reflux pump (13) is connected to a slurry mixing tank (2); a slag discharge port of the sedimentation tank (8) is connected to a high-ash component collection tank (7); the intermediate ore outlet is connected to the slurry mixing tank (2) via a pipeline with a reflux pump (13); the concentrate outlet is connected to a second slag-water separator (9); an overflow port of the second slag-water separator (9) is connected to the slurry mixing tank (2) via a pipeline with a reflux pump (13); and the slag discharge port of the second slag-water separator (9) is connected to a clean coal storage tank (10).

7. The separation system of high-ash components of coal gasification slag according to claim 6 is characterized by: The inner diameter of the spiral separator (5) is 1.00 m, 1.20 m or 1.50 m.

8. The system for separating high-ash components from coal gasification slag according to claim 6, characterized in that: The separation apertures of the first slag-water separator (6) and the second slag-water separator (9) are 0.15 mm.

9. The system for separating high-ash components of coal gasification slag according to claim 6, characterized in that: The sedimentation tank (8) is a horizontal flow or vertical flow sedimentation tank.

10. A method for separating high-ash components from coal gasification slag, characterized in that: include: The linear screen screening part receives the coal gasification slag and screens it, wherein the product on the screen is ground to obtain a high-ash component, and the product under the screen is transported to the slurry mixing tank; The slurry is mixed and stirred by the slurry mixing section, and then the slurry is transported to the spiral separation section; The spiral separation section is used to spirally separate the slag slurry to obtain three products: concentrate, middlings and tailings. The concentrate is separated from the slag water to extract clean coal, the middlings are returned to the slurry mixing section for re-sorting, and the tailings are separated from the slag water and precipitated to obtain high ash components.

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