Desulfurized fly ash recycling device and method

Abstract

The invention discloses a desulfurization ash recycling device and method, and relates to the technical field of solid waste resource utilization. Comprising a raw material bin used for storing desulfurized fly ash, a feeding pipeline, a first airflow classifier used for carrying out primary winnowing on the desulfurized fly ash, a second airflow classifier used for carrying out secondary winnowing on the desulfurized fly ash and a fifth steel bin which are sequentially communicated, the first airflow classifier is further communicated with the first steel bin, and the second airflow classifier is further communicated with a fourth steel bin. The feeding pipeline, the first airflow classifier and the second airflow classifier are all communicated with the hot air pipeline, the desulfurization ash is winnowed through the first airflow classifier and the second airflow classifier, the desulfurization ash of different meshes is fully utilized, dihydrate gypsum in the desulfurization ash is converted into semi-hydrated gypsum through blowing of hot air, and the utilization rate of the desulfurization ash is improved. When the winnowed desulfurized fly ash is used for producing putty powder, qualified strength can be achieved without adding a binding material, and the production cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of resource utilization of solid waste, and particularly relates to a device and method for recycling desulfurization ash. Background Art

[0002] In the production of float glass, the flue gas desulfurization process has been widely promoted and applied. The semi-dry desulfurization process has become the future development trend of flue gas desulfurization technology in glass factories due to its advantages such as less equipment investment, low operating cost, less floor area, simple maintenance, and less wastewater discharge. The characteristic of this kind of process is to use powdered calcium-based absorbent to remove SO2 in the flue gas. The product obtained after desulfurization is dry desulfurization ash, whose main components are calcium hemisulfite (CaSO3·1 / 2H2O), calcium sulfate (CaSO4·2H2O), calcium carbonate (CaCO3), and unreacted calcium hydroxide (Ca(OH)2), etc. Among them, calcium carbonate in the desulfurization ash is 20 - 30%, calcium sulfate is 30 - 40%, calcium sulfite is 20 - 30%, and calcium hydroxide is ≤10%. Compared with the wet process, the composition of the desulfurization ash produced by the semi-dry process is much more complex, and it has the characteristics of high sulfur, high calcium, and high alkalinity.

[0003] Due to the lack of systematic and in-depth research on the properties, reaction characteristics, and action mechanism of semi-dry desulfurization ash, people currently hold a cautious attitude towards its comprehensive utilization, and no effective utilization methods have been formed. As a result, a large amount of semi-dry desulfurization ash is piled up or simply landfilled, which not only occupies a large amount of precious land resources but also increases the burden on enterprises. In addition, long-term stacking is likely to cause the release of sulfur dioxide (SO2) and pose a potential threat to the environment. At the same time, due to the small particle size and light weight of the desulfurization ash, dust pollution is likely to occur in the storage yard.

[0004] Therefore, it is necessary to develop and design a device and method for recycling desulfurization ash to achieve the full utilization of desulfurization ash and avoid environmental pollution, which is an urgent technical problem for those skilled in the art at present. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides a device and method for recycling desulfurization ash. Through multi-stage classification and separation of desulfurization ash, the full utilization of desulfurization ash is realized to produce rubber and plastic fillers, building coatings, etc., and environmental pollution is avoided.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] A desulfurized ash recycling device, comprising a raw material bin for storing desulfurized ash, a feed pipeline, a first air classifier for performing primary air separation on the desulfurized ash, a second air classifier for performing secondary air separation on the desulfurized ash, and a fifth steel bin, which are connected in sequence. The first air classifier is also connected to a first steel bin, the second air classifier is also connected to a fourth steel bin, and the feed pipeline, the first air classifier, and the second air classifier are all connected to a hot air pipeline.

[0008] Preferably, a blower for conveying hot air is respectively provided on the connecting pipelines of the hot air pipeline with the feed pipeline, the first air classifier, and the second air classifier.

[0009] Preferably, the first steel bin is connected to a circulating ash system, or the first steel bin is connected to the circulating ash system through a crusher and a second steel bin in sequence.

[0010] Preferably, the fifth steel bin is respectively connected to a ton bagging machine for ton bagging the products stored in the fifth steel bin, a packaging machine for bagging the products stored in the fifth steel bin, and a third steel bin for canning the products stored in the fifth steel bin.

[0011] Preferably, sampling devices for sampling and analyzing the materials are provided on the discharge pipelines of the first air classifier and the second air classifier.

[0012] The present invention also discloses a desulfurized ash recycling method, which uses the above-mentioned desulfurized ash recycling device and includes the following steps:

[0013] The desulfurized ash enters the feed pipeline with hot air from the raw material bin to remove the water and crystal water in the desulfurized ash.

[0014] The desulfurized ash is subjected to air separation by the first air classifier. The coarse particles below 300 mesh enter the first steel bin, and the fine particles of 300 mesh and above enter the second air classifier for air separation.

[0015] The coarse particles below 1250 mesh after air separation by the second air classifier enter the fourth steel bin to be used as paper-making fillers, production of building coatings or putty powder, and the fine powder of 1250 mesh and above after air separation by the second air classifier enters the fifth steel bin to be used as rubber and plastic fillers.

[0016] Preferably, the feed pipeline, the first air classifier, and the second air classifier are all blown by hot air, and it is ensured that the temperature of the second air classifier is higher than that of the first air classifier, and the temperature of the first air classifier is higher than that of the feed pipeline.

[0017] Preferably, after the desulfurized ash passes through the feed pipeline, the first air classifier, and the second air classifier, the hot air converts the gypsum dihydrate in the desulfurized ash into hemihydrate gypsum.

[0018] Preferably, the temperature of the hot air is 250 degrees Celsius to 300 degrees Celsius.

[0019] Preferably, the mesh number of the materials output by the first air classifier and the second air classifier can be adjusted by adjusting the air volume and rotation speed of the fan.

[0020] The present invention has achieved the following technical effects compared with the prior art:

[0021] Through the air separation of the desulfurized ash by the first air classifier and the second air classifier, the full utilization of desulfurized ash with different mesh numbers is realized, avoiding the problem of environmental pollution caused by the random landfill and discharge of desulfurized ash. Moreover, through the blowing of hot air, the gypsum dihydrate in the desulfurized ash is converted into hemihydrate gypsum, so that the air-separated desulfurized ash has qualified strength without the need to add external gelling materials when used to produce putty powder, reducing the production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0023] Attached Figure 1 is a schematic diagram of the overall structure of the desulfurized ash recycling device disclosed by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0025] The purpose of the present invention is to provide a desulfurized ash recycling device and method, which realizes the full utilization of desulfurized ash through multi-stage classification and separation of desulfurized ash, so as to produce rubber and plastic fillers, building coatings, etc., and avoid environmental pollution.

[0026] In order to make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0027] ReferenceFigure 1 In the desulfurized ash recycling device disclosed in the embodiments of the present invention, it at least includes a raw material bin, in which desulfurized ash is stored. The raw material bin is sequentially connected to a feed pipe through a pneumatic lock, a screw feeder and an aggregate hopper. The feed pipe is connected to a hot air pipe, and the hot air pipe provides hot air for the feed pipe to heat the desulfurized ash in the feed pipe to remove the attached water and partial crystal water. The feed pipe is connected to a first air classifier, and the first air classifier is respectively connected to a first steel bin and a second air classifier. Through the air separation of the desulfurized ash by the first air classifier, the coarse particles with a mesh number less than 300 are transported to the first steel bin, and the fine particles with a mesh number greater than or equal to 300 enter the second air classifier. Moreover, both the first air classifier and the second air classifier are connected to the hot air pipe. By purging with the hot air in the hot air pipe, it can be avoided that the desulfurized ash transported into the first air classifier and the second air classifier adheres to the inner wall (because as the desulfurized ash is transported from the feed pipe to the first air classifier and then to the second air classifier, the temperature will gradually decrease and the humidity will gradually increase. If the inside of the first air classifier and the second air classifier is not purged with hot air, it will inevitably cause the desulfurized ash to adhere to the inside of the first air classifier and the second air classifier). Through continuous air separation by the second air classifier, the second air classifier is respectively connected to a fourth steel bin and a fifth steel bin. The fine powder with a mesh number greater than or equal to 1250 enters the fifth steel bin as a high-quality filler for the plastic industry and the rubber industry, and the coarse particles with a mesh number less than 1250 enter the fourth steel bin as a paper-making filler or for producing building coatings and putty powder;

[0028] In this embodiment, through the air separation of the desulfurized ash by the first air classifier and the second air classifier, the full utilization of desulfurized ash with different particle sizes is realized, avoiding the problem of environmental pollution caused by the random landfill and discharge of desulfurized ash. Moreover, through the purging with hot air, the dihydrate gypsum in the desulfurized ash is converted into hemihydrate gypsum, so that the desulfurized ash obtained by air separation has qualified strength without adding additional cementitious materials when used for producing putty powder, reducing the production cost.

[0029] It should be noted that the material is transported between the first air classifier and the first steel bin through a pneumatic lock and a transfer pump, and during the transportation by the transfer pump, compressed gas is introduced to provide power for the material transportation.

[0030] A sampling device is provided on the discharge pipe at the front end of the fourth steel bin, which can realize the sampling and analysis of the material entering the fourth steel bin.

[0031] Reference Figure 1, in one embodiment, a fan for conveying hot air is respectively provided on the connection pipelines of the hot air pipeline with the feeding pipeline, the first air classifier and the second air classifier, that is, a fan is provided on each connection pipeline. By adjusting the wind speed and flow rate of each fan, the adjustment of the mesh number of the materials output by the first air classifier and the second air classifier can be realized respectively.

[0032] Reference Figure 1 , as a preferred method, the first steel bin is communicated with the circulating ash system, or the first steel bin is sequentially communicated with the circulating ash system through a pulverizer and the second steel bin. Since the coarse particles stored in the first steel bin are those with a mesh number less than 300, and calcium hydroxide (desulfurizer) in the desulfurized ash will be enriched (content exceeding 20%) in the coarse particles below 300 mesh, the coarse particles in the first steel bin can be used as the recycled desulfurizer material and transported to the circulating ash system, which can save 10% of the desulfurizer. Or the coarse particles in the first steel bin can be pulverized by a pulverizer and then transported to the second steel bin and then to the circulating ash system for reuse.

[0033] It should be noted that the circulating ash system sprays dry calcium-based absorbents (such as limestone powder, hydrated lime) to react with SO2 in the flue gas to generate solid desulfurized ash such as calcium sulfate (CaSO4). That is, the circulating ash system is a device for generating desulfurized ash. The desulfurized ash generated by the circulating ash system is transported to the raw material bin. In this embodiment, the desulfurized ash below 300 mesh is reused, which can reduce the use of desulfurizer in the circulating ash system.

[0034] A sampling device is provided on the discharge pipeline at the front end of the first steel bin. Through the sampling of the sampling device, the particle size of the materials entering the first steel bin is analyzed. If the particle size is small, it can be directly introduced into the circulating ash system and used as a desulfurizer. If the particle size is large, it is pulverized by a pulverizer and then transported to the second steel bin and then to the circulating ash system to be used as a desulfurizer.

[0035] Reference Figure 1, in one embodiment, the No. 5 steel silo is respectively connected to the bulk bagging machine, the packaging machine and the No. 3 steel silo. A screw feeder is arranged between the No. 5 steel silo and the bulk bagging machine to convey materials through the screw feeder. The products stored in the No. 5 steel silo are bulk bagged by the bulk bagging machine, and dust is removed by a bag filter during the bulk bagging process. After the bulk bagging is completed, the bulk bagged products are stored in the warehouse through a belt conveyor; A screw feeder is also arranged between the No. 5 steel silo and the packaging machine to convey materials through the screw feeder. The products in the No. 5 steel silo are packaged into 20-kg small bags by the packaging machine, then conveyed through a conveying system, palletized by a robot and stored in the warehouse. During the packaging process of the packaging machine, dust is removed by a bag filter; A pneumatic lock is arranged between the No. 5 steel silo and the No. 3 steel silo to ensure continuous material flow. When the products in the No. 5 steel silo are transported to the No. 3 steel silo (which can be connected to a tank truck), dust is removed by a bag filter and a centrifugal ventilator, and when filling the No. 3 steel silo, dust is also removed by a fan and a dust collector to avoid dust generation in the workshop.

[0036] The present invention also discloses a method for recycling desulfurized ash, which uses the desulfurized ash recycling device as described above and includes the following steps:

[0037] The desulfurized ash enters the feed pipeline with hot air from the raw material silo to remove the water and crystal water in the desulfurized ash.

[0038] The desulfurized ash is separated by air through a No. 1 air classifier. The coarse particles below 300 meshes enter the No. 1 steel silo, and the fine particles of 300 meshes and above enter the No. 2 air classifier for air separation.

[0039] The coarse particles below 1250 meshes separated by the No. 2 air classifier enter the No. 4 steel silo as papermaking fillers, production of building coatings or putty powder, and the fine powder of 1250 meshes and above separated by the No. 2 air classifier enter the No. 5 steel silo as rubber and plastic fillers.

[0040] Reference Figure 1 , as a preferred method, the feed pipeline, the No. 1 air classifier and the No. 2 air classifier are all blown by hot air, and it is ensured that the temperature of the No. 2 air classifier is higher than that of the No. 1 air classifier, and the temperature of the No. 1 air classifier is higher than that of the feed pipeline. By presenting an increasing temperature trend during the transportation of the desulfurized ash material along the feed pipeline, the No. 1 air classifier and the No. 2 air classifier, the problem that the desulfurized ash adheres to the inner walls of the No. 1 air classifier and the No. 2 air classifier due to increased humidity during transportation can be effectively avoided, ensuring the normal transportation of the desulfurized ash.

[0041] Reference Figure 1, as an implementation method, after passing through the feed pipe, the first air classifier, and the second air classifier, the hot air converts the gypsum dihydrate in the desulfurized ash into hemihydrate gypsum, enabling the air-selected desulfurized ash to have qualified strength without the need for additional gelling materials when used in the production of putty powder, thus reducing the production cost.

[0042] Reference Figure 1 , as an implementation method, the hot air temperature is 250 degrees Celsius to 300 degrees Celsius. On the one hand, it is to ensure that the attached water and part of the crystal water in the desulfurized ash are removed in the feed pipe. On the other hand, the temperature range for the conversion of gypsum dihydrate to hemihydrate gypsum is 107 degrees Celsius to 170 degrees Celsius. Therefore, the hot air temperature is set at 250 degrees Celsius to 300 degrees Celsius to maximize the conversion of gypsum dihydrate to hemihydrate gypsum. At this temperature, part of the gypsum dihydrate will turn into type III anhydrous gypsum and be further homogenized in the insulation tank at 150 degrees Celsius, and finally more hemihydrate gypsum is generated.

[0043] Reference Figure 1 , as an implementation method, the mesh number of the materials conveyed by the first air classifier and the second air classifier can be adjusted by adjusting the air volume and rotation speed of the fan, and different specifications of products can be obtained simultaneously to meet the needs of different users.

[0044] It should be noted that for those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the invention. Any reference signs in the claims should not be regarded as limiting the claimed rights.

Claims

1. A desulfurized ash recycling device, characterized in that, It includes a raw material bin for storing desulfurized ash, a feed pipeline, a first air classifier for performing primary air separation on the desulfurized ash, a second air classifier for performing secondary air separation on the desulfurized ash, and a fifth steel bin, which are connected in sequence. The first air classifier is also connected to a first steel bin, and the second air classifier is also connected to a fourth steel bin. The feed pipeline, the first air classifier, and the second air classifier are all connected to a hot air pipeline.

2. The desulfurized ash recycling device according to claim 1, characterized in that, On the connecting pipelines between the hot air pipeline and the feed pipeline, the first air classifier, and the second air classifier, fans for conveying hot air are respectively arranged.

3. The desulfurized ash recycling device according to claim 1, characterized in that, The first steel bin is connected to the circulating ash system, or the first steel bin is connected to the circulating ash system through a crusher and a second steel bin in sequence.

4. The desulfurized ash recycling device according to claim 1, characterized in that The fifth steel bin is respectively connected to a ton bagging machine for ton bagging the products stored in the fifth steel bin, a packaging machine for bagging the products stored in the fifth steel bin, and a third steel bin for canning the products stored in the fifth steel bin.

5. The desulfurized ash recycling device according to claim 1, wherein Sampling devices for sampling and analyzing materials are arranged on the discharge pipelines of the first air classifier and the second air classifier.

6. A method for recycling desulfurized ash, characterized in that, Applying the desulfurized ash recycling device according to any one of claims 1 - 5, it includes the following steps: The desulfurized ash enters the feed pipeline with hot air from the raw material bin to remove the water and crystal water in the desulfurized ash. The desulfurized ash is subjected to air separation by the first air classifier. Coarse particles below 300 meshes enter the first steel bin, and fine particles of 300 meshes and above enter the second air classifier for air separation. Coarse particles below 1250 meshes after air separation by the second air classifier enter the fourth steel bin to be used as papermaking fillers, for producing architectural coatings or putty powders. Fine powders of 1250 meshes and above after air separation by the second air classifier enter the fifth steel bin to be used as rubber and plastic fillers.

7. The method for recycling desulfurized ash according to claim 6, characterized in that, The feed pipeline, the first air classifier, and the second air classifier are all swept by hot air, and it is ensured that the temperature of the second air classifier is higher than that of the first air classifier, and the temperature of the first air classifier is higher than that of the feed pipeline.

8. The method for recycling desulfurized ash according to claim 6, characterized in that, After the desulfurized ash passes through the feed pipeline, the first air classifier, and the second air classifier, the hot air converts the dihydrate gypsum in the desulfurized ash into hemihydrate gypsum.

9. The method for recycling desulfurized ash according to claim 6, characterized in that, The temperature of the hot air is 250 degrees Celsius to 300 degrees Celsius.

10. The method for recycling desulfurized ash according to claim 6, wherein The mesh number of the materials output by the first air classifier and the second air classifier can be adjusted by adjusting the air volume and rotation speed of the fan.

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