Comprehensive treatment device for acrylonitrile furnace ash

Abstract

The utility model discloses an acrylonitrile furnace ash comprehensive treatment device which comprises furnace ash purification equipment, according to the flowing direction of furnace ash and slurry, the furnace ash purification equipment comprises a dissolving box, a primary treatment box, a secondary treatment box, a settling box and an adjusting box which are communicated in sequence, the dissolving box is communicated with an alkali liquor inlet pipe, and the settling box is communicated with an alkali liquor outlet pipe. The primary treatment box is communicated with a heavy metal capturing agent feeding pipe, the secondary treatment box is communicated with a flocculating agent feeding pipe, the settling box is provided with a settling structure for accelerating the settling speed of particles, and the adjusting box is communicated with an acidic / alkaline liquid inlet pipe. According to the acrylonitrile furnace ash recycling system, furnace ash can be changed into an available alkali source, resource utilization of the furnace ash and reduction treatment of solid waste are achieved, a small amount of solid waste obtained after acrylonitrile furnace ash is treated can be treated through the heavy metal recycling device, and the problem that acrylonitrile furnace ash cannot be buried is solved. In addition, the device adopts an integrated design, so that modularization and skid-mounting of the device are realized, and the occupied area of the device is effectively reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to acrylonitrile recycling technical field, specifically relates to acrylonitrile furnace ash comprehensive treatment device. BACKGROUND

[0002] Acrylonitrile is an important organic synthetic material, and is the main raw material for producing acrylon fiber, ABS resin, carbon fiber, acrylamide and other high molecular materials. A large amount of toxic waste liquid containing acrylonitrile, hydrocyanic acid, cyanide polymer, sodium salt and catalyst particles are produced in the acrylonitrile production process. At present, most of the industry adopts the method of thermal incineration for treatment. However, after incineration, the sodium salt and heavy metal components in the catalyst particles in the waste liquid will be discharged from the dust removal unit in the form of furnace ash. The main components of these furnace ash are sodium carbonate, sodium bicarbonate, and a small amount of Mo, Fe, Ni, Bi, Cr, Cu, Mg, Hg, Zn, Pb and other heavy metals.

[0003] In the past ten years, with the rapid development of domestic economy, the market demand for acrylonitrile has been increasing, and the production capacity of acrylonitrile has been rapidly increasing. The device scale is continuously expanded, and a large amount of furnace ash is stored in the warehouse for a long time, which not only wastes land resources but also has great safety risk. Therefore, how to treat acrylonitrile furnace ash has become a problem to be solved.

[0004] The utility model patent with publication number CN220028192U discloses a resource utilization system for furnace ash of sodium salt-containing organic wastewater incinerator. By means of flocculation and heavy metal capture and precipitation, the heavy metals in the furnace ash are removed, and the Na2CO3 alkali solution with neutralized acidic water or biochemical system alkalinity adjustment is configured to realize the resource utilization of the furnace ash. Although this method can remove the heavy metals in the acrylonitrile device furnace ash, it needs to remove large particles through a sedimentation tank first, and then further remove dust through a precision filter after flocculation and sedimentation, which leads to the fact that the precision filter is easy to be blocked in the actual application process. In addition, the whole process is long, and the equipment occupies a large area. UTILITY MODEL CONTENTS

[0005] In view of the above technical problems, the purpose of the utility model is to provide an acrylonitrile furnace ash comprehensive treatment device for separating the heavy metals and alkaline carbonates in the furnace ash. The heavy metal mixture after separation is used as raw material to enter the heavy metal recovery process, and the alkaline solution after removing the heavy metals and organic matter is used as a pH value regulator for sewage treatment instead of part of the reagents in the sewage treatment plant.

[0006] The utility model discloses an acrylonitrile furnace ash comprehensive treatment device, including furnace ash purification equipment, according to furnace ash and slurry flow direction, the furnace ash purification equipment includes the communication of dissolving box, first -stage processing box, two -stage processing box, sedimentation tank and adjusting box in proper order, the dissolving box is connected with lye inlet pipe, the first -stage processing box is connected with heavy metal trapping agent feed pipe, two -stage processing box is connected with flocculating agent feed pipe, the sedimentation tank has the settlement structure for accelerating the particle settlement speed, the adjusting box is connected with acid / alkaline inlet pipe.

[0007] In some embodiments, the device further comprises a conveying unit, the conveying unit comprising an ash bin and a bin pump, the discharge port of the ash bin being in communication with the feed port of the dissolving box through a pipeline, and the bin pump being connected to the pipeline between the ash bin and the dissolving box.

[0008] In some embodiments, the device further comprises a sludge drying device, the sludge drying device comprising a deslagging pump, a sludge storage tank, a sludge conveying pump and a sludge drying equipment in communication in proper order, the feed port of the deslagging pump being in communication with the sludge outlet at the bottom of the sedimentation tank, the first-stage processing box and the two-stage processing box through a pipeline, and the filtrate outlet of the sludge drying equipment being in communication with the dissolving box through a pipeline.

[0009] In some embodiments, a dust remover is further provided on the dissolving box, and the dust remover is connected to an exhaust gas treatment device through a pipeline.

[0010] In some embodiments, the first-stage processing box and the two-stage processing box are in communication through a gate plate at the bottom of the first-stage processing box.

[0011] In some embodiments, the two-stage processing box and the sedimentation tank are in communication through an overflow plate at the top of the two-stage processing box.

[0012] In some embodiments, the sedimentation tank and the adjusting box are in communication through an overflow plate at the top of the sedimentation tank.

[0013] In some embodiments, the settlement structure is an inclined plate settlement structure formed by a group of parallel inclined plates or inclined pipes.

[0014] In some embodiments, the furnace ash purification equipment and the sludge drying device are arranged staggeredly, and the furnace ash purification equipment is located above the sludge drying device.

[0015] In some embodiments, the furnace ash purification equipment and the sludge drying device are separated by a pry frame.

[0016] Compared with the prior art, the utility model has the following beneficial effects:

[0017] The acrylonitrile furnace ash comprehensive treatment device provided by the utility model, aiming at the composition characteristics of acrylonitrile device furnace ash, adopts the heavy metal capturing and flocculation precipitation mode, changes the furnace ash into available alkali source, realizes the resource utilization of the furnace ash, reduces the acrylonitrile furnace ash discharge by more than 80%, realizes the reduction treatment of solid waste, and the small amount of solid waste obtained after the treatment of the originally inapplicable landfill furnace ash can be treated in the heavy metal recovery device, solving the problem that the acrylonitrile furnace ash cannot be landfilled. In addition, the device is integrally designed, realizes the modularization and pry packaging of the device, and effectively reduces the equipment land occupation area. BRIEF DESCRIPTION OF DRAWINGS

[0018] The above characteristics, technical features, advantages and implementation modes of the utility model will be further described in the following in a clear and understandable manner in combination with the preferred embodiments and the drawings.

[0019] Figure 1 is a structure schematic view of the acrylonitrile furnace ash comprehensive treatment device of an embodiment of the utility model.

[0020] 1. conveying unit; 11. ash bin; 12. bin pump;

[0021] 2. integrated treatment unit; 21. dissolving box; 211. dust remover; 212. tail gas fan; 213. slurry conveying pump; 22. first-stage treatment box; 23. second-stage treatment box; 24. sedimentation box; 241. inclined plate structure; 25. adjusting box; 251. purified liquid conveying pump.

[0022] 31. sludge storage tank; 32. deslagging pump; 33. sludge conveying pump; 34. sludge drying equipment. DETAILED DESCRIPTION

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the utility model or the prior art, the specific implementation modes of the utility model will be described in combination with the drawings. Obviously, the drawings in the following description are only some embodiments of the utility model, and other drawings and other implementation modes can be obtained by those skilled in the art without creative labor on the basis of the drawings.

[0024] Figure 1 is a structure schematic view of the acrylonitrile furnace ash comprehensive treatment device in the embodiment of the utility model. As shown in Figure 1 The acrylonitrile furnace ash comprehensive treatment device comprises a conveying unit 1 and an integrated treatment unit 2, the conveying unit 1 is used for conveying the furnace ash generated by the incinerator treatment to the integrated treatment unit 2, and the integrated treatment unit 2 is used for changing the furnace ash into available alkali source, so as to realize the resource utilization of the furnace ash.

[0025] The conveying unit 1 comprises an ash bin 11, which contains the acrylonitrile furnace ash generated by incineration. The ash bin 11 can be directly used as the ash bin of the original dust collector of the incinerator, or can be additionally provided, which is not limited herein. The conveying unit 1 uses pneumatic conveying to transfer the acrylonitrile furnace ash in the ash bin 11. Specifically, the conveying unit 1 further comprises a bin pump 12, and the discharge port of the ash bin 11 is in communication with the feeding port of the bin pump 12. The bin pump 12 is a relatively reliable dense-phase dynamic pressure pneumatic conveying device for conveying powdery materials under high pressure, which drives and conveys materials by compressed air, and is suitable for conveying various powdery materials. In the embodiment, the bin pump 12 is arranged below the ash bin 11, and the acrylonitrile furnace ash in the ash bin 11 is airtightly settled into the bin pump 12 through a vertical pipeline, and the bin pump 12 uniformly conveys the furnace ash to the integrated treatment unit 2 by compressed air.

[0026] The integrated treatment unit 2 comprises a furnace ash purification device, a dynamic device and a sludge drying device, which are designed in an integrated module and divided into two layers, the furnace ash purification device is arranged in the upper layer, and the dynamic device and the sludge drying device are arranged in the lower layer. The two layers can be separated by a prying frame or the like to effectively utilize the space and reduce the equipment footprint.

[0027] According to the flow direction of the furnace ash and the slurry, the furnace ash purification device comprises, in sequence, a dissolving device, a first-stage treatment device, a second-stage treatment device, a settling device and an adjusting device. The dissolving device is used for forming a slurry with uniformity and a predetermined pH value from the acrylonitrile furnace ash, the first-stage treatment device is used for precipitating and removing heavy metals in the slurry and forming a suspended matter, the second-stage treatment device is used for gathering the suspended matter to form larger particles for subsequent precipitation, obtaining a mixed liquid, the settling device is used for precipitating sludge in the mixed liquid, obtaining a purified liquid, and the adjusting device is used for adjusting the pH value of the purified liquid.

[0028] The dissolving device comprises a dissolving box 21, and the feeding port of the dissolving box 21 is in communication with the discharge port of the bin pump 12 through a pipeline. In the pipeline, the acrylonitrile furnace ash flows from the side of the ash bin 11 to the side of the dissolving box 21. An alkali liquid inlet pipe is arranged on the dissolving box 21, and an alkali solution such as sodium hydroxide solution flows into the dissolving box 21 through the alkali liquid inlet pipe. The alkali solution can adjust the pH value of the slurry in the dissolving box 21 to 7.5-9. A dust collector 211 is further arranged on the dissolving box 21, which is used for removing ash in the gas phase. The dust collector 211 is connected to an exhaust gas fan 212 through a pipeline and sent to an exhaust gas treatment device. The exhaust gas treatment device is used for removing harmful substances in the gas phase to achieve standard emission of the exhaust gas. The exhaust gas treatment device can adopt a scrubber, an adsorption tank or the like, which is not limited herein. The slurry outlet of the dissolving box 21 is in communication with the slurry inlet of a slurry conveying pump 213 through a pipeline.

[0029] The primary treatment device comprises a primary treatment tank 22, and a slurry inlet of the primary treatment tank 22 is communicated with a slurry outlet of the slurry delivery pump 213 through a pipeline in which the slurry flows from the side of the slurry delivery pump 213 to the side of the primary treatment tank 22. A heavy metal capturing agent feeding pipe is arranged on the primary treatment tank 22, and a heavy metal capturing agent such as sodium sulfide can flow into the primary treatment tank 22 through the heavy metal capturing agent feeding pipe, and zinc, copper, mercury and other heavy metals in the slurry react with the heavy metal capturing agent to generate corresponding metal sulfide precipitates and suspensions.

[0030] The secondary treatment device comprises a secondary treatment tank 23, and the primary treatment tank 22 is communicated with the secondary treatment tank 23 through a gate plate at the bottom of the primary treatment tank 22. The slurry containing the metal sulfide precipitates and suspensions can be delivered from the primary treatment tank to the secondary treatment tank 23 through the gate plate. A flocculant feeding pipe is arranged on the secondary treatment tank 23, and a flocculant such as polyferric sulfate can flow into the secondary treatment tank 23 through the flocculant feeding pipe, and the slurry and the flocculant form a mixed liquid in the secondary treatment tank 23 after stirring. In the mixing process, the flocculant is adsorbed on the surface of the suspensions and precipitates to form a charged complex, and the attraction between the complexes promotes the aggregation of the suspensions and precipitates into larger clumps, and the size and density of the clumps are greatly increased, which makes the clumps more easily separated and precipitated.

[0031] The settling device comprises a settling tank 24, and the secondary treatment tank 23 is provided with an overflow plate at the top, and the mixed liquid in the secondary treatment tank 23 can flow into the settling tank 24 through the overflow plate. A group of parallel inclined plates or inclined pipes are arranged in the settling tank 24 to form an inclined plate settling structure 241, and the mixed liquid flow can be separated into thin layers through the inclined plate settling structure 241, and the contact area is increased and the settling distance of the particles is shortened by using the shallow pool principle, so as to accelerate the settling speed of the particles, and thus the purified liquid is obtained.

[0032] The adjusting device comprises an adjusting tank 25, and the settling tank 24 is provided with an overflow plate at the top, and the purified liquid in the settling tank 24 can flow into the adjusting tank 25 through the overflow plate. The adjusting tank 25 is communicated with an inlet pipe, and an acidic solution or an alkaline solution can flow into the adjusting tank 25 through the inlet pipe according to the requirement of the downstream device for the acidity or alkalinity, so as to adjust the alkalinity of the purified liquid and maintain the stability of the alkalinity of the purified liquid.

[0033] The sludge drying device is used to discharge the heavy metal precipitate from the system in the form of dry sludge, and send it to the heavy metal recovery device as raw material, recover the heavy metal through the heavy metal recovery device, and return the filtrate to the dissolving device through the pipeline. The sludge drying device comprises a slag discharge pump 32, a sludge storage tank 31, a sludge conveying pump 33 and a sludge drying device 34. The sludge discharge port at the bottom of the settling tank 24, the first-stage treatment tank 22 and the second-stage treatment tank 23 is communicated with the feed port of the slag discharge pump 32 through a pipeline, and the heavy metal precipitate can be transferred from the settling tank 24 to the sludge storage tank 31 through the slag discharge pump 32. The sludge storage tank 31 is a tank for collecting and storing the heavy metal precipitate, the feed port of the sludge storage tank 31 is communicated with the discharge port of the slag discharge pump 32 through a pipeline, the discharge port of the sludge storage tank 31 is communicated with the feed port of the sludge conveying pump 33, and the discharge port of the sludge conveying pump 33 is communicated with the sludge drying device 34. The heavy metal precipitate can be transferred from the sludge storage tank 31 to the sludge drying device 34 through the sludge conveying pump 33. The sludge drying device 34 is a device for reducing the moisture content of sludge, for example, a dry slag machine can be used, which reduces the volume of sludge by physical method and discharges the system in the form of dry sludge. The filtrate outlet of the sludge drying device 34 is communicated with the inner cavity of the dissolving tank 21 through a pipeline, and the filtrate generated in the drying process flows back to the dissolving tank 21 through the pipeline for secondary use.

[0034] It should be noted that the above slurry conveying pump 213, tail gas fan 212 and purification liquid conveying pump 251 are included in the device.

[0035] In a feasible embodiment, the working process of the acrylonitrile furnace ash comprehensive treatment device is as follows:

[0036] The furnace ash 50 kg / h from the acrylonitrile device waste liquid incinerator falls into the bin pump 12 from the dust collector ash bin 11, is transported by air to the dissolving tank 21, 283 kg / h of desalted water is added in the dissolving tank 21, is uniformly stirred and mixed, sodium hydroxide is added to adjust the pH of the slurry in the dissolving tank 21 to 8.5, and then the slurry is sent to the first-stage treatment tank 22 through the slurry conveying pump 2113; the gas phase in the dissolving tank 21 is sent to the tail gas treatment device through the dust collector to remove the ash in the gas phase through the tail gas fan 212.

[0037] The heavy metal capturing agent sodium sulfide 50g / h is added into the first treatment tank 22, and after stirring for a certain time, the slurry enters the second treatment tank 23 through the gate at the bottom of the first treatment tank 22. The flocculating agent polymeric ferric sulfate 3kg / h and PAM 1.5kg / h are added into the second treatment tank 23, and after stirring for a certain time, the mixed liquid enters the settling tank 24 through the overflow plate at the top of the second treatment tank 23. After the inclined plate settling structure 241, the sludge in the mixed liquid settles to the bottom of the settling tank 2424, and the clarified purified liquid enters the adjusting tank 25 from the top overflow plate. In the adjusting tank 25, sodium hydroxide is added to make the pH of the purified liquid about 9. The purified liquid is sent to the subsequent acidic water treatment device by the purified liquid delivery pump 251 as an alkali source. At this time, the purified liquid flow rate at the outlet is 284kg / h.

[0038] The sludge at the bottom of the settling tank 24, the first treatment tank 22 and the second treatment tank 23 is sent to the sludge storage tank 31 by the sludge pump 32, and then enters the sludge drying device 34 by the sludge delivery pump 33. The aqueous sludge becomes a heavy metal-containing mixture after drying and is discharged from the system. The heavy metal mixture of the discharge system is 5.5kg / h. The liquid phase obtained after drying the aqueous sludge is sent to the inlet of the slurry delivery pump 213 through the pipeline, and finally returns to the dissolving tank 21.

[0039] In summary, the acrylonitrile furnace ash comprehensive treatment device provided by the present application, according to the composition characteristics of the acrylonitrile furnace ash, adopts the heavy metal capturing and flocculation precipitation mode, changes the furnace ash into a usable alkali source, realizes the resource utilization of the furnace ash. And, the acrylonitrile furnace ash discharge can be reduced by more than 80%, realizing the reduction of solid waste, and the small amount of solid waste obtained after treatment of the originally unlandfillable furnace ash can be treated in the heavy metal recovery device, solving the problem of acrylonitrile furnace ash that cannot be landfilled. In addition, the device as a whole adopts integrated design, realizing the modularization and skid mounting of the device, effectively reducing the equipment floor area.

[0040] It should be noted that the above embodiments can be freely combined as needed. The above is only a preferred embodiment of the present application, and it should be pointed out that for ordinary skilled persons in the technical field, without departing from the principles of the present application, a number of improvements and refinements can be made, which should be considered as the protection scope of the present application.

Claims

1. A comprehensive treatment device for acrylonitrile furnace ash, characterized by, The furnace ash purification device comprises a dissolving tank, a first treatment tank, a second treatment tank, a settling tank and a regulating tank connected in sequence according to the flow direction of the furnace ash and the slurry, the dissolving tank is connected with a lye inlet pipe, the first treatment tank is connected with a heavy metal capturing agent inlet pipe, the second treatment tank is connected with a flocculating agent inlet pipe, the settling tank is provided with a settling structure for accelerating the settling speed of particles, and the regulating tank is connected with an acid / alkali inlet pipe.

2. The acrylonitrile furnace dust comprehensive treatment device according to claim 1, characterized in that, The conveying unit comprises an ash bin and a bin pump, the discharge port of the ash bin is connected with the feed port of the dissolving tank through a pipeline, and the bin pump is connected to the pipeline between the ash bin and the dissolving tank.

3. The acrylonitrile furnace ash comprehensive treatment device according to claim 1, characterized in that, The sludge drying device comprises a slag discharge pump, a sludge storage tank, a sludge conveying pump and a sludge drying device connected in sequence, the feed port of the slag discharge pump is connected with the sludge outlet ports at the bottoms of the settling tank, the first treatment tank and the second treatment tank through a pipeline, and the filtrate outlet of the sludge drying device is connected with the dissolving tank through a pipeline.

4. The acrylonitrile furnace dust integrated treatment device according to claim 1, characterized in that, A dust remover is arranged on the dissolving tank, and the dust remover is connected with a tail gas treatment device through a pipeline.

5. The acrylonitrile furnace dust integrated treatment device according to claim 1, characterized in that, The first treatment tank and the second treatment tank are connected through a gate plate at the bottom of the first treatment tank.

6. The acrylonitrile furnace dust integrated treatment device according to claim 1, characterized in that, The second treatment tank and the settling tank are connected through an overflow plate at the top of the second treatment tank.

7. The acrylonitrile furnace dust integrated treatment device according to claim 1, characterized in that, The settling tank and the regulating tank are connected through an overflow plate at the top of the settling tank.

8. The acrylonitrile furnace dust integrated treatment device according to claim 1, characterized in that, The settling structure is a group of inclined plates or inclined pipes forming an inclined plate settling structure.

9. The acrylonitrile furnace dust comprehensive treatment device according to claim 3, characterized in that, The furnace ash purification device and the sludge drying device are arranged in a staggered manner, and the furnace ash purification device is located above the sludge drying device.

10. The acrylonitrile furnace dust integrated treatment device according to claim 9, characterized in that, The furnace ash purification device and the sludge drying device are separated by a pry frame.

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