A mixed salt solidification device and solidification method

Abstract

The present invention discloses a mixed salt solidification device, including a concentrating device, a filter press device, a stirring device, and a molding device. The concentrating device is connected to the filter press device through a material delivery pump, a first material conveyor is arranged below the outlet of the filter press device, a stirring device is arranged below the delivery port of the first material conveyor, a second material conveyor is arranged below the discharge port of the stirring device, a molding device is arranged below the material discharge port of the second material conveyor, and the concentrating device is connected to a high-salt wastewater pretreatment system. A solidification method is also disclosed. The device and method of the present invention can utilize the sludge generated in the mixed salt and high-salt wastewater pretreatment system and prepare finished bricks with better performance, and efficiently utilize the sludge generated in the mixed salt and high-salt wastewater pretreatment process, which not only saves the treatment cost of the sludge generated by the high-salt wastewater pretreatment system, but also obtains the treatment results of the dual resource utilization of mixed salt waste and sludge solid waste, with high economic benefits.

Description

Technical Field

[0001] The invention relates to a mixed salt solidification device and a solidification method, belonging to the treatment and comprehensive utilization technology of solid waste. Background Art

[0002] Industrial enterprises, mainly thermal power plants, often produce solid waste such as sludge during the treatment of high-salinity wastewater. Currently, the main treatment method is solidification and landfill, which means that the sludge is stabilized and then buried in a landfill. Although this treatment method is effective in a short period of time, it is not conducive to environmental protection and has high treatment costs. In existing high-salinity wastewater zero-discharge projects, difficult-to-treat salts are often produced. How to effectively utilize the salts produced in high-salinity wastewater zero-discharge projects has become an urgent problem to be solved in the project. Summary of the invention

[0003] The purpose of the present invention is to provide a mixed salt solidification device and a solidification method, which can prepare bricks from the mixed salts generated in the high-salt wastewater zero discharge project and the sludge generated in the process of treating high-salt wastewater, thereby saving the sludge treatment cost and realizing the resource treatment of sludge and mixed salts, which is not only beneficial to environmental protection, but also can obtain certain economic benefits through the sale of the prepared bricks.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions: a salt solidification device, including a concentrating device, a filter press device, a stirring device, and a molding device, wherein the concentrating device is connected to the filter press device through a material conveying pump, a first material conveyor is arranged below the outlet of the filter press device, the stirring device is arranged below the conveying port of the first material conveyor, a second material conveyor is arranged below the discharge port of the stirring device, the molding device is arranged below the material discharge port of the second material conveyor, and the concentrating device is connected to the high-salt wastewater pretreatment system. The concentrating device is used to reduce the moisture content of the sludge from 90% to 95% to 65% to 70% by gravity concentration, so as to improve the working efficiency of the subsequent filter press device.

[0005] In the aforementioned impure salt solidification device, the concentrating device includes a stirring fan and a material concentrating tank, and the stirring fan is connected to the material concentrating tank.

[0006] In the aforementioned impurity salt solidification device, the filter press device includes a first water tank, a second water tank, a compressed air storage tank and a plate-frame filter press, the first water tank, the second water tank and the compressed air storage tank are all connected to the plate-frame filter press, and the first material conveyor is arranged below the outlet of the plate-frame filter press. The first water tank is a cloth washing water tank for the plate-frame filter press, and the second water tank is a pressing water tank for the plate-frame filter press; the plate-frame filter press that has been used for a long time needs to have its filter plates flushed, and the water in the first water tank is used to flush the filter plates in the plate-frame filter press of the filter press device; the high-pressure water in the second water tank is transported to the plate-frame filter press for preparing sludge filter cakes; the air in the compressed air storage tank is used to blow away the residual mud residue on the filter plates in the plate-frame filter press, so as to prepare higher quality sludge filter cakes using the plate-frame filter press.

[0007] In the aforementioned mixed salt solidification device, the stirring device includes a first silo, a second silo and a mixer, the first silo and the second silo are both connected to the mixer, and the second material conveyor is arranged below the discharge port of the mixer. The first silo contains additives, and the second silo contains mixed salts.

[0008] In the aforementioned mixed salt solidification device, the forming device includes a brick-making machine and a brick conveyor. The brick-making machine is arranged below the material discharge port of the second material conveyor, and the brick-making machine is connected to the brick conveyor through a conveyor belt.

[0009] The aforementioned mixed salt solidification device also includes a sludge conveying device and a dehydration and feeding device, both of which are connected to the material concentration tank, and the high-salt wastewater pretreatment system is connected to the material concentration tank through the sludge conveying device.

[0010] The aforementioned mixed salt solidification device also includes a sedimentation and adjustment tank, which is connected to the sludge conveying device.

[0011] The aforementioned curing method of the mixed salt curing device comprises the following steps:

[0012] Step S01: adding sludge with a water content of 90% to 95% into a material concentration tank;

[0013] Step S02: adding the micro-nano composite material into the material concentration tank; the micro-nano composite material is a new type of high-efficiency adsorbent with high water purification capacity prepared from kaolin;

[0014] Step S03: Stirring the sludge and micro-nano composite material added into the material concentration tank to obtain a sludge material with a water content of 65% to 70%;

[0015] Step S04: sending the sludge material with a moisture content of 65% to 70% into a plate-frame filter press to obtain a sludge filter cake and a filtrate, conveying the filtrate to a sedimentation and regulating tank, and conveying the sludge filter cake to a mixing and stirring machine;

[0016] Step S05: adding miscellaneous salts to the mixer; the added miscellaneous salts may be miscellaneous salts generated in industrial production processes such as wastewater treatment and comprehensive utilization of water resources (such as miscellaneous salts with sodium sulfate as the main component), so as to process these miscellaneous salts in a resource-based manner and obtain certain economic benefits while protecting the environment.

[0017] Step S06: Stirring the miscellaneous salt and sludge filter cake added into the mixing mixer to obtain a raw material for brick making;

[0018] Step S07: adding brick-making raw materials into a forming device, and forming brick bodies from the brick-making raw materials through the forming device;

[0019] Step S08: Naturally dry the brick body for 10 to 20 days to obtain a finished brick.

[0020] In the aforementioned solidification method, the impurity salt added to the mixing and stirring machine is a sodium sulfate impurity salt with a water content of 10% to 15%.

[0021] The aforementioned curing method further includes adding additives during step S06, wherein the additives include a curing agent and a bonding agent, wherein the curing agent is cement, and the bonding agent is feldspar powder and / or water glass; and the mass ratio of the brick-making raw materials to the additives is 70:30. The use of the brick-making raw materials and additives in a mass ratio of 70:30 can not only meet the performance requirements of non-fired bricks, but also maximize the utilization rate of the brick-making raw materials, and the solid waste treatment capacity of the method of the present invention is optimal.

[0022] The existing bricks with MU15 compressive strength are compared with the finished bricks made by the device and method of the present invention to obtain the results shown in the following Table 1:

[0023] Table 1 Finished brick performance comparison table

[0024]

[0025] It can be seen from Table 1 that the bricks produced by the mixed salt solidification device and solidification method of the present invention have lower radioactivity, better compressive strength, better antifreeze performance, better carbonization performance and softening performance, and lower water absorption.

[0026] Compared with the prior art, the device of the present invention can utilize the sludge generated in the mixed salt and high-salt wastewater pretreatment system and prepare bricks through the overall equipment structure that organically combines the concentrating device, the filter pressing device, the stirring device, the forming device, the sludge conveying device and the dehydration and feeding device; through the solidification method of the present invention, finished bricks with better performance can be obtained, and the sludge generated in the mixed salt and high-salt wastewater pretreatment process can be efficiently utilized, which not only saves the treatment cost of the sludge generated in the high-salt wastewater pretreatment system and achieves the purpose of protecting the environment, but also obtains the treatment results of the dual resource utilization of mixed salt waste and sludge solid waste, with high economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute an improper limitation to the present invention. In the accompanying drawings:

[0028] Figure 1 It is a structural schematic diagram of the mixed salt solidification device of the present invention;

[0029] Figure 2 is a flow chart of the curing method of the present invention.

[0030] Figure markings: 1-concentrating device, 101-mixing fan, 102-material concentrating tank, 2-filter press device, 201-first water tank, 202-second water tank, 203-compressed air storage tank, 204-plate and frame filter press, 3-mixing device, 301-first silo, 302-second silo, 303-mixing mixer, 3031-discharge port, 4-forming device, 401-brick making machine, 402-brick conveyor, 5-material conveying pump, 6-first material conveyor, 601-conveying port, 7-second material conveyor, 701-material discharge port, 8-sludge conveying device, 801-dehydration and feeding device, 9-dehydration and feeding device, 10-sludge conveying device.

[0031] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. DETAILED DESCRIPTION

[0032] In order to make the technical personnel of the technical field better understand the scheme of the present invention, the technical scheme in the embodiment of the present invention is clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0033] Embodiment 1 of the present invention: A mixed salt solidification device comprises a concentrating device 1, a filter press device 2, a stirring device 3, and a molding device 4, wherein the concentrating device 1 is connected to the filter press device 2 via a material conveying pump 5, a first material conveyor 6 is arranged below the outlet of the filter press device 2, the stirring device 3 is arranged below the conveying port 601 of the first material conveyor 6, a second material conveyor 7 is arranged below the discharge port 3031 of the stirring device 3, the molding device 5 is arranged below the material discharge port 701 of the second material conveyor 7, and the concentrating device 1 is connected to a high-salt wastewater pretreatment system.

[0034] Embodiment 2 of the present invention: A salt solidification device comprises a concentrating device 1, a filter press device 2, a stirring device 3, and a molding device 4, wherein the concentrating device 1 is connected to the filter press device 2 via a material delivery pump 5, a first material conveyor 6 is arranged below the outlet of the filter press device 2, the stirring device 3 is arranged below the delivery port 601 of the first material conveyor 6, a second material conveyor 7 is arranged below the discharge port 3031 of the stirring device 3, the molding device 5 is arranged below the material discharge port 701 of the second material conveyor 7, and the concentrating device 1 is connected to a high-salt wastewater pretreatment system. The concentrating device 1 comprises a stirring fan 101 and a material concentrating tank 102, and the stirring fan 101 is connected to the material concentrating tank 102. The filter press device 2 includes a first water tank 201, a second water tank 202, a compressed air storage tank 203 and a plate-frame filter press 204, wherein the first water tank 201, the second water tank 202 and the compressed air storage tank 203 are all connected to the plate-frame filter press 204, and the first material conveyor 6 is arranged below the outlet of the plate-frame filter press 204. Specifically, the stirring device 3 includes a first silo 301, a second silo 302 and a mixer 303, wherein the first silo 301 and the second silo 302 are all connected to the mixer 303, and the second material conveyor 7 is arranged below the discharge port 3031 of the mixer 303. Further, the forming device 4 includes a brick making machine 401 and a brick conveyor 402, wherein the brick making machine 401 is arranged below the material discharge port 701 of the second material conveyor 7, and the brick making machine 401 is connected to the brick conveyor 402 through a conveyor belt.

[0035] Embodiment 3 of the present invention: A salt solidification device comprises a concentrating device 1, a filter press device 2, a stirring device 3, and a molding device 4, wherein the concentrating device 1 is connected to the filter press device 2 via a material delivery pump 5, a first material conveyor 6 is arranged below the outlet of the filter press device 2, and the first material conveyor 6 adopts a bolt-type conveyor, the stirring device 3 is arranged below the conveying port 601 of the first material conveyor 6, a second material conveyor 7 is arranged below the discharge port 3031 of the stirring device 3, the molding device 5 is arranged below the material discharge port 701 of the second material conveyor 7, and the concentrating device 1 is connected to a high-salt wastewater pretreatment system. The concentrating device 1 comprises a stirring fan 101 and a material concentrating tank 102, and the stirring fan 101 is connected to the material concentrating tank 102. The filter press device 2 includes a first water tank 201, a second water tank 202, a compressed air storage tank 203 and a plate-frame filter press 204, wherein the first water tank 201, the second water tank 202 and the compressed air storage tank 203 are all connected to the plate-frame filter press 204, and the first material conveyor 6 is arranged below the outlet of the plate-frame filter press 204. Specifically, the stirring device 3 includes a first silo 301, a second silo 302 and a mixer 303, wherein the first silo 301 and the second silo 302 are all connected to the mixer 303, and the second material conveyor 7 is arranged below the discharge port 3031 of the mixer 303. Further, the forming device 4 includes a brick making machine 401 and a brick conveyor 402, wherein the brick making machine 401 is arranged below the material discharge port 701 of the second material conveyor 7, and the brick making machine 401 is connected to the brick conveyor 402 through a conveyor belt. Furthermore, the mixed salt solidification device of this example also includes a sludge conveying device 10 and a dehydration feeding device 9, both of which are connected to a material concentration tank 102, and the high-salt wastewater pretreatment system is connected to the material concentration tank 102 through the sludge conveying device 10. The mixed salt solidification device of this example also includes a sedimentation regulating tank 8, and the sedimentation regulating tank 8 is connected to the sludge conveying device 10.

[0036] Embodiment 4 of the present invention: A curing method comprising the following steps:

[0037] Step S01: adding sludge with a water content of 90% to 95% into a material concentration tank;

[0038] Step S02: adding the micro-nano composite material into the material concentration tank; the micro-nano composite material is a new type of high-efficiency adsorbent with high water purification capacity prepared from kaolin;

[0039] Step S03: Stirring the sludge and micro-nano composite material added into the material concentration tank to obtain a sludge material with a water content of 65% to 70%;

[0040] Step S04: sending the sludge material with a moisture content of 65% to 70% into a plate-frame filter press to obtain a sludge filter cake and a filtrate, conveying the filtrate to a sedimentation and regulating tank, and conveying the sludge filter cake to a mixing and stirring machine;

[0041] Step S05: adding sodium sulfate salt with a water content of 10% to 15% into the mixing and stirring machine;

[0042] Step S06: Stirring the miscellaneous salt and sludge filter cake added into the mixing mixer to obtain a raw material for brick making;

[0043] Step S07: adding brick-making raw materials into a forming device, and forming brick bodies from the brick-making raw materials through the forming device;

[0044] Step S08: Naturally dry the brick body for 10 to 20 days to obtain a finished brick.

[0045] Embodiment 5 of the present invention: A curing method comprising the following steps:

[0046] Step S01: adding sludge with a water content of 90% to 95% into a material concentration tank;

[0047] Step S02: adding a micro-nano composite material into a material concentration tank, wherein the micro-nano composite material is a new type of high-efficiency adsorbent with high water purification capacity prepared from kaolin;

[0048] Step S03: Stirring the sludge and micro-nano composite material added into the material concentration tank to obtain a sludge material with a water content of 65% to 70%;

[0049] Step S04: sending the sludge material with a moisture content of 65% to 70% into a plate-frame filter press to obtain a sludge filter cake and a filtrate, conveying the filtrate to a sedimentation and regulating tank, and conveying the sludge filter cake to a mixing and stirring machine;

[0050] Step S05: adding sodium sulfate salt with a water content of 10% to 15% into the mixing and stirring machine;

[0051] Step S06: Stirring the miscellaneous salt and sludge filter cake added into the mixing mixer to obtain a raw material for brick making;

[0052] Step S07: adding brick-making raw materials into a forming device, and forming brick bodies from the brick-making raw materials through the forming device;

[0053] Step S08: Naturally dry the brick body for 15 days to obtain a finished brick. After multiple tests and verifications, the brick body made by the molding device has the best product performance when it is naturally dried for 15 days.

[0054] In this example, additives are added during step S06, and the mass ratio of brick-making raw materials to additives is 70:30.

[0055] When performing step S02, additives are added to reduce the sludge specific resistance, making it easier to separate liquid (such as water) from the sludge by gravity concentration. In this example, the additives include a curing agent and a binder, the curing agent is cement, and the binder is feldspar powder and / or water glass.

[0056] Working process and principle of the present invention:

[0057] The sludge generated during the treatment process of the high-salt wastewater pretreatment system is transported to the concentrating device 1, and the moisture content of the sludge is reduced from 90% to 95% to 65% to 70% by gravity concentration using the concentrating device 1, so that the working efficiency of the pressure device is higher. After the water is removed by the concentrating device, a sludge material with a moisture content of 65% to 70% is obtained. The sludge material with a moisture content of 65% to 70% is transported to the plate and frame press 204 through the material conveying pump 5, and a sludge filter cake is made by the plate and frame press 204. The sludge filter cake is then transported to the mixing In the mixing mixer 303, miscellaneous salt is added to the mixing mixer 303 at the same time. During the mixing process of the mixing mixer 303, feldspar powder and / or water glass adhesive and cement curing agent are added. After being fully mixed by the mixing mixer 303, brick-making raw materials are formed. The brick-making raw materials are conveyed to the brick-making machine 401 of the forming device 4 through the discharge port 3031 of the mixing mixer 303 and the second material conveyor 7. The bricks made by the brick-making machine 401 are conveyed to the brick conveyor 402 by a conveyor belt. The rotating body is transported to the drying site for natural drying for 10 to 20 days, and finally the finished bricks can be used for sale.

[0058] The present invention uses micro-nano composite materials as adsorption flocculants to separate water from sludge, which has good mud-water separation effect and does not introduce new impurity ions. The sludge with a water content of 65% to 70% has extremely high stability, is not easy to decompose, and is not easy to dissolve again, which is beneficial to the subsequent brick making process. Cement is used as a curing agent, and a small amount of feldspar powder and water glass are used as binders to be able to bind to a large amount of Ca in sludge and miscellaneous salts. 2+ and SO4 2-Formation of calcium sulfonate. When cement, feldspar powder and water glass meet water, they undergo complex chemical reactions to form hydrated calcium silicate with a large area and good adsorption performance. Calcium sulfonate is a needle-shaped crystal. After its formation, its volume increases by about 120%, reducing the pores of the sludge solid body (the sludge solid body here refers to the semi-finished bricks from the stirring sludge filter cake stage to the brick body forming stage and the natural drying stage. In this process, the internal materials of the semi-finished bricks bridge each other and form grains, which fill the structural gaps); the needle-shaped crystal calcium sulfonate has a large volume and can cross-exist in the pores of the sludge solid body to form a spatial structure together with the calcium silicate hydrate, forming the skeleton of the entire sludge solid body, thereby enhancing the strength of the sludge solid body and finally forming a finished brick with high compressive strength.

Claims

1. A mixed salt solidification method, characterized in that: A salt solidification device is used, the salt solidification device comprising a concentrating device (1), a filter press device (2), a stirring device (3), and a molding device (4); the concentrating device (1) is connected to the filter press device (2) via a material conveying pump (5); a first material conveyor (6) is arranged below the outlet of the filter press device (2); the stirring device (3) is arranged below the conveying port (601) of the first material conveyor (6); a second material conveyor (7) is arranged below the discharge port (3031) of the stirring device (3); the molding device (4) is arranged below the material discharge port (701) of the second material conveyor (7); the concentrating device (1) is connected to a high-salt wastewater pretreatment system; the concentrating device (1) comprises a stirring fan (101) and a material concentrating tank (102); The stirring fan (101) is connected to the material concentration tank (102); the filter press device (2) comprises a first water tank (201), a second water tank (202), a compressed air storage tank (203) and a plate-frame filter press (204); the first water tank (201), the second water tank (202) and the compressed air storage tank (203) are all connected to the plate-frame filter press (204); the first material conveyor (6) is arranged below the outlet of the plate-frame filter press (204); the stirring device (3) comprises a first silo (301), a second silo (302) and a mixing mixer (303); the first silo (301) and the second silo (302) are all connected to the mixing mixer (303); the second material conveyor (7) is arranged below the discharge port (3031) of the mixing mixer (303); The curing method comprises the following steps: Step S01: adding sludge with a water content of 90% to 95% into a material concentration tank; Step S02: adding the micro-nano composite material into a material concentration tank; Step S03: stirring the sludge and micro-nano composite material added into the material concentration tank to obtain a sludge material with a water content of 65% to 70%; Step S04: sending the sludge material with a moisture content of 65% to 70% into a plate-frame filter press to obtain a sludge filter cake and a filtrate, conveying the filtrate to a sedimentation and regulating tank, and conveying the sludge filter cake to a mixing and stirring machine; Step S05: adding miscellaneous salt to the mixing and blending machine; the miscellaneous salt added to the mixing and blending machine is sodium sulfate miscellaneous salt with a water content of 10% to 15%; Step S06: adding the salt and sludge filter cake in the mixer under stirring to obtain a raw material for brick making; wherein, adding additives during stirring, the additives comprising a curing agent and a bonding agent, the curing agent being cement, and the bonding agent being feldspar powder and / or water glass; the mass ratio of the raw material for brick making to the additives being 70:30; Step S07: adding brick-making raw materials into a forming device, and forming brick bodies from the brick-making raw materials through the forming device; Step S08: Naturally dry the brick body for 10 to 20 days to obtain a finished brick.

2. A mixed salt solidification method according to claim 1, characterized in that: The forming device (4) comprises a brick-making machine (401) and a brick conveyor (402); the brick-making machine (401) is arranged below the material discharge port (701) of the second material conveyor (7); and the brick-making machine (401) is connected to the brick conveyor (402) via a conveyor belt.

3. A mixed salt solidification method according to claim 2, characterized in that: It also includes a sludge conveying device (10) and a dehydration feeding device (9), wherein the sludge conveying device (10) and the dehydration feeding device (9) are both connected to a material concentration tank (102), and the high-salt wastewater pretreatment system is connected to the material concentration tank (102) via the sludge conveying device (10).

4. A mixed salt solidification method according to claim 3, characterized in that: It also comprises a sedimentation regulating tank (8), wherein the sedimentation regulating tank (8) is connected to the sludge conveying device (10).

Images