Resource utilization system for coking coal coking desulfurization waste liquid

Abstract

The utility model discloses a resource utilization system for coking coal coking desulfurization waste liquid. Comprising a reaction tank, a sedimentation tank, a clean water tank, an ultrafiltration device, a first nanofiltration membrane device, a first concentrated solution tank, a second nanofiltration membrane device, a second concentrated solution tank, a third nanofiltration membrane device, a first water producing tank, a first reverse osmosis membrane device, a second water producing tank, a second reverse osmosis membrane device and a concentrate water tank which are sequentially connected on a desulfurization waste liquid water tank through pipelines, the third reverse osmosis membrane device is connected with the evaporative crystallization reactor, the first nanofiltration membrane device is connected with the second water producing tank, and the second nanofiltration membrane device is connected with the first water producing tank. According to the device, the desulfurization waste liquid is subjected to cooperative treatment through all the devices, a high-quality ammonium thiocyanate product with high recovery rate and high purity can be obtained, meanwhile, the device has the advantages of being convenient to operate, easy to control, low in energy consumption, stable in operation, free of seasonal influence, environmentally friendly and the like, the use value is high, and the application prospect is good.

Description

Technical Field

[0001] The utility model relates to a resource utilization system for coking desulfurization waste liquid of coking coal materials. Background Art

[0002] The coking coal materials contain 0.5 - 1.2% sulfur, and 20 - 45% of the sulfur enters the raw gas in the form of sulfide and forms impurities in the gas together with NH3, HCN, etc. At present, the widely used desulfurization method in coking enterprises is the HPF wet oxidation technology. In this technology, hydroquinone, PDS (ammonium hexasulfonate of dicyclic benzonitrile anhydride) and ferrous sulfate are used as catalysts, and ammonia is used as the alkali source. During the desulfurization process, salts such as ammonium thiosulfate and ammonium thiocyanate are generated. However, when the concentration of these salts accumulates to a certain extent (≥250 g / L), the desulfurization efficiency will decrease significantly. Therefore, to ensure the continuous and efficient progress of the desulfurization process, fresh desulfurization liquid must be supplemented, and at the same time, a part of the old desulfurization liquid is drawn out, thus generating the coking desulfurization waste liquid of coking coal materials. The COD in this coking desulfurization waste liquid of coking coal materials > 1×10 5 mg / L, ammonium thiosulfate > 5 g / L, ammonia nitrogen > 20 g / L, ammonium thiocyanate > 2×200 g / L, far exceeding the standards of the biochemical treatment inlet of the coking plant (COD ≤ 3500 mg / L, NH3-N ≤ 300 mg / L, sulfide ≤ 75 mg / L). It can be seen that the coking desulfurization waste liquid of coking coal materials is not only a highly harmful pollution source, but also a utilizable resource rich in useful components such as ammonium thiocyanate salts. Therefore, it is of great significance to develop a process technology that can efficiently separate high-quality ammonium thiocyanate from the coking desulfurization waste liquid of coking coal materials.

[0003] At present, the main methods for treating coking desulfurization waste liquid from coking coal materials are: salt extraction methods (including: evaporation crystallization method, stepwise evaporation crystallization method, preparation of thiocyanate method, membrane separation method, ion exchange method), Kompax method, Hirosaki method and high-temperature pyrolysis method. Among the salt extraction methods, the stepwise evaporation crystallization method has been studied more extensively, but this method has problems such as high operation difficulty, low purity of the obtained salt, and easy generation of secondary pollution. In addition, the existing treatment process for coking sulfur-containing wastewater developed based on the stepwise evaporation crystallization method mainly includes the following steps: successively using a microfiltration or ultrafiltration membrane separator, a nanofiltration membrane separator, a reverse osmosis membrane separator and a reaction kettle for cooling crystallization to treat coking sulfur-containing wastewater, and recovering elemental sulfur, ammonium thiosulfate and ammonium thiocyanate. However, this treatment system / process still has the following defects: (1) Directly using a microfiltration or ultrafiltration membrane separator to treat coking sulfur-containing wastewater can only separate elemental sulfur. However, it is difficult for the microfiltration or ultrafiltration membrane separator to remove impurities such as metal ions in the wastewater, so these metal ions still remain in the microfiltration or ultrafiltration permeate. Although the subsequent nanofiltration membrane separator and reverse osmosis membrane separator can intercept the residual metal ions in the microfiltration or ultrafiltration permeate, it will inevitably increase the operating load of the nanofiltration membrane separator and the reverse osmosis membrane separator, which is not conducive to improving their interception effect. At the same time, since the metal ions are intercepted in the nanofiltration concentrate or the reverse osmosis concentrate, and the metal ions cannot be removed during the purification and drying of the nanofiltration concentrate and the reverse osmosis concentrate, these metal ions are likely to enter ammonium thiosulfate or ammonium thiocyanate, resulting in low purity of ammonium thiosulfate or ammonium thiocyanate, which is not conducive to their subsequent resource utilization. (2) A single-stage nanofiltration membrane separator cannot completely separate ammonium thiocyanate from the wastewater. Generally speaking, after treatment with a single-stage nanofiltration membrane separator, the removal rate of ammonium thiocyanate in the wastewater does not exceed 80%, that is, a large amount of ammonium thiocyanate still remains in the nanofiltration concentrate, resulting in a still low overall recovery rate of ammonium thiocyanate. (3) After passing through a single-stage reverse osmosis membrane separator, the volume of the reverse osmosis concentrate is still very large, which is not conducive to reducing the volume of subsequent evaporation crystallization, and is likely to cause a significant increase in operating costs. In addition, the high-temperature pyrolysis method is widely used in salt decomposition technology due to its low investment and simple operation, but this method has defects such as being greatly affected by seasons and climate, high energy consumption, strong odor, high labor intensity, poor working environment, and long-term backmixing of the waste liquid corroding the belt conveyor and brackets. Therefore, developing a new technology for resource utilization of coking coal material desulfurization waste liquid is of great significance for efficiently separating high-quality ammonium thiocyanate products from coking coal material coking desulfurization waste liquid. Utility Model Content

[0004] The technical problem to be solved by the present utility model is to provide a resource utilization system for coking desulfurization waste liquid of coking coal materials, which is convenient to operate, easy to control, low in energy consumption, stable in operation, not affected by seasons, and green and environment-friendly, aiming at the deficiencies in the prior art. It can not only realize the batch and harmless treatment of desulfurization waste liquid, but also obtain high-quality ammonium thiocyanate products with high recovery rate and high purity.

[0005] To solve the above technical problems, the present utility model adopts the following technical solutions.

[0006] A resource utilization system for coking desulfurization waste liquid of coking coal materials includes a desulfurization waste liquid water tank, which is sequentially connected with a reaction tank, a sedimentation tank, a clear water tank, an ultrafiltration device, a first nanofiltration membrane device, a first concentrated liquid tank, a second nanofiltration membrane device, a second concentrated liquid tank, a third nanofiltration membrane device, a first water production tank, a first reverse osmosis membrane device, a second water production tank, a second reverse osmosis membrane device, a concentrate water tank, a third reverse osmosis membrane device and an evaporation crystallization reactor through pipelines; a pipeline is connected between the water production outlet of the first nanofiltration membrane device and the water inlet of the second water production tank; a pipeline is connected between the water production outlet of the second nanofiltration membrane device and the water inlet of the first water production tank.

[0007] As a further improvement of the above technical solution: a water distribution tank is further included.

[0008] As a further improvement of the above technical solution: the water outlet of the water distribution tank is respectively connected with the water inlets of the first concentrated liquid tank and the second concentrated liquid tank through pipelines.

[0009] As a further improvement of the above technical solution: the water inlets of the water distribution tank are respectively connected with the water production outlets of the second reverse osmosis membrane device, the third reverse osmosis membrane device and the evaporation crystallization reactor through pipelines.

[0010] As a further improvement of the above technical solution: a third concentrated liquid tank is further connected to the concentrated water outlet of the third nanofiltration membrane device.

[0011] As a further improvement of the above technical solution: an ammonia distillation device is further connected to the water outlet of the third concentrated liquid tank; the ammonia distillation device is an ammonia distillation tower.

[0012] As a further improvement of the above technical solution: a filtrate water tank is further connected to the water production outlet of the first reverse osmosis membrane device, and a fourth reverse osmosis membrane device is further connected to the water outlet of the filtrate water tank; a pipeline is connected between the concentrated water outlet of the fourth reverse osmosis membrane device and the water inlet of the first water production tank.

[0013] As a further improvement of the above technical solution: a heat exchanger is further provided between the desulfurization waste liquid water tank and the reaction tank.

[0014] As a further improvement of the above technical solution: A filter is further provided between the clear water tank and the ultrafiltration device. For example, the filter is a multi-media filter, but is not limited thereto.

[0015] As a further improvement of the above technical solution: An ultrafiltration water tank is further provided between the ultrafiltration device and the first nanofiltration membrane device.

[0016] As a further improvement of the above technical solution: A chemical storage tank is further connected to the reaction tank.

[0017] As a further improvement of the above technical solution: A sludge tank is further connected to the sludge outlet of the sedimentation tank.

[0018] As a further improvement of the above technical solution: A filter press is connected to the sludge outlet of the sludge tank.

[0019] As a further improvement of the above technical solution: The filtrate outlet of the filter press is connected to the water inlet of the desulfurization waste liquid water tank through a pipeline.

[0020] Compared with the prior art, the advantages of the present utility model are as follows:

[0021] (1)In the resource utilization system of coking desulfurization waste liquid of coking coal materials of the present utility model, the waste liquid is first introduced into a reaction tank for reaction, so that suspended solids and metal ions (such as iron ions) in the waste liquid form metal hydroxide precipitates. Then, through the sedimentation effect of the sedimentation tank, the effective separation of the metal hydroxide precipitates from the solution is achieved. At the same time, the remaining suspended solids and colloids in the effluent of the sedimentation tank are completely removed after ultrafiltration treatment by an ultrafiltration device, thereby reducing the operating load of the nanofiltration membrane device and the reverse osmosis membrane device, which is conducive to improving their rejection effect. On this basis, the effluent from the ultrafiltration device is introduced into the first nanofiltration membrane device for primary nanofiltration treatment to separate ammonium thiocyanate from the waste liquid. These separated thiocyanates are transferred to the primary nanofiltration product water to complete the primary separation of ammonium thiocyanate from other impurity salts in the waste liquid. The resulting primary nanofiltration product water is introduced into the second product water tank as the main water (inlet water) for secondary reverse osmosis treatment. At the same time, the primary nanofiltration concentrate generated after nanofiltration treatment is introduced into the first concentrate tank, diluted and then introduced into the second nanofiltration membrane device for secondary nanofiltration treatment, so that the remaining ammonium thiocyanate in the primary nanofiltration concentrate enters the secondary nanofiltration product water to complete the secondary separation of ammonium thiocyanate from other impurity salts in the waste liquid. The resulting secondary nanofiltration product water is introduced into the first product water tank as the main water (inlet water) for primary reverse osmosis treatment. Further, the secondary nanofiltration concentrate generated after secondary nanofiltration treatment is introduced into the second concentrate tank, diluted and then introduced into the third nanofiltration membrane device for tertiary nanofiltration treatment, so that the remaining ammonium thiocyanate in the secondary nanofiltration concentrate enters the tertiary nanofiltration product water to complete the tertiary separation of ammonium thiocyanate from other impurity salts in the waste liquid. The resulting product water is introduced into the first product water tank as the makeup water for primary reverse osmosis treatment. It can be seen that through tertiary nanofiltration treatment, more ammonium thiocyanate can be obtained from the wastewater, which can significantly improve the overall recovery rate of ammonium thiocyanate; after the tertiary nanofiltration treatment is completed, the nanofiltration product water collected in the first product water tank is introduced into the first reverse osmosis membrane device for primary reverse osmosis. On the one hand, using the tertiary nanofiltration product water to dilute the secondary nanofiltration product water can reduce the operating load of the first reverse osmosis membrane device and is conducive to improving the reverse osmosis efficiency. On the other hand, through reverse osmosis treatment, the volume of the reverse osmosis concentrate can also be reduced. Further, the primary reverse osmosis concentrate generated after primary reverse osmosis treatment is introduced into the second product water tank, and the primary nanofiltration product water is diluted with the primary reverse osmosis concentrate as the makeup water, which can also reduce the operating load of the second reverse osmosis membrane device. And by using the second reverse osmosis device for secondary reverse osmosis, the volume of the reverse osmosis concentrate can be further reduced. Still further, the secondary reverse osmosis concentrate generated after secondary reverse osmosis treatment is introduced into the third reverse osmosis membrane device for tertiary reverse osmosis, which can further reduce the volume of the reverse osmosis concentrate. It can be seen that through three - stage reverse osmosis treatment, the volume of the ammonium thiocyanate concentrated water can be significantly reduced, which is conducive to reducing the volume of subsequent evaporation and crystallization and reducing the operating cost;Finally, the tertiary reverse osmosis concentrate produced after tertiary reverse osmosis treatment is introduced into an evaporation crystallization reactor for evaporation crystallization to obtain high-quality ammonium thiocyanate products with high recovery rate and high purity.

[0022] (2) In the resource utilization system of coking coal coking desulfurization waste liquid of the present utility model, it further includes a water distribution tank. The water outlet of the water distribution tank is connected to the water inlets of the first concentrate tank and the second concentrate tank through pipelines. At the same time, the water inlet of the water distribution tank is connected to the water production outlets of the second reverse osmosis membrane device, the third reverse osmosis membrane device and the evaporation crystallization reactor through pipelines. Therefore, during the nanofiltration treatment using the nanofiltration device, the water produced by other devices can be effectively utilized, which not only helps to reduce the treatment cost, but also promotes the improvement of the recovery rate of ammonium thiocyanate.

[0023] (3) In the resource utilization system of coking coal coking desulfurization waste liquid of the present utility model, a filtrate water tank is further connected to the water production outlet of the first reverse osmosis membrane device, and a fourth reverse osmosis membrane device is further connected to the water outlet of the filtrate water tank. The concentrated water outlet of the fourth reverse osmosis membrane device is connected to the water inlet of the first water production tank through a pipeline. The water produced in the first reverse osmosis membrane device is introduced into the fourth reverse osmosis device for reverse osmosis treatment. On the one hand, the residual ammonium thiocyanate in the water can be transferred to the first water production tank, which is beneficial to improving the recovery rate of ammonium thiocyanate. On the other hand, it can also improve the purification effect of the water, enabling it to meet the discharge standards.

[0024] (4) In the resource utilization system of coking coal coking desulfurization waste liquid of the present utility model, a third concentrate tank is further connected to the concentrated water outlet of the third nanofiltration membrane device, and an ammonia distillation device is further connected to the water outlet of the third concentrate tank. By introducing the nanofiltration concentrate into the ammonia distillation device for deammoniation treatment, ammonia water is recovered, and the remaining wastewater can also enter the subsequent biochemical treatment system for further treatment.

[0025] (5) The resource utilization system for coking desulfurization waste liquid of coking coal materials of the present utility model includes a reaction tank, a sedimentation tank, a clear water tank, an ultrafiltration device, a first nanofiltration membrane device, a first concentrated liquid tank, a second nanofiltration membrane device, a second concentrated liquid tank, a third nanofiltration membrane device, a first product water tank, a first reverse osmosis membrane device, a second product water tank, a second reverse osmosis membrane device, a concentrate water tank, and a third reverse osmosis membrane device that are sequentially connected on the desulfurization waste liquid water tank. By using each device to cooperate in treating the desulfurization waste liquid, not only can ammonium thiocyanate be quickly and thoroughly separated from the waste liquid, but also the content of impurity salts in the ammonium thiocyanate concentrated liquid can be effectively reduced, so that high-quality ammonium thiocyanate products with high recovery rate and high purity can be obtained. At the same time, the resource utilization system for coking desulfurization waste liquid of coking coal materials of the present utility model does not produce waste liquid, does not cause secondary pollution to the environment, is more environmentally friendly, and has the advantages of convenient operation, easy control, low energy consumption, stable operation and not affected by seasons, and environmental protection. It can be widely used to treat desulfurization waste liquid, can realize the batch treatment and harmless treatment of desulfurization waste liquid, has high use value and good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model.

[0027] Figure 1 It is a schematic structural diagram of the resource utilization system for coking desulfurization waste liquid of coking coal materials in Embodiment 1 of the present utility model.

[0028] Legend:

[0029] 1. Desulfurization waste liquid water tank; 2. Heat exchanger; 3. Reaction tank; 4. Sedimentation tank; 5. Clear water tank; 6. Filter; 7. Ultrafiltration device; 8. Ultrafiltration water tank; 91. First nanofiltration membrane device; 92. First concentrated liquid tank; 93. Second nanofiltration membrane device; 94. Second concentrated liquid tank; 95. Third nanofiltration membrane device; 96. Third concentrated liquid tank; 101. First product water tank; 102. Second product water tank; 201. First reverse osmosis membrane device; 202. Second reverse osmosis membrane device; 203. Concentrate water tank; 204. Third reverse osmosis membrane device; 205. Filtrate water tank; 206. Fourth reverse osmosis membrane device; 301. Evaporation crystallization reactor; 401. Sludge tank; 402. Filter press; 501. Ammonia distillation device; a. Desulfurization waste liquid; b. Chemical agent; c. Flushing water; d. Water distribution; e. Effluent; f. Condensate; g. Ammonium thiocyanate product; h. Reverse osmosis product water; i. Cake; j. Washing liquid. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The present utility model will be further described below in conjunction with the accompanying drawings of the specification and specific preferred embodiments, but the protection scope of the present utility model is not limited thereby.

[0031] Embodiment 1:

[0032] As Figure 1 shown, the resource utilization system for coking desulfurization waste liquid of coking coal material in this embodiment includes a desulfurization waste liquid water tank 1, and a reaction tank 3, a sedimentation tank 4, a clear water tank 5, an ultrafiltration device 7, a first nanofiltration membrane device 91, a first concentrate tank 92, a second nanofiltration membrane device 93, a second concentrate tank 94, a third nanofiltration membrane device 95, a first water production tank 101, a first reverse osmosis membrane device 201, a second water production tank 102, a second reverse osmosis membrane device 202, a concentrate water tank 203, a third reverse osmosis membrane device 204 and an evaporation crystallization reactor 301 are sequentially connected to the desulfurization waste liquid water tank 1 through pipelines; a pipeline is connected between the water production outlet of the first nanofiltration membrane device 91 and the water inlet of the second water production tank 102; a pipeline is connected between the water production outlet of the second nanofiltration membrane device 93 and the water inlet of the first water production tank 101.

[0033] In this embodiment, the waste liquid is first introduced into a reaction tank for reaction, so that the suspended solids and metal ions (such as iron ions) in the waste liquid form metal hydroxide precipitates. Then, through the sedimentation effect of the sedimentation tank, the effective separation of the metal hydroxide precipitates from the solution is achieved. At the same time, the remaining suspended solids and colloids in the effluent of the sedimentation tank are completely removed after ultrafiltration treatment by the ultrafiltration device, which can reduce the operating load of the nanofiltration membrane device and the reverse osmosis membrane device and is conducive to improving their rejection effects. On this basis, the effluent from the ultrafiltration device is introduced into the first nanofiltration membrane device for primary nanofiltration treatment to separate ammonium thiocyanate from the waste liquid. These separated thiocyanates are transferred to the nanofiltration product water and introduced into the second product water tank as the main water (inlet water) for secondary reverse osmosis treatment, completing the primary separation of ammonium thiocyanate from other impurity salts in the waste liquid. At the same time, the primary nanofiltration concentrate generated after nanofiltration treatment is introduced into the first concentrate tank, diluted and then introduced into the second nanofiltration membrane device for secondary nanofiltration treatment, so that the remaining ammonium thiocyanate in the primary nanofiltration concentrate enters the secondary nanofiltration product water and is introduced into the first product water tank as the main water (inlet water) for primary reverse osmosis treatment, completing the secondary separation of ammonium thiocyanate from other impurity salts in the waste liquid. Further, the secondary nanofiltration concentrate generated after secondary nanofiltration treatment is introduced into the second concentrate tank, diluted and then introduced into the third nanofiltration membrane device for tertiary nanofiltration treatment, so that the remaining ammonium thiocyanate in the secondary nanofiltration concentrate enters the tertiary nanofiltration product water. The obtained product water is introduced into the first product water tank as the feed water for primary reverse osmosis treatment, completing the tertiary separation of ammonium thiocyanate from other impurity salts in the waste liquid. It can be seen that through tertiary nanofiltration treatment, more ammonium thiocyanate can be obtained from the wastewater, and the overall recovery rate of ammonium thiocyanate can be significantly improved; after the tertiary nanofiltration treatment is completed, the nanofiltration product water collected in the first product water tank is introduced into the first reverse osmosis membrane device for primary reverse osmosis. On the one hand, diluting the secondary nanofiltration product water with the tertiary nanofiltration product water can reduce the operating load of the first reverse osmosis membrane device and is conducive to improving the reverse osmosis efficiency. On the other hand, through reverse osmosis treatment, the volume of the reverse osmosis concentrate can also be reduced. Further, the primary reverse osmosis concentrate generated after primary reverse osmosis treatment is introduced into the second product water tank, and the primary nanofiltration product water is diluted with the primary reverse osmosis concentrate as the feed water, which can also reduce the operating load of the second reverse osmosis membrane device. And by using the second reverse osmosis device for secondary reverse osmosis, the volume of the reverse osmosis concentrate can be further reduced. Still further, the secondary reverse osmosis concentrate generated after secondary reverse osmosis treatment is introduced into the third reverse osmosis membrane device for tertiary reverse osmosis, which can further reduce the volume of the reverse osmosis concentrate. It can be seen that through three times of reverse osmosis treatment, the volume of the ammonium thiocyanate concentrated water can be significantly reduced, which is conducive to reducing the volume of subsequent evaporation and crystallization and is conducive to reducing the operating cost;Finally, the tertiary reverse osmosis concentrated liquid produced after tertiary reverse osmosis treatment is introduced into an evaporation crystallization reactor for evaporation crystallization to obtain high-quality ammonium thiocyanate products with high recovery rate and high purity.

[0034] In this embodiment, it further includes a water distribution tank; the water outlet of the water distribution tank is connected to the water inlets of a first concentrated liquid tank 92 and a second concentrated liquid tank 94 through pipelines respectively.

[0035] In this embodiment, the water inlet of the water distribution tank is connected to the water production outlets of a second reverse osmosis membrane device 202, a third reverse osmosis membrane device 204 and an evaporation crystallization reactor 301 through pipelines respectively.

[0036] In this embodiment, the water produced in the nanofiltration and reverse osmosis devices can be stored in the water distribution tank, and then these produced waters are used to dilute the nanofiltration and reverse osmosis, which not only helps to reduce the treatment cost, but also can promote the improvement of the recovery rate of ammonium thiocyanate.

[0037] In this embodiment, a third concentrated liquid tank 96 is further connected to the concentrated water outlet of the third nanofiltration membrane device 95.

[0038] In this embodiment, an ammonia distillation device 501 is further connected to the water outlet of the third concentrated liquid tank 96; the ammonia distillation device 501 is an ammonia distillation tower.

[0039] In this embodiment, by introducing the nanofiltration concentrated liquid into the ammonia distillation device for deammoniation treatment, ammonia water can be recovered, and the remaining wastewater can also enter the subsequent biochemical treatment system for further treatment.

[0040] In this embodiment, a filtrate water tank 205 is further connected to the water production outlet of the first reverse osmosis membrane device 201, and a fourth reverse osmosis membrane device 206 is further connected to the water outlet of the filtrate water tank 205; a pipeline is connected between the concentrated water outlet of the fourth reverse osmosis membrane device 206 and the water inlet of the first water production tank 101.

[0041] In this embodiment, the water produced in the first reverse osmosis membrane device is introduced into the fourth reverse osmosis device for reverse osmosis treatment. On the one hand, the residual ammonium thiocyanate in the water can be transferred to the first water production tank, which is beneficial to improving the recovery rate of ammonium thiocyanate. On the other hand, it can also improve the purification effect of the water production, enabling it to meet the discharge standards.

[0042] In this embodiment, a heat exchanger 2 is further provided between the desulfurized waste liquid water tank 1 and the reaction tank 3; a filter 6 is further provided between the clear water tank 5 and the ultrafiltration device 7; an ultrafiltration water tank 8 is further provided between the ultrafiltration device 7 and the first nanofiltration membrane device 91.

[0043] In this embodiment, a reagent storage tank is further connected to the reaction tank 3.

[0044] In this embodiment, a sludge tank 401 is further connected to the sludge outlet of the sedimentation tank 4; a filter press 402 is connected to the sludge outlet of the sludge tank 401; a pipeline is connected between the filtrate outlet of the filter press 402 and the water inlet of the desulfurized waste liquid water tank 1.

[0045] The resource utilization system for coking desulfurized waste liquid of coking coal materials in the above-mentioned embodiment can be used for harmless and resource treatment of coking desulfurized waste liquid of coking coal materials, including the following steps:

[0046] (1) Take the coking desulfurized waste liquid generated in the production process of a certain coking enterprise. The water quality of the desulfurized waste liquid is as follows: the concentration of NH4SCN is 85.78 g / L, the concentration of Ca is 30.2 mg / L, the concentration of Mg is 2.98 mg / L, the concentration of Fe 总 is 265 mg / L, the concentration of (NH4)2S2O3 is 32.34 g / L; the pH is 7.5; the concentration of COD is 392 g / L, and the concentration of ammonia nitrogen is 46.425 g / L; the temperature is 68 °C. At the same time, pump the desulfurized waste liquid into the desulfurized waste liquid water tank 1 for standby.

[0047] (2) Use a feed pump to send the coking desulfurized waste liquid in the desulfurized waste liquid water tank 1 into the heat exchanger 2 for cooling.

[0048] (3) Pump the cooled waste liquid into the reaction tank 3, and add ammonia water for flocculation reaction under stirring conditions.

[0049] (4) Pump the product of the flocculation reaction into the sedimentation tank 4 for flocculation precipitation reaction to remove impurities such as suspended solids and iron ions, obtaining a precipitate and a clear liquid. The precipitate is pumped into the sludge tank 401, and the clear liquid is pumped into the clear water tank 5.

[0050] In step (4), the subsequent treatment of the precipitate in the sludge tank 401 includes: pumping the precipitate into the filter press 402 for filter pressing treatment to obtain a cake and a filtrate. The cake is discharged, and the filtrate is returned to the desulfurized waste liquid water tank 1.

[0051] (5) Pump the effluent (clear liquid) from the sedimentation tank 4 into the filter 6 (specifically a multi-media filter, but not limited to this) in the clear water tank 5 for filtration to further remove suspended solids and colloids. After filtration, it also includes: using flushing water to backwash the filter membrane in the filter 6, and the washing liquid generated during the backwashing process is returned to the desulfurized waste liquid water tank 1.

[0052] (6) Pump the effluent (clear liquid) from the filter 6 into the ultrafiltration device 7 (specifically, a ceramic ultrafilter is used, but not limited to this) for ultrafiltration treatment to obtain clear liquid, which is introduced into the ultrafiltration water tank 8. Additionally, after ultrafiltration is completed, it also includes: backwashing the ceramic membrane in the ultrafiltration device 7 with flushing water, and the washing liquid generated during the backwashing process is returned to the desulfurized waste liquid water tank 1.

[0053] (7) Pump the effluent (clear liquid) from the ultrafiltration device 7 from the ultrafiltration water tank 8 into the first nanofiltration membrane device 91 for primary nanofiltration treatment to separate ammonium thiocyanate from the waste liquid. These separated thiocyanic acids are transferred to the nanofiltration product water, completing the primary separation of ammonium thiocyanate from other impurity salts in the waste liquid, and obtaining primary nanofiltration concentrated liquid and primary nanofiltration product water. Among them, the primary nanofiltration concentrated liquid is pumped into the first concentrated liquid tank 92, and the primary nanofiltration product water is pumped into the second product water tank 102 as the main water (inlet water) for secondary reverse osmosis treatment. Additionally, after the primary nanofiltration treatment is completed, it also includes: backwashing the first nanofiltration membrane device 91 with ultrapure water, and the flushing water generated during the backwashing process is introduced into the clear water tank 5 or used for backwashing the filter 6 and the ultrafiltration device 7.

[0054] (8) According to a volume ratio of 3:1, pump the water stored in the water distribution tank into the first concentrated liquid tank 92 to dilute the primary nanofiltration concentrated liquid, and then pump the diluted primary nanofiltration concentrated liquid into the second nanofiltration membrane device 93 for secondary nanofiltration treatment, so that the remaining ammonium thiocyanate in the primary nanofiltration concentrated liquid enters the secondary nanofiltration product water, completing the secondary separation of ammonium thiocyanate from other impurity salts in the waste liquid, and obtaining secondary nanofiltration concentrated liquid and secondary nanofiltration product water (effluent). Among them, the secondary nanofiltration concentrated liquid is pumped into the second concentrated liquid tank 94, and the secondary nanofiltration product water is pumped into the first product water tank 101 as the main water (inlet water) for primary reverse osmosis treatment.

[0055] (9) According to a volume ratio of 3:1, pump the water stored in the water distribution tank into the second concentrated liquid tank 94 to dilute the secondary nanofiltration concentrated liquid, and then pump the diluted secondary nanofiltration concentrated liquid into the third nanofiltration membrane device 95 for tertiary nanofiltration treatment, so that the remaining ammonium thiocyanate in the secondary nanofiltration concentrated liquid enters the tertiary nanofiltration product water, completing the tertiary separation of ammonium thiocyanate from other impurity salts in the waste liquid, and obtaining tertiary nanofiltration concentrated liquid and tertiary nanofiltration product water (effluent). Among them, the tertiary nanofiltration concentrated liquid is pumped into the third concentrated liquid tank 96, and the tertiary nanofiltration product water is pumped into the first product water tank 101 as the water for diluting the secondary nanofiltration product water in the primary reverse osmosis treatment.

[0056] In step (9), the tertiary nanofiltration concentrate collected in the third concentrate pond 96 also undergoes the following treatment: The tertiary nanofiltration concentrate is pumped into the heat exchanger 2 to exchange heat with the desulfurized waste liquid, raising the temperature of the tertiary nanofiltration concentrate and realizing the reuse of waste heat. Then, the heat-exchanged tertiary nanofiltration concentrate is pumped into the ammonia distillation unit 501 (such as an ammonia distillation tower, but not limited thereto) for denitrification treatment to recover ammonia water (reagent). This ammonia water is pumped into the reagent storage tank, enabling the recycling of ammonia water, which helps reduce the treatment cost.

[0057] (10) The nanofiltration product water collected in the first product pond 101 (obtained by mixing the secondary nanofiltration product water and the tertiary nanofiltration product water) is pumped into the first reverse osmosis membrane device 201 for primary reverse osmosis treatment. On the one hand, diluting the secondary nanofiltration product water with the tertiary nanofiltration product water can reduce the operating load of the first reverse osmosis membrane device, which is beneficial to improving the reverse osmosis efficiency. On the other hand, through reverse osmosis treatment, the volume of the reverse osmosis concentrate can also be reduced, obtaining the primary reverse osmosis concentrate and the primary reverse osmosis product water. Among them, the primary reverse osmosis concentrate is pumped into the second product pond 102, and the primary reverse osmosis product water is pumped into the filtrate water pond 205. At the same time, the primary reverse osmosis product water collected in the filtrate water pond 205 is pumped into the fourth reverse osmosis membrane device 206 for reverse osmosis treatment, separating ammonium thiocyanate from the primary reverse osmosis product water and transferring it to the first product pond, which is beneficial to increasing the recovery rate of ammonium thiocyanate and further reducing the content of ammonium thiocyanate in the reverse osmosis product water, enabling it to meet the discharge standards. After detection, the quality of the reverse osmosis product water in the fourth reverse osmosis membrane device 206 is as follows: the concentration of COD is 65.3 mg / L, the concentration of NH3-N is 7.8 mg / L, the concentration of N 总 is 23 mg / L, the concentration of P 总 is 0.8 mg / L, the concentration of cyanide is 0.17 mg / L, the concentration of sulfide is 0.13 mg / L, and the pH is 6.8, meeting the requirements of the indirect discharge standards in Table 3 of the "Emission Standards for the Iron and Steel and Coking Chemical Industries" (GB 16171-2012).

[0058] (11) The reverse osmosis concentrate collected in the second product water tank 102 (obtained by mixing the first-stage nanofiltration product water and the first-stage reverse osmosis concentrate) is pumped into the second reverse osmosis membrane device 202 for secondary reverse osmosis treatment to complete the secondary separation of ammonium thiocyanate and other impurity salts in the wastewater. On the one hand, using the first-stage reverse osmosis concentrate as makeup water to dilute the first-stage nanofiltration product water can also reduce the operating load of the second reverse osmosis membrane device. On the other hand, by using the second reverse osmosis device for secondary reverse osmosis, the volume of the reverse osmosis concentrate can be further reduced to obtain the secondary reverse osmosis concentrate and the secondary reverse osmosis product water. The secondary reverse osmosis concentrate is pumped into the concentrate water tank 203, and the secondary reverse osmosis product water is pumped into the makeup water tank, enabling the reuse of the secondary reverse osmosis product water and facilitating cost reduction.

[0059] (12) The secondary reverse osmosis concentrate collected in the concentrate water tank 203 is pumped into the third reverse osmosis membrane device 204 for tertiary reverse osmosis treatment to further reduce the volume of the reverse osmosis concentrate and obtain the tertiary reverse osmosis concentrate and the tertiary reverse osmosis product water. The tertiary reverse osmosis product water is pumped into the makeup water tank, enabling the reuse of the tertiary reverse osmosis product water and facilitating cost reduction.

[0060] (13) The tertiary reverse osmosis concentrate generated by the third reverse osmosis membrane device 204 is pumped into an evaporation crystallization reactor 301 (such as an MVR evaporation reactor) for evaporation crystallization to obtain ammonium thiocyanate products and condensate. The ammonium thiocyanate products can be sold as industrial salts, and the condensate can be introduced into the makeup water tank as makeup water, enabling reuse as well.

[0061] After testing, the recovery rate of the ammonium thiocyanate products obtained in this example is 98.435%, and the purity is 99.65%.

[0062] As can be seen from the above results, the resource utilization system for coking desulfurization waste liquid of the present utility model includes a reaction tank, a sedimentation tank, a clear water tank, an ultrafiltration device, a first nanofiltration membrane device, a first concentrated liquid tank, a second nanofiltration membrane device, a second concentrated liquid tank, a third nanofiltration membrane device, a first product water tank, a first reverse osmosis membrane device, a second product water tank, a second reverse osmosis membrane device, a concentrate water tank, and a third reverse osmosis membrane device, which are sequentially connected on the desulfurization waste liquid water tank. By using each device to cooperate in treating the desulfurization waste liquid, not only can ammonium thiocyanate be quickly and thoroughly separated from the waste liquid, but also the content of impurity salts in the ammonium thiocyanate concentrated liquid can be effectively reduced, so that high-quality ammonium thiocyanate products with high recovery rate and high purity can be obtained; at the same time, the resource utilization system for coking desulfurization waste liquid of the present utility model will not produce waste liquid, will not cause secondary pollution to the environment, is more green and environmentally friendly, has the advantages of convenient operation, easy control, low energy consumption, stable operation and being not affected by seasons, and is green and environmentally friendly, etc. It can be widely used to treat desulfurization waste liquid, can realize the batch and harmless treatment of desulfurization waste liquid, has high use value and good application prospects.

[0063] The above are only the preferred embodiments of the present utility model, and do not impose any form of limitation on the present utility model. Although the present utility model has been disclosed above with the preferred embodiments, it is not intended to limit the present utility model. Any person skilled in the art can make many possible changes and modifications to the technical solution of the present utility model by using the methods and technical contents disclosed above, or modify it into an equivalent embodiment with equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments based on the technical essence of the present utility model without departing from the technical solution of the present utility model still fall within the scope of the protection of the technical solution of the present utility model.

Claims

1. A resource utilization system for coking desulfurization waste liquid of coking coal material, characterized in that: The invention comprises a desulfurization waste liquid pool (1), wherein the desulfurization waste liquid pool (1) is connected in sequence to a reaction pool (3), a sedimentation pool (4), a clear water pool (5), an ultrafiltration device (7), a first nanofiltration membrane device (91), a first concentrated liquid pool (92), a second nanofiltration membrane device (93), a second concentrated liquid pool (94), a third nanofiltration membrane device (95), a first water production pool (101), a first reverse osmosis membrane device (201), a second water production pool (102), a second reverse osmosis membrane device (202), a concentrate pool (203), a third reverse osmosis membrane device (204) and an evaporation crystallization reactor (301) through pipelines; the water production outlet of the first nanofiltration membrane device (91) is connected to the water inlet of the second water production pool (102) through a pipeline; and the water production outlet of the second nanofiltration membrane device (93) is connected to the water inlet of the first water production pool (101) through a pipeline.

2. The resource utilization system of coking desulfurization waste liquid of coking coal material according to claim 1 is characterized in that: It also includes a water distribution tank; the water outlet of the water distribution tank is connected to the water inlet of the first concentrated liquid tank (92) and the second concentrated liquid tank (94) through pipelines.

3. The resource utilization system of coking desulfurization waste liquid of coking coal material according to claim 2 is characterized in that: The water inlet of the water distribution tank is connected to the water production outlet of the second reverse osmosis membrane device (202), the third reverse osmosis membrane device (204) and the evaporation crystallization reactor (301) through pipelines.

4. The resource utilization system of coking desulfurization waste liquid of coking coal material according to claim 1, characterized in that: The concentrated water outlet of the third nanofiltration membrane device (95) is also connected to a third concentrated liquid pool (96).

5. The resource utilization system of coking desulfurization waste liquid of coking coal material according to claim 4 is characterized in that: The water outlet of the third concentrated liquid pool (96) is also connected to an ammonia evaporation device (501); the ammonia evaporation device (501) is an ammonia evaporation tower.

6. The resource utilization system of coking desulfurization waste liquid of coking coal material according to claim 1, characterized in that: The water production outlet of the first reverse osmosis membrane device (201) is also connected to a filtrate pool (205), and the water outlet of the filtrate pool (205) is also connected to a fourth reverse osmosis membrane device (206); the concentrated water outlet of the fourth reverse osmosis membrane device (206) is connected to the water inlet of the first water production pool (101) via a pipeline.

7. The resource utilization system of coking desulfurization waste liquid of coking coal material according to any one of claims 1 to 6, characterized in that: A heat exchanger (2) is also provided between the desulfurization waste liquid pool (1) and the reaction pool (3); a filter (6) is also provided between the clean water pool (5) and the ultrafiltration device (7); and an ultrafiltration pool (8) is also provided between the ultrafiltration device (7) and the first nanofiltration membrane device (91).

8. The resource utilization system of coking desulfurization waste liquid of coking coal material according to claim 7, characterized in that: The reaction pool (3) is also connected to a reagent storage tank.

9. The resource utilization system of coking desulfurization waste liquid of coking coal material according to any one of claims 1 to 6, characterized in that: The sludge outlet of the sedimentation tank (4) is also connected to a sludge pool (401); the sludge outlet of the sludge pool (401) is connected to a filter press (402); the filtrate outlet of the filter press (402) and the water inlet of the desulfurization waste liquid pool (1) are connected via a pipeline.

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