Continuous refining device for sodium chloride waste salt

Abstract

The utility model discloses a sodium chloride waste salt continuous refining device which comprises a refining kettle, a feed port and a discharge port are arranged on the refining kettle, the feed port of the refining kettle is respectively connected with a weighing stock bin, a liquid caustic soda tank and a water storage tank, and the discharge port of the refining kettle is connected with a refined salt centrifugal machine. A liquid phase outlet of the refined salt centrifugal machine is connected with the water storage tank, and a salt outlet is connected with the refined salt storage tank. According to the sodium chloride waste salt refining device, automation of the sodium chloride waste salt refining process is achieved through combination of the conveyor, the weighing stock bin, the refining kettle, the refined salt centrifugal machine and the like, the waste salt refining operation process is simplified, operation is relatively simple, the number of supporting facilities is small, the requirement for manual operation is reduced, and the cost of enterprises for treating related waste salt is effectively reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of sodium chloride continuous refining device, belong to sodium chloride refining technical field. BACKGROUND

[0002] A large amount of high-salt organic wastewater is generated in the production process of agricultural chemical industry, which is mainly treated by evaporation and concentration. Due to the mechanisms of embedding, entrainment and co-crystallization, the industrial waste salt produced in the evaporation and crystallization process may contain organic pollutants to varying degrees. Due to the influence of a small amount of organic matter in the salt, industrial waste salt is mostly disposed as hazardous solid waste, and solid waste salt landfill disposal will inevitably lead to resource waste and secondary pollution risk of ecological environment. Therefore, the resource utilization of industrial solid waste salt can greatly realize the recycling of industrial raw materials such as sodium chloride, greatly reduce the landfill load of hazardous waste salt, and reduce the risk of secondary pollution of the environment, which is of great significance. Generally, the refined sodium chloride recovered by resource utilization is mainly used in the chlor-alkali and glass industries. These refined salt users often have strict requirements on the total organic carbon (TOC) content in the recovered sodium chloride crystals. For example, in the chlor-alkali industry, in order to protect the ion membrane equipment from organic pollution, the TOC content of refined sodium chloride is generally required to be less than 30 mg / kg, and the lower the TOC content, the better. Therefore, the main difficulty in the maximum resource utilization of industrial solid waste salt is to remove the organic pollutants TOC in the industrial solid waste salt. The current industry mainly uses melting furnace treatment, high-temperature carbonization and solvent washing to refine the waste salt, which has a certain effect on the removal of organic matter in the salt.

[0003] CN108423692A discloses a method for purifying and refining sodium chloride from waste salt produced in the production of vitamin C, which comprises the following steps: 1) dissolving the waste salt produced in the production of vitamin C in water, adding a precipitating agent to make impurities form a precipitate; the precipitating agent is sodium hydroxide solution, and the precipitating aid is one or more of sodium carbonate solution, calcium chloride solution and ammonium carbonate solution; 2) decolorizing with activated carbon and then filtering; 3) concentrating the filtrate under reduced pressure, recovering purified water, centrifuging the material, and recovering the mother liquor after centrifugation; drying the dehydrated wet product to obtain the product sodium chloride.

[0004] CN215592631U discloses a production system for refining sodium chloride solution containing sodium sulfate impurities, the sodium chloride solution containing sodium sulfate impurities is treated by nanofiltration membrane, and the effluent is evaporated and centrifuged to obtain refined sodium chloride product. The device comprises: the effluent outlet of the nanofiltration membrane is connected with the feed tank, the outlet of the feed tank is connected with the cold side of the sodium chloride preheater through the feed pump, the cold side outlet is connected with the sodium chloride circulating pipe, the sodium chloride circulating pipe is connected with the tube side of the sodium chloride heater through the sodium chloride circulating pump, the tube side outlet is connected with the circulating liquid inlet of the sodium chloride crystallizer, the salt leg outlet at the bottom of the crystallizer is connected with the inlet of the thick tank through the sodium chloride discharge pump, the bottom outlet of the thick tank is connected with the inlet of the centrifuge, and the salt outlet of the centrifuge is connected with the sodium chloride salt pipe. The liquid phase outlet of the centrifuge and the overflow port of the thick tank are respectively connected with the inlet of the mother liquor tank, the outlet of the mother liquor tank is connected with the sodium chloride circulating pipe through the mother liquor pump and the mother liquor pipe, and the sodium chloride mother liquor pipe is also connected with the refrigeration system.

[0005] CN115846356A discloses a method for removing organic pollutants from industrial waste salt, which comprises the following steps: sending the industrial solid waste salt into a mixing device and adding sodium hypochlorite for reaction; after the reaction, entering a drying device and adding metal balls; the temperature of the drying device is 80-100℃, and the time is 0.5-2 hours; the dried industrial solid waste salt enters a thermal desorption device, the waste salt is heated to 550-650℃ in the thermal desorption device for 2-4 hours, and the waste salt from which the organic pollutants are removed enters a screening device; the metal balls and the waste salt are separated, and the separated waste salt enters a cooling device and is ready for subsequent treatment.

[0006] CN112279274A discloses a method for removing COD from industrial by-product salt, which comprises the following steps: (1) mixing the industrial by-product salt with a salt washing solvent (an organic solvent) to obtain a prepared slurry; and (2) performing solid-liquid separation on the prepared slurry obtained in step (1), and drying the solid phase obtained in the solid-liquid separation to obtain a refined salt product.

[0007] CN117026250A discloses a comprehensive treatment and recycling method for waste salt resource utilization, which comprises the following steps: (1) primary refining treatment: dissolving sodium chloride waste salt generated by treating incineration fly ash, acidifying, chemical reaction treatment, flocculation and precipitation, filtering, removing generated hydroxide precipitate and carbonate precipitate, and simultaneously oxidizing and decomposing ammonia nitrogen compounds therein to obtain primary refined brine; (2) secondary brine treatment: removing residual metal ions and heavy metal ions in the primary refined brine by using resin adsorption to obtain secondary refined brine; and (3) ion membrane electrolysis: performing ion membrane electrolysis on the secondary refined brine to obtain a finished alkali liquor.

[0008] The methods reported in the prior art have certain deficiencies, for example, the high-temperature oxidation method for removing organic matters in the salt has high energy consumption, high requirements for the material quality of the equipment, and great influence on the environment due to the generation of flue gas, and thus requires another waste gas treatment facility, and has high investment cost; the membrane treatment and solvent washing have relatively mild reaction conditions and low requirements for the material quality of the equipment compared with the high-temperature oxidation reaction, but still have a complicated process and a risk of safety hazards in the process. Practical new type content

[0009] The utility model aims at providing a continuous refining device for sodium chloride waste salt, which can refine sodium chloride waste salt containing organic matters to meet the requirement of reuse and realize continuous refining and recycling of by-product sodium chloride.

[0010] The specific technical scheme of the utility model is as follows:

[0011] A continuous refining device for sodium chloride waste salt, which comprises a refining kettle, a feed inlet and a discharge outlet are arranged on the refining kettle, the feed inlet of the refining kettle is connected with a weighing bin, a liquid alkali tank and a water storage tank respectively, the discharge outlet of the refining kettle is connected with a refined salt centrifuge, the liquid phase outlet of the refined salt centrifuge is connected with the water storage tank, and the salt outlet of the refined salt centrifuge is connected with a refined salt storage tank.

[0012] Further, a circulating material inlet is further arranged on the refining kettle, and the discharge outlet and the circulating material inlet of the refining kettle are connected through a circulating pump.

[0013] Further, a three-way pipe is arranged on the pipeline between the circulating pump and the circulating material inlet, and the refining kettle is connected with the refined salt centrifuge through the three-way pipe.

[0014] Further, the weighing bin is connected with the refining kettle through a conveyor.

[0015] Further, the feed inlet of the weighing bin is connected with the salt outlet of an original salt centrifuge through a conveyor, and the salt outlet of the original salt centrifuge outputs sodium chloride waste salt.

[0016] Further, a stirring structure, a pH meter and / or a temperature control structure are arranged in the refining kettle.

[0017] Further, a material transferring pump and a three-way pipe are arranged on the pipeline connecting the water storage tank with the refining kettle.

[0018] The device of the utility model is suitable for refining industrial sodium chloride salt, especially for refining a kind of sodium chloride waste salt containing trace organic matters, and the sodium chloride waste salt is preferably sodium chloride waste salt generated in the atrazine industry. If the sodium chloride waste salt generated in the atrazine industry or the waste salt similar to the pollutants of the sodium chloride waste salt in the atrazine industry, the device of the utility model can be directly used for treatment, and if the pollutants are quite different, the device can be combined with other devices to treat the waste salt.

[0019] The utility model has the advantages of the following:

[0020] 1. The sodium chloride waste salt is refined in the refining kettle with liquid caustic soda, the TOC content in the salt is reduced by the principle that the organic matter in the waste salt has high solubility in an alkaline environment, the organic matter in the waste salt is effectively removed by controlling the solution pH and water consumption in the refining kettle, the refining method is simple and effective, the refining effect is good, the reaction conditions are mild, the requirement for the equipment material is low, the safety hidden danger is relatively small, and the cost advantage is achieved in operation.

[0021] 2. The sodium chloride waste salt refining process is automated by the combination of the conveyor, the weighing bin, the refining kettle, the refined salt centrifuge and other devices, the waste salt refining operation process is simplified, the operation is relatively simple, the supporting facilities are few, the demand for human operation is reduced, and the cost of the enterprise for disposing the related waste salt is effectively reduced.

[0022] 3. The device can realize continuous regeneration of the sodium chloride waste salt, and is particularly suitable for the waste salt generated in the production process of atrazine. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 FIG. 1 is a structural schematic view of a sodium chloride waste salt continuous refining device according to an embodiment.

[0024] Figure 2 FIG. 2 is a structural schematic view of a sodium chloride waste salt continuous refining device according to another embodiment.

[0025] In the drawings, 1 is an original salt centrifuge, 2 is a pipe chain conveyor, 3 is a weighing bin, 4 is a screw conveyor, 5 is a refining kettle, 6 is a liquid caustic soda tank, 7 is a circulating pump, 8 is a refined salt centrifuge, 9 is a refined salt storage tank, 10 is a water storage tank, and 11 is a material transfer pump. DETAILED DESCRIPTION

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present utility model, and not all of them. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model. It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in the embodiments of the present utility model are only used to explain the relative positional relationship and movement of the components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indicator will also change accordingly. In addition, the number of components, structures or devices involved in the present utility model can be one or more. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present utility model.

[0027] Example 1

[0028] like Figure 1 The diagram shows one configuration of the continuous refining device for sodium chloride waste salt according to this invention. It includes a refining vessel 5, which has an inlet and an outlet. The number of inlets and outlets can be one, two, or more. The inlet is preferably located at the top or upper part of the refining vessel, and the outlet is preferably located at the bottom or lower part. The inlet of the refining vessel is connected to a weighing silo 3, a liquid alkali tank 6, and a water storage tank 10. The refining vessel and the weighing silo are connected by a conveying device such as a screw conveyor 4 to continuously transport the sodium chloride waste salt into the refining vessel. The liquid alkali tank and the refining vessel are connected by pipelines. The liquid alkali tank contains dilute sodium hydroxide or other alkaline solutions and can be equipped with a flow meter. A transfer pump can be installed between the liquid alkali tank and the refining vessel to continuously add the alkaline solution to the refining vessel in a specific amount. The water storage tank and the refining vessel are also connected by pipelines. The water in the storage tank can be fresh water, water recycled from various industrial processes, or centrifugal water generated during the waste salt refining process. The discharge port of the refining vessel is connected to the refined salt centrifuge 8, and the liquid phase outlet of the refined salt centrifuge is connected to the water storage tank to recycle this portion of the centrifugal water. The salt outlet of the refined salt centrifuge is connected to the refined salt storage tank 9. A transfer pump can be installed between the refining vessel and the refined salt centrifuge to accelerate the transfer of materials.

[0029] Further, the weighing bin contains sodium chloride waste salt, and a weighing module is arranged on the weighing bin, and the weight of the sodium chloride waste salt entering the refining kettle can be determined by the weight difference. Figure 1 As shown in the figure, the weighing bin is connected with the original salt centrifuge 1 through a conveying device such as a pipe chain conveyor 2, and the sodium chloride waste salt obtained from the salt outlet of the original salt centrifuge is continuously fed into the weighing bin through the conveyor, realizing continuous operation and improving the degree of automation.

[0030] Further, the refining kettle is a commonly used reaction kettle in industry, and the shape thereof has no special requirements, and the refining kettle has a shell, and the shell has a hollow reaction zone, and a stirring structure is arranged in the refining kettle to improve the uniformity of the materials in the kettle, and the stirring structure can be a common stirrer in the field, including a motor and a stirring rod driven by the motor, and stirring blades are arranged on the stirring rod, and the stirring blades can be frame type, paddle type, anchor type, screw type, etc., and the frame type is preferred.

[0031] Further, a temperature control structure such as a temperature control jacket can be arranged on the refining kettle to control the temperature of the refining kettle.

[0032] Further, a material transferring pump 11 can be arranged on the pipeline connecting the water storage tank and the refining kettle, and a three-way joint can also be arranged to discharge the water in the water storage tank when the water does not meet the requirements.

[0033] The sodium chloride waste salt suitable for the device of the utility model can be sodium chloride waste salt generated in the pesticide and chemical industry, for example, can be waste salt produced by centrifugation after atezine sodium chloride wastewater evaporation treatment, but is not limited thereto. The utility model reacts sodium chloride waste salt and alkali liquor in the refining kettle, reduces the TOC content in the salt by using the principle that the solubility of organic matter in the waste salt is high in an alkaline environment, the equipment and process are simple, the requirement for the equipment is low, and there is a high cost advantage.

[0034] Example 2

[0035] As Figure 2 Another combination mode of the sodium chloride waste salt continuous refining device is shown in the figure, and a circulating material port is further arranged on the refining kettle, and the discharge port and the circulating material port of the refining kettle are connected through a pipeline, and a circulating pump 7 is arranged on the pipeline, so that the materials in the refining kettle are self-circulated. By combining the stirring structure and the self-circulation, the solid waste salt and water in the kettle are in a uniform distribution state, which can effectively prevent the deposition of solid salt in the kettle and maximize the solid-liquid mass transfer. A three-way joint is arranged on the pipeline between the circulating pump and the circulating material port, one opening of the three-way joint is connected with the refining salt centrifuge, and when the refining in the refining kettle is completed, the refining kettle and the refining salt centrifuge can be connected through the three-way joint.

[0036] Further, the pH meter is connected with the liquid alkali tank to control the amount of the liquid alkali.

[0037] In addition to the above description, the other structure of the sodium chloride waste salt continuous refining device is consistent with that described in Embodiment 1.

[0038] The process of refining the waste salt by using the device is as follows:

[0039] 1. Sodium chloride waste salt conveying: the outlet end of the original salt centrifuge 1 is connected with the input end of the pipe chain conveyor 2, the sodium chloride waste salt centrifuged out of the original salt centrifuge 1 is conveyed to the weighing hopper 3 through the pipe chain conveyor 2, the outlet end of the weighing hopper 3 is connected with the screw conveyor 4, the salt is conveyed to the refining kettle 5, the interface between the screw conveyor and the refining kettle is translucent and soft, so that whether the salt is normally discharged during the conveying process can be observed, and according to the weight loss feedback of the weighing hopper 3, the alkali liquor in the liquid alkali tank and the water in the water storage tank are added into the refining kettle according to the proportion;

[0040] 2. Sodium chloride waste salt refining: the mass ratio of the sodium chloride waste salt to the alkali liquor in the refining kettle is 1.5-2.5:1, the solid content in the kettle is 20-40wt%, and the local salt accumulation is avoided to be too much or too little. The stirring in the kettle is started, the reflux circulation is performed between the circulating pump 7 and the refining kettle 5, the circulating pump is self-circulated at a large flow rate, the flow rate is 10-30m3 / h, the uniform distribution of the solid and liquid in the refining kettle 5 is ensured by the cooperation of the stirring, and the obvious salt deposition is avoided;

[0041] 3. Separation of refined sodium chloride: after sufficient refining, the slurry liquid in the refining kettle is conveyed to the refined salt centrifuge 8 through the three-way pipe by the circulating pump 7, the centrifugal water is conveyed to the water storage tank 10, and the refined salt is conveyed into the refined salt storage tank after being centrifuged. After the refining, the removal rate of the TOC content of the obtained refined sodium chloride is greater than 90%, and the industrial wet salt secondary standard is met;

[0042] 4. Water washing and water reuse and discharge: the water in the water storage tank is conveyed back to the refining kettle 5 for recycling, and when the water quality does not meet the requirements, the water is discharged and disposed through the three-way pipe.

[0043] Embodiment 3

[0044] For example, the refining results of the atilalan waste salt refined by the evaporation of the atilalan waste water are taken as an example, the waste salt is refined according to the device and the mode of Embodiment 2, the alkali liquor used is 5% sodium hydroxide solution, the mass ratio of the waste salt to the alkali liquor is 2:1, the solid content in the kettle is 30wt%, and the circulating flow rate of the circulating pump is 20 m 3 / h. Three batches of waste salt are treated, and the indexes of the finally obtained refined salt are as follows:

[0045]

Claims

1. A continuous refining apparatus for waste sodium chloride salt, characterized by: The refining kettle is provided with a feeding port and a discharging port, the feeding port of the refining kettle is connected with a weighing bin, a liquid alkali tank and a water storage tank respectively, the discharging port of the refining kettle is connected with a refined salt centrifugal machine, the liquid phase outlet of the refined salt centrifugal machine is connected with the water storage tank, and the salt outlet is connected with a refined salt storage tank.

2. The apparatus for continuous refining of sodium chloride waste salt according to claim 1, characterized in that: The refining kettle is further provided with a circulating material port, and the discharging port of the refining kettle is connected with the circulating material port through a circulating pump.

3. The apparatus for continuous refining of sodium chloride waste salt according to claim 2, characterized in that: A three-way pipe is arranged on the pipeline between the circulating pump and the circulating material port, and the refining kettle is connected with the refined salt centrifugal machine through the three-way pipe.

4. The apparatus for continuous refining of sodium chloride waste salt according to claim 1, characterized in that: The weighing bin is connected with the refining kettle through a conveyor.

5. The apparatus for continuous refining of sodium chloride waste salt according to claim 4, characterized in that: The weighing bin is connected with the refining kettle through a screw conveyor.

6. The apparatus for continuous refining of sodium chloride waste salt according to claim 1, characterized in that: The feeding port of the weighing bin is connected with the salt outlet of the original salt centrifugal machine through a conveyor, and the salt outlet of the original salt centrifugal machine outputs sodium chloride waste salt.

7. The apparatus for continuous refining of sodium chloride waste salt according to claim 6, characterized in that: The feeding port of the weighing bin is connected with the original salt centrifugal machine through a pipe chain conveyor.

8. The apparatus for continuous refining of sodium chloride waste salt according to claim 1, characterized in that: The refining kettle is provided with a stirring structure and / or a pH meter.

9. The apparatus for continuous refining of sodium chloride waste salt according to claim 1 or 8, characterized in that: The refining kettle is provided with a temperature control structure.

10. The apparatus for continuous refining of sodium chloride waste salt according to claim 2 or 3, characterized in that: A material transferring pump and a three-way pipe are arranged on the pipeline connecting the water storage tank with the refining kettle.

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