Sodium chloride and sodium sulfate mixed waste salt pretreatment system

Abstract

The embodiment of the utility model discloses a pretreatment system for mixed waste salt of sodium chloride and sodium sulfate. The pretreatment system comprises a carbonization unit and a pretreatment unit, wherein the carbonization unit comprises a charging system connected with a carbonization furnace and a tail gas treatment system connected with the carbonization furnace; the redissolution water treatment unit comprises a dissolution tank connected with a discharge port of the carbonization furnace, the dissolution tank is connected with a reaction tank, an inlet of the reaction tank is further connected with a medicament tank, the reaction tank is connected with a plate-and-frame filter press, and a liquid outlet end of the plate-and-frame filter press is connected with a cache system. Through the arrangement of the system structure, the industrial waste salt treatment process can be more systematized, and waste salt treatment is completed by a better treatment path, so that the treatment efficiency of substances such as salt, organic matters and heavy metals is improved, and the cost is reduced.

Description

Technical Field

[0001] The disclosed embodiments relate to the technical field of industrial waste salt treatment, and specifically to a sodium chloride and sodium sulfate mixed waste salt pretreatment system. Background Art

[0002] The information disclosed in this background technology section is only intended to increase the understanding of the overall background of the present disclosure, and shall not necessarily be regarded as an admission or any form of suggestion that the information constitutes the relevant technology that has been known to ordinary technicians in the field.

[0003] The treatment of industrial waste salt is a major problem in the environmental protection industry. Since most industrial waste salts pollute the environment, most of them are hazardous wastes and cannot be directly landfilled, but need further treatment. The current method of industrial waste salt disposal is mainly to pre-treat the waste salt to obtain high-salt wastewater, then evaporate the salt to obtain one or more by-product salts in steps, and finally sell the by-product salts or use them in other industries, thereby realizing the resource utilization of waste salt.

[0004] Currently, industrial waste salt is mainly sodium salt, which has the characteristics of high COD and high hardness. If it is dissolved in water without pretreatment, it will affect the continuity and stability of subsequent processes, especially causing scaling and blockage of evaporation equipment, affecting the evaporation effect. Utility Model Content

[0005] To this end, the embodiments of the present disclosure provide a sodium chloride and sodium sulfate mixed waste salt pretreatment system and method to solve the problem in the related art that sodium salt in industrial waste salt has high COD and high hardness, which causes its solubility in water to affect the stability of subsequent process treatment.

[0006] In order to achieve the purpose of reducing the blockage of evaporation equipment and the impact on evaporation effect caused by industrial waste salt during the subsequent evaporation treatment process, the embodiments of the present disclosure provide the following technical solutions:

[0007] In a first aspect of the embodiments of the present disclosure, a sodium chloride and sodium sulfate mixed waste salt pretreatment system is provided, comprising a carbonization unit and a redissolved water treatment unit.

[0008] Carbonization unit: comprising a feeding system, wherein the feeding system is connected to the carbonization furnace and the tail gas treatment system of the carbonization furnace;

[0009] The heavy dissolving water treatment unit includes a dissolving tank connected to the discharge port of the carbonization furnace, the dissolving tank is connected to the reaction tank, the inlet of the reaction tank is also connected to the reagent tank, the inlet of the reaction tank is connected to the first neutralizer tank, the reaction tank is connected to the plate and frame filter press, and the liquid outlet of the plate and frame filter press is connected to the buffer system.

[0010] In one embodiment, the exhaust gas treatment system includes a furnace air heat exchanger connected to an air outlet of a combustion chamber of the carbonization furnace, and a heat exchange port of the furnace air heat exchanger is connected to an air inlet of the furnace of the carbonization furnace.

[0011] In one example, the exhaust gas treatment system further comprises a combustion-supporting air heat exchanger connected to the furnace air outlet of the carbonization furnace via a separation device, and the heat exchange port of the combustion-supporting air heat exchanger is connected to the burner of the carbonization furnace.

[0012] In one example, the separation device includes a cyclone separator connected to the air outlet of the furnace of the carbonization furnace, the outlet of the cyclone separator is connected to a bag filter, and the air outlet of the bag filter is connected to the air inlet of the combustion air heat exchanger.

[0013] In one embodiment, the cyclone separator includes a straight cylinder, an air outlet pipe is provided above the straight cylinder and inserted into the interior of the straight cylinder, an oblique air inlet pipe is provided on the outer wall of the straight cylinder, the fixed bottom of the straight cylinder is connected to a conical cylinder, the bottom of the conical cylinder is provided with a conical discharge port, and the bottom side of the conical discharge port is connected to an ash hopper.

[0014] In one example, the carbonization furnace includes a base, on which is provided a furnace body capable of axial rotation, a spiral guide plate is provided inside the furnace body, a combustion chamber is provided outside the furnace body, a plurality of burners are provided at the bottom of the combustion chamber, a feed inlet and a furnace air outlet are provided at one end of the furnace body, a feed outlet and a furnace air inlet are provided at the other end of the furnace body, and a combustion chamber air outlet is provided at the top of the combustion chamber.

[0015] In one embodiment, a rotating gear fixed to the outer surface of the furnace body is disposed on the base, and a central shaft mounted on the base is disposed at both ends of the furnace body.

[0016] In one embodiment, two rows of chains are symmetrically arranged on the inner wall of the furnace body, and the chains are arranged at intervals between the pitches of the spiral guide plates.

[0017] In one example, the feeding system includes a feeding bin, the bottom of which is connected to a lifting bucket via a screw conveyor, a crusher is provided at a top outlet of the lifting bucket, and a discharge port of the crusher is connected to a feeding port of a carbonization furnace.

[0018] In one example, the cache system includes a cache tank, a water supply tank and a neutralization tank, the outlets of the cache tank and the water supply tank are connected to the inlet of the neutralization tank, and the inlet of the neutralization tank is also connected to a second neutralizer tank.

[0019] In a second aspect of the embodiments of the present disclosure, a method for pretreating a mixture of sodium chloride and sodium sulfate waste salt is provided, and the method includes the following steps when the above system is used:

[0020] Step 1: The waste salt is transported to the feed bin for short-term storage, and then transported to the crusher through a screw conveyor and a bucket elevator for crushing;

[0021] Step 2: The crushed waste salt is transported to the carbonization furnace through a feeding screw conveyor for carbonization treatment, and most of the organic matter in the waste salt is carbonized and decomposed;

[0022] Step 3: The carbonized waste salt enters the dissolution tank and is mixed with water in proportion to dissolve the waste salt into a saturated salt solution, which fully reacts with the chemical agent in the reaction tank;

[0023] Step 4: The material is filtered through a plate and frame filter press, and the filter cake is unloaded every 4 to 6 hours. The filter cake produced is organic carbide and the reaction precipitate produced in step 3. The filtrate passes through a buffer tank and adjusts the pH to 6 to 8 to obtain a qualified finished liquid for storage and standby use.

[0024] In one embodiment, the storage time of the waste in the feed bin in step 1 is 1 to 2 hours.

[0025] In one embodiment, the temperature of the carbonization furnace in step 2 is above 550° C., and the carbonization time is 1.5 to 2 hours.

[0026] In one example, in step 3, the mixing ratio of the carbonized waste salt and water is 1:3, and the reaction time of adding the chemical agent is 5 to 10 hours.

[0027] According to the embodiments of the present disclosure, the pretreatment system and method have the following advantages:

[0028] The setting of the system structure can make the implementation of the industrial waste salt treatment process more systematic, so that the waste salt treatment has been completed through a better treatment path, thereby accelerating the treatment efficiency of desalination, organic matter, heavy metals and other substances and reducing costs;

[0029] Through the implementation of the system and method, organic matter, heavy metals, fluoride ions and other water-insoluble substances in the mixed waste salt can be removed, and the total hardness in the finished liquid can be reduced to below 200 ppm, COD can be reduced to 60-80 ppm, heavy metal ions, fluoride ions, etc. can be reduced to 5-50 ppm, and turbidity can be reduced to below 10 NTU.

[0030] The pretreatment method for resource disposal of waste salt disclosed in the present invention can continuously and stably convert hazardous solid waste salt into high-salt water with low COD and low hardness at a relatively low operating cost, thus continuously providing raw materials for the back-end process. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the related technologies, the following briefly introduces the drawings required for the embodiments or the related technical descriptions. Obviously, the drawings described below are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0032] The structures, proportions, sizes, etc. illustrated in this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which the present disclosure can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by the present disclosure, should still fall within the scope of the technical contents disclosed in the present disclosure.

[0033] Figure 1 The present invention is a schematic flow chart of a sodium chloride and sodium sulfate mixed waste salt pretreatment system according to an exemplary embodiment;

[0034] Figure 2 It is a flow chart of a carbonization unit in a sodium chloride and sodium sulfate mixed waste salt pretreatment system according to an exemplary embodiment;

[0035] Figure 3 It is a flow chart of a sodium chloride and sodium sulfate mixed waste salt pretreatment system according to an exemplary embodiment;

[0036] Figure 4 It is a structural diagram of a combustion chamber in a sodium chloride and sodium sulfate mixed waste salt pretreatment system according to an exemplary embodiment;

[0037] Figure 5 It is a structural diagram of a cyclone separator in a sodium chloride and sodium sulfate mixed waste salt pretreatment system according to an exemplary embodiment.

[0038] In the figure: 1, feeding system; 101, feeding bin; 102, screw conveyor; 103, lifting bucket; 104, crusher;

[0039] 2. Carbonization furnace; 201. Base; 202. Furnace body; 203. Spiral guide plate; 204. Combustion chamber; 205. Burner; 206. Feed inlet; 207. Furnace air outlet; 208. Discharge port; 209. Furnace air inlet; 210. Combustion chamber air outlet; 211. Rotating gear; 212. Chain;

[0040] 3. Tail gas treatment system; 301. Furnace air heat exchanger; 302. Combustion air heat exchanger;

[0041] 4. Separation equipment; 401. Cyclone separator; 4011. Straight cylinder; 4012. Air outlet pipe; 4013. Oblique air inlet pipe; 4014. Cone cylinder; 4015. Cone discharge port; 4016. Ash hopper; 402. Bag filter;

[0042] 5. Dissolving tank;

[0043] 6a, reaction tank A; 6b, reaction tank B;

[0044] 7a, medicine tank A; 7b, medicine tank B;

[0045] 8a, plate and frame filter press A; 8b, plate and frame filter press B;

[0046] 9. Cache system; 901. Cache pool; 902. Water supply pool; 903. Neutralization tank; 904. Hydrochloric acid tank B;

[0047] 10. Hydrochloric acid tank A;

[0048] 11. Liquid alkali tank. DETAILED DESCRIPTION

[0049] The following is a description of the implementation methods of the present disclosure by specific specific embodiments. People familiar with the technology can easily understand other advantages and effects of the present disclosure from the contents disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present disclosure, but not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present disclosure.

[0050] The terms such as "upper", "lower", "left", "right", "middle", etc. cited in this specification are only for the convenience of description and are not used to limit the scope of implementation of the present disclosure. Changes or adjustments to their relative relationships should be regarded as the scope of implementation of the present disclosure without substantially changing the technical content.

[0051] like Figure 1 As shown, it shows a sodium chloride and sodium sulfate mixed waste salt pretreatment system shown in an exemplary embodiment of the present disclosure. It includes a carbonization unit and a heavy dissolution water treatment unit,

[0052] like Figure 2 As shown, it shows a carbonization unit in a sodium chloride and sodium sulfate mixed waste salt pretreatment system shown in an exemplary embodiment of the present disclosure: comprising a feeding system 1, the feeding system 1 is connected to a carbonization furnace 2, and a tail gas treatment system 3 connected to the carbonization furnace 2;

[0053] like Figure 3As shown, it shows a re-dissolving water treatment unit in a sodium chloride and sodium sulfate mixed waste salt pretreatment system shown in an exemplary embodiment of the present disclosure: it includes a dissolving tank 5 connected to the discharge port 208 of the carbonization furnace 2, the dissolving tank 5 is connected to the reaction tank, the inlet of the reaction tank is also connected to the reagent tank, the inlet of the reaction tank is connected to the first neutralizer tank, the reaction tank is connected to a plate and frame filter press, and the liquid outlet of the plate and frame filter press is connected to the buffer system 9.

[0054] The setting of the system structure can make the implementation of the industrial waste salt treatment process more systematic, so that the waste salt treatment can be completed through a better treatment path, thereby accelerating the treatment efficiency of desalination, organic matter, heavy metals and other substances and reducing costs.

[0055] Among them, the reaction pool includes reaction pool A6a and reaction pool B6b, the reagent tank includes reagent tank A7a and reagent tank B7b, the first neutralizer tank includes hydrochloric acid tank A10 and liquid alkali tank 11, and the plate and frame filter press includes plate and frame filter press A8a and plate and frame filter press B8b.

[0056] In one example, the tail gas treatment system 3 includes a furnace air heat exchanger 301 connected to the combustion chamber air outlet 210 of the carbonization furnace 2, and the heat exchange port of the furnace air heat exchanger 301 is connected to the furnace air inlet 209 of the carbonization furnace 2. The combustion chamber 204 uses natural gas as fuel, and the tail gas of 400-600°C after the combustion of natural gas is discharged from this port. The discharged tail gas passes through the furnace air heat exchanger 301 to heat the external air and is sent to the roof by the jacket induced draft fan for emptying. The heated air is added to the carbonization furnace 2 to prevent the external cold air from directly entering the furnace and exploding the furnace. The external air provides the oxygen required for the high-temperature oxidation and decomposition of organic matter, ensures that the excess oxygen in the furnace is about 5%, and takes away the water vapor generated by the drying of the waste salt in the furnace. The hot air temperature is about 100-300°C.

[0057] In one example, the tail gas treatment system 3 also includes a combustion-supporting air heat exchanger 302 connected to the furnace air outlet 207 of the carbonization furnace 2 through the separation device 4, and the heat exchange port of the combustion-supporting air heat exchanger 302 is connected to the burner 205 of the carbonization furnace 2. The water vapor evaporated in the furnace, the organic oxidation tail gas and the hot air are all discharged from the furnace air outlet 207, and enter the combustion-supporting air heat exchanger 302 through the separation device 4, and the air temperature is about 60-200°C. The external air is preheated and discharged, and the heated external air enters the burner 205 to support combustion.

[0058] Among them, see again Figure 1As shown, the separation device 4 includes a cyclone separator 401 connected to the furnace outlet 207 of the carbonization furnace 2, the outlet of the cyclone separator 401 is connected to the bag filter 402, and the air outlet of the bag filter 402 is connected to the air inlet of the combustion air heat exchanger 302. The flue gas generated after the carbonization of the waste salt organic matter is about 60-200°C. After the large particles of dust are removed by the cyclone dust collector, it enters the bag filter 402 to remove dust and other particulate matter. The dust removal efficiency is above 99.9%, and the outlet dust concentration is 10-50 mg / Nm 3 , and then the flue gas enters the combustion air heat exchanger 302, and after heat exchange with the combustion air, the temperature is reduced and sent to the flue gas main duct by the furnace induced draft fan for proper treatment.

[0059] Among them, Figure 5 As shown, the cyclone separator 401 includes a straight cylinder 4011, an air outlet pipe 4012 is provided above the straight cylinder 4011 and is inserted into the interior of the straight cylinder 4011, an oblique air inlet pipe 4013 is provided on the outer wall of the straight cylinder 4011, the fixed bottom of the straight cylinder 4011 is connected to the conical cylinder 4014, the bottom of the conical cylinder 4014 is provided with a conical discharge port 4015, and the bottom side of the conical discharge port 4015 is connected to the ash hopper 4016.

[0060] The interior of the straight cylinder 4011 is provided with a spiral structure, which is connected to the external oblique tangential air inlet pipe 4013. The spiral structure is provided on the outer wall of the air outlet pipe 4012 located in the inner part of the straight cylinder 4011 section. The straight cylinder 4011 section is composed of a height H1 and a diameter D. The diameter D is the most basic dimension of the cyclone dust collector. Reducing the diameter of the straight cylinder 4011 can increase the tangential velocity of the airflow, increase the centrifugal force on the dust particles, and make the dust particles easier to capture. However, the diameter should not be too small. A too small diameter will result in limited processing air volume and easily cause blockage, which in turn reduces the dust removal efficiency. The height H1 of the straight cylinder 4011 section is 1.8D.

[0061] The exhaust gas after capturing coarse particles is discharged from the equipment through the air outlet. The diameter D1 is 0.6D, and the length H2 extending into the equipment is 1.3D.

[0062] The conical cylinder 4014 part connects the straight cylinder 4011 section and the conical section discharge port, and the diameter gradually decreases, the tangential velocity of the airflow gradually increases, the centrifugal force on the dust particles gradually increases, and the gas-solid separation effect is better. The cone angle of the conical section is 16°, and its height can be calculated based on the diameter D of the straight cylinder 4011 section and the diameter D2 of the conical section discharge port. The conical discharge port 4015 is provided at the bottom, and its diameter D2 is 0.4D.

[0063] The ash hopper 4016 connected to the conical discharge port 4015 is used to store the captured dust particles, and its diameter is 0.5 to 0.6 D. The discharge port 208 of the ash hopper 4016 is generally connected to a lock valve at the back to prevent air leakage.

[0064] like Figure 4 As shown, the carbonization furnace 2 includes a base 201, on which is provided a furnace body 202 capable of axial rotation, a spiral guide plate 203 is provided inside the furnace body 202, a combustion chamber 204 is provided outside the furnace body 202, a plurality of burners 205 are provided at the bottom of the combustion chamber 204, a feed port 206 and a furnace air outlet 207 are provided at one end of the furnace body 202, a discharge port 208 and a furnace air inlet 209 are provided at the other end of the furnace body 202, and a combustion chamber air outlet 210 is provided at the top of the combustion chamber 204.

[0065] The carbonization furnace 2 can remove organic matter in the waste salt at high temperature, and the removal effect is obvious. A spiral guide plate 203 is arranged inside, which can continuously transport the waste salt forward under the action of the rotation of the furnace body 202, and remove the organic matter in the process. The furnace body 202 adopts 310S high temperature resistant material, with the front end connected to the feed chamber and the rear end connected to the discharge chamber. The total length is 30m, which is the area for drying and carbonizing the waste salt; the filling rate of the waste salt in the furnace is about 5% to 7%, and the residence time is about 1.5 to 2h.

[0066] The burner 205 provides a heat source for the carbonization of waste salt, and is divided into 9 groups (18) of burners 205, and each group (2) of burners 205 is placed on both sides of the combustion chamber 204; these 9 groups of burners 205 divide the combustion chamber 204 into 9 heating zones, and the temperature of each heating zone can be controlled independently without affecting each other; because the first three heating zones are in contact with cold materials with a high moisture content, they need to be dried and heated, so when choosing the burners 205 in the first three heating zones, choose a burner 205 with a larger power.

[0067] The base 201 is provided with a rotating gear 211 fixed to the outer surface of the furnace body 202, and both ends of the furnace body 202 are provided with a central shaft installed on the base 201. The rotating gear 211 provided outside the furnace body 202 drives the furnace body 202 to rotate axially, and the rotating motor drives the furnace body 202 to rotate, so that the furnace body 202 rotates once every 1 to 5 minutes.

[0068] In order to prevent the waste salt from getting stuck on the inner wall of the furnace body 202 during rotation, two rows of chains 212 are symmetrically arranged on the inner wall of the furnace body 202. The chains 212 are arranged at intervals between the pitches of the spiral guide plate 203. One end of the chain 212 is fixed and the other end is free. During the rotation of the furnace body 202, the waste salt on the inner wall of the furnace body 202 can be cleaned. The lateral spacing of the chains 212 is 300 to 500 mm.

[0069] In order to enable the waste salt to be carbonized quickly and thoroughly, the feeding system 1 includes a feeding bin 101, the bottom of which is connected to a screw conveyor 103 via a screw conveyor 102, and a crusher 104 is provided at the top outlet of the screw conveyor 103, and the discharge port 208 of the crusher 104 is connected to the feed port 206 of the carbonization furnace 2.

[0070] In the system disclosed in the present invention, the mixed material first enters the feed bin 101 for buffering, and a stable feeding process is achieved through the screw conveyor 102. An intermediate tank, including an intermediate tank A and an intermediate tank B, can be set between the reaction tank and the plate and frame filter press to perform secondary precipitation of the reaction solution. Since the material entering the plate and frame filter press has relatively high requirements for the pump, the reaction tank is equipped with an ordinary centrifugal pump and the intermediate tank is equipped with a high-lift pump, which can save costs.

[0071] The treated waste salt solution is subsequently stored and can further adjust the pH value of the waste salt. The cache system 9 includes a cache pool 901, a water supply pool 902 and a neutralization tank 903. The outlets of the cache pool 901 and the water supply pool 902 are connected to the inlet of the neutralization tank 903. The inlet of the neutralization tank 903 is also connected to the second neutralizer tank. The second neutralizer tank is a hydrochloric acid tank B904.

[0072] In a second aspect of the embodiments of the present disclosure, a method for pretreating a mixture of sodium chloride and sodium sulfate waste salt is provided, which is applied to the above-mentioned sodium chloride and sodium sulfate mixed waste salt pretreatment system and comprises the following steps:

[0073] Step 1: The waste salt is transported to the feed bin 101 for short-term storage, and then transported to the crusher 104 through the screw conveyor 102 and the bucket elevator for crushing;

[0074] In order to avoid the impact of materials on the equipment and realize a stable feeding process, the storage time of the waste in the feed bin 101 is 1 to 2 hours.

[0075] Step 2: The crushed waste salt is transported to the carbonization furnace 2 through the feeding screw conveyor 102 for carbonization treatment, and most of the organic matter in the waste salt is carbonized and decomposed;

[0076] During this process, the temperature of the carbonization furnace 2 is above 550° C., and the carbonization time is 1.5 to 2 hours.

[0077] Step 3: The carbonized waste salt enters the dissolution tank 5 and is mixed with water in proportion to dissolve the waste salt into a saturated salt solution, and fully reacts with the chemical agent in the reaction tank;

[0078] The mixing ratio of the carbonized waste salt and water is 1:3, and the reaction time of adding chemical agents is 5 to 10 hours.

[0079] Step 4: The material is filtered through a plate and frame filter press, and the filter cake is unloaded every 4 to 6 hours. The filter cake produced is organic carbide and the reaction precipitate produced in step 3. The filtrate passes through a buffer tank 901 and adjusts the pH to 6 to 8 to obtain a qualified finished liquid for storage and standby use.

[0080] Through the implementation of the above method steps, the organic matter, heavy metals, fluoride ions and other water-insoluble substances contained in the waste salt can be quickly removed, the total hardness in the finished liquid can be reduced to below 200 ppm, the COD can be reduced to 60-80 ppm, the heavy metal ions, fluoride ions, etc. can be reduced to 5-50 ppm, and the turbidity can be reduced to below 10 NTU.

[0081] The specific implementation steps of this disclosure are as follows:

[0082] At room temperature, the mixed waste salt of sodium chloride and sodium sulfate is fed to the feed bin 101 by a forklift. After being stored for 1 to 2 hours, it is transported to the feed port 206 at the lower end of the bucket elevator by the screw conveyor 102 at the bottom of the feed bin 101. After being lifted to a certain height by the bucket elevator, it slides from the outlet chute at the upper end of the bucket elevator to the entrance of the crusher 104. The crushed waste salt meets the particle size of less than 30 mm and falls into the feed hopper. It is then fed to the carbonization furnace 2 by the feed screw conveyor 102. The waste salt in the carbonization furnace 2 is dried and pyrolyzed under the combustion-supporting effect of natural gas and air disturbance. The furnace temperature can reach above 550°C, the total residence time is about 1.5 to 2 hours, and the entire carbonization process is in a state of slight negative pressure. After carbonization, the waste salt is discharged from the tail of the carbonization furnace 2 to the next processing unit.

[0083] The waste salt after carbonization falls directly from the tail end of the carbonization furnace 2 to the dissolution tank 5, where it is mixed with water in a ratio of 1:3 to salt water and fully dissolved by stirring in the dissolution tank 5. The concentration of the saturated salt solution after dissolution is about 25%, and it is fed to the reaction tank A6a by the dissolution pump. When the liquid level of the reaction tank A6a reaches the set value, the pipeline is switched to feed the reaction tank B6b. After 4 to 6 hours, the solution in the reaction tank A6a is fed to the intermediate tank A / B through the reaction pump A; similarly, when the liquid level of the reaction tank B6b reaches the set value, the pipeline is switched to feed the reaction tank A6a. After 4 to 6 hours, the solution in the reaction tank B6b is fed to the intermediate tank A / B through the reaction pump B; this cycle is repeated. In the reaction tanks A6a and B6b, the solution and the added chemical agents fully react under the action of stirring and generate precipitation, removing impurities such as fluorine, calcium, magnesium and heavy metals.

[0084] Among them, the chemical agent is poured into the agent tank A / B, and water is added to stir and fully dissolve, and then quantitatively delivered to the reaction tank A / B through the agent pump A / B, where it is fully stirred and reacted with the material to generate precipitation, and impurities such as fluorine, calcium, magnesium and heavy metals are removed. The hydrochloric acid in the hydrochloric acid tank A10 can flow to the reaction tank A6a and the reaction tank B6b by valve adjustment to adjust the pH of the material in the reaction tank A / B; the hydrochloric acid in the hydrochloric acid tank B904 can flow to the neutralization tank 903 by valve adjustment to adjust the pH of the material in the neutralization tank 903; the liquid alkali in the liquid alkali tank 11 can flow to the reaction tank A6a and the reaction tank B6b by valve adjustment to adjust the pH of the material in the reaction tank A / B.

[0085] The material in the intermediate tank A is sent to the plate and frame filter press A8a for filtration through the intermediate pump A, and the filter cake is unloaded every 4 to 6 hours. The filter cake formed by organic carbides and reaction precipitates is properly disposed of by the delivery system, and the filtrate flows by gravity to the buffer tank 901. Similarly, the material in the intermediate tank B is sent to the plate and frame filter press B8b for filtration through the intermediate pump B. The filter cake formed by organic carbides and reaction precipitates is properly disposed of by the delivery system, and the filtrate flows by gravity to the buffer tank 901.

[0086] The material in the buffer tank 901 is pumped to the precision filter through the buffer pump, and enters the neutralization tank 903 after filtering out impurities larger than 5μm. The pH is adjusted to 6-8 in the neutralization tank 903, and the material is pumped to the water supply tank 902 through the neutralization pump for storage for 24h-48h, providing continuous and stable raw material liquid for subsequent processes.

[0087] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0088] Although the present disclosure has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements may be made to the present disclosure. Therefore, these modifications or improvements made without departing from the spirit of the present disclosure are within the scope of protection claimed by the present disclosure.

Claims

1. A sodium chloride and sodium sulfate mixed waste salt pretreatment system, characterized in that: Including carbonization unit and re-dissolved water treatment unit, Carbonization unit: comprising a feeding system, wherein the feeding system is connected to the carbonization furnace and the tail gas treatment system of the carbonization furnace; The heavy dissolving water treatment unit includes a dissolving tank connected to the discharge port of the carbonization furnace, the dissolving tank is connected to the reaction tank, the inlet of the reaction tank is also connected to the reagent tank, the inlet of the reaction tank is connected to the first neutralizer tank, the reaction tank is connected to the plate and frame filter press, and the liquid outlet of the plate and frame filter press is connected to the buffer system.

2. The sodium chloride and sodium sulfate mixed waste salt pretreatment system according to claim 1, characterized in that: The tail gas treatment system comprises a furnace air heat exchanger connected to the combustion chamber air outlet of the carbonization furnace, and the heat exchange port of the furnace air heat exchanger is connected to the furnace air inlet of the carbonization furnace.

3. The sodium chloride and sodium sulfate mixed waste salt pretreatment system according to claim 2, characterized in that: The tail gas treatment system also includes a combustion-supporting air heat exchanger connected to the furnace air outlet of the carbonization furnace via a separation device, and the heat exchange port of the combustion-supporting air heat exchanger is connected to the burner of the carbonization furnace.

4. The sodium chloride and sodium sulfate mixed waste salt pretreatment system according to claim 3, characterized in that: The separation equipment comprises a cyclone separator connected to the air outlet of the furnace of the carbonization furnace, the outlet of the cyclone separator is connected to the bag filter, and the air outlet of the bag filter is connected to the air inlet of the combustion air heat exchanger.

5. The sodium chloride and sodium sulfate mixed waste salt pretreatment system according to claim 4, characterized in that: The cyclone separator includes a straight cylinder, an air outlet pipe inserted into the straight cylinder is arranged above the straight cylinder, an oblique air inlet pipe is arranged on the outer wall of the straight cylinder, the fixed bottom of the straight cylinder is connected to the conical cylinder, the bottom of the conical cylinder is provided with a conical discharge port, and the bottom side of the conical discharge port is connected to the ash hopper.

6. The sodium chloride and sodium sulfate mixed waste salt pretreatment system according to claim 1, characterized in that: The carbonization furnace includes a base, on which is provided a furnace body capable of axial rotation, a spiral guide plate is provided inside the furnace body, a combustion chamber is provided outside the furnace body, a plurality of burners are provided at the bottom of the combustion chamber, a feed port and a furnace air outlet are provided at one end of the furnace body, a discharge port and a furnace air inlet are provided at the other end of the furnace body, and a combustion chamber air outlet is provided at the top of the combustion chamber.

7. The sodium chloride and sodium sulfate mixed waste salt pretreatment system according to claim 6, characterized in that: The base is provided with a rotating gear fixed to the outer surface of the furnace body, and both ends of the furnace body are provided with a central shaft installed on the base.

8. The sodium chloride and sodium sulfate mixed waste salt pretreatment system according to claim 7, characterized in that: Two rows of chains are symmetrically arranged on the inner wall of the furnace body, and the chains are arranged at intervals between the pitches of the spiral guide plates.

9. The sodium chloride and sodium sulfate mixed waste salt pretreatment system according to claim 1, characterized in that: The feeding system comprises a feeding bin, the bottom of which is connected to a lifting bucket via a screw conveyor, a crusher is provided corresponding to the top outlet of the lifting bucket, and the discharge port of the crusher is connected to the feeding port of the carbonization furnace.

10. The sodium chloride and sodium sulfate mixed waste salt pretreatment system according to claim 1, characterized in that: The cache system includes a cache pool, a water supply pool and a neutralization tank. The outlets of the cache pool and the water supply pool are both connected to the inlet of the neutralization tank, and the inlet of the neutralization tank is also connected to the second neutralizer tank.

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