A waste salt resourceful pretreatment system

Abstract

The utility model relates to a kind of waste salt resourceful pretreatment systems, wherein, the discharge outlet of salt dissolving tank is communicated with the import of first multi-medium filter, the outlet of first multi-medium filter is communicated with multi-medium water production pool, the sludge outlet of first multi-medium filter is communicated with the first import of sludge collection pool, the outlet of sludge collection pool is communicated with the import of plate-and-frame filter press, the filtrate outlet of plate-and-frame filter press is communicated with the liquid supplementing port of multi-medium water production pool by first backwater pipeline;The outlet of multi-medium water production pool is communicated with the import of wet catalytic oxidation device, the outlet of wet catalytic oxidation device is communicated with the import of oxidation water production pool, the outlet of oxidation water production pool is communicated with the import of double-alkali softening device, the outlet of double-alkali softening device is communicated with the import of tubular membrane, the outlet of tubular membrane is communicated with the import of adjusting pool, the outlet of adjusting pool is communicated with the import of second multi-medium filter;The sludge outlet of tubular membrane is communicated with the second import of sludge collection pool.

Description

Technical Field

[0001] This utility model relates to the field of waste salt treatment technology, specifically to a waste salt resource recovery pretreatment system. Background Technology

[0002] With the rapid development of industrialization and urbanization, the amount of waste salt generated is constantly increasing, and the market demand for waste salt resource utilization is also growing accordingly. Waste salt mainly comes from industries such as chemicals, pharmaceuticals, and pesticides, and is characterized by its wide variety, complex composition, and high toxicity. Domestically and internationally, there are various methods for treating waste salt with different compositions, with resource utilization technology being the most common. For example, Chinese patent CN209502536U discloses an industrial waste salt resource utilization device that dissolves and refines waste salt, then concentrates and crystallizes it, and finally recycles it as an industrial raw material and additive.

[0003] Currently, the waste salt to be treated by enterprises contains a large amount of suspended solids (SS > 500 mg / L) and colloids, with low organic matter concentration and high hardness. Directly using the above-mentioned technology has the following drawbacks: First, the waste brine only undergoes one multi-media filtration, leaving residual small-molecule organic matter, colloids, and small particulate suspended solids. When the waste brine is ultrafiltered, the residual colloids and small particulate suspended solids in the brine will penetrate the ultrafiltration membrane and deposit in the resin layer, affecting the ion exchange effect. In addition, if the ultrafiltration membrane is damaged or the operating parameters are abnormal, small-molecule organic matter that is not intercepted by ultrafiltration will directly enter the ion exchange device, adsorb on the resin surface or in the pores, and block the ion exchange sites, leading to "organic pollution" of the resin. Second, the filter residue after dissolving and filtering the waste salt, as well as the filter residue after ultrafiltration, are all discharged into the sedimentation and concentration tank for direct dehydration and drying without further treatment of the filtrate, resulting in incomplete resource utilization and resource waste. Utility Model Content

[0004] The purpose of this invention is to provide a waste salt resource pretreatment system.

[0005] The purpose of this utility model is achieved by the following technical solution: a waste salt resource pretreatment system, which includes a salt dissolving tank, a first multi-media filter, a multi-media water production tank, a wet catalytic oxidation device, an oxidation water production tank, a dual alkali softening device, a tubular membrane, an equalization tank, a second multi-media filter, a sludge collection tank, and a plate and frame filter press. The discharge port of the salting tank is connected to the inlet of the first multi-media filter; the liquid outlet of the first multi-media filter is connected to the multi-media permeate tank; the sludge outlet of the first multi-media filter is connected to the first inlet of the sludge collection tank; the outlet of the sludge collection tank is connected to the inlet of the plate and frame filter press; the filtrate outlet of the plate and frame filter press is connected to the replenishment port of the multi-media permeate tank via a first return water pipeline; the outlet of the multi-media permeate tank is connected to the inlet of the wet catalytic oxidation device; the outlet of the wet catalytic oxidation device is connected to the inlet of the oxidation permeate tank; the outlet of the oxidation permeate tank is connected to the inlet of the dual-alkali softening device; the outlet of the dual-alkali softening device is connected to the inlet of the tubular membrane; the liquid outlet of the tubular membrane is connected to the inlet of the equalization tank; the sludge outlet of the tubular membrane is connected to the second inlet of the sludge collection tank; and the outlet of the equalization tank is connected to the inlet of the second multi-media filter.

[0006] Preferably, the impurity solution outlet of the second multi-media filter is connected to the replenishment port of the oxidation product water tank through a second return water pipeline.

[0007] Preferably, the dual-alkali softening device includes a primary reaction tank, a secondary reaction tank, a stirrer, a sodium hydroxide storage tank, and a sodium carbonate storage tank; the outlet of the primary reaction tank is connected to the inlet of the secondary reaction tank via a pipeline, the dosing port of the primary reaction tank is connected to the outlet of the sodium hydroxide storage tank via a pipeline, and the dosing port of the secondary reaction tank is connected to the outlet of the sodium carbonate storage tank via a pipeline; the stirrer is provided in both the primary reaction tank and the secondary reaction tank.

[0008] Preferably, it also includes a crusher, the discharge port of which is connected to the inlet of the salt dissolving tank via a belt conveyor.

[0009] Preferably, the hydrochloric acid inlet of the regulating tank is connected to the outlet of the hydrochloric acid storage tank via a pipeline.

[0010] The advantages of this utility model are as follows: First, this utility model sets up a multi-media water production tank after the first filtration and before catalytic oxidation. The multi-media water production tank is used in conjunction with a sludge collection tank and a plate and frame filter press. The water produced by the first multi-media filter enters the multi-media water production tank, and the sludge produced by the first multi-media filter is sent to the sludge collection tank. After the sludge is collected, it is sent to the plate and frame filter press for filtration. The filtrate is returned to the multi-media water production tank and mixed with the filtered water to continue to participate in catalytic oxidation, further recovering the waste salt in the sludge filter residue, improving the resource utilization rate, and reducing resource waste.

[0011] Secondly, this utility model employs a first multi-media filter, a tubular membrane, and a second multi-media filter for triple filtration. The first multi-media filter intercepts large suspended particles such as silt and rust, the tubular membrane intercepts a large amount of suspended solids generated by the residual double-alkali softening method, and the second multi-media filter further intercepts small molecule organic matter, small suspended particles, and colloids to ensure the stability of the brine water quality. An oxidation product water tank is set up after catalytic oxidation and before softening filtration. The oxidation product water tank also acts as a buffer, preventing the tubular membrane from operating under overload due to the large amount of brine. In addition, the oxidation product water tank can also recover the impurity solution intercepted by the second multi-media filter for further softening treatment, further improving the resource utilization rate and reducing wastewater discharge. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a schematic diagram of the structure of this utility model.

[0014] The components in the attached diagram are labeled as follows: 1. Crusher; 2. Belt conveyor; 3. Salt dissolving tank; 4. First multi-media filter; 5. Multi-media product water tank; 6. Wet catalytic oxidation device; 7. Oxidation product water tank; 8. Dual alkali softening device; 8.1 Primary reaction tank; 8.2 Secondary reaction tank; 8.3 Agitator; 8.4 Sodium hydroxide storage tank; 8.5 Sodium carbonate storage tank; 9. Tubular membrane; 10. Equalization tank; 11. Second multi-media filter; 12. Sludge collection tank; 13. Plate and frame filter press; 14. First return water pipeline; 15. Hydrochloric acid storage tank; 16. Second return water pipeline. Detailed Implementation

[0015] 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 some embodiments of the present utility model, and not all embodiments. 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 protection scope of the present utility model.

[0016] In the description of this utility model, it should be noted that the terms "center", "upper", "lower", "front", "rear", "top", "bottom", "left", "right", "vertical", "horizontal", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0017] like Figure 1 As shown, a waste salt resource utilization pretreatment system includes a crusher 1, a belt conveyor 2, a salt dissolving tank 3, a first multi-media filter 4, a multi-media water production tank 5, a wet catalytic oxidation device 6, an oxidation water production tank 7, a dual alkali softening device 8, a tubular membrane 9, an equalization tank 10, a second multi-media filter 11, a sludge collection tank 12, and a plate and frame filter press 13. The discharge port of the crusher 1 is connected to the inlet of the salt dissolving tank 3 via a belt conveyor 2. The discharge port of the salt dissolving tank 3 is connected to the inlet of the first multi-media filter 4 via a pipeline. The liquid outlet of the first multi-media filter 4 is connected to the multi-media water production tank 5 via a pipeline. The sludge outlet of the first multi-media filter 4 is connected to the first inlet of the sludge collection tank 12. The outlet of the sludge collection tank 12 is connected to the inlet of the plate and frame filter press 13 via a pipeline. The filtrate outlet of the plate and frame filter press 13 is connected to the liquid replenishment port of the multi-media water production tank 5 via a first return water pipeline 14. Because waste salt is prone to moisture absorption and clumping during storage, it is necessary to crush and screen the clumped salt mixture. The waste salt is transported to the crusher 1 for crushing pretreatment and temporary storage. After crushing, the waste salt that meets the requirements is sent to the salt tank 3 via a fully enclosed conveyor belt to make saturated brine. It is then transported to the first multi-media filter 4 for solid-liquid separation via a conveyor pump. When the saturated brine passes through the quartz sand bed and anthracite coal seam in the first multi-media filter 4, large suspended particles such as mud, sand, and rust are trapped on the surface and in the internal pores of the filter media, thereby effectively removing suspended impurities and clarifying the water, avoiding mechanical damage to the tubular membrane 9. The permeate produced by the first multi-media filter 4 enters the multi-media permeate tank 5. The sludge produced by the first multi-media filter 4 is sent to the sludge collection tank 12. After centralized collection, the sludge is sent to the plate and frame filter press 13 for filtration. The filter cake is sent to the plant's safe landfill for landfill disposal, and the filtrate is returned to the multi-media permeate tank 5. The outlet of the multi-media product water tank 5 is connected to the inlet of the wet catalytic oxidation unit 6 via a pipeline. The wet catalytic oxidation unit 6 can be a wet catalytic oxidation unit 6 manufactured by Zhejiang Fantai Instrument Co., Ltd., which is existing equipment. Its specific structure will not be described here. The outlet of the wet catalytic oxidation unit 6 is connected to the inlet of the oxidation product water tank 7 via a pipeline. The outlet of the oxidation product water tank 7 is connected to the inlet of the dual-alkali softening unit 8 via a pipeline. The outlet of the dual-alkali softening unit 8 is connected to the inlet of the tubular membrane 9 via a pipeline. The outlet of the liquid is connected to the inlet of the equalization tank 10 via a pipeline; the sludge outlet of the tubular membrane 9 is connected to the second inlet of the sludge collection tank 12 via a pipeline; the hydrochloric acid inlet of the equalization tank 10 is connected to the outlet of the hydrochloric acid storage tank 15 via a pipeline; the outlet of the equalization tank 10 is connected to the inlet of the second multi-media filter 11 via a pipeline; the outlet of the second multi-media filter 11 is connected to the replenishment port of the oxidation product water tank 7 via the second return water pipeline 16; and the discharge port of the second multi-media filter 11 is connected to the inlet of the pretreatment product tank. The dual-alkali softening device 8 includes a primary reaction tank 8.1, a secondary reaction tank 8.2, a stirrer 8.3, a sodium hydroxide storage tank 8.4, and a sodium carbonate storage tank 8.5. The inlet of the primary reaction tank 8.1 is the inlet of the dual-alkali softening device 8, and the outlet of the secondary reaction tank 8.2 is the outlet of the dual-alkali softening device 8. The outlet of the primary reaction tank 8.1 and the inlet of the secondary reaction tank 8.2 are connected by a pipeline. The dosing port of the primary reaction tank 8.1 is connected by a pipeline to the outlet of the sodium hydroxide storage tank 8.4, and the dosing port of the secondary reaction tank 8.2 is connected by a pipeline to the outlet of the sodium carbonate storage tank 8.5. A stirrer 8.3 is installed in both the primary reaction tank 8.1 and the secondary reaction tank 8.2. Sodium hydroxide solution is added to the primary reaction tank 8.1, and sodium carbonate solution is added to the secondary reaction tank 8.2. The mixture is stirred to soften saturated brine using the dual-alkali method to remove most of the calcium and magnesium ions, silica, and heavy metal ions from the brine, forming a large amount of suspended solids. The saturated brine in the multi-media production tank 5 is pumped into the wet catalytic oxidation device 6 for oxidation treatment. Hydrogen peroxide, as the oxidant, reacts with organic pollutants under the action of a catalyst (manganese dioxide). The chemical bonds of the organic pollutants are broken through electrophilic addition and hydrogen atom abstraction, thus oxidizing them. Hydrogen peroxide also decomposes in water to produce hydroxyl radicals. The generation of hydroxyl radicals can greatly enhance the oxidation capacity and further improve the degradation effect on organic pollutants, completely converting them into harmless inorganic substances such as CO2, N2, O2, and H2O. The organic matter removal efficiency is about 85%. The permeate after wet oxidation treatment is collected in oxidation permeate tank 7 and then sent to a dual-alkali softening unit 8 to remove most of the calcium and magnesium ions, silica, and heavy metal ions from the brine. The resulting suspended solids are then directly sent to a tubular membrane 9 for separation, achieving a heavy metal removal efficiency of over 99%. This process reduces the inorganic scaling components in the permeate from the tubular membrane 9 to extremely low levels. The solid filter cake from the tubular membrane 9 then sequentially enters the sludge collection tank 12 and the plate and frame filter press 13 for further recycling of the filtrate. The permeate produced by the tubular membrane 9 enters the equalization tank 10, where hydrochloric acid is added to adjust the pH to neutral to prevent calcium carbonate and magnesium ions from escaping during subsequent filtration. After the particles settle and clog the filtration equipment again, the brine is sent to the second multi-media filter 11 after the pH is adjusted to remove fine suspended particles, colloids, small molecule organic matter, and color. The filter media of the second multi-media filter 11 is more refined, including a quartz sand bed, anthracite layer, magnetite layer, and activated carbon layer. Activated carbon can adsorb organic matter, pigments, and odors in the brine, while magnetite helps to remove fine suspended particles in the brine. The product water filtered by the second multi-media filter 11 enters the pretreatment product tank. The impurity solution (containing suspended solids, colloids, small molecule organic matter, etc.) intercepted during the filtration process of the second multi-media filter 11 is returned to the oxidation product water tank 7 for further softening treatment.

[0018] This invention features a multi-media permeate tank 5 after the first filtration and before catalytic oxidation. Firstly, the permeate produced by the first multi-media filter 4 enters the multi-media permeate tank 5 for temporary storage, preventing subsequent treatment units from overloading due to a sudden increase in permeate volume. Secondly, the multi-media permeate tank 5 is used in conjunction with a sludge collection tank 12 and a plate and frame filter press 13. The sludge and filter residue produced after filtration by the first multi-media filter 4 and the tubular membrane 9 are both sent to the sludge collection tank 12. After centralized collection, the sludge is sent to the plate and frame filter press 13 for filtration. The filtrate is returned to the multi-media permeate tank 5 and mixed with the filtered permeate to continue participating in catalytic oxidation, thereby recovering waste salts from the sludge and filter residue, improving resource utilization, and reducing resource waste. Furthermore, a triple filtration process is employed, consisting of a first multi-media filter 4, a tubular membrane 9, and a second multi-media filter 11. The first multi-media filter 4 intercepts large suspended particles such as silt and rust, while the tubular membrane 9 intercepts a large amount of suspended solids generated by the residual double-alkali softening method. The second multi-media filter 11 further traps small molecule organic matter, small suspended particles, and colloids, ensuring the stability of the brine water quality. An oxidation product water tank 7 is set up after catalytic oxidation and before softening filtration. The oxidation product water tank 7 also serves as a buffer, preventing the tubular membrane 9 from overloading due to the large amount of brine. In addition, the oxidation product water tank 7 can also recover the impurity solution trapped by the second multi-media filter 11 for further softening treatment, further improving resource utilization and reducing wastewater discharge.

[0019] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A waste salt resource recovery pretreatment system, characterized in that, It includes a salting tank, a first multi-media filter, a multi-media product water tank, a wet catalytic oxidation device, an oxidation product water tank, a dual alkali softening device, a tubular membrane, an equalization tank, a second multi-media filter, a sludge collection tank, and a plate and frame filter press. The discharge port of the salting tank is connected to the inlet of the first multi-media filter; the liquid outlet of the first multi-media filter is connected to the multi-media permeate tank; the sludge outlet of the first multi-media filter is connected to the first inlet of the sludge collection tank; the outlet of the sludge collection tank is connected to the inlet of the plate and frame filter press; the filtrate outlet of the plate and frame filter press is connected to the replenishment port of the multi-media permeate tank via a first return water pipeline; the outlet of the multi-media permeate tank is connected to the inlet of the wet catalytic oxidation device; the outlet of the wet catalytic oxidation device is connected to the inlet of the oxidation permeate tank; the outlet of the oxidation permeate tank is connected to the inlet of the dual-alkali softening device; the outlet of the dual-alkali softening device is connected to the inlet of the tubular membrane; the liquid outlet of the tubular membrane is connected to the inlet of the equalization tank; the sludge outlet of the tubular membrane is connected to the second inlet of the sludge collection tank; and the outlet of the equalization tank is connected to the inlet of the second multi-media filter.

2. The waste salt resource utilization pretreatment system according to claim 1, characterized in that, The impurity solution outlet of the second multi-media filter is connected to the replenishment port of the oxidation product water tank through a second return water pipeline.

3. A waste salt resource utilization pretreatment system according to claim 1 or 2, characterized in that, The dual-alkali softening device includes a primary reaction tank, a secondary reaction tank 8.2, a stirrer, a sodium hydroxide storage tank, and a sodium carbonate storage tank. The outlet of the primary reaction tank is connected to the inlet of the secondary reaction tank 8.2 via a pipeline, the dosing port of the primary reaction tank is connected to the outlet of the sodium hydroxide storage tank via a pipeline, and the dosing port of the secondary reaction tank 8.2 is connected to the outlet of the sodium carbonate storage tank via a pipeline. The stirrer is installed in both the primary reaction tank and the secondary reaction tank 8.

2.

4. The waste salt resource utilization pretreatment system according to claim 3, characterized in that, It also includes a crusher, the discharge port of which is connected to the inlet of the salt slurry tank via a belt conveyor.

5. The waste salt resource utilization pretreatment system according to claim 1, characterized in that, The hydrochloric acid inlet of the regulating tank is connected to the outlet of the hydrochloric acid storage tank via a pipeline.

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