Circulating water filtering treatment system for slag treatment

Abstract

The invention discloses a circulating water filtration treatment system for slag treatment. The circulating water filtration treatment system comprises a separation module, a multi-stage gradient precipitation module, a filtration integration module, a storage and supply module and a collection treatment module which are sequentially arranged and communicated along a slag wastewater treatment flow. Three-stage precipitation, namely physical rotational flow, inclined plate sedimentation and chemical coagulation, is innovatively adopted, meanwhile, three-stage filtration, namely a combined process procedure of rough filtration, softening and fine filtration is also adopted, particles with different particle sizes, colloids and ions with different hardness in the slag wastewater are accurately removed, and the high-end recycling requirement is met.

Description

Technical Field

[0001] This invention belongs to the field of industrial wastewater recycling technology, and particularly relates to a circulating water filtration system for slag treatment. Background Technology

[0002] With the acceleration of urbanization, municipal solid waste incineration has become one of the main methods of waste disposal, generating a large amount of incinerator slag. Slag has a complex composition, containing scrap iron, stainless steel, non-ferrous metals (aluminum, copper, zinc), glass, ceramics, and unburned organic matter. Simple landfill disposal not only occupies a large amount of land resources, but the heavy metals and other harmful substances it contains can also cause long-term pollution of soil and groundwater. Therefore, effective resource recovery of slag has become an inevitable trend in the industry.

[0003] Currently, most common slag treatment processes focus on metal recovery, typically employing a simple "crushing-magnetic separation-screening" process. These processes have the following significant drawbacks: 1) They recover only a limited range of metals, primarily ferromagnetic materials, with low efficiency in recovering large quantities of non-ferrous metals (such as aluminum); 2) If aluminum is mixed into building materials, its subsequent oxidation and expansion can cause brick cracking, severely impacting product quality—a problem that has long remained unresolved; 3) The process lacks effective pretreatment, and the crushing stage is susceptible to impacts from large pieces of metal and hard objects, resulting in a high equipment failure rate; 4) Fine-grained materials (e.g., <0.15mm) are often discarded as sludge, leading to underutilization of resources and the generation of large amounts of sludge requiring disposal; 5) Wastewater treatment systems are simple, making it difficult to achieve zero discharge and creating significant environmental pressure; 6) The entire treatment process lacks systematic dust control and suppression measures, resulting in a harsh working environment. Summary of the Invention

[0004] (a) Technical problems to be solved

[0005] To address the shortcomings of existing technologies, this invention utilizes a multi-stage sorting and integrated processing technology to achieve a comprehensive and innovative slag treatment process that is both clean and stable in operation.

[0006] (II) Technical Solution

[0007] To achieve the above objectives, the present invention provides the following technical solution: a circulating water filtration system for slag treatment, comprising: [systems] sequentially arranged and connected along the slag wastewater treatment process.

[0008] The separation module is used to receive high-temperature slag-containing wastewater from the slag treatment process and perform hydrocyclone centrifugal separation to output an underflow containing coarse slag and an overflow containing fine particles.

[0009] A multi-stage gradient sedimentation module is connected to the overflow output end of the separation module and is used to perform at least two stages of physicochemical synergistic sedimentation on the overflow to remove small and medium-sized particulate suspended solids and colloidal substances in sequence, and output clear water.

[0010] A filtration integration module, connected to the outlet end of the multi-stage gradient sedimentation module, includes components connected in series:

[0011] The pre-filtration unit is used to perform the first-stage mechanical filtration of the clarified water to remove residual suspended solids;

[0012] The chemical crystallization softening unit is used to adjust the pH and induce crystallization of the water after the first stage of filtration, and to remove scale-forming calcium and magnesium ions.

[0013] The post-filter is used for final fine filtration of softened water to remove precipitated microcrystalline particles and output high-quality reclaimed water.

[0014] As a preferred embodiment, the system further includes a storage and supply module connected to the outlet of the post-security filter unit, for storing the high-quality recycled water and pressurizing and supplying it to the water point of the slag treatment process.

[0015] The collection and processing module is connected to the underflow outlet of the separation module, the sludge discharge port of the multi-stage gradient sedimentation module, and the slag discharge port of the chemical crystallization softening unit, respectively, and is used to concentrate and dewater the sludge generated by each module to form sludge cakes for external transportation.

[0016] The wastewater generated after use at the water point in the slag treatment process is returned to the separation module, forming a closed-loop water treatment system, which is controlled by an intelligent control module.

[0017] As a preferred embodiment, the separation module is a hydrocyclone assembly; the multi-stage gradient sedimentation module includes a series-connected inclined plate sedimentation unit and a high-efficiency coagulation and clarification unit, and the high-efficiency coagulation and clarification unit is equipped with a dosing device.

[0018] As a preferred embodiment, the pre-filter unit is an automatic backwashing filter with a filtration accuracy of 100-300 micrometers; the post-security filter unit is a cartridge-type precision filter with a filtration accuracy of 1-20 micrometers.

[0019] As a preferred embodiment, the chemical crystallization softening unit includes a pH adjustment tank, a crystallization reaction tank, and a solid-liquid separation device connected in sequence; the pH adjustment tank is connected to an alkali storage tank via a dosing pump; the crystallization reaction tank is equipped with a stirrer and seed crystal packing is added; the solid-liquid separation device is a hydrocyclone separator or a horizontal centrifuge.

[0020] As a preferred embodiment, a circulating water cooling unit is connected in parallel on the return water pipeline between the storage supply module and the separation module.

[0021] As a preferred embodiment, the intelligent control module includes a central controller, a data acquisition unit, and a human-machine interface. The intelligent control module automatically controls whether the water flow is diverted through the circulating water cooling unit based on the temperature of the recycled water. The data acquisition unit includes a flow meter, a pressure sensor, a turbidity meter, a pH meter, an online hardness analyzer, and a temperature sensor, all located at key nodes of the system.

[0022] As a preferred embodiment, the intelligent control module has a built-in adaptive optimization algorithm, which is used to adjust the dosage of the dosing device in real time according to the influent turbidity and flow rate of the multi-stage gradient sedimentation module, and to dynamically adjust the alkali dosing acceleration according to the effluent hardness value of the chemical crystallization softening unit.

[0023] As a preferred embodiment, the collection and processing module includes a sludge homogenizing tank, a sludge transfer pump, and a plate and frame filter press, wherein the filtrate from the plate and frame filter press is returned to the inlet of the separation module or the multi-stage gradient sedimentation module.

[0024] As a preferred option, the filtering process includes:

[0025] S1. The wastewater generated in the slag treatment process is pumped into the separation module, and the coarse slag is quickly separated and discharged by cyclone centrifugal force.

[0026] S2. The effluent separated in step S1 is introduced into a multi-stage gradient sedimentation module. First, small and medium-sized particles are naturally removed by inclined plate sedimentation. Then, chemical agents are added for coagulation and clarification to deeply remove colloids and fine suspended solids.

[0027] S3. The supernatant produced in step S2 is pumped into the integrated filtration module. First, the pre-filtration unit removes residual impurities. Then, in the chemical crystallization softening unit, the pH value is increased and crystal seeds are induced to crystallize and separate the dissolved hardness ions. Finally, the microcrystals are retained by the post-security filtration unit to obtain softened purified water.

[0028] S4: Store the purified water obtained in step S3 in the storage supply module, and pressurize and send it back to the slag treatment process as needed;

[0029] S5: Collect the sludge generated by each module into the collection and treatment module for concentration and dewatering, and return the filtrate to the front end of the system;

[0030] S6: Wastewater from the slag treatment process is returned to step S1, forming a closed loop.

[0031] (III) Beneficial Effects

[0032] Compared with the prior art, the present invention provides a circulating water filtration system for slag treatment, which has the following beneficial effects:

[0033] First, this invention innovatively employs a three-stage sedimentation process, namely physical cyclone + inclined plate sedimentation + chemical coagulation, and also adopts a three-stage filtration process, namely a combination of coarse filtration + softening + fine filtration, to accurately remove particulate matter, colloids and hardness ions of different sizes from slag wastewater, thus meeting the requirements for high-end reuse.

[0034] Second, this invention also integrates a dedicated hardening and softening unit and uses an enhanced crystallization process to actively remove calcium and magnesium ions that cause scaling, thereby preventing scaling in the system from the source, greatly extending the service life of the equipment, and reducing maintenance costs.

[0035] Third, this invention uses an intelligent control system to monitor and automatically control the entire process online, achieving precise optimization of chemical dosage, backwash cycle, and water flow path, ensuring stable operation of the system under optimal conditions, and reducing manual intervention and operating energy consumption. Attached Figure Description

[0036] Figure 1 This is a system module diagram of the present invention. Detailed Implementation

[0037] To better understand the purpose, structure, and function of this invention, the circulating water filtration system for slag treatment will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0038] refer to Figure 1 As shown, the circulating water filtration system for slag treatment of the present invention is an organic whole with the goals of water purification and stable circulation, based on modular functional units, and uniformly scheduled by an intelligent control module. Its system composition and principle are as follows:

[0039] The core design of the system lies in simulating and optimizing the water purification process in nature, and enhancing it to suit the characteristics of industrial slag wastewater. Its operation follows a progressive purification logic from physical separation to chemical transformation to precision protection.

[0040] Among them, the separation module: the hydrocyclone uses the tangential inlet to generate a high-speed rotating flow field. Coarse slag particles (>74 microns) are thrown against the wall due to the huge centrifugal force and spiral down to the bottom outlet for discharge, effectively avoiding rapid clogging of the subsequent sedimentation tank and filter.

[0041] Multi-stage gradient sedimentation module: The inclined plate sedimentation unit efficiently removes medium-sized particles (20-74 microns) under gravity by increasing the settling area. The high-efficiency coagulation and clarification unit adds agents such as PAC and PAM, which, through charge neutralization and adsorption bridging, coagulate colloids and fine particles (<20 microns) in the water that are difficult to settle naturally into dense flocs, thus enabling rapid separation. These two stages of sedimentation constitute a gradient barrier from physical to chemical processes.

[0042] The integrated filtration module is key to achieving water quality improvement and long-term system operation.

[0043] Further includes:

[0044] Pre-filter unit: intercepts suspended solids that slip through the filter, providing stable water inlet conditions for the subsequent softening unit.

[0045] Chemical crystallization softening unit: An alkali (such as NaOH) is added to the pH adjustment tank to raise the pH to 10.5-11.0, so that... Transform into ,and , A tendency to precipitate. In the crystallization reaction tank, existing seed crystals (such as...) Particles provide a preferred template for precipitation, avoiding the problem of difficult separation of tiny crystals caused by homogeneous nucleation, and promoting the formation of large crystal particles from hardness ions. Solid-liquid separation devices (such as centrifuges) then separate the grown crystals.

[0046] Post-filter security unit: Uses high-precision filter elements to capture trace crystals or fragments that may remain during the softening process, ensuring that the water supplied to slag treatment equipment (especially precision nozzles) is absolutely clean.

[0047] Storage and supply module and circulating water cooling unit: Variable frequency constant pressure water supply pump set ensures stable pressure at water usage points. The parallel cooling tower unit, under intelligent control, automatically starts when the water temperature exceeds the set threshold to cool part of the recycled water, actively regulating the thermal balance of the entire circulation system and preventing excessively high water temperature from affecting processing efficiency or equipment safety.

[0048] Collection and processing module: Collects sludge from each stage of the system, dewaters it under high pressure using a plate and frame filter press to form low-moisture sludge cakes, which are easy to transport and dispose of. The filtrate is returned to the front end of the system to achieve zero liquid discharge.

[0049] Intelligent control module: When the online hardness meter shows an increase in the hardness of the water effluent from the softening unit, the controller can automatically increase the alkali dosage; when the pressure difference of the self-cleaning filter reaches the set value, the backwashing program is automatically started. This dynamic regulation ensures that the system always operates under optimal conditions.

[0050] Through the close integration and intelligent collaboration of the above modules, the system of this invention successfully transforms highly polluting and easily scaled slag wastewater into high-quality process water that can be stably reused, forming an efficient, reliable, and resource-efficient closed-loop ecosystem.

[0051] Its specific manifestations are as follows:

[0052] High-temperature, high-slag wastewater first enters the separation module (such as a hydrocyclone), where the centrifugal force field is used to achieve initial solid-liquid separation and quickly reduce the load.

[0053] Subsequently, the wastewater containing fine particles enters the multi-stage gradient sedimentation module, where it undergoes a synergistic effect of natural sedimentation (inclined plate sedimentation) and chemical agglomeration sedimentation (coagulation clarification) to achieve deep removal of suspended solids. Afterward, the focus of water purification shifts from suspended solids to dissolved impurities, which then enter the integrated filtration module.

[0054] Here, a pre-filtration unit ensures safety before the water enters the crucial chemical crystallization softening unit. This unit artificially creates a supersaturated crystallization environment (by adding alkali to raise the pH) and adds seed crystals to provide nucleation sites. This causes calcium and magnesium ions, which are prone to scaling, to precipitate directionally from the water onto the surface of the seed crystals, rather than onto the equipment pipes. In this way, while removing hardness, it turns a harmful substance into a beneficial one, producing usable crystal byproducts.

[0055] After the precipitated crystals are separated, the water undergoes final polishing in a post-filter unit to ensure its purity. The treated water is then stored in a storage and supply module, completing its purification process, and is returned to the production end for use.

[0056] The wastewater, carrying new pollutants, is recycled again after use. All sludge generated throughout the process is collected and treated in a centralized collection and treatment module for volume reduction. The intelligent control module acts as the nerve center of the system, sensing the water quality, flow rate, and pressure status at each stage through a network of sensors. Based on preset algorithms, it dynamically adjusts the dosage, backwash frequency, valve opening, and other parameters to ensure the stable, efficient, and economical automatic operation of this complex process.

[0057] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.

Claims

1. A circulating water filtration treatment system for slag treatment, characterized by, The system comprises, in sequence along a slag wastewater treatment flow, a separation module, a multi-stage gradient precipitation module, a filtration integrated module, and a storage supply module. The separation module is used for receiving high-temperature slag-containing wastewater from the slag treatment process and performing cyclone centrifugal separation to output a bottom flow containing coarse slag and an overflow containing fine particles. The multi-stage gradient precipitation module is connected with the overflow output end of the separation module and used for performing at least two-stage physical and chemical synergistic precipitation on the overflow to sequentially remove medium and small particle suspensions and colloidal substances and output clarified water. The filtration integrated module is connected with the water outlet end of the multi-stage gradient precipitation module and comprises, in sequence, a front filter unit, a chemical crystallization softening unit, and a rear security filter unit. The front filter unit is used for performing first-stage mechanical filtration on the clarified water to remove residual suspensions. The chemical crystallization softening unit is used for performing pH adjustment and inducing crystallization on the water filtered by the first-stage filtration to remove scaling calcium and magnesium ions. The rear security filter unit is used for performing terminal precision filtration on the softened water to remove precipitated microcrystalline particles and output high-quality recycled water.

2. A circulating water filtration treatment system for slag treatment according to claim 1, wherein The storage supply module is connected with the water outlet end of the rear security filter unit and used for storing the high-quality recycled water and supplying the stored water to water use points of the slag treatment process under pressure. A collection and treatment module is connected with the bottom flow outlet of the separation module, the sludge discharge port of the multi-stage gradient precipitation module, and the residue discharge port of the chemical crystallization softening unit, respectively, and used for concentrating and dewatering the sludge generated by each module to form sludge cakes for external transportation. The wastewater generated after the water use points of the slag treatment process are used is returned to the separation module to form a closed circulating water treatment system, and the system is controlled by an intelligent control module.

3. A recirculating water filtration system for slag treatment according to claim 2, wherein The separation module is a hydrocyclone group.

4. A recirculating water filtration system for slag treatment according to claim 3, characterised in that The front filter unit is an automatic backwashing filter with a filtration precision of 100-300 microns.

5. A recirculating water filtration system for slag processing according to claim 2, wherein The rear security filter unit is a filter core type precision filter with a filtration precision of 1-20 microns.

6. A recirculating water filtration system for slag treatment as claimed in claim 2, wherein The chemical crystallization softening unit comprises, in sequence, a pH adjustment tank, a crystallization reaction tank, and a solid-liquid separation device.

7. A recirculating water filtration system for slag treatment as claimed in claim 2, wherein, A circulating water cooling unit is connected in parallel on a return water pipeline between the storage supply module and the separation module.

8. A recirculating water filtration system for slag treatment according to claim 7, wherein, The intelligent control module comprises a central controller, a data acquisition unit, and a man-machine interface. The intelligent control module automatically controls whether the water flow is divided to pass through the circulating water cooling unit according to the recycled water temperature. The data acquisition unit comprises flow meters, pressure sensors, turbidity meters, pH meters, hardness online analyzers, and temperature sensors arranged at key nodes of the system. The intelligent control module is internally provided with a self-adaptive optimization algorithm for adjusting the dosing amount of the dosing device according to the water inflow turbidity and flow rate of the multi-stage gradient precipitation module and dynamically feedback adjusting the alkali dosing speed according to the water outflow hardness value of the chemical crystallization softening unit.

9. A recirculating water filtration system for slag treatment as claimed in claim 2, wherein The collecting and processing module comprises a sludge homogenizing tank, a sludge conveying pump and a plate-and-frame filter press, and filtrate of the plate-and-frame filter press is returned to the water inlet end of the separating module or the multi-stage gradient precipitation module.

10. A recirculating water filtration system for slag treatment as claimed in claim 2, wherein The filtration process comprises: S1, pumping the wastewater generated in the slag treatment process into the separating module to realize rapid separation and discharge of coarse slag by using cyclone centrifugal force; S2, introducing the effluent after the separation in step S1 into the multi-stage gradient precipitation module, removing medium and small particles by inclined plate sedimentation naturally, and then removing colloids and micro-fine suspended solids by adding chemical reagents for coagulation and clarification; S3, pumping the supernatant generated in step S2 into the filtration integrated module, removing residual impurities by a pre-filtering unit, inducing crystallization of soluble hardness ions by increasing pH value and seed in a chemical crystallization softening unit, and finally intercepting microcrystals by a post-security filtering unit to obtain softened clean water; S4, storing the clean water obtained in step S3 in the storage and supply module, and returning the clean water to the slag treatment process under pressure according to requirements; S5, collecting the sludge generated in each module to the collecting and processing module for concentration and dewatering treatment, and returning the filtrate to the front end of the system; S6, returning the wastewater after use in the slag treatment process to step S1 again to form a closed loop.

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