A multi-stage adjuvant synergistic chelation fly ash treatment system and method

Abstract

The present application relates to the field of solid waste treatment, and specifically discloses a multi-stage auxiliary material synergistic chelated fly ash treatment system and method, which comprises a chelated fly ash pretreatment unit, a water washing unit, a mixing unit, a granulation unit and a high-temperature melting unit, the water washing unit is provided with a first coarse particle auxiliary material feeding device and a first intelligent control device, the mixing unit is provided with a second coarse particle auxiliary material feeding device and a fine particle auxiliary material feeding device, the high-temperature melting unit is provided with a second intelligent control device, and an evaporation crystallization unit is additionally arranged and connected to the water washing wastewater outlet of the water washing unit, comprising two parts of pretreatment and evaporation crystallization, and the evaporation crystallization is thermally coupled to the waste heat outlet of the high-temperature melting unit, and the treatment method comprises the steps of crushing pretreatment, water washing dechlorination, dynamic regulation of process parameters according to particle size distribution, drying and crushing and adding auxiliary materials, granulation molding, high-temperature melting and intelligent adjustment of parameters based on viscosity and image characteristics.

Description

Technical Field

[0001] This invention relates to the field of solid waste treatment, and in particular to a multi-stage auxiliary material synergistic chelation fly ash treatment system and method. Background Technology

[0002] Municipal solid waste incineration fly ash contains toxic heavy metals such as lead, cadmium, mercury, and chromium, as well as dioxins, and is classified as hazardous waste. Chelation stabilization is the mainstream landfill disposal technology for it. However, landfilling occupies a large amount of land resources and produces malodorous gases that affect the surrounding environment. In recent years, the national policy of "reducing landfilling" has been fully implemented, and the chelated fly ash that has already been landfilled must be excavated and disposed of in a resource-based manner.

[0003] High-temperature melting is the core technology for the resource utilization of chelated fly ash, which can completely decompose dioxins and solidify heavy metals. However, the chloride content of chelated fly ash is as high as 15% to 25%. Direct melting will cause serious equipment corrosion, a surge in energy consumption, and secondary volatilization of heavy metal chlorides. Therefore, it is necessary to remove chloride salts through water washing pretreatment first.

[0004] Existing conventional water washing processes are difficult to adapt to the characteristics of chelated fly ash: chelated fly ash is mostly in the form of tightly agglomerated clumps, and it is difficult for chloride ions and heavy metals inside to be fully released into the liquid phase; at the same time, traditional water washing lacks effective particle collision and crushing enhancement methods and precise pH control mechanisms, resulting in incomplete leaching of chlorine and heavy metals, which cannot meet the feeding requirements for subsequent high-temperature melting, thus restricting the industrial application of chelated fly ash resource utilization. Summary of the Invention

[0005] This invention addresses the shortcomings of existing technologies that require addressing the agglomeration of chelated fly ash by providing a multi-stage auxiliary material synergistic chelation fly ash treatment system.

[0006] To solve the above-mentioned technical problems, the present invention provides a multi-stage auxiliary material synergistic chelation fly ash treatment system, comprising: The chelated fly ash pretreatment unit is configured to crush the chelated fly ash. The water washing unit is connected to the discharge end of the chelated fly ash pretreatment unit and is configured to perform water washing treatment on the crushed chelated fly ash. The water washing unit is equipped with a first coarse-grained auxiliary material feeding device, which is used to feed the first coarse-grained auxiliary material that forms mechanical collision crushing of the chelated fly ash. The mixing unit is connected to the discharge end of the washing unit and is configured to perform pressure filtration and mixing treatment on the washed material. The mixing unit is equipped with a second coarse-grained auxiliary material feeding device and a fine-grained auxiliary material feeding device. The second coarse-grained auxiliary material feeding device is used to add second coarse-grained auxiliary material to the chelated fly ash to disperse the auxiliary material during the pressure filtration process. The fine-grained auxiliary material feeding device is used to melt and mix the chelated fly ash at high temperature. The granulation unit is connected to the discharge end of the mixing unit and is configured to granulate the chelated fly ash after it has passed through the mixing unit. A high-temperature melting unit is connected to the discharge end of the granulation unit and is configured to perform high-temperature melting treatment on the granulated material. The high-temperature melting unit is equipped with a melting auxiliary material feeding device. The washing unit is equipped with a first intelligent control device, which is configured to detect the particle size distribution of the material during the washing process in real time and dynamically adjust the washing process parameters according to the particle size distribution. The high-temperature melting unit is equipped with a second intelligent control device, which is configured to monitor the state parameters of the material in real time during the melting process and dynamically adjust the melting process parameters and auxiliary material ratio according to the state parameters.

[0007] By adopting the above technical solution, this multi-stage auxiliary material synergistic chelation fly ash treatment system significantly improves the specific surface area of ​​chelated fly ash through the pretreatment unit's crushing and de-agglomeration, creating favorable conditions for water washing and dechlorination. In the water washing unit, the addition of the first coarse-grained auxiliary material and the first intelligent control device, based on the dynamic parameter adjustment of real-time particle size distribution, synergistically optimize the water washing intensity, greatly improving the chloride ion removal efficiency and effectively suppressing the risk of heavy metal leaching. The addition of the second coarse-grained auxiliary material in the mixing unit further improves the particle size distribution and structural uniformity of the material, laying a solid foundation for granulation. The precise addition of fine-grained auxiliary material in the granulation unit promotes the formation of dense and uniformly sized particles, significantly improving melt adaptability. The high-temperature melting unit is equipped with a melting auxiliary material addition device and a second intelligent control device that adjust the melting temperature, time, and auxiliary material ratio in real time according to the melting state parameters to ensure production. This system produces high-quality, stable vitreous products while significantly reducing the risk of chlorine corrosion to equipment and energy consumption. The entire system achieves organic synergy through the distribution of multi-stage auxiliary materials in different process stages according to particle size gradients. This not only specifically addresses the core technical bottleneck of high chlorine content in chelated fly ash restricting resource utilization, but also utilizes the separate addition of auxiliary materials in the washing and mixing units. Simultaneously, it utilizes the physical characteristics of the auxiliary materials to physically crush the chelated fly ash during washing through physical collision, and the mixing unit crushes the chelated fly ash filter cake after pressure filtration during drying. The system is equipped with a second coarse-grained auxiliary material addition device and a fine-grained auxiliary material addition device. The second coarse-grained auxiliary material addition device is used to add the second coarse-grained auxiliary material to the chelated fly ash to disperse the auxiliary material during pressure filtration. The fine-grained auxiliary material addition device is used for high-temperature melting and blending of the chelated fly ash.

[0008] The present invention is further configured such that: the washing unit is also equipped with a pH monitoring device for detecting the pH of the washing wastewater after washing by the washing unit, and the pH monitoring device is signal-connected to the first intelligent control device; The first intelligent control device adjusts the washing process parameters to regulate the heavy metal elution behavior based on the deviation between the pH value detected by the pH monitoring device and the preset pH target value. It calculates the chlorine elution rate based on the initial chlorine content of the chelated fly ash, the flow rate of the washing wastewater, and the real-time chloride ion content in the washing wastewater, and dynamically adjusts the washing process parameters based on the chlorine elution rate. The washing process parameters include solid-liquid ratio, stirring rate, washing temperature, and washing residence time. The first intelligent control device is also connected to the second intelligent control device. The second intelligent control device feeds back the real-time melting process parameters to the first intelligent control device. The first intelligent control device dynamically controls the addition ratio of the first coarse-grained auxiliary material and the second coarse-grained auxiliary material according to the melting process parameters.

[0009] By adopting the above technical solution, this system can achieve precise control over the elution behavior of heavy metals and the chlorine elution rate when washing chelated fly ash. The pH monitoring device provides real-time feedback on the acidity and alkalinity of the washing wastewater, enabling the first intelligent control device to dynamically adjust the washing process parameters based on the deviation between the pH value and the target value. This optimizes the dissolution and removal efficiency of heavy metals. Simultaneously, by calculating the chlorine elution rate and adjusting the washing process parameters accordingly, it ensures that chloride ions are efficiently and thoroughly eluted from the fly ash, effectively reducing the risk of chlorine corrosion to equipment during subsequent high-temperature melting and improving the stability of the molten products. Furthermore, the system facilitates communication between the first and second intelligent control devices. The signal connection enables coordinated optimization of the washing and high-temperature melting stages. The second intelligent control device feeds back the real-time melting process parameters to the first intelligent control device, allowing the first intelligent control device to dynamically adjust the addition ratio of the first and second coarse-grained auxiliary materials according to the actual needs of the melting process. This cross-stage intelligent coordinated control not only optimizes the utilization efficiency of auxiliary materials and reduces unnecessary waste, but also allows for pre-regulation of material properties in the washing and mixing stages based on the real-time conditions of the melting stage. This ensures the smooth operation of the entire processing flow and the quality stability of the final product, significantly improving the refinement and efficiency of chelated fly ash treatment.

[0010] The present invention is further configured to include an evaporation crystallization unit, wherein the washing unit is provided with a wastewater outlet connected to the evaporation crystallization unit, the evaporation crystallization unit includes a washing wastewater pretreatment subunit and an evaporation crystallization subunit, the washing wastewater pretreatment subunit performs weight removal pretreatment on the washing wastewater, the evaporation crystallization subunit is configured with a heat source end and a condensate outlet, the high-temperature melting unit is configured with a waste heat outlet, the heat source end and the waste heat outlet are thermally coupled, and the condensate outlet of the evaporation crystallization unit is connected to a water inlet provided on the washing unit; The mixing unit is equipped with a second condensate outlet, which is connected to the water inlet of the washing unit.

[0011] By adopting the above technical solution, this application effectively solves the problem of wastewater treatment and resource utilization generated during the washing and dechlorination process. After the washing wastewater undergoes degravation treatment in the pretreatment subunit, it enters the evaporation and crystallization subunit for evaporation and concentration, recovering pure condensate. Importantly, the heat source end of the evaporation and crystallization subunit is thermally coupled with the waste heat outlet of the high-temperature melting unit, making full use of the waste heat inside the system, significantly reducing the energy consumption of the evaporation and crystallization process, and improving the energy efficiency of the entire system. The recovered condensate, including condensate outlet one from the evaporation and crystallization unit and condensate outlet two from the mixing unit, is recycled back to the water supply inlet of the washing unit, realizing closed-loop recycling of water resources. This not only significantly reduces the consumption of fresh water and the amount of wastewater discharged, reducing operating costs and environmental impact, but also ensures the environmental friendliness and sustainability of the entire chelated fly ash treatment system through effective management of the washing wastewater, further improving the economic benefits and comprehensive treatment capacity of the system.

[0012] The present invention is further configured such that the first intelligent control device is configured to adjust at least one of the solid-liquid ratio, stirring rate, water washing temperature and water washing residence time according to the particle size distribution.

[0013] By adopting the above technical solution, the first intelligent control device can adjust the washing process parameters, including solid-liquid ratio, stirring rate, washing temperature, and washing residence time, according to the real-time detected particle size distribution of the material. This refined and dynamic control mechanism enables the washing process to better adapt to the characteristics of fly ash with different particle sizes, avoiding the inefficiency and resource waste caused by traditional fixed parameters or empirical adjustments. For example, when the fly ash particle size is large, the stirring rate and washing temperature can be appropriately increased, and the residence time can be extended to enhance the mechanical crushing effect and the dissolution and elution efficiency of pollutants (such as chloride ions and heavy metals). When the particle size is small, the stirring rate can be reduced and the residence time shortened to prevent over-crushing and save energy. This not only ensures the efficient removal of pollutants but also optimizes the utilization of water resources and energy, significantly improving the overall effect and economy of chelated fly ash washing treatment.

[0014] The present invention is further configured such that: the second intelligent control device is configured to adjust at least one of the melting time, melting temperature and auxiliary material ratio according to the viscosity and image characteristics of the molten product.

[0015] By adopting the above technical solution, the second intelligent control device can use the viscosity and image features of the molten product as key, quantifiable state parameters to finely control the high-temperature melting process. Real-time monitoring of the viscosity of the molten product directly reflects the fluidity and uniformity of the melt, providing a direct basis for adjusting the melting temperature and auxiliary material ratio. This avoids incomplete melting or excessive energy consumption caused by improper viscosity. At the same time, combined with the analysis of image features, the smoothness of the molten liquid surface, the bubble situation, color changes, etc., can be intuitively evaluated, further assisting in judging the uniformity and integrity of the melt, and timely detecting and correcting problems such as local overheating, underheating, or incomplete melting. This intelligent control mechanism based on multi-dimensional, real-time feedback makes the adjustment of melting time, melting temperature, and auxiliary material ratio more precise and timely, thereby ensuring that the chelated fly ash can be fully and uniformly melted to form a stable glassy product, effectively solidifying heavy metals. At the same time, it optimizes the energy consumption and auxiliary material consumption of the melting process, significantly improving the efficiency and product quality of high-temperature melting treatment.

[0016] The present invention is further configured as follows: a multi-stage auxiliary material synergistic chelation fly ash treatment method, comprising the following steps: S1: Perform crushing pretreatment on chelated fly ash, and adjust the crushing degree according to the initial characteristic parameters of chelated fly ash so that the particle size of the crushed chelated fly ash is smaller than the preset mesh size. S2: The crushed chelated fly ash is subjected to water washing and dechlorination treatment. During the water washing process, the first coarse-grained auxiliary material is added to mechanically crush the chelated fly ash. At the same time, the particle size distribution of the chelated fly ash particles is monitored in real time during the water washing process, and the water washing process parameters are dynamically adjusted according to the particle size distribution. S3: The fly ash solid-liquid mixture after water washing is filtered by pressure to separate the solid and liquid components of the fly ash solid-liquid mixture, and obtain the filtered fly ash filter cake and water washing wastewater. S4: The fly ash filter cake is crushed and mixed. During the crushing and mixing process, the second coarse-grained auxiliary material is added first, followed by the fine-grained auxiliary material. S5: Granulate the fly ash material after crushing and mixing; S6: Perform high-temperature melting treatment on the granulated material, monitor the state parameters of the material in real time during the melting process, and dynamically adjust the melting process parameters and auxiliary material ratio according to the state parameters.

[0017] By adopting the above technical solutions, this treatment method improves the specific surface area by de-agglomerating through crushing pretreatment, adds coarse-grained auxiliary materials in the washing stage and dynamically adjusts parameters based on particle size distribution to achieve efficient dechlorination and heavy metal stabilization, optimizes the physical properties of materials through secondary crushing and auxiliary material addition in the drying and crushing stage, promotes uniform particle formation through fine-grained auxiliary materials in the granulation stage, and adds molten auxiliary materials in the melting stage and intelligently adjusts the process based on state parameters to ensure the generation of high-quality glass. The entire method, through multi-level auxiliary material gradient synergy and adaptive control of parameters throughout the process, not only completely solves the industry problem of high chlorine in chelated fly ash restricting the melting and resource utilization, but also significantly improves treatment efficiency, product quality and process stability, realizing an efficient conversion path from hazardous waste to high-value resources.

[0018] The present invention is further configured such that the initial characteristic parameters in step S1 include at least one of the following: initial particle size of chelated fly ash, chlorine content, heavy metal content, and elemental ratio.

[0019] By adopting the above technical solution, the degree of crushing can be adjusted based on more comprehensive and specific initial characteristic parameters such as initial particle size, chlorine content, heavy metal content, and element ratio when pre-treating chelated fly ash. This precise parameter guidance makes the crushing process more targeted, avoiding under- or over-crushing caused by ambiguous parameters. For fly ash with larger initial particle size or higher heavy metal content, the crushing intensity can be increased in a targeted manner to increase the specific surface area, thereby effectively improving the efficiency of subsequent water washing dechlorination and heavy metal elution. For fly ash with abnormal chlorine content or specific element ratios, the crushing strategy can be adjusted according to its characteristics, providing more accurate input for the optimization of auxiliary material ratio in the subsequent high-temperature melting process, ensuring the stability and safety of the molten products. This refined pre-treatment not only optimizes energy consumption, but more importantly, it significantly improves the overall efficiency and final treatment effect of the entire multi-stage auxiliary material synergistic chelating fly ash treatment system, ensuring the harmless and resource-based utilization of fly ash.

[0020] The present invention is further configured such that, in the water washing process, laser diffraction is used to detect the particle size distribution of the material.

[0021] By adopting the above technical solution and using laser diffraction to detect the particle size distribution of materials during the washing process in real time, high-precision and real-time particle size data can be obtained. This accurate real-time data provides a reliable and timely basis for the first intelligent control device to dynamically adjust washing process parameters such as solid-liquid ratio, stirring rate, washing temperature, and washing residence time. This not only ensures that the mechanical collision and crushing effect of chelated fly ash particles during the washing and dechlorination process is optimal, effectively improving the washing efficiency of heavy metals and chlorine, but also avoids deviations in process parameter adjustment caused by inaccurate or delayed particle size detection. This significantly improves the stability and efficiency of the washing process. At the same time, the precisely controlled particle size distribution also helps to optimize subsequent pressure filtration, mixing, and high-temperature melting processes, laying a solid foundation for the efficient operation of the entire multi-stage auxiliary material synergistic chelation fly ash treatment system.

[0022] The present invention is further configured to include, before adding the first coarse-grained auxiliary material and / or the second coarse-grained auxiliary material to the water washing treatment step, pre-testing the first coarse-grained auxiliary material and / or the second coarse-grained auxiliary material and the fine-grained auxiliary material to obtain the particle size distribution, hardness parameters, particle shape characteristics, chlorine content, heavy metal content and element ratio of the coarse-grained auxiliary material. Based on the pre-detection results, when the physical properties of the coarse-grained auxiliary material deviate from the preset range, the dosage of the coarse-grained auxiliary material feeding device is adjusted.

[0023] By adopting the above technical solution, pre-testing is performed on the excipients before they are put into use, and the dosage of the excipients is dynamically adjusted based on the test results. This application can effectively address the problem of fluctuations in the physicochemical properties between or within batches of excipients. Specifically, a comprehensive evaluation is conducted on the particle size distribution, hardness parameters, particle shape characteristics, chlorine content, heavy metal content, and elemental ratio of the first coarse-grained excipient and / or the second coarse-grained excipient and the fine-grained excipient. This allows the system to identify excipient characteristics that do not meet the requirements in advance. When the physical properties of the coarse-grained excipient deviate from the preset range, such as insufficient hardness or unsatisfactory particle size distribution, the system can promptly adjust the dosage of the coarse-grained excipient dosing device to compensate for the performance of the excipient. To address the shortcomings of the first coarse-grained auxiliary material, this system ensures that during the water washing and dechlorination step, the first coarse-grained auxiliary material continuously provides a stable mechanical impact crushing effect, effectively promoting the dissociation of chelated fly ash and the elution of chlorine. Simultaneously, during the mixing and pressure filtration step, the second coarse-grained auxiliary material maintains its proper dispersing effect, preventing excessive filter cake density from affecting subsequent processing. This dynamic dosage adjustment mechanism based on auxiliary material pre-detection significantly improves the stability and adaptability of the entire multi-stage auxiliary material synergistic chelation fly ash treatment system, avoiding the risk of decreased processing efficiency or substandard product quality due to fluctuations in auxiliary material quality. This ensures the continuity and efficiency of the fly ash treatment process, and ultimately guarantees the quality of the molten products and environmental safety.

[0024] This invention, by employing the above technical solutions, achieves significant technical effects: The multi-stage auxiliary material synergistic chelation fly ash treatment system and method constructs an intelligent integrated system encompassing crushing, washing, drying, granulation, and melting wastewater treatment. Through the precise distribution of multi-stage auxiliary materials according to particle size gradients and the synergistic effect of intelligent full-process control, it completely overcomes the industry's technical bottleneck of high chlorine content in chelated fly ash restricting high-temperature melting and resource utilization. The washing stage achieves efficient dechlorination and dual stabilization of heavy metals, while the melting stage generates high-quality vitreous resource utilization products. Waste heat recovery and water resource recycling design significantly reduce energy consumption and emissions. The entire solution not only stably controls the chlorine content of fly ash below the safe threshold, greatly improving the efficiency of harmless treatment and the resource utilization value of the products, but also achieves energy saving, consumption reduction, environmental friendliness, and economic feasibility through process adaptive control and resource recycling. It provides an innovative system solution for the efficient resource utilization of hazardous waste, demonstrating outstanding technological progress and significant environmental and economic benefits. Attached Figure Description

[0025] Figure 1 This is a structural block diagram of a multi-stage auxiliary material synergistic chelation fly ash treatment system. Detailed Implementation

[0026] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0027] Example: This application proposes a multi-stage auxiliary material synergistic chelation fly ash treatment system, comprising: The chelated fly ash pretreatment unit is configured to crush the chelated fly ash. The water washing unit is connected to the discharge end of the chelated fly ash pretreatment unit and is configured to perform water washing treatment on the crushed chelated fly ash. The water washing unit is equipped with a first coarse-grained auxiliary material feeding device, which is used to feed the first coarse-grained auxiliary material that forms mechanical collision crushing of the chelated fly ash. The mixing unit is connected to the discharge end of the washing unit and is configured to perform pressure filtration and mixing treatment on the washed material. The mixing unit is equipped with a second coarse-grained auxiliary material feeding device and a fine-grained auxiliary material feeding device. The second coarse-grained auxiliary material feeding device is used to add second coarse-grained auxiliary material to the chelated fly ash to disperse the auxiliary material during the pressure filtration process. The fine-grained auxiliary material feeding device is used to melt and mix the chelated fly ash at high temperature. The granulation unit is connected to the discharge end of the mixing unit and is configured to granulate the chelated fly ash after it has passed through the mixing unit. A high-temperature melting unit is connected to the discharge end of the granulation unit and is configured to perform high-temperature melting treatment on the granulated material. The high-temperature melting unit is equipped with a melting auxiliary material feeding device. The washing unit is equipped with a first intelligent control device, which is configured to detect the particle size distribution of the material in real time during the washing process and dynamically adjust the washing process parameters according to the particle size distribution. The high-temperature melting unit is equipped with a second intelligent control device, which is configured to monitor the state parameters of the material in real time during the melting process and dynamically adjust the melting process parameters and auxiliary material ratios based on the state parameters.

[0028] Through the synergistic effect of multi-stage auxiliary materials and intelligent control mechanism, the problems of tight agglomeration of chelated fly ash, difficulty in completely washing away chloride ions and heavy metals, and difficulty in controlling the high-temperature melting process are solved. This system can improve the dechlorination efficiency and heavy metal washing rate of chelated fly ash, optimize the stability of molten products, and reduce equipment corrosion and energy consumption. Thus, it provides a highly efficient, environmentally friendly and controllable solution for the resource utilization of chelated fly ash, and promotes the implementation of the "zero landfill" policy.

[0029] A pH monitoring device is installed in the washing unit to acquire the real-time pH value of the washing wastewater. This device is connected to a first intelligent control device. The pH monitoring device typically uses an industrial-grade online pH meter, with a pH electrode as its core component. It can continuously and accurately measure the acidity or alkalinity of the aqueous solution. Through signal connection with the first intelligent control device, such as using a 4-20mA current signal or RS485 digital signal transmission, the real-time pH data can be transmitted to the first intelligent control device for analysis and processing. Upon receiving the real-time pH value from the pH monitoring device, the first intelligent control device compares it with a preset pH target value. When the detected pH value deviates from the target value, the first intelligent control device dynamically adjusts the washing process parameters, such as the solid-liquid ratio, stirring rate, washing temperature, or washing residence time, according to a preset control strategy to regulate the elution behavior of heavy metals. For example, if the pH value is too high, leading to a decrease in the solubility of some heavy metals, the intelligent control device may instruct an increase in the dosage of acidic regulator or adjust the solid-liquid ratio to change the ion concentration, thereby optimizing the elution efficiency of heavy metals. Simultaneously, the first intelligent control device... The chlorine elution rate is calculated based on the initial chlorine content of the chelated fly ash, the flow rate of the washing wastewater, and the real-time chloride ion content in the washing wastewater. The washing process parameters are then dynamically adjusted based on this chlorine elution rate. The initial chlorine content can be obtained through offline analysis or online XRF; the washing wastewater flow rate can be monitored in real-time using a flow meter; and the real-time chloride ion content can be detected using an online chloride ion selective electrode or ion chromatograph. Based on the calculated chlorine elution rate, the first intelligent control device will dynamically adjust the washing process parameters, such as increasing the washing residence time or raising the washing temperature, to ensure high chloride ion concentration. Effectively washing away chlorides from fly ash to achieve the desired dechlorination effect, the adjustment of water washing process parameters can specifically include: solid-liquid ratio, which can be achieved by adjusting the concentration of chelated fly ash slurry entering the water washing unit or the flow rate of supplementary water. For example, increasing the water volume can reduce the solid-liquid ratio and promote dissolution; stirring rate, which can be adjusted by controlling the motor speed of the stirrer in the water washing unit through a frequency converter to change the mixing intensity and mass transfer efficiency of the materials; and water washing temperature, which can be adjusted by controlling the heating or cooling system of the water washing unit to affect the solubility and reaction rate of chlorides and heavy metal salts.The water washing residence time can be controlled by adjusting the inlet and outlet flow rates of the water washing unit or changing the effective volume of the water washing tank to ensure sufficient contact time for thorough washing and removal of materials. Furthermore, the first intelligent control device is signal-connected to the second intelligent control device. The second intelligent control device feeds back real-time melting process parameters to the first intelligent control device. The first intelligent control device dynamically adjusts the addition ratio of the first and second coarse-grained auxiliary materials based on these melting process parameters. A signal connection is established between the first and second intelligent control devices, for example, through industrial Ethernet or fieldbus protocols for data exchange. The second intelligent control device feeds back real-time melting process parameters from the high-temperature melting unit, such as melt viscosity, melting temperature, and energy consumption, to the first intelligent control device. Based on this feedback information, the first intelligent control device dynamically adjusts the addition ratio of the first and second coarse-grained auxiliary materials. If the melt viscosity feedback during the melting process is too high, more flux may be needed, and the first intelligent control device can instruct an increase in the addition ratio of coarse-grained auxiliary materials with fluxing properties. If the melting energy consumption is too high, the auxiliary material ratio may need to be adjusted to lower the melting point.

[0030] To achieve water resource recycling and reduce wastewater discharge, the system also includes an evaporation crystallization unit. The washing unit is equipped with a wastewater outlet connected to the evaporation crystallization unit to introduce washing wastewater into the evaporation crystallization unit. The evaporation crystallization unit includes a washing wastewater pretreatment subunit and an evaporation crystallization subunit. The washing wastewater pretreatment subunit performs heavy metal removal pretreatment on the washing wastewater to remove heavy metals. The evaporation crystallization subunit is equipped with a heat source end and a condensate outlet one. The high-temperature melting unit is equipped with a waste heat outlet. The heat source end and the waste heat outlet are thermally coupled to utilize the waste heat generated by the high-temperature melting unit to provide energy for the evaporation crystallization process. The condensate outlet one of the evaporation crystallization unit is connected to the water inlet on the washing unit to reuse the recovered condensate in the washing unit. In addition, the mixing unit is also equipped with a condensate outlet two, which is also connected to the water inlet of the washing unit, further increasing the water resource recycling rate.

[0031] This evaporation crystallization unit is designed to perform advanced treatment of wastewater generated by the water washing unit, enabling the recycling of water resources and the concentration of pollutants. It can employ various evaporation crystallization technologies, such as multi-effect evaporators, mechanical vapor recompression (MVR) evaporators, or flash evaporators. The specific selection can be optimized based on the characteristics of the wastewater, the treatment capacity, and energy consumption requirements.

[0032] The wastewater pretreatment subunit pretreats the wastewater before evaporation and crystallization. The main purpose is to remove heavy metal ions from the wastewater to prevent scaling, equipment corrosion, or impact on condensate quality during subsequent evaporation and crystallization. The specific pretreatment method for heavy metal removal involves adding ferric chloride coagulant to remove heavy metals from the wastewater; then adding sodium sulfide heavy metal precipitant to further remove residual heavy metals after initial precipitation; after heavy metal removal, decalcification is performed by adding sodium sulfate to the filtrate, stirring for a certain period of time to allow the calcium sulfate to fully mature, and then using a decalcification centrifuge for solid-liquid separation to remove calcium sulfate from the filtrate; the chloride ions in the calcium sulfate are rinsed, and then the calcium sulfate is separated again by a vacuum belt filter, resulting in a final calcium sulfate product with a chloride ion content of less than 0.5%. Sodium carbonate is added to the filtrate for secondary decalcification, and the resulting precipitate is returned to the washing section. The purpose of heavy metal removal is to reduce the heavy metal content of the washing liquid to avoid affecting the quality of sodium chloride and potassium chloride obtained by evaporation and crystallization, and the purpose of decalcification is to reduce the calcium ion content of the washing liquid to avoid affecting the quality of sodium chloride and potassium chloride obtained by evaporation and crystallization.

[0033] The evaporation crystallization sub-unit is the core of the evaporation crystallization unit. It is responsible for evaporating and concentrating the pretreated wastewater, and then evaporating and crystallizing the filtrate after heavy decalcification. Since potassium chloride and sodium chloride have different solubilities (potassium chloride is more soluble than sodium chloride, and its solubility increases with temperature), while the solubility of sodium chloride remains relatively stable with temperature. After evaporation and concentration, pure condensate and high-concentration salt solution or crystalline salt are separated. Sodium salt is preferentially precipitated, and as sodium salt precipitates, the potassium salt content gradually increases. The MVR evaporator increases the temperature and pressure of the secondary steam by compressing it, allowing it to be reused as heating steam for evaporation, thus significantly reducing energy consumption.

[0034] The high-temperature melting unit generates a large amount of waste heat during operation, such as the sensible heat of high-temperature flue gas or molten slag. This application thermally couples the heat source end of the evaporation crystallization subunit with the waste heat outlet of the high-temperature melting unit, for example by setting up a heat exchanger, to transfer the waste heat of the high-temperature melting unit to the evaporation crystallization subunit as the heating energy for its evaporation process. This thermal coupling design greatly improves the energy utilization efficiency of the entire system and reduces the operating cost of the evaporation crystallization process.

[0035] The condensate generated by the evaporation and crystallization unit is discharged through condensate outlet one and can be directly reused as makeup water for the washing unit. At the same time, the mixing unit may also generate some condensate during the pressure filtration and mixing process of the washed material, which is discharged through condensate outlet two. For example, the condensate generated during the drying or steam treatment of the filter cake is discharged through condensate outlet two. This recovered condensate is transported to the water inlet of the washing unit through the pipeline system, realizing a closed-loop water resource circulation and significantly reducing the amount of fresh water used and wastewater discharged.

[0036] The intelligent control device is configured to adjust at least one of the following based on the particle size distribution: solid-liquid ratio, stirring rate, water washing temperature, and water washing residence time.

[0037] Specifically, the solid-liquid ratio refers to the mass or volume ratio of solid materials to liquids during the washing process. It directly affects the dispersion of materials in water, mass transfer efficiency, and the difficulty of subsequent solid-liquid separation. The first intelligent control device can dynamically adjust the solid-liquid ratio based on the particle size distribution by controlling actuators such as the inlet pump flow rate and material feeding amount. For example, when the material particle size is detected to be too large, the solid-liquid ratio may need to be adjusted to increase the collision probability between particles, promote mechanical crushing and release of pollutants; conversely, when the particle size is too small, the solid-liquid ratio may need to be adjusted to avoid excessive wear or the formation of a slurry that is difficult to separate.

[0038] The stirring rate refers to the rotational speed of the agitator in the washing unit. The stirring rate affects the uniformity of material mixing in water, the collision intensity between particles, and the mass transfer rate. The first intelligent control device adjusts the stirring rate by controlling the speed of the stirring motor through a frequency converter. For materials with larger particle sizes, it may be necessary to increase the stirring rate to enhance the mechanical crushing effect and mass transfer efficiency; for materials with smaller particle sizes, it may be necessary to reduce the stirring rate to avoid over-crushing, fine powdering, or equipment wear.

[0039] Washing temperature refers to the temperature of the water during the washing process. It affects the solubility, diffusion rate, and chemical reaction rate of pollutants. The first intelligent control device adjusts the washing temperature by controlling the power or flow rate of the heating device. When the particle size distribution indicates a need for stronger elution, such as larger particles making it difficult to release internal pollutants, the washing temperature can be appropriately increased. Conversely, when the particle size is smaller and the elution efficiency is higher, the washing temperature can be reduced to save energy. Washing residence time refers to the time the material spends in the washing unit. Residence time determines the extent to which pollutants come into contact with water and undergo mass transfer, dissolution, and elution. The first intelligent control device adjusts the washing residence time by controlling the flow rate of material entering and leaving the washing unit or the batch processing time. When larger particle sizes or insufficient pollutant elution are detected, the washing residence time can be extended; when smaller particle sizes or the elution effect has met the standard, the residence time can be shortened to increase throughput.

[0040] The second intelligent control device is configured to adjust at least one of the following based on the viscosity and image characteristics of the molten product: melting time, melting temperature, and auxiliary material ratio. This device acquires the viscosity and image characteristics of the molten product by integrating or connecting corresponding sensors and analysis modules. The viscosity of the molten product is a key physical parameter for measuring the flowability, uniformity, and internal structure of the melt. During high-temperature melting, viscosity directly affects the mixing of materials, heat transfer efficiency, and the quality of the final vitrified product. To obtain the viscosity of the molten product in real time, an online viscometer, such as a rotary viscometer or a vibratory viscometer, can be used. Its probe is immersed in the molten material, and the viscosity value is calculated by measuring the resistance of the molten material to the probe's movement. Alternatively, the torque and angular velocity of the stirring device inside the melting furnace can be monitored. The viscosity of the molten product is indirectly calculated by combining parameters such as the preset calibration model. The second intelligent control device can also acquire image features of the molten product. Image features refer to the quantifiable information extracted from the material in the melting furnace in real time by a vision system such as a high-temperature industrial camera and using image processing technology. These features may include, but are not limited to, the flatness of the molten liquid surface, the number and size of bubbles, the color, transparency, flow texture of the melt, and the presence of unmelted solid particles. Through advanced image recognition and analysis algorithms, such as edge detection, region segmentation, feature extraction, and pattern recognition, this visual information can be converted into digital signals that can be processed by the control device. For example, the uniformity of melting can be evaluated by analyzing the bubble distribution, and color changes can indicate changes in temperature or composition.

[0041] Based on the obtained viscosity and image characteristics of the molten product, the second intelligent control device can dynamically adjust at least one of the melting time, melting temperature, and auxiliary material ratio. When the viscosity of the molten product is detected to deviate from the preset range, the second intelligent control device can issue an instruction to appropriately increase the melting temperature to reduce the viscosity, or adjust the addition ratio of the molten auxiliary material to promote melting. When the image analysis shows that the molten liquid surface is uneven, there are too many bubbles, or there are unmelted particles, the second intelligent control device can extend the melting time to ensure full melting, or make local or overall adjustments to the melting temperature to eliminate unevenness. The adjustment of the auxiliary material ratio involves the types and proportions of various auxiliary materials such as flux and stabilizer. These auxiliary materials directly affect the melting point, viscosity, glass transition properties, and solidification effect of heavy metals in the molten material. The second intelligent control device achieves precise adjustment of the auxiliary material ratio by controlling the addition amount of the molten auxiliary material addition device.

[0042] A multi-stage auxiliary material synergistic chelation fly ash treatment method is also provided, including the following steps: S1: Perform crushing pretreatment on chelated fly ash, and adjust the crushing degree according to the initial characteristic parameters of chelated fly ash so that the particle size of the crushed chelated fly ash is smaller than the preset mesh size. S2: The crushed chelated fly ash is subjected to water washing and dechlorination treatment. During the water washing process, the first coarse-grained auxiliary material is added to mechanically crush the chelated fly ash. At the same time, the particle size distribution of the chelated fly ash particles is monitored in real time during the water washing process, and the water washing process parameters are dynamically adjusted according to the particle size distribution. S3: The fly ash solid-liquid mixture after water washing is filtered by pressure to separate the solid and liquid components of the fly ash solid-liquid mixture, and obtain the filtered fly ash filter cake and water washing wastewater. S4: The fly ash filter cake is crushed and mixed. During the crushing and mixing process, the second coarse-grained auxiliary material is added first, followed by the fine-grained auxiliary material. S5: Granulate the fly ash material after crushing and mixing; S6: Perform high-temperature melting treatment on the granulated material, monitor the state parameters of the material in real time during the melting process, and dynamically adjust the melting process parameters and auxiliary material ratio according to the state parameters.

[0043] By introducing a first coarse-grained auxiliary material in the water washing step to mechanically crush the chelated fly ash through collision, combined with real-time particle size distribution detection and dynamic adjustment mechanism of water washing process parameters, the leaching barrier of chloride ions and heavy metals caused by the dense agglomeration structure of chelated fly ash is effectively solved. At the same time, by real-time monitoring of state parameters and dynamic control of process parameters in the high-temperature melting step, the stability of the melting process and the solidification effect of heavy metals are ensured, thus systematically solving the technical problems of incomplete dechlorination and poor melting adaptability of traditional water washing processes.

[0044] In specific implementation, in step S1, the crushing intensity is adjusted according to the initial particle size, chloride content, and heavy metal content of the chelated fly ash to control the particle size after crushing to below 100 mesh, providing a sufficiently exposed reaction interface for subsequent water washing. In step S2, the first coarse-grained auxiliary material added is quartz sand with a particle size of 1-5 mm. Through stirring, it mechanically collides with the fly ash particles, breaking their agglomeration structure. At the same time, the first intelligent control device acquires particle size distribution data in real time based on laser diffraction. When the proportion of particles larger than 500 μm in the particle size distribution exceeds the threshold, the stirring rate is automatically increased to 150-200 rpm and the water washing residence time is extended to ensure that chloride ions are fully dissolved. In step S3, a plate and frame filter press is used to achieve solid-liquid separation. To obtain fly ash filter cake with a moisture content lower than a preset ratio, in step S4, slag particles with a particle size of 0.5-2mm are first added as a second coarse-grained auxiliary material to form a porous skeleton structure during the filter pressing process, improving the water permeability of the filter cake. Subsequently, silica powder with a particle size of less than 0.1mm is added as a fine-grained auxiliary material to provide a compatibility basis for high-temperature melting. In step S5, particles with a diameter of 3-8mm are prepared by a disc granulator to enhance the thermal stability of the material during the melting process. In step S6, the second intelligent control device monitors the torque and angular velocity of the molten material in real time, dynamically adjusts the melting temperature to 1400-1500℃ according to the viscosity calculation formula μ=KM / ω, and optimizes the addition ratio of molten auxiliary materials to ensure that heavy metals are completely solidified in the glass product.

[0045] In step S1, the specific content of the initial characteristic parameters includes at least one of the following: initial particle size of chelated fly ash, chlorine content, heavy metal content, and elemental ratio. The initial particle size of the chelated fly ash refers to the original particle size distribution of the untreated chelated fly ash. This parameter can be accurately measured using various particle size analysis technologies such as laser particle size analyzer and sieving methods. Accurately obtaining the initial particle size distribution helps assess the crushing difficulty of the fly ash and provides a basis for selecting appropriate crushing equipment and setting the crushing intensity, ensuring that the particle size of the crushed fly ash meets the requirements of subsequent washing and melting processes. Chlorine content refers to the mass percentage of chlorine in the chelated fly ash. Chlorine is a key harmful component in fly ash, and its content directly affects the efficiency of water washing and dechlorination, as well as the corrosion risk of equipment and the formation of harmful substances such as dioxins during subsequent high-temperature melting. Chlorine content can be detected by X-ray fluorescence spectroscopy (XRF), ion chromatography, or chemical titration. Heavy metal content refers to… The concentration of typical heavy metals such as lead, cadmium, mercury, and chromium in chelated fly ash is determined. These heavy metals are the main target pollutants in fly ash treatment, and their content determines the complexity of the treatment and the type and amount of chelating agent required. The heavy metal content is usually determined by analytical methods such as atomic absorption spectrometry (AAS) and inductively coupled plasma optical emission spectrometry (ICP-OES). The element ratio refers to the relative content of the main oxides (such as SiO2, Al2O3, CaO, Fe2O3, etc.) in chelated fly ash. The ratio of these elements has a significant impact on the physicochemical properties of fly ash, such as melting point, viscosity, and chemical reactivity. It is a key basis for the auxiliary material ratio design and the performance control of melt products during high-temperature melting. The element ratio can be comprehensively analyzed by XRF or ICP-OES. Through the accurate detection and quantification of the above initial characteristic parameters, scientific and comprehensive data support can be provided for the crushing pretreatment in step S1, thereby achieving fine adjustment of the crushing degree.

[0046] In the washing process, laser diffraction is used to detect the particle size distribution of the material. Specifically, laser diffraction is a non-contact technique based on the principle of light diffraction to measure particle size distribution. When a laser beam passes through a group of chelated fly ash particles dispersed in the washing slurry, the particles cause the laser to diffract. The angle of diffracted light is inversely proportional to the size of the particles; smaller particles produce larger diffraction angles, while larger particles produce smaller diffraction angles. By detecting the intensity of the diffracted light at different angles and combining it with appropriate mathematical models, such as Fraunhofer diffraction theory or Mie scattering theory, the particle size distribution data of the chelated fly ash particles can be accurately derived. In actual operation, an online or bypass sampling system can be set up in the washing unit to extract the material slurry during the washing process. After appropriate dilution and dispersion, it is sent to the measuring cell of the laser particle size analyzer for real-time detection. This analyzer can quickly and accurately provide detailed particle size distribution information, including key parameters such as median particle size, average particle size, and percentage of different particle size ranges.

[0047] In the high-temperature melting process, the viscosity μ is calculated by monitoring the torque M and angular velocity ω of the molten material. The formula for calculating viscosity μ is: μ = KM / ω, where μ represents the viscosity of the molten product, K represents the calibration constant of the viscosity detection equipment, M represents the torque, and ω represents the angular velocity. Based on the viscosity μ and the image characteristics of the molten product, at least one of the following is adjusted: melting time, melting temperature, and auxiliary material ratio. In the high-temperature melting process, the viscosity μ is calculated by monitoring the torque M and angular velocity ω of the molten material. Torque M refers to the torque borne by the agitator or rotor in the melting equipment when overcoming the internal resistance of the molten material, and angular velocity ω refers to the rotational speed of the agitator or rotor. Viscosity μ is... Viscosity, a physical quantity measuring fluid flow resistance, directly reflects the fluidity, uniformity, and degree of melting of molten materials. The formula for calculating viscosity μ is μ = KM / ω, where K represents the calibration constant of the viscosity measuring equipment. This constant is usually provided by the equipment manufacturer or obtained through experimental calibration. By installing torque and speed sensors on the melting equipment, the values ​​of M and ω can be acquired in real time, thereby accurately calculating the real-time viscosity of the molten product. The image features of the molten product refer to the macroscopic visual characteristics of the molten material acquired and analyzed by a vision system using an industrial camera and image processing software. These features may include, but are not limited to, the color, transparency, and surface smoothness of the molten material. Integrity, bubble content, impurity distribution, flow texture, and the presence of unmelted particles are all important parameters. For example, image analysis can identify whether the color change of the molten material reaches a preset uniform state, whether the number of bubbles is within an acceptable range, and whether there is agglomeration or stratification. These image features provide intuitive information about the molten material at the macroscopic level, which is crucial for judging whether the melting is sufficient and uniform and whether there are any abnormalities. Based on the real-time calculated viscosity μ and the analyzed image features of the molten product, the melting process parameters can be dynamically adjusted. When the viscosity μ is too high, it may indicate poor material flowability and insufficient melting. In this case, the melting time can be appropriately extended or the melting temperature can be increased to promote melting. The process involves ensuring the complete melting and uniform mixing of the feed material; or adjusting the ratio of auxiliary materials, such as adding auxiliary materials with a fluxing effect. When the viscosity μ is too low, it may lead to excessive flow or separation of the material. In this case, the melting time can be shortened or the melting temperature can be lowered, or the ratio of auxiliary materials can be adjusted to increase the viscosity of the material. At the same time, combined with image features, for example, when the image shows that there are a large number of bubbles or unmelted particles in the molten material, the melting time or temperature can be adjusted to improve the melting effect. When the image shows uneven color or obvious impurities, it may be necessary to adjust the ratio of auxiliary materials or extend the melting time to promote homogenization and impurity removal. This dynamic adjustment mechanism based on multi-parameter synergy can achieve precise control of the high-temperature melting process.

[0048] In the high-temperature melting process, a real-time monitoring and feedback mechanism for the viscosity μ and image features of the molten material is introduced. The viscosity μ of the molten material is obtained through precise measurement and calculation of torque M and angular velocity ω, providing a quantitative indicator for the rheological properties of the molten material. This accurately reflects the material's flowability and melting uniformity. At the same time, the image features of the molten product provide intuitive visual information at the macroscopic level, supplementing the comprehensive judgment of the melting state. Based on these precise viscosity μ data and image features, the system can more accurately judge the actual state of the molten material, thereby dynamically and finely adjusting the melting time, melting temperature, and auxiliary material ratio. This collaborative monitoring and control method overcomes the limitations of relying solely on generalized state parameters for adjustment, significantly improving the control accuracy and stability of the high-temperature melting process. It ensures the uniformity, density, and final quality of the chelated fly ash melting product, effectively avoiding performance degradation caused by insufficient or excessive melting, and thus improving the efficiency and product utilization value of the entire fly ash treatment system.

[0049] Pre-testing is conducted on auxiliary materials before their use, and the dosage of auxiliary materials is dynamically adjusted based on the test results. Specifically, this scheme includes pre-testing the first coarse-grained auxiliary material and / or the second coarse-grained auxiliary material and the fine-grained auxiliary material. This pre-testing aims to conduct quality control and characteristic evaluation of various auxiliary materials that will be put into the fly ash treatment system, ensuring that the auxiliary materials used meet the preset quality standards and process requirements, and avoiding poor subsequent treatment results due to auxiliary material quality problems. Pre-testing can be carried out before the auxiliary materials are put into storage, before use, or at the inlet of the auxiliary material feeding device. It can be achieved through various methods such as sampling analysis and online monitoring. For example, representative samples can be periodically drawn from the batch of auxiliary materials and sent to the laboratory for detailed analysis; or sensors can be installed on the auxiliary material conveying pipeline to monitor certain key characteristics of the auxiliary materials in real time or near real time.

[0050] During the pre-testing process, it is necessary to obtain the particle size distribution, hardness parameters, particle shape characteristics, chlorine content, heavy metal content, and element ratio of the coarse-grained auxiliary materials. Among these, particle size distribution is a key factor affecting the mechanical collision crushing effect of coarse-grained auxiliary materials during water washing. A suitable particle size distribution can ensure effective collision between the auxiliary materials and fly ash particles, promoting the dissociation of fly ash agglomerates and the elution of chlorine. Detection methods can include laser particle size analyzers, sieving methods, etc. The hardness parameters of the auxiliary materials are directly related to their efficiency and wear during the mechanical collision crushing process, and can be measured using equipment such as Rockwell hardness testers and Vickers hardness testers. Particle shape characteristics affect the contact area and collision efficiency between the auxiliary materials and fly ash particles, and morphological analysis of the auxiliary material particles can be performed using an image analysis system. The chlorine content, heavy metal content, and element ratio are crucial for ensuring the quality and environmental safety of the final melt product, and can be detected using analytical instruments such as X-ray fluorescence spectrometry (XRF) and inductively coupled plasma optical emission spectrometry (ICP-OES).

[0051] Based on the pre-detection results, when the physical properties of the coarse-grained auxiliary material deviate from the preset range, the dosage of the coarse-grained auxiliary material feeding device will be adjusted. The preset range is the qualified range of auxiliary material characteristics set according to process requirements and experience. When auxiliary material characteristics such as particle size and hardness are detected to exceed this range, it indicates that the performance of the current batch of auxiliary material may differ from that of the standard auxiliary material. In order to compensate for this difference, the system will adjust the dosage of the auxiliary material through the coarse-grained auxiliary material feeding device. For example, if the hardness of the auxiliary material is too low, the dosage may need to be increased appropriately to maintain sufficient mechanical impact crushing effect; if the particle size is too large, the dosage may need to be increased to ensure sufficient effective collision surface area. This adjustment can be linear, segmented, or based on a preset control strategy. The coarse-grained auxiliary material feeding device usually includes a metering pump, screw feeder, vibrating feeder, etc., and its dosage can be precisely adjusted by frequency conversion speed regulation, valve opening control, etc.

[0052] The overall real-time solution involves sending the chelated fly ash to be treated into the chelated fly ash pretreatment unit. This unit is equipped with crushing equipment to perform preliminary crushing treatment on the fly ash. Based on the initial characteristic parameters of the fly ash, such as the initial particle size and chlorine content, the operating parameters of the crushing equipment are adjusted to ensure that the particle size of the crushed fly ash is less than the preset mesh size, thereby increasing the specific surface area of ​​the fly ash and creating favorable conditions for subsequent water washing and dechlorination.

[0053] The crushed fly ash enters the washing unit for dechlorination treatment. During the washing process, a first coarse-grained auxiliary material is added to the washing unit through a first coarse-grained auxiliary material feeding device. These auxiliary materials undergo mechanical collisions with the fly ash particles in the washing liquid, further breaking up the fly ash agglomerates and promoting the more complete release of chloride ions and heavy metals into the liquid phase. At the same time, the first intelligent control device configured in the washing unit monitors the particle size distribution of the material in real time during the washing process, for example, by using laser diffraction. If the fly ash particle size is still detected to be too large, the first intelligent control device will dynamically adjust the washing process parameters according to the particle size distribution, such as increasing the stirring rate or extending the washing residence time, to enhance the particle crushing and chloride leaching effect.

[0054] The washing unit is also equipped with a pH monitoring device to detect the pH value of the washing wastewater in real time and transmit the data to the first intelligent control device. The first intelligent control device dynamically adjusts the washing process parameters based on the deviation between the detected pH value and the preset pH target value to precisely control the elution behavior of heavy metals. At the same time, the first intelligent control device also calculates the chlorine elution rate based on the initial chlorine content of the chelated fly ash, the flow rate of the washing wastewater, and the real-time chloride ion content in the washing wastewater. If the chlorine elution rate does not reach the target value, the first intelligent control device will further adjust the washing process parameters, such as the solid-liquid ratio or the washing temperature, to ensure the complete removal of chlorine. Compared with the traditional washing process, this dynamic and intelligent control mechanism significantly improves the elution efficiency of chlorine and heavy metals and solves the problem of incomplete dechlorination caused by the lack of effective particle collision and crushing and precise pH control in traditional washing.

[0055] The solid-liquid mixture of fly ash after washing enters the mixing unit. This unit first performs pressure filtration to achieve solid-liquid separation, obtaining fly ash filter cake and washing wastewater. During the pressure filtration process, a second coarse-grained auxiliary material is added through a second coarse-grained auxiliary material addition device. These auxiliary materials play a dispersing role in the filter cake, improving the permeability of the filter cake, preventing clogging of the pressure filtration equipment, and improving the pressure filtration efficiency. The fly ash filter cake after pressure filtration is then crushed and mixed. During the mixing process, the second coarse-grained auxiliary material is added first, and then fine-grained auxiliary material is added through a fine-grained auxiliary material addition device. The fine-grained auxiliary material is used to adjust the chemical composition of the fly ash, making it more compatible with the subsequent high-temperature melting process, and ensuring the stability and vitrification effect of the melt product.

[0056] After mixing, the fly ash material enters the granulation unit for granulation. The granulation process turns the loose fly ash material into uniform particles, which helps to improve the feeding stability of the subsequent high-temperature melting unit, reduce dust flying, and optimize melting efficiency.

[0057] The granulated material is fed into a high-temperature melting unit for high-temperature melting. During the melting process, the second intelligent control device configured in the high-temperature melting unit monitors the state parameters of the molten material in real time. For example, it calculates the viscosity by monitoring the torque and angular velocity of the molten material and analyzes the image features of the molten product. If the viscosity of the molten product deviates from the target range or the image features are not ideal, the second intelligent control device will dynamically adjust the melting process parameters, such as melting time and melting temperature, and adjust the ratio of the molten auxiliary materials through the molten auxiliary material addition device. This real-time and dynamic control ensures the stable progress of the melting process, avoids equipment corrosion and secondary volatilization of heavy metal chlorides caused by fluctuations in chlorine content, and ultimately forms a stable glassy product, completely solidifying heavy metals and decomposing dioxins. Compared with traditional melting processes, this system significantly improves the control accuracy of the melting process and the quality of the product through real-time monitoring and dynamic adjustment.

[0058] There is a signal connection between the first and second intelligent control devices. The second intelligent control device feeds back real-time melting process parameters to the first intelligent control device. Based on these melting process parameters, the first intelligent control device dynamically adjusts the addition ratio of the first and second coarse-grained auxiliary materials to achieve synergistic optimization of the washing and melting processes, ensuring the efficiency and stability of the entire treatment process. To achieve the recycling of energy and water resources, the wastewater outlet of the washing unit is connected to the evaporation and crystallization unit. The evaporation and crystallization unit includes a washing wastewater pretreatment subunit and an evaporation and crystallization subunit. The washing wastewater pretreatment subunit performs weight removal pretreatment on the washing wastewater, and the evaporation and crystallization subunit is equipped with a heat source end and a condensate outlet. First, the waste heat outlet of the high-temperature melting unit is thermally coupled to the heat source end of the evaporation crystallization sub-unit. The waste heat generated during the melting process is used to evaporate and crystallize the washing wastewater. The condensate outlet of the evaporation crystallization unit is connected to the water inlet of the washing unit, so that the treated condensate is reused in the washing unit, reducing the consumption of fresh water. At the same time, the mixing unit is also equipped with a second condensate outlet, whose condensate is also connected to the water inlet of the washing unit, further realizing the recycling of water resources. This overall solution of multi-stage auxiliary material synergy, intelligent control and resource recycling effectively solves the problems of incomplete chlorine removal, unstable heavy metal solidification and high energy consumption in the treatment of chelated fly ash, and realizes the resource utilization and harmless treatment of fly ash.

Claims

1. A multi-stage auxiliary material synergistic chelation fly ash treatment system, characterized in that, include: The chelated fly ash pretreatment unit is configured to crush the chelated fly ash. The water washing unit is connected to the discharge end of the chelated fly ash pretreatment unit and is configured to perform water washing treatment on the crushed chelated fly ash. The water washing unit is equipped with a first coarse-grained auxiliary material feeding device, which is used to feed the first coarse-grained auxiliary material that forms mechanical collision crushing of the chelated fly ash. The mixing unit is connected to the discharge end of the washing unit and is configured to perform pressure filtration and mixing treatment on the washed material. The mixing unit is equipped with a second coarse-grained auxiliary material feeding device and a fine-grained auxiliary material feeding device. The second coarse-grained auxiliary material feeding device is used to add second coarse-grained auxiliary material to the chelated fly ash to disperse the auxiliary material during the pressure filtration process. The fine-grained auxiliary material feeding device is used to melt and mix the chelated fly ash at high temperature. The granulation unit is connected to the discharge end of the mixing unit and is configured to granulate the chelated fly ash after it has passed through the mixing unit. A high-temperature melting unit is connected to the discharge end of the granulation unit and is configured to perform high-temperature melting treatment on the granulated material. The high-temperature melting unit is equipped with a melting auxiliary material feeding device. The washing unit is equipped with a first intelligent control device, which is configured to detect the particle size distribution of the material during the washing process in real time and dynamically adjust the washing process parameters according to the particle size distribution. The high-temperature melting unit is equipped with a second intelligent control device, which is configured to monitor the state parameters of the material in real time during the melting process and dynamically adjust the melting process parameters and auxiliary material ratio according to the state parameters.

2. The multi-stage auxiliary material synergistic chelation fly ash treatment system according to claim 1, characterized in that, The washing unit is also equipped with a pH monitoring device for detecting the pH of the washing wastewater after washing in the washing unit. The pH monitoring device is connected to the first intelligent control device. The first intelligent control device adjusts the washing process parameters to regulate the heavy metal elution behavior based on the deviation between the pH value detected by the pH monitoring device and the preset pH target value. It calculates the chlorine elution rate based on the initial chlorine content of the chelated fly ash, the flow rate of the washing wastewater, and the real-time chloride ion content in the washing wastewater, and dynamically adjusts the washing process parameters based on the chlorine elution rate. The washing process parameters include solid-liquid ratio, stirring rate, washing temperature, and washing residence time. The first intelligent control device is also connected to the second intelligent control device. The second intelligent control device feeds back the real-time melting process parameters to the first intelligent control device. The first intelligent control device dynamically controls the addition ratio of the first coarse-grained auxiliary material and the second coarse-grained auxiliary material according to the melting process parameters.

3. The multi-stage auxiliary material synergistic chelation fly ash treatment system according to claim 1 or 2, characterized in that, It also includes an evaporation crystallization unit. The water washing unit is provided with a wastewater outlet connected to the evaporation crystallization unit. The evaporation crystallization unit includes a water washing wastewater pretreatment subunit and an evaporation crystallization subunit. The water washing wastewater pretreatment subunit performs weight removal pretreatment on the water washing wastewater. The evaporation crystallization subunit is equipped with a heat source end and a condensate outlet. The high-temperature melting unit is equipped with a waste heat outlet. The heat source end and the waste heat outlet are thermally coupled. The condensate outlet of the evaporation crystallization unit is connected to the water supply port provided on the water washing unit. The mixing unit is equipped with a second condensate outlet, which is connected to the water inlet of the washing unit.

4. The multi-stage auxiliary material synergistic chelation fly ash treatment system according to claim 1, characterized in that, The first intelligent control device is configured to adjust at least one of the following according to the particle size distribution: solid-liquid ratio, stirring rate, water washing temperature, and water washing residence time.

5. The multi-stage auxiliary material synergistic chelation fly ash treatment system according to claim 1, characterized in that, The second intelligent control device is configured to adjust at least one of the following based on the viscosity of the molten product and image characteristics: melting time, melting temperature, and auxiliary material ratio.

6. A method for treating fly ash by multi-stage auxiliary material synergistic chelation, characterized in that, Includes the following steps: S1: Perform crushing pretreatment on chelated fly ash, and adjust the crushing degree according to the initial characteristic parameters of chelated fly ash so that the particle size of the crushed chelated fly ash is smaller than the preset mesh size. S2: The crushed chelated fly ash is subjected to water washing and dechlorination treatment. During the water washing process, the first coarse-grained auxiliary material is added to mechanically crush the chelated fly ash. At the same time, the particle size distribution of the chelated fly ash particles is monitored in real time during the water washing process, and the water washing process parameters are dynamically adjusted according to the particle size distribution. S3: The fly ash solid-liquid mixture after water washing is filtered by pressure to separate the solid and liquid components of the fly ash solid-liquid mixture, and obtain the filtered fly ash filter cake and water washing wastewater. S4: The fly ash filter cake is crushed and mixed. During the crushing and mixing process, the second coarse-grained auxiliary material is added first, followed by the fine-grained auxiliary material. S5: Granulate the fly ash material after crushing and mixing; S6: Perform high-temperature melting treatment on the granulated material, monitor the state parameters of the material in real time during the melting process, and dynamically adjust the melting process parameters and auxiliary material ratio according to the state parameters.

7. The multi-stage auxiliary material synergistic chelation fly ash treatment method according to claim 6, characterized in that, The initial characteristic parameters mentioned in step S1 include at least one of the following: initial particle size of chelated fly ash, chlorine content, heavy metal content, and elemental ratio.

8. The multi-stage auxiliary material synergistic chelation fly ash treatment method according to claim 6, characterized in that, In the water washing process, laser diffraction is used to detect the particle size distribution of the material.

9. The multi-stage auxiliary material synergistic chelation fly ash treatment method according to claim 6, characterized in that, Before adding the first coarse-grained auxiliary material and / or the second coarse-grained auxiliary material to the water washing treatment step, the method further includes: performing pre-testing on the first coarse-grained auxiliary material and / or the second coarse-grained auxiliary material and the fine-grained auxiliary material to obtain the particle size distribution, hardness parameters, particle shape characteristics, chlorine content, heavy metal content and element ratio of the coarse-grained auxiliary material. Based on the pre-detection results, when the physical properties of the coarse-grained auxiliary material deviate from the preset range, the dosage of the coarse-grained auxiliary material feeding device is adjusted.

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