Fly ash washing detoxification and recovery method

Abstract

The invention provides a fly ash washing detoxification and recovery method, which belongs to the technical field of solid waste treatment, and comprises the following steps: collecting parameter information of feeding fly ash in real time; according to the parameter information of the feeding fly ash, determining the water amount and the stirring speed required for pulping, and completing fly ash pulping to obtain fly ash slurry; washing the fly ash slurry with water, detecting the parameter information of the eluent in real time in the washing process, and dynamically adjusting the washing times and the countercurrent rate according to the parameter information of the eluent; carrying out solid-liquid separation on the mixed system obtained by washing to obtain a mud cake and an eluent; the mud cake is dried; adsorbing heavy metals in the eluent to obtain a primarily purified eluent; and carrying out evaporative crystallization on the primarily purified eluent so as to recover the soluble salt. According to the fly ash washing detoxification and recovery method provided by the invention, through dynamic adjustment and precise treatment of each link, the harmless treatment effect of the fly ash is improved.

Description

Technical Field

[0001] This invention belongs to the technical field of solid waste treatment, and more specifically, relates to a method for detoxification and recycling of fly ash by water washing. Background Technology

[0002] Fly ash, a typical hazardous solid waste generated during incineration, has a complex composition and is highly hazardous. It contains not only various heavy metals such as lead, cadmium, and mercury, but also a large amount of soluble salts such as sodium chloride and potassium chloride. If simply disposed of through landfill or stockpiling, heavy metals can easily pollute the soil and groundwater through leaching, while soluble salts will exacerbate salinization of the surrounding environment, posing serious ecological and environmental risks. At the same time, the soluble salts in fly ash have high recycling value, and failure to effectively recover them will result in significant resource waste. Currently, water washing detoxification technology has become the mainstream technology for the harmless treatment and resource recovery of fly ash because it can effectively remove soluble salts and some heavy metals.

[0003] Existing fly ash treatment technologies suffer from the following drawbacks: Fluctuations in the characteristics of different batches of fly ash – Fly ash from different sources and under different incineration conditions exhibits significant differences in core parameters such as particle size distribution, soluble salt content, and heavy metal concentration. Current fly ash washing and detoxification technologies generally employ fixed parameters, failing to adequately adapt to the fluctuations in particle size, soluble salt content, and heavy metal concentration among different batches of fly ash. This leads to problems such as substandard treatment or waste of energy and reagents in each stage of washing, drying, adsorption purification, and evaporation crystallization. Summary of the Invention

[0004] The purpose of this invention is to provide a method for detoxifying and recycling fly ash by washing, which aims to solve the problem that the existing fly ash treatment process uses fixed parameters, making it difficult to adapt to the parameters of different batches of fly ash.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: to provide a method for fly ash water washing detoxification and recycling, comprising: Real-time acquisition of parameter information for feed fly ash; Based on the parameter information of the fed fly ash, determine the required water volume and stirring rate for pulping, and complete the fly ash pulping to obtain fly ash slurry; The fly ash slurry is washed with water. During the washing process, the parameters of the eluent are monitored in real time, and the number of washes and the countercurrent rate are dynamically adjusted according to the parameters of the eluent. The mixture obtained by water washing is subjected to solid-liquid separation to obtain mud cake and eluent; The mud cake is dried; The heavy metals in the eluent are adsorbed to obtain a preliminarily purified eluent. The preliminarily purified eluent is evaporated and crystallized to recover soluble salts.

[0006] In one possible implementation, the parameter information of the fly ash includes particle size distribution data and mass fraction of soluble salts.

[0007] In one possible implementation, the step of determining the required water volume and stirring rate for pulping based on the parameter information of the feed fly ash, and completing the fly ash pulping to obtain fly ash slurry, includes: The required amount of water for pulping is determined based on the parameter information of the fly ash, and water injection is completed. Obtain parameter information of agglomerates in fly ash slurry; The stirring rate is dynamically adjusted based on the parameter information of the agglomerates and the particle size distribution data.

[0008] In one possible implementation, obtaining the parameter information of agglomerates in fly ash slurry includes: Acquire image information of the fly ash slurry; The number and average particle size of agglomerates in the fly ash slurry are calculated based on the image information.

[0009] In one possible implementation, dynamically adjusting the stirring rate based on the parameter information of the agglomerates and the particle size distribution data includes: The parameter information of the aggregate is compared with the aggregate parameter threshold. If the parameter information of the aggregate is not higher than the aggregate parameter threshold, the stirring rate is controlled to a first rate. If the parameter information of the aggregate is higher than the aggregate parameter threshold, the stirring rate is adjusted to a second rate according to the parameter information of the aggregate.

[0010] In one possible implementation, the step of washing the fly ash slurry with water, monitoring the parameters of the eluent in real time during the washing process, and dynamically adjusting the number of washes and the countercurrent rate based on the parameters of the eluent, includes: The initial number of washes and the initial countercurrent rate are set according to the mass fraction information of the soluble salts, and the fly ash slurry is subjected to countercurrent washing. Obtain the real-time conductivity and pH value of the eluent; The number of washes and the countercurrent rate are dynamically adjusted based on the real-time conductivity and pH of the eluent.

[0011] In one possible implementation, drying the mud cake includes: Obtain the real-time moisture content information of the mud cake; The real-time moisture content information is compared with the moisture content threshold, and the drying temperature is adjusted in real time based on the comparison result.

[0012] In one possible implementation, comparing the real-time moisture content information with a moisture content threshold and adjusting the drying temperature in real time based on the comparison result includes: Calculate the difference between the real-time moisture content information and the moisture content threshold; The drying temperature is adjusted in real time based on the difference.

[0013] In one possible implementation, the adsorption of heavy metals in the eluent to obtain a preliminarily purified eluent comprises: Develop a batch-by-batch adsorbent dosing plan, determine the initial adsorbent dosing amount, and set the initial stirring rate. The adsorbent is added in batches. After the adsorbent is added, the real-time heavy metal concentration information of the eluent is obtained, and the stirring rate is dynamically adjusted based on the real-time heavy metal concentration.

[0014] In one possible implementation, the step of dispensing the adsorbent in batches includes: The real-time heavy metal concentration information is compared with a safety threshold. If the real-time heavy metal concentration information is not lower than the safety threshold, then the next batch of adsorbent needs to be added; if the real-time heavy metal concentration information is lower than the safety threshold, then the next batch of adsorbent needs to be added. If the next batch of adsorbent needs to be added, the change range is calculated based on the real-time heavy metal concentration information; if the change range is not lower than the change threshold, the next batch of adsorbent will not be added temporarily; if the change range is lower than the change threshold, the next batch of adsorbent will be added, and the amount of adsorbent added in the next batch will be determined based on the real-time heavy metal concentration information.

[0015] The beneficial effects of the fly ash washing detoxification and recovery method provided by this invention are as follows: Compared with the prior art, this invention's fly ash washing detoxification and recovery method, by collecting parameter information of the feed fly ash in real time, can accurately grasp the specific characteristics of each batch of fly ash, providing a targeted basis for subsequent processing steps and avoiding the problem of unstable treatment effect due to differences in fly ash characteristics. Determining the required water volume and stirring rate for pulping based on the feed fly ash parameter information ensures the rationality of the fly ash pulping process, preventing the slurry quality from being affected by too much or too little water, and preventing uneven mixing of the slurry due to improper stirring rate, thus laying a good foundation for the subsequent washing stage.

[0016] During the washing process, the eluent parameters are monitored in real time, and the number of washes and the countercurrent rate are dynamically adjusted. This allows for flexible optimization of the washing operation based on the actual conditions of the eluent, effectively improving washing efficiency and ensuring that soluble salts and some heavy metals are fully eluted. This avoids energy waste caused by incomplete or excessive washing. The resulting mixture undergoes solid-liquid separation to obtain a mud cake and eluent, achieving effective separation of the two phases and facilitating subsequent drying of the mud cake and processing of the eluent. Drying the mud cake removes moisture, reduces its volume, facilitates subsequent handling and utilization, and minimizes moisture interference in later processing stages.

[0017] Adsorbing heavy metals from the eluent effectively removes harmful heavy metals, reducing the environmental hazard of the eluent and yielding a pre-purified eluent, providing clean raw materials for subsequent evaporation and crystallization. Evaporation and crystallization of the pre-purified eluent allows for the effective recovery of soluble salts, transforming potentially wasted resources into usable substances, thus improving the resource utilization rate of fly ash treatment and meeting the requirements of resource recycling. Overall, this method, through dynamic adjustment and precise processing at each stage, effectively solves the problem of traditional treatment technologies that struggle to adapt to the characteristics of different batches of fly ash due to fixed parameters. It improves the harmless treatment effect of fly ash, reduces environmental risks, and simultaneously achieves the recovery and utilization of soluble salts, reducing resource waste and demonstrating significant environmental and resource benefits. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the main steps of the fly ash washing detoxification and recycling method provided in the embodiments of the present invention; Figure 2 This is a schematic flowchart of the fly ash washing detoxification and recycling method provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the process for batch-dispensing adsorbent according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the process for evaporating and crystallizing a preliminarily purified eluent, provided in an embodiment of the present invention. Detailed Implementation

[0020] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0021] Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0022] It should be further noted that the accompanying drawings and embodiments of the present invention mainly describe the concept of the present invention. Based on this concept, some specific forms and arrangements of connection relationships, positional relationships, power mechanisms, power supply systems, hydraulic systems and control systems may not be fully described. However, under the premise that those skilled in the art understand the concept of the present invention, they can implement the above-mentioned specific forms and arrangements in a well-known manner.

[0023] When a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0024] In the description of this invention, "a plurality of" means two or more, and "several" means one or more, unless otherwise explicitly specified.

[0025] The directional terms "inner" and "outer" refer to the inner and outer contours of each component itself. The terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0026] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," and "above" are used here to describe the spatial positional relationship between a device or feature and other devices or features, as shown in the figure. It should be understood that spatial relative terms are intended to... The invention includes different orientations of the device in use or operation, in addition to those described in the figures. For example, if a device in the figures is inverted, a device described as "above" or "on top of" other devices or structures will be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below". The device may also be positioned in other different ways, and the spatial relative descriptions used herein are interpreted accordingly. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the invention, "a plurality of" means two or more, and "a number" means one or more, unless otherwise explicitly specified.

[0027] Reference Figures 1 to 4 The method for fly ash detoxification and recycling provided by the present invention will now be described. The method includes: S100. Real-time acquisition of parameter information of feed fly ash.

[0028] In one possible implementation, the parameter information of fly ash includes particle size distribution data and mass fraction of soluble salts.

[0029] A laser particle size sensor and a near-infrared spectroscopy sensor are installed on the fly ash feed conveying pipeline. The laser particle size sensor collects the particle size distribution data of fly ash particles in real time, and the near-infrared spectroscopy sensor detects the mass fraction of soluble salts in fly ash in real time. The sampling frequency is set to 1 time / minute, and the collected data is filtered to remove outliers.

[0030] The filtering process is as follows: A sliding window is constructed using the average particle size or soluble salt mass fraction data from five consecutive collections. The filtered data is then calculated using the following formula to achieve data smoothing and noise reduction:

[0031] in, For the first 1 filtered data; N is the sliding window size; For the first Secondary raw data collection.

[0032] Removing outliers specifically includes: Based on the filtered data, the mean and standard deviation of the filtered data are calculated using the following formulas:

[0033]

[0034] in, This represents the mean of the filtered data. This represents the total number of valid data points after filtering. For the first Filtered data; denoted as the standard deviation of the filtered data sequence.

[0035] Based on the mean and standard deviation of the filtered data, and The principle is to identify outliers. If the filtered data exceeds... If it is, then it is determined to be an outlier.

[0036] Calculate the arithmetic mean of the two adjacent valid data points for each outlier using the following formula, and then replace the outlier with this arithmetic mean:

[0037] in, This refers to the abnormal data that was replaced. , These are the effective filtered data preceding and following the abnormal data, respectively.

[0038] S200. Determine the required water volume and stirring rate for pulping based on the parameter information of the fed fly ash, and complete the fly ash pulping to obtain fly ash slurry.

[0039] In one possible implementation, step S200 involves determining the required water volume and stirring rate for pulping based on the parameter information of the feed fly ash, and completing the fly ash pulping process to obtain fly ash slurry, including: S210. Determine the amount of water required for pulping based on the parameter information of fly ash, and complete the water injection.

[0040] Calculate the required water volume for pulping using the following formula:

[0041]

[0042] in, This refers to the amount of water used in pulping; For the quality of the feed fly ash; The optimal liquid-to-solid ratio; This represents the average fly ash particle size. This represents the mass fraction of soluble salts.

[0043] S220. Obtain parameter information of agglomerates in fly ash slurry.

[0044] In one possible implementation, S220. Obtain parameter information of agglomerates in fly ash slurry, including: S221. Obtain image information of fly ash slurry.

[0045] Two symmetrically arranged high-speed industrial cameras are installed on the side wall of the pulping tank, with the camera lenses facing the stirring area and equipped with anti-fog light-transmitting covers; at the same time, LED supplementary lights are installed inside the tank to ensure image clarity.

[0046] S222. Calculate the number and average particle size of agglomerates in fly ash slurry based on image information.

[0047] The acquired slurry images are transmitted to the image processing system, where aggregate regions are extracted using grayscale, threshold segmentation, and morphological filtering algorithms. The number of aggregates and the average particle size are calculated, and the detection results are output every 30 seconds while outliers are removed.

[0048] The image processing system adopts a traditional four-stage machine vision model of "preprocessing-segmentation-feature extraction-parameter calculation," which does not require deep learning training and is suitable for real-time industrial requirements. The machine vision model includes an image acquisition module, a preprocessing module, a segmentation module, and a feature extraction module.

[0049] After acquiring image information, the image processing system first performs a 3×3 median filter to remove random noise, then uses gamma correction to improve the edge sharpness of the clusters, and finally converts the image to grayscale to reduce computation. Next, cluster segmentation is performed. Adaptive thresholding is used to convert the grayscale image into a binary image. Opening operations remove small impurity points, and closing operations fill in tiny holes inside the clusters. Feature extraction and filtering are then performed. The connected regions in the binary image are traversed, and features such as area, perimeter, and circularity of each region are extracted. Regions with an area ≥ 50 pixels and a circularity ≥ 0.6 are selected as valid clusters. Finally, parameter calculation and output are performed. Based on the camera calibration parameters, pixel units are converted to actual physical units, and the number of clusters and average particle size are calculated. Abnormal data deviating from the mean by ±10% are removed to ensure accurate results.

[0050] The specific structure, parameter configuration, operation logic, and calculation formulas used in the image processing system are existing technologies in this field. Those skilled in the art can find corresponding existing technical solutions, and will not elaborate further in this application.

[0051] S230. The stirring rate is dynamically adjusted based on the parameter information of the agglomerates and the particle size distribution data.

[0052] In one possible implementation, S230. Dynamically adjust the stirring rate based on the parameter information and particle size distribution data of the agglomerates, including: The parameters of the aggregates are compared with the aggregate parameter threshold. If the parameters of the aggregates are not higher than the aggregate parameter threshold, the stirring rate is controlled at the first rate. If the parameters of the aggregates are higher than the aggregate parameter threshold, the stirring rate is adjusted to the second rate according to the parameters of the aggregates.

[0053] Specifically, the parameters for agglomerates include the number of agglomerates and their average particle size. If the number of agglomerates does not exceed a quantity threshold, or the average particle size does not exceed an average particle size threshold, the stirring rate is controlled at a first rate. If the number of agglomerates exceeds the quantity threshold, and the average particle size exceeds the average particle size threshold, the stirring rate is adjusted to a second rate using the following formula:

[0054] in, This is the adjusted second rate; The first speed; This represents the actual number of aggregates. For quantity threshold; The average particle size of the aggregates; This represents the average particle size threshold.

[0055] S300. The fly ash slurry is washed with water. During the washing process, the parameters of the eluent are monitored in real time, and the number of washes and the countercurrent rate are dynamically adjusted according to the parameters of the eluent.

[0056] In one possible implementation, S300. The fly ash slurry is washed with water. During the washing process, the parameters of the eluent are monitored in real time, and the number of washes and the countercurrent rate are dynamically adjusted based on the parameters of the eluent, including: S310. Set the initial number of washes and the initial countercurrent rate based on the mass fraction information of soluble salts, and perform countercurrent washing on the fly ash slurry.

[0057] The initial number of water washes is set using the following formula:

[0058] in, This refers to the initial number of washes. It is a rounding function; This represents the mass fraction of soluble salts.

[0059] The initial countercurrent rate is set using the following formula:

[0060] in, The initial countercurrent rate; It is a rounding function; This represents the mass fraction of soluble salts.

[0061] S320. Obtain the real-time conductivity and pH value of the eluent.

[0062] Conductivity and pH sensors are installed at the eluent outlet of the washing device to collect the conductivity and pH value of the eluent in real time; the sampling frequency is once every 30 seconds, and the monitoring data is transmitted and stored in real time.

[0063] S330. The number of washes and the countercurrent rate are dynamically adjusted based on the real-time conductivity and pH of the eluent.

[0064] The real-time conductivity of the eluent is compared with a conductivity threshold. If the real-time conductivity is not higher than the conductivity threshold, the initial number of washes and the initial backflow rate are maintained. If the real-time conductivity is higher than the conductivity threshold, the number of washes and the backflow rate are adjusted using the following formula:

[0065]

[0066] in, This refers to the final number of washes; This refers to the initial number of washes. The conductivity of the eluent; The conductivity threshold; It is a rounding function; This is the final reverse flow rate; The initial countercurrent rate.

[0067] Compare the pH value with the pH range. If the pH value is within the range, maintain the initial number of washes and the initial backflow rate. If the pH value is outside the range, adjust the backflow rate using the following formula:

[0068] in, This is the final reverse flow rate; The initial countercurrent rate is denoted as .

[0069] S400. The mixed system obtained by water washing is subjected to solid-liquid separation to obtain mud cake and eluent.

[0070] The washed mixture was fed into a plate and frame filter press for solid-liquid separation. The initial filtration pressure was set to P0 = 0.8 MPa and the filtration time to t0 = 30 min. After separation, a sludge cake and eluent were obtained.

[0071] S500. Dry the mud cake.

[0072] In one possible implementation, S500. drying the mud cake includes: S510. Obtain the real-time moisture content information of the mud cake.

[0073] A moisture content sensor is installed at the cake outlet of the plate and frame filter press to collect real-time moisture content information of the cake.

[0074] S520. Compare the real-time moisture content information with the moisture content threshold, and adjust the drying temperature in real time based on the comparison results.

[0075] In one possible implementation, S520. compares the real-time moisture content information with a moisture content threshold, and adjusts the drying temperature in real time based on the comparison result, including: S521. Calculate the difference between the real-time moisture content information and the moisture content threshold.

[0076] If the real-time moisture content is not higher than the moisture content threshold, drying will stop. If the real-time moisture content is higher than the moisture content threshold, the difference between the real-time moisture content and the moisture content threshold will be calculated.

[0077] S522. Adjust the drying temperature in real time based on the difference.

[0078] Adjust the drying temperature in real time using the following formula: ,when hour; ,when hour; ,when hour; in, This refers to the drying temperature. This provides real-time moisture content information for the mud cake. This represents the moisture content threshold.

[0079] S600 adsorbs heavy metals in the eluent to obtain a preliminarily purified eluent.

[0080] After the crude eluent is fed into a pretreatment unit to remove suspended solids, the concentration of heavy metals in the eluent is monitored in real time using an atomic absorption spectrometer. A heavy metal concentration emission standard is established. The dosage of adsorbent is calculated using the following formula:

[0081] in, This refers to the total amount of adsorbent added; This represents the initial heavy metal concentration. For heavy metal emission standards; This is the volume of the elution buffer; This is for the safety factor.

[0082] In one possible implementation, S600 adsorbs heavy metals from the eluent to obtain a preliminarily purified eluent, comprising: S610. Develop a batch-by-batch adsorbent dosing plan, the initial adsorbent dosing amount, and determine the initial stirring rate.

[0083] Based on the initial monitoring of heavy metal concentrations and emission standards, a phased dosing plan was developed according to the total dosage, with 3-5 batches administered. The first batch dosage was 30% of the total dosage. An initial stirring rate was set, and the initial concentration was recorded simultaneously as a benchmark for subsequent parameter adjustments.

[0084] S620. The adsorbent is added in batches. After the adsorbent is added, the real-time heavy metal concentration information of the eluent is obtained, and the stirring rate is dynamically adjusted based on the real-time heavy metal concentration.

[0085] In one possible implementation, the adsorbent is dispensed in batches in S620, including: The real-time heavy metal concentration information is compared with the safety threshold. If the real-time heavy metal concentration information is not lower than the safety threshold, then the next batch of adsorbent needs to be added; if the real-time heavy metal concentration information is lower than the safety threshold, then the next batch of adsorbent needs to be added. If another batch of adsorbent needs to be added, the change rate is calculated based on the real-time heavy metal concentration information. The change rate of real-time heavy metal concentration information is calculated using the following formula:

[0086] in, For the first The magnitude of the concentration decrease in the second monitoring; For the first The concentration of heavy metals monitored this time.

[0087] If the change is not lower than the change threshold, the next batch of adsorbent will not be added for the time being; if the change is lower than the change threshold, the next batch of adsorbent will be added, and the amount of adsorbent added for the next batch will be determined based on the real-time heavy metal concentration information.

[0088] if This indicates a significant decrease in the concentration of heavy metals in the eluent, suggesting that the adsorbent dosage was sufficient. ;if This indicates that the concentration of heavy metals in the eluent decreases slowly, suggesting insufficient adsorbent dosage. .

[0089] In a preferred embodiment, step S620, which dynamically adjusts the stirring rate based on the real-time heavy metal concentration, includes: The stirring rate and stirring time are dynamically adjusted based on the real-time changes in heavy metal concentration.

[0090] Calculate the adjusted stirring rate using the following formula:

[0091] in, For the first The magnitude of the concentration decrease in the second monitoring; For the first The adjusted stirring rate; This represents the largest decrease in concentration in history. This is the function for finding the maximum value.

[0092] Calculate the adjusted stirring time using the following formula:

[0093] in, For the first The adjusted stirring time; Based on the mixing time; For the first The magnitude of the concentration decrease in the second monitoring; This is the function for finding the maximum value.

[0094] S700. The preliminarily purified eluent is evaporated and crystallized to recover soluble salts.

[0095] In a preferred embodiment, S700. Evaporation and crystallization of the preliminarily purified eluent to recover soluble salts includes: S710. Set the initial evaporation temperature and initial evaporation time according to the volume and conductivity of the pre-purified eluent, and begin evaporation and crystallization.

[0096] S720. During the evaporation and crystallization process, obtain real-time crystallization rate information of the crystallization slurry.

[0097] A density sensor is installed at the bottom of the crystallizer in the evaporation crystallization device to calculate the crystallization rate by monitoring the density of the crystallization slurry; the sampling frequency is 1 time / 1 minute, and the crystallization rate data is transmitted in real time.

[0098] The real-time crystallization rate is calculated using the following formula:

[0099] in, Real-time crystallization rate; Density of the crystallization slurry; The density of the pure eluent; This represents the density of soluble salt crystals.

[0100] S730. Compare the real-time crystallization rate information with the target crystallization rate. If the real-time crystallization rate is not lower than the target crystallization rate, maintain the current parameters until evaporation is complete. After evaporation, obtain the recovered salt and evaporation residue by centrifugation. If the real-time crystallization rate is lower than the target crystallization rate, adjust the evaporation temperature and evaporation time using the following formula:

[0101]

[0102] in, The adjusted evaporation temperature; This is the initial evaporation temperature; Real-time crystallization rate; The target crystallinity; This is the adjusted evaporation time; This is the initial evaporation time.

[0103] The beneficial effects of the fly ash washing detoxification and recovery method provided by this invention are as follows: Compared with the prior art, this invention's fly ash washing detoxification and recovery method, by collecting parameter information of the feed fly ash in real time, can accurately grasp the specific characteristics of each batch of fly ash, providing targeted data support for subsequent processing stages and avoiding the problem of unstable treatment effects due to differences in fly ash characteristics. Based on the collected parameter information, the required water volume and stirring rate for pulping are determined, ensuring the rationality of the fly ash pulping process. This prevents the slurry quality from being affected by too much or too little water, and also prevents uneven mixing of the slurry due to improper stirring rate, laying a good foundation for the subsequent washing stage and ensuring the adaptability and scientific nature of the initial steps of the entire processing flow.

[0104] During the fly ash slurry washing process, real-time monitoring of eluent parameters and dynamic adjustment of the washing cycle and countercurrent rate allow for flexible optimization of the washing operation based on the actual conditions of the eluent. This dynamic adjustment method effectively improves washing efficiency, ensuring that soluble salts and some heavy metals are fully eluted, while avoiding energy waste caused by incomplete or excessive washing. This allows the washing process to achieve rational resource utilization while ensuring treatment effectiveness.

[0105] The mixed system obtained from water washing undergoes solid-liquid separation to obtain a sludge cake and eluent, achieving effective separation of the solid and liquid phases. This creates independent and suitable conditions for subsequent drying of the sludge cake and subsequent treatment of the eluent, avoiding interference from solid-liquid mixing in subsequent processing steps and improving the overall orderliness of the treatment process. Drying the sludge cake removes moisture, reduces its volume, facilitates subsequent disposal and utilization, and reduces the potential adverse effects of moisture on other treatment stages, further improving the harmless treatment process for fly ash.

[0106] By adsorbing heavy metals from the eluent, harmful heavy metals can be effectively removed, reducing the environmental hazard of the eluent and yielding a pre-purified eluent. This provides clean raw materials for subsequent evaporation and crystallization, ensuring the safety and purity of the recovered materials. Evaporation and crystallization of the pre-purified eluent allows for the effective recovery of soluble salts, transforming potentially wasted resources into usable substances. This improves the resource utilization rate of fly ash treatment and meets the requirements of resource recycling.

[0107] Furthermore, when determining the pulping water volume and stirring rate, dynamic adjustments are made based on parameters such as fly ash particle size distribution, soluble salt mass fraction, and agglomerates in the slurry, further improving the accuracy of pulping. In the heavy metal adsorption stage, adsorbent is added in batches, and the stirring rate and dosage are adjusted according to the real-time heavy metal concentration, ensuring sufficient heavy metal adsorption and rational use of the reagent, avoiding reagent waste. Overall, this technical solution effectively solves the problem of traditional treatment technologies being unable to adapt to different fly ash characteristics due to fixed parameters through dynamic adjustment and precise treatment at each stage. It improves the harmless treatment effect of fly ash, reduces environmental risks, and achieves resource recovery, thus possessing both environmental and resource benefits.

[0108] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0109] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0110] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

Claims

1. A method for detoxifying and recovering fly ash by water washing, characterized in that, include: Real-time acquisition of parameter information for feed fly ash; Based on the parameter information of the fed fly ash, determine the required water volume and stirring rate for pulping, and complete the fly ash pulping to obtain fly ash slurry; The fly ash slurry is washed with water. During the washing process, the parameters of the eluent are monitored in real time, and the number of washes and the countercurrent rate are dynamically adjusted according to the parameters of the eluent. The mixture obtained by water washing is subjected to solid-liquid separation to obtain mud cake and eluent; The mud cake is dried; The heavy metals in the eluent are adsorbed to obtain a preliminarily purified eluent. The preliminarily purified eluent is evaporated and crystallized to recover soluble salts.

2. The fly ash washing detoxification and recycling method as described in claim 1, characterized in that, The parameters of the fly ash include particle size distribution data and the mass fraction of soluble salts.

3. The fly ash washing detoxification and recycling method as described in claim 2, characterized in that, The process of determining the required water volume and stirring rate for pulping based on the parameter information of the fed fly ash, and completing the fly ash pulping to obtain fly ash slurry includes: The required amount of water for pulping is determined based on the parameter information of the fly ash, and water injection is completed. Obtain parameter information of agglomerates in fly ash slurry; The stirring rate is dynamically adjusted based on the parameter information of the agglomerates and the particle size distribution data.

4. The fly ash water washing detoxification and recycling method as described in claim 3, characterized in that, The acquisition of parameter information of agglomerates in fly ash slurry includes: Acquire image information of the fly ash slurry; The number and average particle size of agglomerates in the fly ash slurry are calculated based on the image information.

5. The fly ash water washing detoxification and recovery method as described in claim 3, characterized in that, The step of dynamically adjusting the stirring rate based on the parameter information of the agglomerates and the particle size distribution data includes: The parameter information of the aggregate is compared with the aggregate parameter threshold. If the parameter information of the aggregate is not higher than the aggregate parameter threshold, the stirring rate is controlled to a first rate. If the parameter information of the aggregate is higher than the aggregate parameter threshold, the stirring rate is adjusted to a second rate according to the parameter information of the aggregate.

6. The fly ash washing detoxification and recycling method as described in claim 2, characterized in that, The step of washing the fly ash slurry with water, and monitoring the parameters of the eluent in real time during the washing process, and dynamically adjusting the number of washes and the countercurrent rate based on the parameters of the eluent, includes: The initial number of washes and the initial countercurrent rate are set according to the mass fraction information of the soluble salts, and the fly ash slurry is subjected to countercurrent washing. Obtain the real-time conductivity and pH value of the eluent; The number of washes and the countercurrent rate are dynamically adjusted based on the real-time conductivity and pH of the eluent.

7. The fly ash water washing detoxification and recycling method as described in claim 1, characterized in that, The drying of the mud cake includes: Obtain the real-time moisture content information of the mud cake; The real-time moisture content information is compared with the moisture content threshold, and the drying temperature is adjusted in real time based on the comparison result.

8. The fly ash washing detoxification and recycling method as described in claim 7, characterized in that, The step of comparing the real-time moisture content information with a moisture content threshold and adjusting the drying temperature in real time based on the comparison result includes: Calculate the difference between the real-time moisture content information and the moisture content threshold; The drying temperature is adjusted in real time based on the difference.

9. The fly ash washing detoxification and recycling method as described in claim 1, characterized in that, The adsorption of heavy metals in the eluent yields a preliminarily purified eluent, comprising: Develop a batch-by-batch adsorbent dosing plan, determine the initial adsorbent dosing amount, and set the initial stirring rate. The adsorbent is added in batches. After the adsorbent is added, the real-time heavy metal concentration information of the eluent is obtained, and the stirring rate is dynamically adjusted based on the real-time heavy metal concentration.

10. The fly ash washing detoxification and recycling method as described in claim 9, characterized in that, The step of dispensing the adsorbent in batches includes: The real-time heavy metal concentration information is compared with a safety threshold. If the real-time heavy metal concentration information is not lower than the safety threshold, then the next batch of adsorbent needs to be added; if the real-time heavy metal concentration information is lower than the safety threshold, then the next batch of adsorbent needs to be added. If the next batch of adsorbent needs to be added, the change range is calculated based on the real-time heavy metal concentration information; if the change range is not lower than the change threshold, the next batch of adsorbent is temporarily not added; if the change range is lower than the change threshold, the next batch of adsorbent is added, and the amount of adsorbent added in the next batch is determined based on the real-time heavy metal concentration information.

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