Garbage fly ash water treatment method and system

Abstract

The invention relates to the technical field of garbage fly ash treatment, and provides a garbage fly ash washing treatment method and system.The garbage fly ash washing treatment method comprises the steps that fly ash washing liquid is evaporated to obtain concentrated feed liquid; the concentrated feed liquid enters an evaporation crystallizer to be evaporated and crystallized to obtain crystal slurry liquid; centrifugally separating the crystal slurry to obtain sodium chloride crystal salt; controlling the water-salt ratio to wash the sodium chloride crystal salt to obtain mother liquor; the water-salt ratio is the ratio of the mass of the washing water to the mass of the sodium chloride crystal salt; evaporating the mother liquor to obtain sodium chloride wet crystal salt; fluidizing and drying the sodium chloride wet crystallized salt to obtain a sodium chloride crystallized salt product; obtaining the purity of the sodium chloride crystal salt product, and determining the purity fluctuation; when the purity fluctuation of the sodium chloride crystal salt product exceeds a target fluctuation range, triggering to adjust the water-salt ratio, so that the purity fluctuation of the sodium chloride crystal salt product is within the target fluctuation range. According to the method and the system, the purity fluctuation of the sodium chloride crystal salt product is reduced to be within + / -1.2% from + / -2.5%.

Description

Technical Field

[0001] The present invention relates to the technical field of garbage fly ash treatment, and in particular to a garbage fly ash water treatment method and system. Background Art

[0002] With the acceleration of urbanization, the amount of fly ash generated by the incineration of municipal solid waste has increased dramatically. Fly ash contains large amounts of soluble salts (such as sodium chloride and potassium chloride). If not properly treated, these salts not only pollute soil and water but can also re-enter the ecological environment through rainwater and other channels. Therefore, the harmless and resourceful treatment of salts in fly ash has become a major issue in the field of environmental protection.

[0003] Currently, the resource recovery of fly ash salts primarily relies on flash crystallization. The basic process involves washing the fly ash to remove impurities, then subjecting the concentrated liquid to evaporation and crystallization, centrifugation, washing, and drying to produce the sodium chloride crystal salt product. The washing step currently employs a fixed water-to-salt ratio (e.g., 1:1), meaning that one ton of wash water is consumed for every ton of sodium chloride crystal salt. However, in actual production, the crystallinity and impurity adsorption characteristics of fly ash salts vary with process fluctuations. This fixed water-to-salt ratio can lead to two extreme problems: over-washing. When impurities are low on the surface of the crystallized salt, excessive wash water increases wastewater discharge (according to statistics, over-washing can account for 15%-20%) and wastes water resources. Under-washing. When impurity content is high, a fixed water-to-salt ratio cannot effectively remove impurities, resulting in elevated impurity concentrations in the mother liquor, impacting subsequent evaporation and crystallization efficiency and the purity of the salt product.

[0004] Furthermore, the water-salt ratio directly impacts the purity of the resulting sodium chloride crystals. For example, if the water-salt ratio is too high, some sodium chloride will redissolve in the mother liquor, reducing the purity of the crystallized salt. If the water-salt ratio is too low, impurities cannot be fully removed, resulting in contamination of the salt product. The traditional fixed water-salt ratio makes it difficult to balance purity and energy consumption, further exacerbating process fluctuations. Summary of the Invention

[0005] To this end, the technical problem to be solved by the present invention is to overcome the problems of water resource waste and purity fluctuation of sodium chloride crystalline salt products caused by fixed water-salt ratio in the prior art, and to provide a method and system for treating fly ash water. By monitoring the purity fluctuation of sodium chloride crystalline salt products and dynamically adjusting the water-salt ratio based on the monitoring data, a closed-loop control mechanism is formed to reduce the purity fluctuation of sodium chloride crystalline salt products from ±2.5% to within ±1.2%, thereby significantly improving the quality consistency of sodium chloride crystalline salt products and meeting the high-purity application requirements of industrial salt.

[0006] In the first aspect, in order to solve the above technical problems, the present invention provides a method for treating fly ash water, comprising: Evaporating the fly ash water washing liquid to obtain a concentrated feed liquid; the concentrated feed liquid enters an evaporation crystallizer for evaporation and crystallization to obtain a slurry liquid; centrifuging the slurry liquid to obtain sodium chloride crystal salt; The mother liquor is obtained by washing the sodium chloride crystal salt with water at a controlled water-salt ratio; the water-salt ratio is the ratio of the mass of the washing water to the mass of the sodium chloride crystal salt; Evaporating the mother liquor to obtain sodium chloride wet crystal salt; fluidizing and drying the sodium chloride wet crystal salt to obtain a sodium chloride crystal salt product; The purity of the sodium chloride crystalline salt product is obtained, and the purity fluctuation is determined; when the purity fluctuation of the sodium chloride crystalline salt product exceeds a target fluctuation range, the water-salt ratio is triggered to adjust so that the purity fluctuation of the sodium chloride crystalline salt product is within the target fluctuation range.

[0007] In one embodiment of the present invention, the process parameters of the entire process of fly ash salt precipitation treatment are identified to obtain process parameter data; wherein the process parameters include the temperature and pressure of the evaporation crystallizer, the centrifugal force and centrifugal time of centrifugal separation, the temperature and pressure of evaporating the mother liquor to obtain sodium chloride wet crystallized salt, and the temperature and time of fluidized drying; the process parameter data are input into a pre-built purity predictor to obtain the predicted purity of the sodium chloride crystallized salt product; and the water-salt ratio is adjusted according to the predicted purity.

[0008] In one embodiment of the present invention, constructing the purity predictor includes obtaining a sample process parameter data set for waste fly ash salt precipitation treatment; and obtaining a sample purity data set of sodium chloride crystallized salt products under the sample process parameter data set; initializing a long short-term memory network, and training the sample process parameter data set and the sample purity data set based on the long short-term memory network to obtain the purity predictor.

[0009] In one embodiment of the present invention, the long short-term memory network includes a trust function, and the trust function is used to memorize a data set with a confidence level greater than a preset level.

[0010] In one embodiment of the present invention, before training the sample process parameter dataset and the sample purity dataset based on the long short-term memory network, the method further includes performing differential transformation on the sample process parameter dataset to obtain a differential process parameter dataset; performing differential transformation on the sample purity dataset to obtain a differential purity dataset; converting the differential process parameter dataset and the differential purity dataset into a supervised learning format to obtain a training dataset; and training the training dataset based on the long short-term memory network.

[0011] In one embodiment of the present invention, triggering the adjustment of the water-salt ratio includes obtaining a crystallization rate and a viscosity of a slurry obtained by evaporative crystallization; if the crystallization rate is greater than a crystallization rate threshold and the viscosity of the slurry is less than a viscosity threshold, adjusting the water-salt ratio according to the following method: ; in, represents the water-salt ratio; Kp represents the adjustment coefficient, which is related to the purity fluctuation of the sodium chloride crystalline salt product; C1 represents the actual purity value of the sodium chloride crystalline salt product, and C represents the target purity value of the sodium chloride crystalline salt product.

[0012] In one embodiment of the present invention, triggering the adjustment of the water-salt ratio further includes: if the crystallization rate is less than or equal to a crystallization rate threshold, or the viscosity of the crystallization liquid is less than or equal to a viscosity threshold: then determining the angular ambiguity of the sodium chloride crystal salt: if the angular ambiguity is greater than the angular ambiguity threshold, taking 1:1.2 as the basic water-salt ratio, and reducing the water-salt ratio in a certain step; if the angular ambiguity is less than or equal to the angular ambiguity threshold, maintaining the current water-salt ratio.

[0013] In one embodiment of the present invention, after performing the salt precipitation treatment on the fly ash using the adjusted water-salt ratio, the method further includes real-time monitoring of the purity of the sodium chloride crystal salt product and updating the water-salt ratio according to the monitoring results.

[0014] In one embodiment of the present invention, the method further includes triggering adjustment of separation parameters of centrifugal separation when the purity fluctuation of the sodium chloride crystal salt product exceeds a target fluctuation range; the separation parameters include centrifugal force and centrifugal time.

[0015] In the second aspect, based on the same inventive concept, in order to solve the above technical problems, the present invention also provides a garbage fly ash water treatment system, comprising: a first evaporator for evaporating the fly ash water wash liquid to obtain a concentrated feed liquid; an evaporation crystallizer, which performs evaporation and crystallization on the concentrated liquid to obtain a slurry liquid; a centrifugal separator for centrifugally separating the slurry to obtain sodium chloride crystal salt; a water washing device for washing the sodium chloride crystal salt with water by controlling the water-salt ratio to obtain a mother liquor; the water-salt ratio is the ratio of the mass of the washing water to the mass of the sodium chloride crystal salt; a second evaporator for evaporating the mother liquor to obtain sodium chloride wet crystallized salt; a dryer for drying the wet crystalline sodium chloride salt to obtain a crystalline sodium chloride salt product; A water-salt ratio regulator adjusts the water-salt ratio according to the purity of the obtained sodium chloride crystal salt product and when the purity fluctuation exceeds the target fluctuation range, so that the purity fluctuation of the sodium chloride crystal salt product is within the target fluctuation range.

[0016] The above technical solution of the present invention has the following beneficial effects compared with the prior art: The fly ash water treatment method and system described in the present invention monitor the purity fluctuations of the sodium chloride crystalline salt product and dynamically adjust the water-salt ratio based on the monitoring data to form a closed-loop control mechanism, thereby reducing the purity fluctuations of the sodium chloride crystalline salt product from ±2.5% to within ±1.2%, significantly improving the quality consistency of the sodium chloride crystalline salt product and meeting the high-purity application requirements of industrial salt. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings, wherein: Figure 1 This is a flow chart of a method for treating fly ash water in a preferred embodiment of the present invention; Figure 2 Schematic diagram of the process for adjusting the water-salt ratio in a preferred embodiment of the present invention; Figure 3 This is a flow structure diagram of the garbage fly ash water treatment system in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0018] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention. Example

[0019] The present invention discloses a method for treating fly ash water, which aims to solve the problems of water waste caused by a fixed water-salt ratio and fluctuations in the purity of sodium chloride crystal salt products. The technical solution of this application will be clearly and completely described below with reference to the accompanying drawings: Reference Figure 1As shown, a method for treating fly ash water includes: S100, evaporating fly ash washing liquid to obtain concentrated feed liquid; the concentrated feed liquid enters an evaporation crystallizer for evaporation and crystallization to obtain a slurry liquid; centrifuging the slurry liquid to obtain sodium chloride crystalline salt; S200, washing the sodium chloride crystalline salt with water by controlling the water-salt ratio to obtain a mother liquor; the water-salt ratio is the ratio of the mass of washing water to the mass of sodium chloride crystalline salt; S300, evaporating the mother liquor to obtain wet sodium chloride crystalline salt; fluidized drying the wet sodium chloride crystalline salt to obtain a sodium chloride crystalline salt product; S400, obtaining the purity of the sodium chloride crystalline salt product and determining the purity fluctuation; when the purity fluctuation of the sodium chloride crystalline salt product exceeds a target fluctuation range, triggering adjustment of the water-salt ratio so that the purity fluctuation of the sodium chloride crystalline salt product is within the target fluctuation range.

[0020] The fly ash water treatment method described in the present invention monitors the purity fluctuations of the sodium chloride crystalline salt product and dynamically adjusts the water-salt ratio based on the monitoring data to form a closed-loop control mechanism, thereby reducing the purity fluctuations of the sodium chloride crystalline salt product from ±2.5% to within ±1.2%, significantly improving the quality consistency of the sodium chloride crystalline salt product and meeting the high-purity application requirements of industrial salt.

[0021] It should be noted that the association mechanism of the water-salt ratio affecting the purity fluctuation of sodium chloride crystal salt products includes physical and chemical effects, among which the physical effect includes the ability of the water-salt ratio to regulate the shear force of liquid-solid two-phase flow, and the chemical effect includes affecting the solubility equilibrium of impurities. Specifically, in liquid-solid two-phase flow, the shear force is the force acting on the surface of solid particles to cause them to move relative to each other. When the water-salt ratio changes, the rheological properties of the fluid, such as viscosity, will change. For example, in the case of a higher water-salt ratio, the viscosity of the solution may increase. When the viscosity increases, the shear force will increase under the same velocity gradient. Adjusting the water-salt ratio causes changes in the shear force, and the change in shear force affects the particle movement and mass transfer process, ultimately affecting the fluctuation of product purity.

[0022] Among them, the impact on particle movement: changes in shear force will affect the movement state of solid particles in the fluid. Larger shear force may make the agglomerates between particles easier to disperse. If the water-salt ratio decreases and the shear force decreases, the originally dispersed fine particles may re-aggregate. This change in the particle agglomeration state will affect the subsequent separation process. For example, in filtration or sedimentation operations, if the particle agglomerates become larger, they may clog the filter cloth during filtration, resulting in reduced filtration efficiency and thus affecting product purity.

[0023] Impact on mass transfer: In purification processes involving solid-liquid mass transfer (such as the purification of saline solutions using ion exchange resins), the shear force of the liquid-solid two-phase flow affects the diffusion rate of solutes on the particle surfaces. Appropriate shear force facilitates the diffusion of solutes from the solid particle surface into the solution. When the shear force changes due to changes in the water-salt ratio, the mass transfer coefficient also changes. Excessive shear force can disrupt the adsorption equilibrium of solutes on the particle surface, disrupting the mass transfer process and ultimately affecting product purity.

[0024] The factors affecting the solubility equilibrium of impurities are as follows: (1) When the water-salt ratio changes, the concentration of ions in the solution changes; (2) The change in the water-salt ratio affects the equilibrium of the complex reaction; (3) The change in the water-salt ratio affects the acid-base equilibrium of the solution, thereby affecting the solubility of impurities.

[0025] In specific application scenarios, evaporating the fly ash wash liquid to obtain a concentrated feed solution involves fly ash pretreatment and evaporation concentration. Initially, the fly ash is screened to remove large impurities such as rocks and metal fragments. This can be done using a vibrating screen, with the mesh size determined based on the actual particle size of the impurities in the fly ash, for example, a 5-10mm mesh. The fly ash is then washed in a water washing tank. During the washing process, the agitation speed is controlled at 300-500 rpm, and the washing time is 30-60 minutes to ensure that the soluble salts in the fly ash are fully dissolved in the water. The washed fly ash solution is transported through a pipeline to a multiple-effect evaporator for evaporation. The number of effects of the multiple-effect evaporator can be determined based on factors such as the actual processing volume and energy cost. For example, a triple-effect evaporator is used. During the evaporation process, the evaporation temperature is controlled at 80-100°C and the pressure is controlled at 0.05-0.1MPa. Through evaporation, the water content of the fly ash washing liquid is gradually reduced to obtain a concentrated liquid. When the specific gravity of the concentrated liquid reaches 1.1-1.3 (the specific gravity can be measured by a hydrometer), the evaporation operation is stopped.

[0026] The concentrated liquid enters the evaporation crystallizer for evaporation and crystallization to obtain slurry liquid. The concentrated liquid is fed into the evaporation crystallizer at a flow rate of 1-2m / s. The evaporation crystallizer adopts a forced circulation crystallizer with a stirring device inside. The stirring speed is 100-200r / min. In the evaporation crystallizer, the remaining water continues to evaporate, and at the same time, the salt crystallization is promoted. The temperature and pressure in the crystallizer are controlled. When the volume of the slurry liquid in the crystallizer reaches 80-90% of the effective volume of the crystallizer, the evaporation crystallization operation is stopped.

[0027] The slurry is centrifuged to obtain sodium chloride crystals. The slurry is then fed into a centrifuge for centrifugation. The speed and time of the centrifuge are set, for example, to 3000-5000 r / min and 10-20 minutes. During the centrifugation process, the flow rate at the centrifuge inlet is adjusted to ensure uniform distribution of the slurry within the centrifuge, thereby ensuring effective centrifugal separation. After centrifugation, the lower layer is sodium chloride crystals, and the upper layer is mother liquor (containing uncrystallized impurities and a small amount of salt). The sodium chloride crystals are collected in a designated container.

[0028] The sodium chloride crystals are washed with water using a controlled water-salt ratio to obtain a mother liquor. The water-salt ratio is initially set based on the characteristics and processing requirements of the sodium chloride crystals, for example, a ratio of 1:3-1:5 (the ratio of the mass of the wash water to the mass of the sodium chloride crystals). For example, for 100g of sodium chloride crystals, the initial wash water mass can be set to 300-500g. During the washing process, the purity of the sodium chloride crystals is monitored in real time using online monitoring equipment. The wash water is slowly added to the reactor containing the sodium chloride crystals. The stirring speed and washing time are set, for example, at 200-300 r / min and 20-40 minutes, to fully dissolve impurities in the sodium chloride crystals in the wash water, thereby obtaining a mother liquor containing impurities.

[0029] Evaporating the mother liquor to obtain sodium chloride wet crystal salt includes mother liquor pretreatment and evaporation operations. The mother liquor pretreatment includes filtering the mother liquor before feeding it into the evaporation equipment to remove possible solid impurities, such as undissolved fine particles. Filter paper filtration or precision filter filtration can be used. The evaporation operation includes feeding the filtered mother liquor into a single-effect evaporator for evaporation. The evaporation temperature and pressure are set, for example, the evaporation temperature is set to 70-90°C and the pressure is set to 0.08-0.12MPa. As the evaporation proceeds, the water content in the mother liquor gradually decreases, and sodium chloride gradually crystallizes and precipitates. When the sodium chloride concentration in the mother liquor reaches saturation (measured by a refractometer), the evaporation operation is stopped to obtain sodium chloride wet crystal salt.

[0030] Fluidizing and drying the wet crystalline sodium chloride salt to obtain a crystalline sodium chloride salt product comprises feeding the wet crystalline sodium chloride salt into a fluidized bed dryer for drying, setting the inlet air temperature, outlet air temperature, flow rate of drying air, and drying time of the fluidized bed dryer, for example, setting the inlet air temperature to 80-100° C., controlling the outlet air temperature to 50-70° C., controlling the flow rate of drying air to 1-3 m³ / kg (based on the wet crystalline sodium chloride salt), and drying time to 30-60 minutes, so that the moisture content of the wet crystalline sodium chloride salt is reduced to below 1%, thereby obtaining the crystalline sodium chloride salt product.

[0031] Chemical analysis methods are used to test the purity of sodium chloride crystals. For example, silver nitrate titration is used to determine the chloride ion content, which can then be used to calculate the purity of the sodium chloride. A conductivity meter can also be used to measure the conductivity of the solution to assist in determining purity. Purity testing is performed on the product at regular intervals (e.g., hourly or batch-by-batch), and the purity data is recorded.

[0032] Set the target purity fluctuation range, for example, set the target purity fluctuation range to ±1%. Calculate the purity fluctuation range based on the purity data obtained from continuous testing. If the purity fluctuation range exceeds ±1%, the water-salt ratio adjustment mechanism is triggered.

[0033] Impurities in fly ash are gradually removed through a multi-step process, including evaporation and crystallization, centrifugation, water washing, and further evaporation and crystallization. For example, during the evaporation and crystallization process, most soluble impurities remain in the mother liquor, while sodium chloride crystals precipitate. Centrifugation further separates the mother liquor from the sodium chloride crystals, and water washing removes a small amount of impurities adsorbed on the surface of the sodium chloride crystals, significantly improving the purity of the product.

[0034] Dynamically adjusting the water-salt ratio based on real-time monitoring of product purity allows for precise control of the washing process, preventing impurity residues from insufficient washing or resource waste from overwashing, further ensuring a high and stable purity of the sodium chloride crystals. Furthermore, dynamically adjusting the water-salt ratio avoids over- or underwashing, reducing wash water usage and subsequent mother liquor treatment costs, ultimately lowering overall processing costs.

[0035] Furthermore, in the embodiment of the present invention, the control strategy for adjusting the water-salt ratio includes real-time monitoring of the crystallization rate, slurry viscosity and crystal morphology, and dynamically adjusting the water-salt ratio based on the real-time monitoring results to achieve a balance between washing efficiency and crystal quality, thereby improving the purity fluctuation of the sodium chloride crystal product.

[0036] Specifically, triggering the adjustment of the water-salt ratio includes obtaining a crystallization rate and a viscosity of a slurry obtained by evaporative crystallization in the evaporative crystallizer; if the crystallization rate is greater than a crystallization rate threshold and the viscosity of the slurry is less than a viscosity threshold, adjusting the water-salt ratio according to the following method: ; in, represents the water-salt ratio; Kp represents the adjustment coefficient, which is related to the purity fluctuation of the sodium chloride crystal salt product; C1 represents the actual purity value of the sodium chloride crystal salt product, and C represents the target purity value of the sodium chloride crystal salt product; If the crystallization rate is less than or equal to the crystallization rate threshold, or the viscosity of the crystallization liquid is less than or equal to the viscosity threshold: the angular ambiguity of the sodium chloride crystal salt is further determined: if the angular ambiguity is greater than the angular ambiguity threshold, 1:1.2 is used as the basic water-salt ratio, and the water-salt ratio is reduced in a certain step until the purity fluctuation is improved to within the target fluctuation range; if the angular ambiguity is less than or equal to the angular ambiguity threshold, the current water-salt ratio is maintained.

[0037] In specific application scenarios, a crystallization rate greater than the crystallization rate threshold indicates high system supersaturation and rapid crystal growth, potentially leading to impurity inclusion (such as mother liquor entrainment). A slurry viscosity less than the viscosity threshold indicates good fluidity, making it easier for wash water to penetrate the crystal gaps. However, excessive flow rates may result in insufficient effective contact time. In this case, set the base water-to-salt ratio to 1:0.8. If purity is insufficient, increase the water-to-salt ratio to intensify washing. When purity meets the standard, maintain the base water-to-salt ratio to conserve wash water.

[0038] Dissolution or mechanical wear of the crystal surface leads to loss of edges and corners, causing blurred edges and corners, excessive surface washing or unstable crystallization conditions. The basic water-salt ratio is set at 1:1.2 to avoid further damage to the crystal structure.

[0039] Furthermore, when the angular ambiguity is greater than the angular ambiguity threshold, PID control is introduced to reduce the water-salt ratio in a certain step. The specific adjustment method is as follows: ; in, represents the water-salt ratio; Ki represents the adjustment coefficient, which is related to the purity fluctuation of the sodium chloride crystal salt product; k represents the PID control time step number; n represents the number of time steps; e(k) represents the difference between the actual purity value and the target purity value of the sodium chloride crystal salt product at the kth time step; Indicates the time step size.

[0040] Among them, the crystallization rate is obtained by an online crystallization detector (such as FBRM), the slurry viscosity is obtained by a rotational viscometer, and the angular fuzziness is obtained based on image analysis (SEM or optical microscope); the crystallization rate threshold, viscosity threshold and angular fuzziness threshold are set based on experience or mining historical data, for example, the crystallization rate threshold is set to 5kg / (M 3 ·H); set the viscosity threshold to 3mPa·s; set the angular blur threshold to 30%.

[0041] Based on the dynamic control strategy of dynamically adjusting the water-salt ratio based on the real-time monitoring results of the crystallization rate, slurry viscosity and crystal morphology in the embodiment of the present invention, the crystal breakage rate was reduced from 12% to 5%, the average water consumption was reduced by 18%, the purity compliance rate was increased to 95%, and the purity fluctuation of the stable sodium chloride crystal product was within ±1.2%.

[0042] Furthermore, after executing the adjusted water-salt ratio to treat the fly ash for salt precipitation, the method further includes real-time monitoring of the purity of the sodium chloride crystallized salt product and updating the water-salt ratio according to the monitoring result.

[0043] In specific application scenarios, an appropriate purity monitoring frequency should be determined based on the fly ash processing volume and the stability of the crystallization process. For example, when processing large volumes and experiencing significant fluctuations in the initial crystallization process, purity testing should be conducted every 15-30 minutes. After the crystallization process stabilizes, the frequency can be extended to every 1-2 hours. The purity of the sodium chloride crystal product can be determined using one of three methods: Chemical analysis: Silver nitrate titration is used to determine the chloride ion content, and the purity of the sodium chloride is calculated based on known parameters such as the sample mass. Conductivity measurement: This utilizes the specific relationship between the conductivity and concentration (which correlates with purity) of a sodium chloride solution. An online conductivity sensor measures the conductivity of the crystallized salt solution in real time and converts it to sodium chloride purity using a pre-calibrated curve. X-ray diffraction (XRD): XRD analysis of the crystallized salt product determines the purity of the sodium chloride by comparing the intensity of the characteristic peaks of the sodium chloride crystals with those of the impurities.

[0044] By real-time monitoring and timely adjustment of the water-salt ratio, the purity of sodium chloride crystals can be stably controlled at a high level. For example, the purity can be stabilized between 97% and 99%, meeting the stringent purity requirements of industries such as high-end chemical raw materials and food additives.

[0045] In addition, the composition of fly ash from different batches of garbage may vary. Real-time monitoring and adjustment of the water-salt ratio can adapt to such changes. Whether it is the change in the salt content in the fly ash or the change in the type of impurities, the quality and output consistency of the crystallized salt can be ensured by adjusting the water-salt ratio.

[0046] Furthermore, the embodiment of the present invention introduces process parameter identification and purity prediction of the sodium chloride crystal product on the basis of the existing waste fly ash water treatment method, accurately predicts the final purity of the sodium chloride crystal salt and makes timely adjustments, thereby maintaining the product purity within the target range, avoiding quality problems caused by parameter fluctuations, and achieving more accurate process control and product quality stability, thereby stably optimizing the purity of the sodium chloride crystal salt product. Specifically, the embodiment of the present invention includes: Step 1: Identify process parameters for the entire process of fly ash salt precipitation treatment to obtain process parameter data; wherein the process parameters include water-salt ratio, temperature and pressure of the evaporation crystallizer, centrifugal force and centrifugal time, temperature and pressure of evaporating mother liquor to obtain sodium chloride wet crystallized salt, and temperature and time of fluidized bed drying; Step 2: inputting the process parameter data into a pre-built purity predictor to obtain the predicted purity of the sodium chloride crystalline salt product; Step 3: Adjust the water-salt ratio according to the predicted purity.

[0047] In specific application scenarios, the entire process of fly ash salt precipitation treatment uses sensors and control systems to obtain real-time key process parameters at each conversion point. These parameters include: water-salt ratio: the mass ratio of water to sodium chloride crystallized salt, which is a key factor affecting the purity of the crystallized salt; temperature and pressure of the evaporation crystallizer: affecting the crystallization rate and purity of the crystallized salt during the crystallization process; centrifugal force and centrifugation time: affecting the separation efficiency of sodium chloride crystallized salt from other impurities; temperature and pressure of the evaporation mother liquor: affecting the evaporation rate of water in the mother liquor, thereby affecting the quality of the sodium chloride wet crystallized salt; fluidized bed drying temperature and time: determining the final dryness and purity of the sodium chloride crystallized salt. These parameters are continuously tracked by the online monitoring system and recorded in real time by the data acquisition system, providing a basis for subsequent process optimization and prediction.

[0048] Based on historically recorded process parameter data, a purity predictor is established using machine learning or artificial intelligence algorithms (such as regression analysis or neural networks). This predictor is capable of predicting the purity of sodium chloride crystallized salt based on the input real-time process parameter data. Constructing the purity predictor includes obtaining a sample process parameter dataset for fly ash salt precipitation treatment; obtaining a sample purity dataset of sodium chloride crystallized salt products derived from the sample process parameter dataset; initializing a long-short-term memory network (LSTM), and training the sample process parameter dataset and sample purity dataset using the LSTM network to obtain the purity predictor.

[0049] Based on the output of the purity predictor, the system determines whether the current process will cause the purity of the sodium chloride crystals to fluctuate beyond the target range. If the predicted purity falls short, the water-salt ratio is automatically adjusted. The goal of adjusting the water-salt ratio is to optimize production efficiency while maintaining the purity of the crystals. A high water-salt ratio may reduce the purity of the crystals; a low water-salt ratio may affect the effectiveness of the washing process.

[0050] Based on real-time data on process parameters and predicted purity, the system adjusts other relevant process parameters through an automated feedback control mechanism. For example, it adjusts the temperature and pressure in the evaporative crystallizer to optimize the crystallization process. It also adjusts the centrifugal force and time in the centrifuge to ensure separation efficiency and purity. It also optimizes the temperature and time of the fluidized bed drying process to produce a dry and pure crystallized salt product.

[0051] Furthermore, the long short-term memory network includes a trust function, and the trust function is used to memorize a data set with a degree of trust greater than a preset degree of trust.

[0052] In specific application scenarios, the Long Short-Term Memory (LSTM) network is initialized. The LSTM is a special type of recurrent neural network (RNN) used to process and predict time series data. Initializing the LSTM involves constructing an empty LSTM network structure and assigning appropriate parameters and weights. This is the first step in training the LSTM network. During initialization, random weights are assigned to each layer of the LSTM network, and appropriate parameters such as the learning rate and batch size are set. The LSTM includes a trust function, a component within the LSTM that determines which datasets are most valuable for network training. This trust function is used to filter out datasets that have a greater impact on prediction results and assign them greater weights. The trust function is used to memorize data sets that are greater than a preset trust level. Specifically, a threshold for the trust function is set, which determines which data sets will be used for training. The trust function examines the features and attributes of each input data point. By calculating and analyzing these features, the trust function evaluates the reliability and relevance of the data point. If the trust level of a data point is higher than the preset threshold, the data point is considered reliable and valuable information and is used by the LSTM network for training and prediction. Conversely, if the trust level of a data point is lower than the threshold, it is considered unreliable or insignificant information and is excluded from training. By using the trust function, it is ensured that the LSTM network only uses high-quality and reliable data for training, thereby improving the accuracy and reliability of predictions. At the same time, the trust function is used to help reduce the impact of noise, outliers, and other bad data on model performance, thereby optimizing model performance.

[0053] Furthermore, before training the sample process parameter dataset and the sample purity dataset based on the long short-term memory network, it also includes performing differential transformation on the sample process parameter dataset to obtain a differential process parameter dataset; performing differential transformation on the sample purity dataset to obtain a differential purity dataset; converting the differential process parameter dataset and the differential purity dataset into a supervised learning format to obtain a training dataset; and training the training dataset based on the long short-term memory network.

[0054] In specific application scenarios, differential transformation is performed on recorded process parameter data (such as water-salt ratio, evaporator crystallizer temperature, and pressure). Differential transformation eliminates trends and seasonal variations in the data by calculating the differences between consecutive time points, making the data more stable. Specifically, each data point except the first is replaced by its difference from the previous one. For example, suppose a data sequence: 5, 7, 10, 12, 15. After applying differential transformation, this sequence becomes: 5, 2, 3, 2, 3. This differential transformation generates differential process parameter datasets and differential purity datasets. These datasets eliminate seasonality and trends in the data, allowing the model to focus on learning and predicting short-term data fluctuations. Using differentially transformed process parameter and purity data as input, the LSTM can more accurately predict future purity fluctuations, enabling timely process adjustments to reduce fluctuations. This ensures more consistent purity of the produced sodium chloride crystals and mitigates quality issues caused by production fluctuations.

[0055] Supervised learning requires that each input data point be assigned a label (output). In this solution, the differenced process parameter and purity data sets are organized into a time series format. The process parameter changes (inputs) at each moment are combined with the corresponding purity changes (outputs) to form training samples. For example, for data at time t and time t+1, the change in the differenced process parameter data set serves as input, while the change in the differenced purity data set serves as output, forming the input-output pairs for the supervised learning task. This process converts the differenced data set into a supervised learning format (providing corresponding labels or values ​​for the target variable) for supervised learning.

[0056] LSTM is a recurrent neural network (RNN) suitable for time series prediction. It has memory units and can handle long-term dependency problems. LSTM can predict current or future sodium chloride crystal salt purity fluctuations by inputting past process parameter data. The model input is the differentiated process parameter data (such as changes in water-salt ratio, temperature, pressure, etc.), and the output is the purity prediction value at the corresponding moment.

[0057] The introduction of the LSTM model for process prediction has realized the automation and intelligence of the production process. The model can not only predict future purity fluctuations, but also automatically adjust production parameters when problems arise, thereby reducing manual intervention and optimizing the production process.

[0058] In other embodiments of the present invention, when the purity fluctuation of the sodium chloride crystal salt product exceeds the target fluctuation range, the separation parameters of the centrifugal separation are triggered to adjust; the separation parameters include centrifugal force and centrifugal time.

[0059] In specific application scenarios, during the centrifugal separation process, centrifugal force determines the separation effect between the crystallized salt and the mother liquor; higher centrifugal force helps to more efficiently separate impurities in the sodium chloride crystallized salt; if the purity fluctuates too much, increasing the centrifugal force will improve the separation efficiency, thereby reducing impurity residues and improving purity.

[0060] Centrifugation time determines the duration of the separation process, which directly affects the separation efficiency and the purity of the sodium chloride crystals. When the purity fluctuates greatly, the centrifugation time can be extended to increase the removal rate of impurities during the separation process and further improve the purity of the crystals.

[0061] Combined with the predictions of the aforementioned LSTM purity predictor, the centrifugal force and time are adjusted in real time. By predicting and providing feedback on process parameters (such as the water-salt ratio, temperature, and pressure), the LSTM model not only anticipates purity fluctuations but also collaborates with the centrifugal separation control system to adjust separation parameters in real time. Adjustment logic: For example, if the LSTM predicts that the purity is about to exceed the set range, the centrifugal separation system automatically adjusts the centrifugal force and time. During the production process, the system dynamically adjusts the centrifugal parameters based on real-time purity data and the preset fluctuation range to maintain product purity within the target range.

[0062] By incorporating real-time purity monitoring and automated centrifugation parameter adjustments into the sodium chloride crystallization process, the purity stability and production efficiency of sodium chloride crystallization can be significantly improved. This solution, combined with intelligent prediction and automated adjustment systems, reduces manual intervention, enhances the intelligence of the production process, and ensures the stable production of high-quality products. Example

[0063] Reference Figure 3 As shown, based on the same inventive concept as that of Example 1, the embodiment of the present invention discloses a garbage fly ash water treatment system, comprising a first evaporator, an evaporation crystallizer, a centrifugal separator, a water washing device, a second evaporator, a dryer and a water-salt ratio regulator; the first evaporator is used to evaporate fly ash water washing liquid to obtain concentrated feed liquid; the evaporation crystallizer is used to evaporate and crystallize the concentrated feed liquid to obtain slurry liquid; the centrifugal separator is used to centrifugally separate the slurry liquid to obtain sodium chloride crystalline salt; the water washing device washes the sodium chloride crystalline salt by controlling the water-salt ratio to obtain mother liquor; the water-salt ratio is the ratio of the mass of washing water to the mass of sodium chloride crystalline salt; the second evaporator is used to evaporate the mother liquor to obtain wet sodium chloride crystalline salt; the dryer is used to dry the wet sodium chloride crystalline salt to obtain a sodium chloride crystalline salt product; the water-salt ratio regulator adjusts the water-salt ratio according to the purity of the obtained sodium chloride crystalline salt product and when the purity fluctuation exceeds the target fluctuation range, so that the purity fluctuation of the sodium chloride crystalline salt product is within the target fluctuation range.

[0064] The garbage fly ash water treatment system of the embodiment of the present invention is used to execute the garbage fly ash water treatment method of the embodiment, has the same inventive concept and the same technical effect, and will not be described in detail here.

[0065] In summary, the fly ash water treatment method and system described in the present invention monitors the purity fluctuations of the sodium chloride crystalline salt product and dynamically adjusts the water-salt ratio based on the monitoring data to form a closed-loop control mechanism, thereby reducing the purity fluctuations of the sodium chloride crystalline salt product from ±2.5% to within ±1.2%, significantly improving the quality consistency of the sodium chloride crystalline salt product and meeting the high-purity application requirements of industrial salt.

[0066] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0067] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0068] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0069] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0070] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A method for treating fly ash water, characterized by: include, Evaporating the fly ash water washing liquid to obtain a concentrated feed liquid; the concentrated feed liquid enters the evaporation crystallizer for evaporation and crystallization to obtain a slurry liquid; Centrifugally separating the slurry to obtain sodium chloride crystal salt; The mother liquor is obtained by washing the sodium chloride crystal salt with water at a controlled water-salt ratio; the water-salt ratio is the ratio of the mass of the washing water to the mass of the sodium chloride crystal salt; Evaporating the mother liquor to obtain sodium chloride wet crystal salt; fluidizing and drying the sodium chloride wet crystal salt to obtain a sodium chloride crystal salt product; The purity of the sodium chloride crystalline salt product is obtained, and the purity fluctuation is determined; when the purity fluctuation of the sodium chloride crystalline salt product exceeds a target fluctuation range, the water-salt ratio is triggered to adjust so that the purity fluctuation of the sodium chloride crystalline salt product is within the target fluctuation range.

2. The method for treating fly ash water according to claim 1, wherein: Triggering the adjustment of the water-salt ratio, including, Obtaining a crystallization rate and a viscosity of a slurry obtained by evaporation crystallization in the evaporation crystallizer; If the crystallization rate is greater than the crystallization rate threshold and the viscosity of the slurry is less than the viscosity threshold, the water-salt ratio is adjusted according to the following method: ； in, represents the water-salt ratio; Kp represents the adjustment coefficient, which is related to the purity fluctuation of the sodium chloride crystal salt product; C1 represents the actual purity value of the sodium chloride crystal salt product, and C represents the target purity value of the sodium chloride crystal salt product.

3. The method for treating fly ash water according to claim 2, wherein: Triggering the adjustment of the water-salt ratio also includes, If the crystallization rate is less than or equal to the crystallization rate threshold, or the viscosity of the crystallization solution is less than or equal to the viscosity threshold, then the angular fuzziness of the sodium chloride crystal salt is determined: If the angular ambiguity is greater than the angular ambiguity threshold, the water-salt ratio is set to 1:1.2 as the basic water-salt ratio, and the water-salt ratio is reduced in a certain step; If the angular ambiguity is less than or equal to the angular ambiguity threshold, the current water-salt ratio is maintained.

4. The method for treating waste fly ash water according to claim 1, wherein: After executing the adjusted water-salt ratio to treat the fly ash for salt precipitation, the method further includes real-time monitoring of the purity of the sodium chloride crystal salt product and updating the water-salt ratio according to the monitoring results.

5. The method for treating waste fly ash water according to claim 1, wherein: Also includes, Identify the process parameters of the entire process of fly ash salt precipitation treatment and obtain process parameter data; Inputting the process parameter data into a pre-built purity predictor to obtain the predicted purity of the sodium chloride crystalline salt product; adjusting the water-salt ratio according to the predicted purity; The process parameters include the water-salt ratio, the temperature and pressure of the evaporation crystallizer, the centrifugal force and time of centrifugal separation, the temperature and pressure of evaporating the mother liquor to obtain the sodium chloride wet crystal salt, and the temperature and time of fluidized bed drying.

6. The method for treating fly ash water according to claim 5, characterized in that: Constructing the purity predictor includes, Obtain a sample process parameter data set for fly ash salt precipitation treatment; and obtaining a sample purity data set of a sodium chloride crystal salt product under the sample process parameter data set; Initializing a long short-term memory network, training the sample process parameter dataset and the sample purity dataset based on the long short-term memory network, and obtaining the purity predictor.

7. The method for treating waste fly ash water according to claim 6, characterized in that: The long short-term memory network includes a trust function, which is used to memorize a data set with a confidence level greater than a preset level.

8. The method for treating garbage fly ash water according to claim 6, characterized in that: Before training the sample process parameter dataset and the sample purity dataset based on the long short-term memory network, the method further includes: Performing differential transformation on the sample process parameter data set to obtain a differential process parameter data set; Performing differential transformation on the sample purity dataset to obtain a differential purity dataset; Converting the differential process parameter dataset and the differential purity dataset into a supervised learning format to obtain a training dataset; The training data set is trained based on the long short-term memory network.

9. The method for treating fly ash water according to any one of claims 1 to 8, characterized in that: Also includes, When the purity fluctuation of the sodium chloride crystal salt product exceeds the target fluctuation range, triggering the adjustment of separation parameters of the centrifugal separation; The separation parameters include centrifugal force and centrifugation time.

10. A garbage fly ash water treatment system, characterized by: include, The first evaporator is used to evaporate the fly ash water washing liquid to obtain a concentrated feed liquid; an evaporation crystallizer, used for evaporating and crystallizing the concentrated liquid to obtain a slurry liquid; a centrifugal separator, for centrifugally separating the slurry to obtain sodium chloride crystal salt; a water washing device for washing the sodium chloride crystal salt with water by controlling the water-salt ratio to obtain a mother liquor; the water-salt ratio is the ratio of the mass of the washing water to the mass of the sodium chloride crystal salt; a second evaporator, used for evaporating the mother liquor to obtain sodium chloride wet crystallized salt; A dryer, used for drying wet sodium chloride crystal salt to obtain sodium chloride crystal salt product; The water-salt ratio regulator adjusts the water-salt ratio according to the purity of the obtained sodium chloride crystal salt product and when the purity fluctuation exceeds the target fluctuation range, so that the purity fluctuation of the sodium chloride crystal salt product is within the target fluctuation range.

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