Process for the recovery of nickel from a spent nickel-containing catalyst

Abstract

The application discloses a method for recovering nickel from a nickel-containing waste catalyst, and comprises the following steps: S1, pretreatment: dry grinding or wet grinding the nickel-containing waste catalyst; S2, alkali washing and aluminum and oil removal: adding deionized water to form a solid-liquid mixture; then, adding solid sodium hydroxide and sodium dodecyl benzene sulfonate; heating the mixture to 55-65 DEG C under the condition of ultrasonic auxiliary stirring; S3, solid-liquid separation and neutralization: carrying out solid-liquid separation on the reacted mixture; adding dilute sulfuric acid to the obtained filtrate to recover aluminum hydroxide; S4, oxidation acid leaching: adding the obtained filter residue into a sulfuric acid solution and stirring for 0.5-1.5 hours until the filter residue is completely dissolved; S5, impurity removal by precipitation and crystallization: adding a small amount of hydrogen peroxide to the leaching solution to oxidize residual Fe2+ first, continuously stirring, and filtering; collecting the filtrate, concentrating and crystallizing, centrifugally separating, and obtaining a nickel sulfate product. The application can improve product purity, is simple in process, convenient in operation, and low in cost.

Description

Technical Field

[0001] This invention relates to the field of nickel recovery technology, and more specifically to a method for recovering nickel from nickel-containing waste catalysts. Background Technology

[0002] Nickel is an important metal, and nickel-based catalysts are widely used in hydrogenation, reforming, and other processes. Deactivated catalysts have high nickel content and significant recovery value. Existing wet recovery processes suffer from low nickel recovery rates (especially for insoluble phases such as NiAl₂O₄), complex impurity separation, and high costs. This invention aims to provide an improved recovery method to solve these problems. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the existing technology and to propose a method for recovering nickel from nickel-containing waste catalysts.

[0004] The technical solution provided by this invention to solve the above problems is: a method for recovering nickel from nickel-containing waste catalysts, the method comprising the following steps: S1. Pretreatment: Dry or wet grinding of nickel-containing waste catalyst; S2, Alkali washing to remove aluminum and oil: Add deionized water to the powder obtained in step S1 to form a solid-liquid mixture; then, add solid sodium hydroxide and sodium dodecylbenzene sulfonate; heat the mixture to 55°C to 65°C under ultrasonic-assisted stirring. S3. Solid-liquid separation and neutralization: The mixture after the reaction in step S2 is subjected to solid-liquid separation; dilute sulfuric acid is added to the obtained filtrate to recover aluminum hydroxide; the obtained filter residue is used for later use. S4. Oxidative acid leaching: Add the filter residue obtained in step S3 to a 3M to 6M sulfuric acid solution containing 0.2M to 0.4M sodium hypochlorite, control the solid-liquid ratio to be 1:6 to 1:10, and stir at 40℃ to 50℃ for 0.5 to 1.5 hours until the filter residue is completely dissolved. S5. Precipitation and crystallization: Add a small amount of hydrogen peroxide to the leachate obtained in step S4 to remove residual Fe²⁺, stir continuously, adjust the pH of the system to 7.2 to 7.8, filter; collect the filtrate, concentrate and crystallize, centrifuge to obtain nickel sulfate product.

[0005] Preferably, the particle size after grinding in S1 is controlled to be between 10 and 50 micrometers.

[0006] Preferably, the mass ratio of deionized water to nickel-containing waste catalyst in S2 is 8:1 to 20:1.

[0007] Preferably, the amount of solid sodium hydroxide added in S2 is 8% to 15% of the mass of the nickel-containing waste catalyst, and the amount of sodium dodecylbenzenesulfonate added is 1% to 3% of the mass of solid sodium hydroxide.

[0008] Preferably, the pH of the S2 reaction process control system is not lower than 12, and the reaction is kept at a constant temperature for 1.5 to 2.5 hours.

[0009] Preferably, the method for controlling the pH of the system includes the following steps: The transducer's various operating parameters are collected, and the sound pressure effect value, flow velocity value, and flow direction change value are obtained through sound pressure propagation attenuation and fluid motion direction deduction. The sound pressure change amplitude and flow velocity change amplitude are calculated and superimposed to generate the synergistic effect value and real-time spatial synergistic distribution map. Based on the real-time spatial collaborative distribution map, the three-dimensional coordinate parameters and collaborative effect values ​​of the current dosing port are extracted. All spatial coordinate collaborative effect values, movement stroke parameters, and liquid delivery pressure parameters are called up. The spatial coordinates are sorted in descending order of collaborative effect value. The movement distance, liquid delivery pressure, and movement path are judged. After deleting coordinates that do not meet the conditions, the first target coordinate is selected to obtain the coordinates of the current dosing port. Read multiple driving current waveform cycles and extract the peak, trough and zero intersection positions, calculate the time difference between the current peak time and the sound pressure peak time, establish an energy release window, determine whether the dosing trigger signal is within the window, and obtain the current dosing valve opening status. Based on the real-time spatial collaborative distribution map, a continuous spatial boundary is formed by connecting the collaborative effect values. The spatial distance from each dosing port to the center of the boundary area is calculated. The initial flow rate is allocated according to the distance difference. The target flow rate is adjusted according to the rate of change of the collaborative effect value and converted into the dosing valve opening value to obtain the current target flow rate allocation ratio of each dosing port.

[0010] Preferably, the operating parameters include drive power parameters, drive current amplitude parameters, drive current phase parameters, operating frequency parameters, stirring speed parameters, and stirring shaft output torque parameters.

[0011] Preferably, the method for controlling the pH of the system further includes the following steps: Collect pH monitoring point data and time parameters, calculate pH change value, pH difference value, change end time, start time difference and stable duration. Establish three sets of correspondences based on synergistic effect value, energy release window parameter and target flow distribution ratio. After performing chi-square test, correct the synergistic effect value ranking, energy release window opening time and target flow ratio of each dosing port to obtain the corrected synergistic effect value ranking, corrected energy release window opening time and corrected target flow ratio of each dosing port.

[0012] Preferably, in step S4, a 1M sulfuric acid solution is used to maintain the pH value of the system at no higher than 1.0.

[0013] Compared with the prior art, the advantages of this invention are: the efficiency of degreasing and dealuminization is improved by ultrasonic-assisted alkaline washing; the complete dissolution of sparingly soluble nickel-aluminum spinel is achieved by oxidative acid leaching (NaClO+HSO) at an appropriate temperature, greatly improving the nickel recovery rate; the addition of H2O2 for pre-oxidation ensures complete precipitation of Fe³⁺, improving product purity; the process is simple, easy to operate, and low in cost. Attached Figure Description

[0014] The accompanying drawings, which are provided to further illustrate the invention and constitute a part of this invention, are illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention.

[0015] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation

[0016] The following will describe in detail the implementation of the present invention with reference to the accompanying drawings and embodiments, so that the process of how the present invention uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly. Example 1

[0017] Pretreatment: Take 100 g of nickel-containing waste catalyst and dry grind it to control the average particle size to 30 μm.

[0018] Alkaline washing for aluminum removal and deoiling: Add 1000 g of deionized water (water to spent catalyst mass ratio 10:1) to the ground powder and stir to form a suspension. Then add 10 g of solid sodium hydroxide (10% of the spent catalyst mass) and 0.2 g of sodium dodecylbenzenesulfonate (2% of the sodium hydroxide mass). Place the mixture in an ultrasonic cleaning tank with an ultrasonic power of 200 W and a frequency of 28 kHz, while mechanically stirring. Heat to 60 ℃ and maintain the temperature for 2 hours. During the reaction, adjust the pH of the system to not fall below 12 every 10 minutes with 1 M NaOH solution.

[0019] Solid-liquid separation and neutralization: After the reaction is complete, filter while hot. Add dilute sulfuric acid to the filtrate until pH=5, causing aluminum hydroxide precipitate to form. Filter and recover the precipitate. Keep the filter residue for later use.

[0020] Oxidative acid leaching: Add the filter residue to a 4 M H2SO4 solution containing 0.3 M NaClO, maintaining a solid-liquid ratio of 1:8, and stir at 45 °C for 1 hour. During the reaction, adjust the pH every 5 minutes with 1 M H2SO4 solution to ensure it does not exceed 1.0, until the filter residue is completely dissolved.

[0021] Precipitation and crystallization: Add 1 mL of 30% H2O2 solution to the leachate and stir for 10 minutes to fully oxidize the residual Fe²⁺. Then slowly add 1 M NaOH solution dropwise while stirring continuously to adjust the pH of the system to 7.5. Filter to remove Fe(OH)3 and Al(OH)3 precipitates. Collect the filtrate, heat and evaporate to concentrate to a density of 1.6 g / mL, cool naturally to room temperature, crystallize, centrifuge, wash the crystals three times with distilled water, and dry to obtain nickel sulfate hexahydrate product. Example 2

[0022] Pretreatment: Take 100 g of nickel-containing waste catalyst, add 150 g of deionized water and perform wet grinding (material:ball:water = 1:1.5:0.8), and control the average particle size to 15 μm.

[0023] Alkali washing for aluminum removal and deoiling: Add 850 g of deionized water (total water to spent catalyst mass ratio 10:1) to the ground slurry, stir, and then add 12 g of solid sodium hydroxide (12% of the spent catalyst mass) and 0.36 g of sodium dodecylbenzenesulfonate (3% of the sodium hydroxide mass). Place the mixture in an ultrasonic-assisted stirring device with an ultrasonic power of 250 W and a frequency of 40 kHz, heat to 55 ℃, and maintain the temperature for 2.5 hours. Maintain the pH at no less than 12 during the reaction.

[0024] Solid-liquid separation and neutralization: Same as in Example 1.

[0025] Oxidative acid leaching: Add the filter residue to a 5 M H2SO4 solution containing 0.4 M NaClO, with a solid-liquid ratio of 1:9, and stir at 40°C for 1.5 hours, maintaining pH ≤ 1.0, until completely dissolved.

[0026] Precipitation and crystallization: Same as in Example 1, but the final concentration density was 1.55 g / mL, and the number of washes was 4. Example 3

[0027] This embodiment discloses a method for controlling the pH of a system, specifically including the following steps: S1. Collect various operating parameters of the transducer, and obtain the sound pressure effect value, flow velocity value, and flow direction change value through sound pressure propagation attenuation and fluid motion direction deduction. Calculate the sound pressure change amplitude and flow velocity change amplitude, and superimpose them to generate the synergistic effect value and real-time spatial synergistic distribution map. S2. Based on the real-time spatial collaborative distribution map, extract the three-dimensional coordinate parameters and collaborative effect value of the current dosing port, call all spatial coordinate collaborative effect values, movement stroke parameters, and liquid delivery pressure parameters, sort the spatial coordinates in descending order of collaborative effect value, determine the movement distance, liquid delivery pressure, and movement path, delete coordinates that do not meet the conditions, select the first target coordinate, and obtain the coordinates of the current dosing port. S3. Read multiple driving current waveform cycles and extract the peak, trough and zero intersection positions, calculate the time difference between the current peak time and the sound pressure peak time, establish an energy release window, determine whether the dosing trigger signal is within the window, and obtain the current dosing valve opening status. S4. Based on the real-time spatial collaborative distribution map, connect the collaborative effect values ​​to form a continuous spatial boundary, calculate the spatial distance from each dosing port to the center of the boundary area, allocate the initial flow rate according to the distance difference, adjust the target flow rate according to the rate of change of the collaborative effect value and convert it into the dosing valve opening value, and obtain the current target flow rate allocation ratio of each dosing port.

[0028] S5. Collect pH detection point data and time parameters, calculate pH change value, pH difference value, change end time, start time difference and stable duration, establish three sets of correspondence based on synergistic effect value, energy release window parameter and target flow distribution ratio, perform chi-square test and correct the synergistic effect value ranking, energy release window opening time and target flow ratio of each dosing port, and obtain the corrected synergistic effect value ranking, corrected energy release window opening time and corrected target flow ratio of each dosing port.

[0029] The above scheme, by collecting transducer operating parameters and using sound pressure propagation attenuation and fluid motion direction extrapolation, generates synergistic values ​​and spatial synergistic distribution maps in real time. This accurately reflects the mixing uniformity and energy distribution at various locations within the reaction system under ultrasonic-assisted stirring conditions, overcoming the limitation of traditional single-point pH detection in characterizing spatial non-uniformity. It maintains a strongly alkaline environment with a pH not lower than 12 throughout the alkaline washing and dealuminization processes, ensuring the complete dissolution and removal of aluminum hydroxide, while avoiding localized low pH leading to aluminum residue or excessively high pH causing alkali waste. Secondly, based on the descending order of synergistic values, the coordinates of the dosing port are selected, and an energy release window is established to determine the dosing trigger signal, enabling the solid hydroxide... The timing of adding sodium chloride and sodium dodecylbenzenesulfonate synchronized with the peak of ultrasonic energy release significantly improves reagent dispersion efficiency and reaction rate, reduces agglomeration and local overconcentration, thereby shortening the heat preservation reaction time in step S2 (1.5 to 2.5 hours) and reducing reagent dosage. Finally, by dynamically allocating the target flow rate of each dosing port and adjusting the opening in real time according to the rate of change of synergistic effect value, pH fluctuations caused by changes in the stirring flow field, reagent consumption, or catalyst particle sedimentation can be effectively compensated, keeping the entire reaction process stable. This not only improves the dealuminization and deoiling rate but also provides filter residue with fewer impurities for the subsequent oxidative acid leaching step, reducing the consumption of sodium hypochlorite and sulfuric acid, and ultimately improving the purity and yield of nickel sulfate products. This control method transforms traditional empirical operation into intelligent regulation based on multi-parameter coupling, enhancing the process controllability and reproducibility of the ultrasonic-assisted alkaline washing process, and becoming an important technical means to improve the economy and environmental protection of the entire recovery method.

[0030] The operating parameters include drive power parameters, drive current amplitude parameters, drive current phase parameters, operating frequency parameters, stirring speed parameters, and stirring shaft output torque parameters.

[0031] The real-time spatial collaborative distribution map includes the collaborative effect level distribution, spatial region distribution, and spatial coordinate correspondence. The current dosing port coordinates include spatial location coordinates, coordinate identification information, and corresponding functional areas. The pH adjustment start command includes start time, execution object, and start mode. The current target flow allocation ratio of each dosing port includes the flow percentage of each dosing port, the flow percentage of each dosing branch, and the flow supply ratio of each area.

[0032] in: Drive power parameter: refers to the power consumed when the transducer is operating. This parameter can be used to evaluate the intensity of sound energy.

[0033] Drive current amplitude parameter: refers to the maximum value of the current applied to the transducer, which directly affects the intensity of the sound wave output.

[0034] Operating frequency parameter: refers to the frequency of sound waves in the reactor. This parameter plays a key role in sound pressure and flow mode.

[0035] Three-dimensional coordinate parameters of the dosing port: The three-dimensional position coordinate information of each dosing port, used to guide the precise placement of the liquid medicine.

[0036] Drug delivery pressure parameter: refers to the pressure value provided by the drug delivery system, which affects the stability and effectiveness of drug flow.

[0037] Cavitation energy release delay time: refers to the time delay of energy transfer between the dosing port and the sound pressure wave, which affects the reaction time of the drug solution.

[0038] Dosing trigger signal: This signal controls the opening and closing of the dosing valve to ensure that the medicine is added at the appropriate time.

[0039] pH measurement data: refers to pH value measurements taken at multiple locations, used to monitor and adjust pH levels.

[0040] For example, S1 specifically includes the following steps: The process involves collecting transducer drive power parameters, drive current amplitude parameters, drive current phase parameters, operating frequency parameters, stirring speed parameters, and stirring shaft output torque parameters. Based on the reactor space dimensions, coordinate intervals are set, and the reactor space is meshed according to these intervals to obtain a mesh parameter set. The specific steps are: collecting transducer drive power parameters... Drive current amplitude parameters Drive current phase parameters Operating frequency parameters Stirring speed parameters Stirring shaft output torque parameters These parameters are read in real time from the transducer drive controller, current sensor, speed sensor, and torque sensor, respectively, at a sampling frequency of 100 Hz. The average value of each parameter over the last 10 seconds is recorded as the current value. Based on the reactor's spatial dimensions, coordinate intervals are set, and the reactor's internal space is divided into uniform three-dimensional grid units with intervals of 10 mm along the length direction (X-axis), 10 mm along the width direction (Y-axis), and 5 mm along the height direction (Z-axis). Each grid unit is assigned a unique spatial coordinate number. Where i ranges from 1 to I, j ranges from 1 to J, and k ranges from 1 to K, with I, J, and K representing the number of grid cells in each direction, the coordinates of the center point of each grid cell are recorded, and a grid parameter set is constructed. This parameter set contains the spatial coordinates, volume, and adjacent grid indices of each grid cell. The volume is calculated by multiplying the grid side lengths, for example, 10 mm × 10 mm × 5 mm equals 500 cubic millimeters. The purpose of this scheme is to discretize the continuous space, providing a basis for subsequent point-by-point calculations, while collecting multi-dimensional working parameters to ensure the integrity of the data source for sound field and flow field deduction.

[0041] Based on the grid parameter set, sound pressure propagation attenuation is simulated for each grid cell. The sound pressure values ​​at each spatial coordinate are calculated based on the transducer power parameters and operating frequency parameters. Fluid motion direction is simulated for each grid cell, and the flow velocity and direction changes at each spatial coordinate are calculated based on the stirring speed and stirring shaft output torque parameters. The sound pressure and velocity changes of adjacent coordinates are then called to calculate the sound pressure and velocity differences between the current coordinate and surrounding coordinates, obtaining the sound pressure and velocity change amplitudes, which are then combined into a sound pressure-velocity change amplitude value. The specific execution steps are as follows: Based on the grid parameter set, sound pressure propagation attenuation is simulated for each grid cell, and the transducer drive power parameters are called... With operating frequency parameters The sound pressure level at each spatial coordinate is calculated based on the spherical wave diffusion attenuation model. Specifically, for each grid cell, the coordinates of its center point are calculated. straight-line distance to the transducer emitting surface ,in The coordinates of the transducer's emitting surface center are obtained from the equipment installation data; the sound pressure level is... From the formula It is derived that, in the formula The sound absorption coefficient of the medium is taken as 0.01 nepes per meter. This value was obtained through experimental measurement, specifically by measuring the sound pressure attenuation at different distances after emitting sound waves at a fixed power in clear water. The unit is watts, read from the transducer drive controller. The unit is meters; please ensure that the calculation is performed correctly. To avoid division by zero, if The meter value is directly taken as 0.01 meters. The purpose of this scheme is to convert the driving power into sound pressure amplitude at various points in space, taking into account medium absorption, so that the calculation results are closer to the actual physical process. Fluid motion direction deduction is performed for each grid cell, and the stirring speed parameter is called. With the output torque parameters of the stirring shaft The flow velocity values ​​at each spatial coordinate were calculated based on the turbulent vortex model. With change in flow direction Specifically, for each grid cell, calculate the radial distance from its center point coordinates to the centerline of the stirring shaft (located on the vertical axis of the reactor center). ,in The horizontal coordinates of the stirring shaft center and the vertical distance , The installation height of the agitator blades; the flow velocity value is given by the formula. It is derived that, in the formula The fluid density is taken as 1200 kg / m³, obtained from the reactor material property parameter table. The radius of the agitator blades is taken as 0.15 meters, obtained from the agitator design drawings. Read from the torque sensor in Newton-meters. The flow direction change value is read from the speed sensor in revolutions per second. The horizontal angle between the grid center point and the stirring shaft center point is calculated. and vertical angle Then overlay the next level of mesh. Flow direction deviation ,get ,in Extracted from the flow direction change value of the previous grid; the purpose of this scheme is to convert the stirring input into the flow velocity and flow direction at various points in space, quantify the fluid motion state, and provide data for subsequent collaborative analysis. It calls the sound pressure change and flow velocity change values ​​of adjacent coordinates for each grid cell. Calculate its relationship with the six adjacent grid cells in front, behind, left, right, up, and down (i.e., ...). , , (If the index is out of range, it will be ignored) sound pressure difference value Wait, and get the absolute value. Similarly, calculate the velocity difference. And take the absolute value Take the maximum value of the results for all adjacent directions, that is and The combination yields the amplitude of the sound pressure velocity change, which is a two-dimensional vector. The maximum change in each grid cell is recorded. The purpose of this scheme is to quantify the gradient of sound pressure and flow velocity in space. The larger the gradient, the more drastic the energy change at that location, which is more beneficial for drug mixing.

[0042] Based on the amplitude of sound pressure and flow velocity changes, both amplitudes are normalized to a uniform numerical range. At each spatial coordinate, the normalized amplitudes of sound pressure and flow velocity are added to obtain the synergistic effect value. These synergistic effect values ​​are then arranged in coordinate order to generate a real-time spatial synergistic distribution map. The specific steps are as follows: Based on the amplitude of sound pressure and flow velocity changes, both amplitudes are normalized. First, the amplitudes of sound pressure and flow velocity in all grid cells are calculated... maximum value and maximum value Then, for each grid cell, the normalized sound pressure variation amplitude is calculated. and normalized velocity variation This transforms both values ​​to the range of 0 to 1; at each spatial coordinate location, the normalized sound pressure change amplitude value and the flow velocity change amplitude value are added together to obtain the synergistic effect value. This value ranges from 0 to 2; a higher value indicates a greater degree of drastic change in the combined effect of sound pressure and flow velocity at that location. The synergistic effect values ​​are arranged in coordinate order, with the coordinates of each grid cell... Its corresponding synergistic value The system is correlated to generate a real-time spatial cooperation distribution map. This map includes the cooperation level distribution, which divides the cooperation value into four levels: 0.0–0.5 for low cooperation, 0.5–1.0 for medium cooperation, 1.0–1.5 for high cooperation, and 1.5–2.0 for extremely high cooperation. It also includes the spatial region distribution, which merges continuous grids into different regions according to the cooperation level. For example, grids with cooperation values ​​greater than 1.0 are clustered into high cooperation regions, and the boundary coordinates of each region are recorded to establish the correspondence between spatial coordinates and cooperation level. The overall function of this step is to accurately characterize the energy coupling state at various locations within the reactor through the synergistic quantification of sound pressure and flow, providing a spatial reference for subsequent dosing port selection and flow rate allocation. Advantages include unifying multidimensional physical parameters into a single synergistic value, reducing computational complexity, while retaining spatial distribution information and avoiding the one-sidedness of single sound field or flow field analysis. The advantage of the formula is that by normalizing and adding, it unifies the changes in sound pressure and flow velocity of different dimensions to the same scale, giving the synergistic value a clear physical meaning, namely the comprehensive intensity of energy changes.

[0043] For example, S2 specifically includes the following steps: Based on the real-time spatial collaborative distribution map, the current three-dimensional coordinate parameters of the dosing port are read. The corresponding collaborative effect value is extracted from the distribution map based on these three-dimensional coordinates. Simultaneously, the collaborative effect values ​​of all spatial coordinates in the distribution map are read, along with the current dosing port's travel distance parameter and the current liquid delivery pressure parameter. All spatial coordinate collaborative effect values ​​are then sorted in descending order of numerical value to obtain a sorted list of collaborative effect values. The specific execution steps are as follows: The current three-dimensional coordinate parameters of the dosing port are read based on the real-time spatial collaborative distribution map; these parameters represent the position coordinates of the dosing port at the previous moment. Extract the synergistic effect value corresponding to the coordinate from the distribution map. Specifically, this involves finding the match in the distribution map. The nearest grid coordinates are retrieved; if a perfect match is found, they are returned directly; otherwise, the cooperative interaction value of the nearest neighbor grid is used. Simultaneously, the set of cooperative interaction values ​​for all spatial coordinates in the distribution map is read. This set is extracted directly from the previously generated distribution map; the current dosing port movement parameters are read. This parameter, read from the robotic arm control system, is 0.5 meters, representing the maximum single movement distance to prevent the machine from exceeding its limits; the current liquid delivery pressure parameter is also read. The pressure values ​​are read from the pressure sensor of the drug delivery system, in Pascals; the synergistic effect values ​​of all spatial coordinates are sorted in descending order of numerical value to obtain a sorted list of synergistic effect values. Each element in the list contains coordinates. and its synergistic effect value The sorting uses the quicksort algorithm, with a time complexity of O(n log n). ,in The total number of grid cells represents the total number of cells in the grid. The purpose of this scheme is to transform spatial coordination information into an ordered list, providing a priority basis for subsequent screening.

[0044] Based on the synergy value sorting list, the sorted spatial coordinates are read one by one. Coordinates with distances greater than the travel distance parameter, coordinates with liquid pressures lower than the lower pressure threshold, and coordinates whose paths pass through the transducer installation area or the stirrer movement area are excluded. The remaining coordinates are retained to obtain a feasible coordinate candidate set. The specific execution steps are as follows: Based on the synergy value sorting list, the sorted spatial coordinates are read one by one starting from the first position of the list. For each candidate coordinate... First, calculate its Euclidean distance to the current dosing port coordinates. ,like Then exclude that coordinate, where The value is 0.5 meters, indicating the maximum distance the robotic arm can move in a single operation; beyond this distance, it cannot reach the target. Secondly, the current drug delivery pressure parameter is read from the pressure sensor of the drug delivery system. The unit is Pascal. If Then exclude that coordinate, where The lower pressure threshold is set to 100,000 Pa. This threshold is calculated using the Darcy-Weisbach formula based on the drug solution viscosity (0.01 Pa·s) and the delivery pipe diameter (0.01 m) to ensure that the drug solution can overcome pipeline resistance to reach this coordinate position. Next, the reactor layout database is read to obtain the set of coordinates for the transducer installation area. Coordinates of the stirrer's motion area The minimum distance between the candidate coordinates and the above-mentioned area is calculated. If the minimum distance is less than 0.02 meters, the coordinate is excluded because the risk of mechanical collision or sound field interference will destroy the stability of the system. All the coordinates that have not been excluded are retained to form a feasible coordinate candidate set. The purpose of this scheme is to select physically reachable and safe candidate locations from coordinates with high synergy values ​​through multiple constraints, and to exclude infeasible areas.

[0045] Based on the feasible coordinate candidate set, the coordinates of the first-ranked synergistic value are read and set as the current dosing port coordinates, thus obtaining the current dosing port coordinates. The specific execution steps are: based on the feasible coordinate candidate set, read the coordinates of the first-ranked synergistic value, i.e., the coordinates of the first-ranked synergistic value in the candidate set... The largest coordinate is set as the current dosing port coordinate to obtain the new dosing port position. Simultaneously, the system records the identification information of the coordinate, such as the coordinate number (e.g., "G-123") and the functional area it belongs to (e.g., "high synergy zone"). This information is extracted from the area division of the distribution map. For example, if the synergy value of this coordinate is 1.2, it belongs to the high synergy zone. The current dosing port coordinates are output for flow allocation and window calculation in subsequent steps. The overall purpose of this step is to achieve dynamic optimization and adjustment of the dosing port position. Through synergy value sorting and multiple condition constraints, it ensures that the dosing port is always located at the position with the most intense energy coupling and physical accessibility. The advantage is that after eliminating infeasible areas, the highest synergy point is retained, improving the utilization rate of the liquid, while avoiding mechanical interference and insufficient delivery pressure, thus improving the reliability of continuous system operation.

[0046] For example, S3 specifically includes the following steps: Based on the current dosing port coordinates, the driving current amplitude parameters, driving current phase parameters, and corresponding sound pressure amplitude and phase parameters are retrieved. Multiple driving current waveform cycles are read in a continuous sampling sequence. The peak, trough, and zero-intersection positions of each cycle are extracted. The peak time of the corresponding sound pressure waveform is read, and the peak times of the current and sound pressure are matched point-by-point. The time difference for each pair of data is calculated. Multiple consecutive time differences are arranged in the sampling order. Data whose time differences deviate from the preset fluctuation range are deleted. The arithmetic mean of the remaining time differences is calculated to obtain the cavitation energy release delay time. The specific execution steps are as follows: Based on the current dosing port coordinates... Call the drive current amplitude parameter Drive current phase parameters and the corresponding sound pressure amplitude parameters Sound pressure phase parameters These parameters are read in real time from the transducer drive controller and the sound pressure sensor array (installed near the dosing port), respectively, where the drive current waveform is determined by a function. The sound pressure waveform is described as follows: describe, The operating frequency is obtained from the operating parameters; multiple drive current waveform cycles are read in a continuous sampling sequence, with the sampling frequency set to 10 kHz, and 200 points sampled per cycle. The peak position of the current waveform in each cycle is extracted (i.e., The moment when the maximum value is reached ), trough position (i.e. The moment when the minimum value is reached ) and the position of the zero intersection (i.e. And the moment when it changes from positive to negative or from negative to positive. Simultaneously, the peak occurrence time of the sound pressure waveform at the corresponding moment is read. That is, the moment when the sound pressure reaches its maximum value; the peak current time. With peak sound pressure time Point-by-point correspondence, calculate the difference of each pair of data. ,in The period number is 1 to N, where N is the number of consecutive sampling periods, set to 50. Multiple consecutive time differences are arranged in the sampling order to obtain the difference sequence. For each difference in the sequence, calculate its relationship with the preset fluctuation range. The deviation, of which The value is set to 0.0001 seconds, which is based on twice the transducer response time (0.00005 seconds). The data point is then determined to be abnormal and deleted. The remaining difference sequence after deletion is denoted as... , arrive , The arithmetic mean of the remaining time differences is used to obtain the cavitation energy release delay time. This value represents the time delay from the peak current to the peak sound pressure level, in seconds. The purpose of this scheme is to calculate the cavitation energy release delay time using measured data, providing an accurate offset for subsequent window establishment and avoiding errors caused by theoretical assumptions.

[0047] Based on the cavitation energy release delay time, the durations of multiple consecutive sound pressure peaks are read. For each peak, its duration, peak end time, peak descent rate, and interval between adjacent peaks are statistically analyzed. The delay time is used as the window start offset, and the window start and end times are calculated to obtain the energy release window. The specific execution steps are as follows: Based on the cavitation energy release delay time... Read the duration of multiple consecutive sound pressure peaks, that is, the length of time it takes for each sound pressure peak to rise and fall to half its amplitude. Statistically record the duration and end time of each peak. Peak descent rate (i.e., peak amplitude divided by duration) and the time interval between adjacent peaks Delay time The start time of the energy release window is calculated using the window start offset. and end time ,in The current actual peak sound pressure level, with a window width of [value missing]. This window represents the optimal time range for the release of drug energy, meaning that the drug should be added within the delay time before and after the sound pressure peak to maximize the cavitation-assisted mixing effect. The purpose of this scheme is to convert the delay time into a time window and establish timing constraints for the drug addition action.

[0048] Based on the energy release window, the dosing trigger signal is continuously monitored. When the dosing trigger signal appears, the trigger time is compared with the start and end times of the window to determine whether the trigger time is within the window. If it is within the window, the dosing valve is opened; otherwise, it remains closed, thus obtaining the dosing valve open state. The specific execution steps are as follows: Based on the energy release window, the dosing trigger signal is continuously monitored. This signal is generated by the host computer control system according to the preset pH adjustment plan. The signal is a binary level. A high level (1) indicates that dosing is triggered, and a low level (0) indicates that it is not triggered. It is read through the digital input interface, and the sampling frequency is 1 kHz. When the dosing trigger signal appears at a high level, the trigger time is recorded. ,Compare With window start time and end time ,like If the trigger time is within the window, a high level is output to the dosing valve drive circuit to open the dosing valve. or If the device is not within the specified window, a low-level output is used to keep the dosing valve closed, thus determining the valve's open / closed state. A value of 1 indicates the valve is open, and 0 indicates it is closed. This state value is recorded in the control system log. The overall purpose of this step is to ensure that the dosing action is synchronized with the sound pressure peak by accurately calculating the cavitation energy release delay time and establishing an energy release window, thereby maximizing the cavitation-assisted mixing effect. Its advantages include using the current-sound pressure time difference to adaptively adjust the window, avoiding phase deviations caused by fixed delays, improving the uniformity of drug dispersion, and reducing waste caused by ineffective dosing. The formula's benefit lies in eliminating random noise through mean value calculation, making window positioning more robust.

[0049] For example, S4 specifically includes the following steps: Based on the real-time spatial collaborative distribution map, all spatial coordinates are continuously read according to the collaborative effect value. The difference in collaborative effect value between adjacent coordinates is calculated one by one. The direction of change is determined by the sign of the difference. Adjacent coordinates with the same direction of change are connected by straight lines to form a continuous spatial boundary. The geometric center coordinates are extracted from each boundary region. At the same time, the three-dimensional coordinates of each dosing port, the current opening value of each dosing valve, and the real-time flow value of the corresponding dosing branch are read to obtain the center coordinate set of the boundary region. The specific execution steps are as follows: Based on the real-time spatial collaborative distribution map, all spatial coordinates are continuously read according to the collaborative effect value, that is, the coordinates of each grid are extracted from the map in sequence. and its synergistic effect value Calculate the difference in cooperative effect value between adjacent grids (up, down, left, right, front, back, i.e., six directions) one by one. Take the absolute value, and determine the direction of change based on the sign of the difference. The direction of change is increasing, if The direction of change is decreasing, if The direction remains unchanged; connect adjacent grids with the same direction of change with straight lines, i.e., all... The grid points form the gradient ascent path, all The grid points form gradient descent paths, and the boundaries of these paths are the isosurfaces of the cooperative effect values, thus forming continuous spatial boundaries. For example, the boundary of a region where the cooperative effect value changes from 1.0 to 1.5 can be extracted by setting an isosurface threshold. For multiples of 0.5, such as 1.0, 1.5, etc., Greater than The grid with values ​​greater than 0 is designated as the interior, and those smaller than 0 are designated as the exterior. The boundary is the grid chain that connects the interior and exterior. Geometric center coordinates are extracted from each boundary region; that is, for each boundary region, the average of all grid coordinates within that region is taken. ,in This represents the number of grid cells within the area; simultaneously, it reads the 3D coordinates of each dosing port within the system (the current location of each dosing port; assuming there are K dosing ports, their coordinates are...). , arrive ), Current opening value of each dosing valve (Range 0 to 1, representing the opening percentage, initial default value is 0.5, read from the valve controller) and the corresponding real-time flow value of the dosing branch. (Unit: liters per minute, read from the flow meter), obtain the set of coordinates of the center of the boundary region. , arrive , The number of boundary regions; the purpose of this scheme is to transform the spatial distribution of the synergy value into boundary regions and extract the center coordinates as the target point for subsequent flow allocation.

[0050] The process involves: calling the coordinate set of the boundary region center and the coordinates of each dosing port; calculating the Euclidean distance from each dosing port to the center of each boundary region and taking the minimum value; sorting the dosing ports in ascending order according to this minimum value; extracting the coordinates of the first two dosing ports; and calculating the Euclidean distance between these two coordinates as the difference, thus obtaining the distance difference between the first two dosing ports. The specific execution steps are: calling the coordinate set of the boundary region center and the coordinates of each dosing port; calculating the Euclidean distance from each dosing port to the center of each boundary region. And take the minimum distance from each dosing port to the center of all boundary areas. Sort all dosing ports in ascending order of this minimum value to obtain a sequential list. Extract the coordinates of the first two dosing ports (i.e., the two closest dosing ports) and calculate the Euclidean distance between these two dosing ports. , which serves as the difference in distance between the first two dosing ports;

[0051] Based on a comparison of the distance difference between the first two dosing ports and the allowable threshold, if the difference is within the allowable range, the two dosing ports are allocated the same initial flow rate; otherwise, the initial flow rate is allocated proportionally based on the distance difference. The difference in synergistic effect value between adjacent boundary regions is calculated, divided by the distance between the region centers as the rate of change. After sorting, the boundary region with the highest rate of change is selected. The target flow rate of the nearest dosing port in this region is increased by a fixed percentage, while the target flow rate of the farthest dosing port is subtracted by the same value. Each target flow rate is divided by the maximum flow rate of the corresponding dosing valve and multiplied by the maximum opening to obtain the opening value, thus yielding the current target flow rate allocation ratio for each dosing port. The specific execution steps are: based on the distance difference between the first two dosing ports... With allowable range threshold Compare, Take 0.1 meters; this threshold is set at 5% of the reactor size (2 meters). Then assign the same initial flow rate to both dosing ports, i.e. ,in The total dosing flow rate is read from the system setpoint, for example, 1 liter per minute; if The initial flow rate is then allocated proportionally to the distance difference. Normalized to between 0 and 1, i.e. , Assuming the reactor's maximum length is 2 meters, then... , Ensure the sum is The greater the distance difference, the greater the difference in flow rates between the two dosing ports. This scheme aims to allocate initial flow rates based on the distance between the dosing ports and the boundary regions, ensuring that the dosing ports closer to the synergistic boundary receive more pesticide. The rate of change is calculated by dividing the difference in synergistic effect between adjacent boundary regions by the distance between the region centers; that is, for each pair of adjacent boundary regions... and Calculate the difference in synergistic effect values Distance from the regional center The rate of change is obtained. After sorting, the boundary region with the largest rate of change is selected, i.e. The corresponding region; the target flow rate of the nearest dosing port in that region (i.e., the dosing port closest to the center of the region, calculated by taking the minimum distance from all dosing ports to the center of the region) is increased by a fixed percentage, which is 0.1. Simultaneously, the target flow rate from the furthest dosing port (i.e., the dosing port furthest from the center of the area, calculated by taking the maximum value of the distances from all dosing ports to the center of the area) is subtracted by the same amount. However, it is necessary to ensure that the flow rate is non-negative; if the result after subtraction is less than 0, then set it to 0. Divide the target flow rate of each dosing port by the maximum flow rate of the corresponding dosing valve (obtained from the valve calibration data, such as 1.5 liters per minute), and then multiply by the maximum opening (1.0) to obtain the opening value. Finally, the target flow allocation ratio for each dosing port is obtained, that is, the flow share for each dosing port is... Similarly, the flow rate proportions for each dosing branch are calculated, while the flow rate supply ratio for each area is based on statistics of the area to which the dosing port belongs. The overall effect of this step is to dynamically adjust the flow rate distribution of each dosing port according to the spatial distribution of synergistic effects, so that the liquid is preferentially supplied to the boundary areas where synergistic effects change drastically. The advantage is that it achieves precise delivery and improves local reaction efficiency through dual optimization of distance and rate of change, while avoiding waste caused by over-dosing. The benefit of the formula is that it filters key areas by the rate of change, so that the flow rate adjustment is focused on the position with the largest energy gradient.

[0052] For example, S5 specifically includes the following steps: The rate of change is obtained by dividing the pH change at each monitoring point by the time interval. The pH difference between all pairs of monitoring points is calculated. The end time of the change at each monitoring point is determined based on the pH stabilization time. The difference between the time of drug injection and the time of the first pH change is recorded, as well as the duration from the start of the change to the stabilization time, are recorded to obtain the rate measurement value. The specific execution steps are as follows: The rate of change is obtained by dividing the pH change at each monitoring point by the time interval. The monitoring points are numbered as follows. arrive , The number of detection points is, for example, 5. Each detection point is equipped with a pH electrode, and the pH value is continuously collected at a sampling interval of 1 second, recording the pH value at two consecutive moments. and Calculate the change Time interval Seconds, to obtain the rate of change The unit is pH per second. Positive values ​​indicate a pH increase, and negative values ​​indicate a decrease; calculate the pH difference between any two detection points. and ,calculate The absolute value is obtained. This value reflects the spatial pH uniformity; the end time of pH change at each detection point is determined based on the pH stabilization time. When the absolute value of the pH change rate is less than 0.01 pH per second in three consecutive samplings, the detection point is considered to have reached stability, and this time is recorded as [the end time of pH change]. Record the time of drug injection. Compared with the time of the first pH change The difference, i.e., the delay time ,in The moment when the pH value at the detection point first deviates from the initial value by more than 0.02 pH is recorded from the pH time series; the duration from the start of the change to the point of stabilization is also recorded. The rate measurements were obtained, including... , , , , The purpose of this scheme is to extract key characteristic parameters from pH detection data, providing observations for subsequent chi-square tests.

[0053] Based on the current synergistic effect value, current energy release window parameters, current target flow distribution ratios at each dosing port, and rate measurements, three corresponding relationship groups are established. For each group, the square of the difference between the observed value and the expected value is calculated, divided by the sum of the expected values ​​to obtain the chi-square statistic. The root mean square of the three chi-square statistics is taken as the chi-square deviation value. The specific execution steps are: based on the current synergistic effect value... (The collaborative effect value for each spatial coordinate, extracted from the distribution map), current energy release window parameters (including window start time). End time Delay time ), Current target flow rate allocation ratio for each dosing port In addition to the rate measurement values, three corresponding sets of relationships were established: the first set is the synergistic effect value. With the rate of pH change at each detection point The correspondence, that is, for each detection point, extract the cooperative effect value of its spatial coordinates, and... Pairing, getting The data; the second set consists of energy release window parameters (window opening time). With window width ) and drug injection delay time The correspondence will and Merge into feature vectors, and Pairing; the third group is the target traffic allocation ratio. Duration of pH change at each detection point The correspondence will After regional weighted average and Pairing; for each group, calculate the chi-square statistic by dividing the square of the difference between the observed value and the expected value by the sum of the expected values. For example, for the first group, the actual pH change rate at the detection point... As observed value, expected value If the value is set to the average rate of pH change at all detection points, then the chi-square statistic is... Similarly, the second group Group 3 ,in and These are the average values ​​of the corresponding parameters. All expected values ​​are calculated based on historical normal operation data, and the root mean square of the three chi-square statistics is taken as the chi-square deviation value. The purpose of this scheme is to quantify the deviation between the actual response and the expected response of the system through chi-square test, and to provide a statistical basis for parameter correction.

[0054] The chi-square deviation value is compared with a preset deviation threshold. If it is greater than the threshold, a deviation is determined. The synergistic effect values ​​are then reordered, the energy release window opening time is adjusted, and the target flow rate ratio at each dosing port is adjusted to obtain the corrected configuration value. The specific execution steps are: [The chi-square deviation value is then compared with the preset deviation threshold.] Deviation from preset threshold Compare, The value is set to 2.0. This threshold is based on statistical experimental data. A chi-square value less than 2.0 indicates normal system operation, while a value greater than 2.0 indicates a significant deviation, requiring multiple experiments to determine. For example, collecting 100 sets of data under normal operating conditions, calculating the chi-square value, and using the 95th percentile as the threshold. If a deviation is detected, a correction is performed: for the sorting of synergy values, the synergy value for each spatial coordinate is recalculated, and the original synergy value is multiplied by a correction factor. Then, the values ​​are reordered to obtain the corrected synergy values. The correction factor amplifies the overall synergy values, thus changing the sorting order. For the energy release window opening time, the window start time is adjusted to... ,in Take 0.1, if If the value is large, the window offset should be appropriately increased to make the window open earlier or later, thus obtaining the corrected energy release window opening time; for the target flow rate ratio of each dosing port, based on the third set of chi-square statistics, if If the flow rate is relatively high, reduce the proportion of dosing ports far from the high-variability area by 0.05, while increasing the proportion of dosing ports near the high-variability area by 0.05, and then renormalize. For example, change the proportion of the five dosing ports from... Adjusted to This ensures the sum is 1, yielding the corrected target flow rate ratio for each dosing port. The overall purpose of this step is to perform closed-loop correction of key system parameters through a chi-square test, enabling adaptive optimization of synergistic effect assessment, dosing timing, and flow rate allocation. Its advantages include using actual pH response data as feedback, avoiding model bias accumulation, and improving pH control accuracy. Simultaneously, by integrating multiple indicators through the root mean square (RMS) method, robustness is enhanced. The formula's benefit lies in unifying the three different dimensions of chi-square statistics through the RMS method, ensuring that correction decisions are based on comprehensive bias and avoiding misleading results from a single indicator.

[0055] The above description only illustrates the preferred embodiments of the present invention and should not be construed as limiting the scope of the claims. The present invention is not limited to the above embodiments, and variations in its specific structure are permitted. All modifications made within the scope of the independent claims of this invention are also within the scope of protection of this invention.

Claims

1. A method for recovering nickel from nickel-containing waste catalyst, characterized in that, The method includes the following steps: S1. Pretreatment: Dry or wet grinding of nickel-containing waste catalyst; S2, Alkali washing to remove aluminum and oil: Add deionized water to the powder obtained in step S1 to form a solid-liquid mixture; then, add solid sodium hydroxide and sodium dodecylbenzene sulfonate; heat the mixture to 55°C to 65°C under ultrasonic-assisted stirring. S3. Solid-liquid separation and neutralization: The mixture after the reaction in step S2 is subjected to solid-liquid separation; dilute sulfuric acid is added to the obtained filtrate to recover aluminum hydroxide; the obtained filter residue is used for later use. S4. Oxidative acid leaching: Add the filter residue obtained in step S3 to a 3M to 6M sulfuric acid solution containing 0.2M to 0.4M sodium hypochlorite, control the solid-liquid ratio to be 1:6 to 1:10, and stir at 40℃ to 50℃ for 0.5 to 1.5 hours until the filter residue is completely dissolved. S5. Precipitation and crystallization: Add a small amount of hydrogen peroxide to the leachate obtained in step S4 to remove residual Fe²⁺, stir continuously, adjust the pH of the system to 7.2 to 7.8, filter; collect the filtrate, concentrate and crystallize, centrifuge to obtain nickel sulfate product.

2. The method for recovering nickel from nickel-containing waste catalyst according to claim 1, characterized in that, The particle size after grinding in S1 is controlled to be 10-50 micrometers.

3. The method for recovering nickel from nickel-containing waste catalyst according to claim 1, characterized in that, The mass ratio of deionized water to nickel-containing waste catalyst in S2 is 8:1 to 20:

1.

4. The method for recovering nickel from nickel-containing waste catalyst according to claim 1, characterized in that, The amount of solid sodium hydroxide added in S2 is 8% to 15% of the mass of the nickel-containing waste catalyst, and the amount of sodium dodecylbenzenesulfonate added is 1% to 3% of the mass of solid sodium hydroxide.

5. The method for recovering nickel from nickel-containing waste catalyst according to claim 1, characterized in that, The pH of the S2 reaction system is controlled to be no lower than 12, and the reaction is kept at a constant temperature for 1.5 to 2.5 hours.

6. The method for recovering nickel from nickel-containing waste catalyst according to claim 1, characterized in that, The method for controlling the pH of the system includes the following steps: The transducer's various operating parameters are collected, and the sound pressure effect value, flow velocity value, and flow direction change value are obtained through sound pressure propagation attenuation and fluid motion direction deduction. The sound pressure change amplitude and flow velocity change amplitude are calculated and superimposed to generate the synergistic effect value and real-time spatial synergistic distribution map. Based on the real-time spatial collaborative distribution map, the three-dimensional coordinate parameters and collaborative effect values ​​of the current dosing port are extracted. All spatial coordinate collaborative effect values, movement stroke parameters, and liquid delivery pressure parameters are called up. The spatial coordinates are sorted in descending order of collaborative effect value. The movement distance, liquid delivery pressure, and movement path are judged. After deleting coordinates that do not meet the conditions, the first target coordinate is selected to obtain the coordinates of the current dosing port. Read multiple driving current waveform cycles and extract the peak, trough and zero intersection positions, calculate the time difference between the current peak time and the sound pressure peak time, establish an energy release window, determine whether the dosing trigger signal is within the window, and obtain the current dosing valve opening status. Based on the real-time spatial collaborative distribution map, a continuous spatial boundary is formed by connecting the collaborative effect values. The spatial distance from each dosing port to the center of the boundary area is calculated. The initial flow rate is allocated according to the distance difference. The target flow rate is adjusted according to the rate of change of the collaborative effect value and converted into the dosing valve opening value to obtain the current target flow rate allocation ratio of each dosing port.

7. The method for recovering nickel from nickel-containing waste catalyst according to claim 6, characterized in that, The operating parameters include drive power parameters, drive current amplitude parameters, drive current phase parameters, operating frequency parameters, stirring speed parameters, and stirring shaft output torque parameters.

8. The method for recovering nickel from nickel-containing waste catalyst according to claim 6, characterized in that, The method for controlling the pH of the system further includes the following steps: Collect pH monitoring point data and time parameters, calculate pH change value, pH difference value, change end time, start time difference and stable duration. Establish three sets of correspondences based on synergistic effect value, energy release window parameter and target flow distribution ratio. After performing chi-square test, correct the synergistic effect value ranking, energy release window opening time and target flow ratio of each dosing port to obtain the corrected synergistic effect value ranking, corrected energy release window opening time and corrected target flow ratio of each dosing port.

9. The method for recovering nickel from nickel-containing waste catalyst according to claim 1, characterized in that, In step S4, a 1M sulfuric acid solution is used to maintain the pH value of the system at no higher than 1.0.

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