A method for preparing high-purity cobalt by deeply purifying copper and nickel ions in a cobalt solution

Abstract

The present invention discloses a method for preparing high-purity cobalt by deeply purifying copper and nickel ions in a cobalt solution, which relates to the technical field of cobalt metal purification and preparation. High-purity cobalt is prepared through three steps: replacing Cu ions with cobalt powder, adsorbing Ni ions with resin, and cobalt electrowinning. Cobalt powder is added to the cobalt solution containing Cu and Ni impurity ions, stirred and mixed to replace Cu elemental precipitation and obtain a filtrate, and a Cu-rich pure solution is obtained after extraction. The filtrate passes through an ion exchange resin column to adsorb Ni<supgt;2+< / supgt; on the ion exchange resin, and the resin exchange post-liquid is subjected to insoluble anode electrowinning to obtain high-purity cobalt with a purity of 5N. Through the analysis and prediction of the Ni<supgt;2+< / supgt; adsorption process, the adjustment of the ion adsorption time is realized; the present invention has low cost, simple operation, high production efficiency, and maximizes the resource utilization of recycled copper and nickel, which is of great significance to the industrial preparation technology of high-purity cobalt.

Description

Technical Field

[0001] The present invention relates to the technical field of cobalt metal purification and preparation, and particularly relates to a method for preparing high-purity cobalt by deeply purifying copper and nickel ions in a cobalt solution. Background Art

[0002] Cobalt metal is an important material with wide applications and plays a crucial role in the manufacture of electronic components, magnetic materials, optoelectronic materials, superalloys, etc. However, with the continuous increase in demand, the purity requirements for cobalt metal have gradually increased, especially for the preparation field of high-purity cobalt materials with a purity of 5N or above, and the demand is extremely urgent.

[0003] Currently, the mainstream method for preparing high-purity cobalt is to obtain a high-purity cobalt solution through purification and impurity removal, and then obtain high-purity metallic cobalt through electrowinning. The key to this method lies in the purification and impurity removal of the cobalt solution. Since impurity ions such as Cu and Ni have similar precipitation potentials to cobalt in the electrochemical process and are difficult to remove through electrochemical means, it is necessary to control the impurity content in the pre-electrowinning solution. In addition, the control of process parameters during electrowinning is also particularly important, which directly affects the surface quality of the cobalt plate.

[0004] Patent CN117661036A discloses a method for industrial production of high-purity cobalt. It uses the method of oxidizing and dissolving metallic cobalt and then separating by precipitation to obtain a pure cobalt ion solution, and then obtains high-purity cobalt through diaphragm electrolysis. However, this method has low efficiency, a long process, high costs, and strong corrosiveness of fluoride ions to equipment.

[0005] Patent CN114192792A discloses a method for preparing high-purity cobalt and its application. It uses precipitation to remove impurities, and after concentrating the filtrate, high-purity cobalt salt is obtained and high-purity cobalt is obtained through reduction. This method causes relatively large cobalt losses, introduces other impurity ions, affects the cobalt purity, and is prone to generating toxic gases.

[0006] Patent CN112831802A discloses a method for producing high-purity cobalt sheets with a content of 99.999%. It uses a secondary electrolysis method to prepare high-purity cobalt. First, cobalt plates with a purity of 99.95% are produced as anodes, and titanium plates are used as cathodes for secondary electrolytic refining, and finally high-purity cobalt with a purity of 5N is obtained. This method uses the secondary electrolytic refining method, has high production costs, low efficiency, and poor practicability and was rejected.

[0007] Patent CN115627499A discloses a method for preparing a cobalt sulfate electrolyte for ultra-high-purity cobalt. It uses a combination of various chelating resins and ion exchange resins for adsorption and impurity removal. This method has expensive resins, a large amount of regeneration liquid consumption, high acidity, and still relatively high Cu and Ni concentrations, making it difficult to meet the requirements for high-purity cobalt.

[0008] In the prior art, in the resin adsorption process, a fixed adsorption time is adopted without dynamically adjusting in combination with real-time concentration data. If the actual adsorption rate changes due to factors such as resin aging and solution composition fluctuations, it may lead to insufficient adsorption; by analyzing the real-time adsorption deviation change curve, the saturated adsorption time is predicted in segments through the pseudo-second-order kinetic model and the intraparticle diffusion model, and the predicted time is dynamically adjusted based on the historical error table. This is beneficial to matching the adsorption time with the actual demand and reducing the risk of nickel residue.

[0009] In the prior art, the adsorption process uses a single kinetic model, ignoring the differences between the rapid adsorption period and the diffusion control period. When the adsorption enters the diffusion control period, the model prediction error increases significantly; if the adsorption process is divided into the rapid adsorption period, the diffusion control period, and the mixed control period by analyzing the slope of the adsorption deviation ratio curve and different models are used for prediction respectively, it is beneficial to improve the accuracy of model prediction. Summary of the Invention

[0010] Aiming at the problems existing in the above prior art, the present invention provides a method for preparing high-purity cobalt by deeply purifying copper and nickel ions in a cobalt solution. By using the method of the present invention, a high-purity cobalt solution can be obtained, and the surface of the prepared high-purity cobalt plate is flat, without pores, warping, cracks and other phenomena, and the purity reaches 5N, meeting the requirements of downstream customers.

[0011] In the first aspect, the present invention provides a method for preparing high-purity cobalt by deeply purifying copper and nickel ions in a cobalt solution, including the following steps:

[0012] S1: Add cobalt powder to the cobalt solution containing Cu and Ni impurity ions and stir to mix. The cobalt powder reacts with Cu to obtain Cu elemental precipitate. After reacting for a period of time, filter to obtain a filtrate. The Cu-containing filter residue is acid-leached and extracted to obtain a Cu-rich pure solution;

[0013] S2: Pass the filtrate obtained in S1 through an ion exchange resin column. Ni 2+ exchanges ions with H + on the ion exchange resin to obtain a post-resin-exchange solution, so that Ni 2+ is adsorbed on the ion exchange resin, and Co 2+ remains in the solution, achieving the purpose of purifying and removing Ni 2+ . The Ni-rich solution after acid regeneration is purified by extraction to obtain a Ni-rich pure solution;

[0014] S3: Perform insoluble anode electrowinning on the post-resin-exchange solution obtained in S2, and high-purity cobalt with a purity of 5N is obtained after electrowinning.

[0015] In the second aspect, the present invention provides a nickel ion adsorption monitoring method for monitoring the adsorption purification of nickel ions in step S2, including the following steps:

[0016] Step 1: Obtain the historical nickel ion adsorption data and construct a resin adsorption kinetics model;

[0017] Step 2: Based on the resin adsorption kinetics model, perform statistical analysis on the ion segmentation sequences in the historical nickel ion adsorption data to determine the equilibrium ion concentration of the ion segmentation sequences;

[0018] Step 3: Obtain the equilibrium ion concentrations of multiple ion segmentation sequences, calculate the equilibrium adsorption capacity through the resin adsorption kinetics model, and screen the equilibrium adsorption capacity to obtain the saturated ion adsorption capacity;

[0019] Step 4: Measure the nickel ion adsorption capacity in real time and perform curve analysis, extract different periods of the curve, select different models to predict and analyze the saturated adsorption capacity, and obtain the predicted saturated adsorption capacity;

[0020] Step 5: Based on the saturated adsorption capacities predicted by different models, use the resin adsorption kinetics model to determine the saturated adsorption time and adjust the estimated adsorption time.

[0021] In a third aspect, the present invention provides a nickel ion adsorption monitoring system for implementing a nickel ion adsorption monitoring method, including the following modules:

[0022] Model construction module: used to obtain the historical nickel ion adsorption data and construct a resin adsorption kinetics model;

[0023] Equilibrium analysis module: based on the resin adsorption kinetics model, used to perform statistical analysis on the ion segmentation sequences in the historical nickel ion adsorption data to determine the equilibrium ion concentration of the ion segmentation sequences;

[0024] Saturation determination module: used to obtain the equilibrium ion concentrations of multiple ion segmentation sequences, calculate the equilibrium adsorption capacity through the resin adsorption kinetics model, and screen the equilibrium adsorption capacity to obtain the saturated ion adsorption capacity;

[0025] Real-time prediction module: used to measure the nickel ion adsorption capacity in real time and perform curve analysis, extract different periods of the curve, select different models to predict and analyze the saturated adsorption capacity, and obtain the predicted saturated adsorption capacity;

[0026] Analysis and adjustment module: based on the saturated adsorption capacities predicted by different models, use the resin adsorption kinetics model to determine the saturated adsorption time and adjust the estimated adsorption time.

[0027] Advantages of the present invention:

[0028] 1. The method of removing copper by cobalt powder replacement can effectively remove the impurity copper ions in the cobalt solution without introducing impurity ions, and the copper can be recycled. The use of hydrogen-type cation exchange resin is cheaper than the method disclosed in CN115627499A, which uses at least one chelating resin and at least one ion exchange resin for deep impurity removal of cobalt sulfate stock solution. It can effectively reduce the impurity nickel ions in the cobalt solution, and the resin can be recycled. The nickel-containing solution after regeneration can be made into a nickel-rich pure solution after extraction and purification.

[0029] 2. The purity of the high-purity cobalt plate prepared by the present invention reaches 99.9995%, and the contents of Cu and Ni are both lower than 0.000015%, meeting the requirements. It not only ensures the purity of high-purity cobalt but also maximally recovers copper and nickel, increasing the economic value and having broad industrial application prospects. Compared with the method disclosed in CN117661036A, the present invention uses a cobalt solution containing Cu and Ni impurity ions, with higher efficiency, shorter process, lower cost, and no harm of fluoride ion corrosion to equipment.

[0030] 3. By constructing a resin adsorption kinetic model, determining the equilibrium ion concentration in combination with historical adsorption data, and then calculating and screening to obtain the saturated ion adsorption capacity. At different adsorption stages, select a suitable model to predict the saturated adsorption capacity according to the adsorption deviation ratio change curve, which can grasp the adsorption process and provide reliable data support for production.

[0031] 4. Use different models to predict the saturated adsorption capacity, determine the saturated adsorption time in combination with historical error analysis, and adjust the predicted adsorption time. Avoid the influence of residual nickel ions on cobalt purity due to insufficient adsorption, or resource waste and reduced production efficiency caused by excessive adsorption. If the calculated saturated adsorption time is higher than expected, the adsorption time of subsequent production can be adjusted, which is beneficial to maintaining the high efficiency of the adsorption process. Real-time monitor the nickel ion adsorption capacity, and judge the resin adsorption equilibrium state by comparing with the saturated adsorption capacity. When the adsorption is not in equilibrium, deeply analyze the adsorption deviation ratio change curve, timely discover problems and optimize the adsorption conditions, which is beneficial to improving the removal rate of nickel ions in the cobalt solution and enhancing the quality of the final high-purity cobalt product. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0033] Figure 1 It is the process flow chart of the method for industrial production of high-purity cobalt of the present invention;

[0034] Figure 2It is a flowchart of a method for monitoring nickel ion adsorption according to the present invention;

[0035] Figure 3 It is a module diagram of the same nickel ion adsorption monitoring according to the present invention. Specific embodiments

[0036] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0037] Embodiment 1

[0038] As Figure 1 shown, a method for preparing high-purity cobalt by deeply purifying copper and nickel ions in a cobalt solution includes the following steps:

[0039] S1: Add cobalt powder to the cobalt solution containing Cu and Ni impurity ions and stir to mix. The cobalt powder undergoes a displacement reaction with Cu to obtain Cu elemental precipitate. After reacting for a period of time, filter to obtain a filtrate. The Cu-containing filter residue is acid-leached and extracted to obtain a Cu-rich pure solution.

[0040] Specifically, take 10 L of cobalt solution containing Cu and Ni impurity ions, with a cobalt ion concentration of 118.6 g / L, a copper ion concentration of 0.021 g / L, and a nickel ion concentration of 0.033 g / L. The addition amount of cobalt powder is 1.5 times the molar amount of copper ions. After filtration, the copper ion concentration measured in the clear liquid is 0.004 g / L;

[0041] Among them, the cobalt solution can be a cobalt sulfate solution or a cobalt chloride solution, with a Cu concentration lower than 0.1 g / L and a Ni concentration lower than 0.1 g / L;

[0042] The particle size of the cobalt powder is 100 mesh, and the addition amount of the cobalt powder is 1.0 times the molar amount of Cu in the cobalt solution.

[0043] S2: Pass the filtrate obtained in S1 through an ion exchange resin column. Ni 2+ carries out ion exchange with H + on the ion exchange resin to obtain a post-resin exchange solution, so that Ni 2+ is adsorbed on the ion exchange resin, and Co 2+ remains in the solution, achieving the purpose of purifying and removing Ni 2+ . The Ni-rich solution after acid regeneration is purified by extraction to obtain a Ni-rich pure solution.

[0044] The filtered liquid is passed through a resin column filled with 50 mL of D854 hydrogen-type cation exchange resin, the inlet liquid flow rate is controlled at 5.0 BV / h, and after 40 hours of adsorption, the nickel ion concentration is detected to be 0.002 g / L;

[0045] Among them, the ion exchange resin is D854 hydrogen-type cation exchange resin, the inlet liquid flow rate of the cobalt solution is controlled at 5.0 BV / h, adsorbed at room temperature for 20 hours, and D854 hydrogen-type cation exchange resin is used for Ni 2+ It has a good removal effect.

[0046] S3: The resin-exchanged liquid obtained in S2 is subjected to insoluble anode electrowinning, and high-purity cobalt with a purity of 5N is obtained after electrowinning.

[0047] In order to further verify the effect of preparing high-purity cobalt by electrowinning of cobalt solution after removing copper by cobalt powder replacement and removing nickel by resin adsorption, the purified cobalt solution in the above Example 1 is taken for electrowinning test. After electrowinning, the cobalt plate is sampled and tested for its composition, and the results are shown in Table 1 below:

[0048] Table 1 GDMS test results of electrowinning cobalt plate

[0049]

[0050] Among them, the insoluble anode material is titanium coated with iridium electrode, titanium coated with ruthenium electrode or titanium coated with ruthenium iridium electrode, and the cathode is titanium plate to produce electrowinning cobalt.

[0051] Example 2

[0052] As Figure 1 shown, a method for preparing high-purity cobalt by deeply purifying copper and nickel ions in cobalt solution includes the following steps:

[0053] S1: Cobalt powder is added to the cobalt solution containing Cu and Ni impurity ions and stirred and mixed. The cobalt powder reacts with Cu to obtain Cu elemental precipitation. After reacting for a period of time, the filtrate is obtained by filtration. The Cu-containing filter residue is obtained by acid leaching and extraction to obtain a Cu-rich pure solution.

[0054] Specifically, 10 L of cobalt solution containing Cu and Ni impurity ions is taken, the cobalt ion concentration is 118.6 g / L, the copper ion concentration is 0.021 g / L, the nickel ion concentration is 0.033 g / L, the addition amount of cobalt powder is 2.0 times the molar amount of copper ions, the reaction time is 30 min, and the copper ion concentration of the supernatant is measured to be 0.001 g / L after filtration;

[0055] Among them, the cobalt solution can be cobalt sulfate solution or cobalt chloride solution, the Cu concentration is lower than 0.1 g / L, and the Ni concentration is lower than 0.1 g / L;

[0056] The particle size of the cobalt powder is 200 mesh, and the addition amount of the cobalt powder is 2.0 times the molar amount of Cu in the cobalt solution.

[0057] S2: Pass the filtrate obtained in S1 through an ion exchange resin column, and Ni 2+ undergoes ion exchange with H + on the ion exchange resin, so that Ni 2+ is adsorbed on the ion exchange resin, while Co 2+ remains in the solution, achieving the purpose of purifying and removing Ni 2+ The Ni-rich solution after acid regeneration is purified by extraction to obtain a Ni-rich pure solution;

[0058] Specifically, pass the filtered solution through a resin column filled with 50 mL of D854 hydrogen-form cation exchange resin, control the inlet flow rate of the solution to be 5.0 BV / h, and after adsorption for 35 h, the nickel ion concentration is detected to be 0.0008 g / L;

[0059] Among them, the ion exchange resin is D854 hydrogen-form cation exchange resin, control the inlet flow rate of the cobalt solution to be 5.0 BV / h, adsorb at room temperature for 35 h, and D854 hydrogen-form cation exchange resin has a good removal effect on Ni 2+

[0060] S3: Perform insoluble anode electrowinning on the resin-exchanged solution obtained in S2, and high-purity cobalt with a purity of 5N is obtained after electrowinning;

[0061] In order to further verify the effect of preparing high-purity cobalt by electrowinning of cobalt solution after removing copper by cobalt powder replacement and removing nickel by resin adsorption, take the cobalt solution purified in Example 2 above for electrowinning tests. Samples of the electrowon cobalt plate are taken for composition detection, and the results are shown in Table 2 below:

[0062] Table 2 GDMS detection results of electrowon cobalt plate

[0063]

[0064] Among them, the insoluble anode material is a titanium-coated iridium electrode, a titanium-coated ruthenium electrode or a titanium-coated ruthenium-iridium electrode, and the cathode is a titanium plate to produce electrowon cobalt.

[0065] Example Three

[0066] As Figure 1 shown, a method for deeply purifying copper and nickel ions in a cobalt solution to prepare high-purity cobalt includes the following steps:

[0067] S1. Add cobalt powder to the cobalt solution containing Cu and Ni impurity ions, stir and mix, the cobalt powder undergoes a displacement reaction with Cu to obtain Cu elemental precipitate, filter after reacting for a period of time to obtain a filtrate, and the Cu-containing filter residue is acid-leached and extracted to obtain a Cu-rich pure solution;

[0068] ​Specifically, take 10 L of cobalt solution containing Cu and Ni impurity ions, with a cobalt ion concentration of 118.6 g / L, a copper ion concentration of 0.021 g / L, and a nickel ion concentration of 0.033 g / L. The addition amount of cobalt powder is 2.5 times the molar amount of copper ions, and the reaction time is 30 min. After filtration, the copper ion concentration in the clear liquid is measured to be 0.0003 g / L;

[0069] Among them, the cobalt solution can be cobalt sulfate solution or cobalt chloride solution, with a Cu concentration lower than 0.1 g / L and a Ni concentration lower than 0.1 g / L;

[0070] The particle size of the cobalt powder is 250 mesh, and the addition amount of cobalt powder is 3.0 times the molar amount of Cu in the cobalt solution.

[0071] S2: Pass the filtrate obtained in S1 through an ion exchange resin column, and Ni 2+ carries out ion exchange with the H + on the ion exchange resin, so that Ni 2+ is adsorbed on the ion exchange resin, and Co 2+ remains in the solution, achieving the purpose of purifying and removing Ni 2+ The Ni-rich solution after acid regeneration is purified by extraction to obtain a Ni-rich pure solution.

[0072] Specifically, pass the filtered liquid through a resin column filled with 50 mL of D854 hydrogen-form cation exchange resin, control the inlet liquid flow rate to be 5.0 BV / h, and after adsorption for 30 h, the nickel ion concentration is detected to be 0.0004 g / L;

[0073] Among them, the ion exchange resin is D854 hydrogen-form cation exchange resin, control the inlet liquid flow rate of the cobalt solution to be 5.0 BV / h, adsorb at room temperature for 30 h, and D854 hydrogen-form cation exchange resin has a good removal effect on Ni 2+

[0074] S3: Carry out insoluble anode electrowinning on the resin-exchanged liquid obtained in S2, and high-purity cobalt with a purity of 5N is obtained after electrowinning;

[0075] To further verify the effect of preparing high-purity cobalt by electrowinning of the cobalt solution after removing copper by cobalt powder replacement and removing nickel by resin adsorption, take the cobalt solution purified in Example 3 above for electrowinning experiments. Samples of the cobalt plate after electrowinning are taken for component detection, and the results are shown in Table 3 below:

[0076] Table 3 GDMS detection results of electrowon cobalt plate

[0077]

[0078] Among them, the insoluble anode material is titanium coated with iridium electrode, titanium coated with ruthenium electrode or titanium coated with ruthenium-iridium electrode, and the cathode is a titanium plate to produce electrowon cobalt. ​

[0079] Example 4

[0080] As Figure 1 shown, a method for preparing high-purity cobalt by deeply purifying copper and nickel ions in a cobalt solution includes the following steps:

[0081] S1: Add cobalt powder to the cobalt solution containing Cu and Ni impurity ions and stir to mix. The cobalt powder undergoes a displacement reaction with Cu to obtain Cu elemental precipitate. After reacting for a period of time, filter to obtain a filtrate. The Cu-containing filter residue is acid-leached and extracted to obtain a Cu-rich pure solution.

[0082] Specifically, take 10 L of cobalt solution containing Cu and Ni impurity ions, with a cobalt ion concentration of 118.6 g / L, a copper ion concentration of 0.021 g / L, and a nickel ion concentration of 0.033 g / L. The addition amount of cobalt powder is 3.0 times the molar amount of copper ions. After reacting for 30 min, take the supernatant after filtration and measure the copper ion concentration to be 0.0003 g / L;

[0083] Among them, the cobalt solution can be cobalt sulfate solution or cobalt chloride solution, with a Cu concentration lower than 0.1 g / L and a Ni concentration lower than 0.1 g / L;

[0084] The particle size of the cobalt powder is 300 mesh, and the addition amount of cobalt powder is 2.0 times the molar amount of Cu in the cobalt solution.

[0085] S2: Pass the filtrate obtained in S1 through an ion exchange resin column. Ni 2+ undergoes ion exchange with H + on the ion exchange resin, so that Ni 2+ is adsorbed on the ion exchange resin, and Co 2+ remains in the solution, achieving the purpose of purifying and removing Ni 2+ . The Ni-rich solution after acid regeneration is purified by extraction to obtain a Ni-rich pure solution;

[0086] Specifically, pass the filtered solution through a resin column filled with 50 mL of D854 hydrogen-form cation exchange resin, control the inlet liquid flow rate at 5.0 BV / h, and after adsorbing for 25 h, the nickel ion concentration is detected to be 0.0004 g / L.

[0087] S3: Perform insoluble anode electrowinning on the resin-exchanged solution obtained in S2, and high-purity cobalt with a purity of 5N is obtained after electrowinning;

[0088] In order to further verify the effect of preparing high-purity cobalt by electrowinning the cobalt solution after removing copper by cobalt powder displacement and removing nickel by resin adsorption, take the cobalt solution purified in Example 4 above for electrowinning tests. Samples of the cobalt plate after electrowinning are taken for component detection, and the results are shown in Table 4 below:

[0089] Table 4 GDMS detection results of electrowon cobalt plate

[0090]

[0091] Among them, the insoluble anode material is an iridium-coated titanium electrode, a ruthenium-coated titanium electrode or a ruthenium-iridium-coated titanium electrode, and the cathode is a titanium plate for producing electrowinning cobalt;

[0092] It can be seen from the results of the above embodiments that Example 3 is selected as the best experimental scheme, and the purity of the cobalt plate is 99.9996%, meeting the requirements.

[0093] Example 5

[0094] As Figure 2 shown, a nickel ion adsorption monitoring method is used to monitor the adsorption and purification of nickel ions in step S2, including the following steps:

[0095] Step 1: Obtain the historical adsorption data of nickel ions and construct a resin adsorption kinetic model;

[0096] In some embodiments, the nickel ion concentrations at the inlet and outlet of the adsorption resin column are monitored online by a near-infrared spectrometer and uploaded to the ion concentration database;

[0097] Based on the ion concentration database, obtain the historical adsorption concentrations of nickel ions in multiple production cycles and construct a resin adsorption kinetic model;

[0098] Specifically, based on the historical adsorption concentrations of nickel ions, construct an ion adsorption sequence, and segment the ion adsorption sequence according to the production cycle to obtain an ion segmented sequence;

[0099] It should be noted that the production conditions in each production cycle are kept consistent, where the production conditions include but are not limited to: resin type, flow rate, temperature, initial concentration of nickel ions; the production cycle includes the nickel ion concentration at each monitoring moment from the start of nickel ion adsorption to reaching equilibrium;

[0100] Perform data preprocessing on the ion segmented sequence, and construct a resin adsorption kinetic model with the pseudo-second-order kinetic model as the core;

[0101] Among them, data preprocessing includes but is not limited to: removing noise from the nickel ion concentration data in the ion segmented sequence, removing high-frequency noise in the ion segmented sequence; detecting outliers for abnormal adsorption amount data caused by adsorption equipment fluctuations or environmental interference, and removing the outliers; calculating the transmission delay of the concentration data at the inlet and outlet of the resin exchange membrane according to the flow rate to achieve time series synchronization;

[0102] Specifically, through the formula: Construct a pseudo-second-order kinetic model, where k2 is the pseudo-second-order kinetic rate constant, t is the adsorption time, and q tDenote the adsorption capacity within the adsorption time t as q e Denote the equilibrium adsorption capacity;

[0103] Through the formula: Obtain the adsorption capacity q within the adsorption time t t , where C o Denote the initial concentration of nickel ions, C t Denote the adsorption concentration of nickel ions at the moment of adsorption time t;

[0104] It should be noted that the equilibrium adsorption capacity q e Reflects the maximum adsorption capacity of the resin when the adsorption reaches equilibrium;

[0105] The initial concentration C of nickel ions o Is directly measured by on-line monitoring of the nickel ion concentration at the inlet of the resin column with a near-infrared spectrometer;

[0106] C t Is obtained by on-line monitoring of the nickel ion concentration at the outlet of the resin column with a near-infrared spectrometer and recorded in real time. V and m respectively represent the total volume of the solution and the dry basis mass of the ion exchange resin, which are measured by professionals in the field;

[0107] It should be noted that in an acidic environment, the standard electrode potential value of copper ions is 0.342V, and the standard electrode potential values of nickel ions and cobalt ions are -0.257V and -0.280V respectively. The standard electrode potential value of copper ions is significantly higher than that of cobalt ions. Copper ions can be removed more thoroughly through a displacement reaction, and the measured copper ion concentration in the supernatant after filtration is 0.0003g / L;

[0108] Since the difference in the standard electrode potential values of cobalt ions and nickel ions is only 0.037V, cobalt ions and nickel ions will co-deposit during the electrowinning of cobalt, resulting in a decrease in the purity of cobalt ions. Therefore, it is necessary to monitor the adsorption state of nickel ions;

[0109] It should be noted that the role of constructing the resin adsorption kinetic model is as follows:

[0110] Role 1: Predict the adsorption behavior. By fitting the adsorption process of nickel ions on the resin with a mathematical model, quantitatively describe the relationship between the adsorption rate and time and concentration, and achieve dynamic prediction of the adsorption process;

[0111] Role 2: Determine the equilibrium adsorption state. Analyze the equilibrium ion concentration in the historical adsorption data, and combine with the model to calculate the saturated adsorption capacity, providing a basis for judging whether the resin has reached adsorption saturation;

[0112] Step 3: Optimize the adsorption time control, monitor the change of the adsorption curve in real time, identify different stages such as the rapid adsorption period and the diffusion control period, dynamically adjust the estimated adsorption time, and reduce nickel residue caused by insufficient adsorption or waste of resources caused by excessive adsorption.

[0113] Step 2: Based on the resin adsorption kinetic model, perform statistical analysis on the ion segmentation sequence in the historical adsorption data of nickel ions to determine the equilibrium ion concentration of the ion segmentation sequence;

[0114] Based on the preprocessed ion segmentation sequence, extract and analyze the ion concentration in the ion segmentation sequence to determine whether the equilibrium ion concentration appears in the ion segmentation sequence;

[0115] Specifically, divide the ion segmentation sequence into multiple subsequences of a fixed length, and standardize the subsequences;

[0116] Based on the standardized subsequences, construct an ADF test model to obtain the statistic of ADF ;

[0117] In some embodiments, calculate the p2 value of the hypothesis test by the Dickey-Fuller distribution method;

[0118] Compare the ADF statistic with with a preset critical value. If it is lower than the preset critical value and the p2 value is lower than the significance level value, it is considered that the subsequence is stationary, that is, the equilibrium ion concentration appears. Otherwise, it is unbalanced;

[0119] Exemplarily, divide the preprocessed ion segmentation sequence to obtain subsequence A1, standardize A1, construct an ADF test model, determine P = 2 by the AIC criterion, calculate the statistic of ADF is -3.2, the preset critical value is -2.86, and the p value of 0.03 is lower than 0.05. Subsequence A1 is stationary, and the ion concentration of the subsequence reaches equilibrium;

[0120] If the subsequence is stationary, perform the inverse operation of standardization on the subsequence, restore the subsequence, and calculate the mean value of the ion concentration of the subsequence as the equilibrium ion concentration;

[0121] If the subsequence is not stationary, perform linear fitting based on the pseudo-second-order kinetic model equation to calculate the equilibrium ion concentration of the ion segmentation sequence;

[0122] It should be noted that the function of calculating the equilibrium ion concentration of the ion segmentation sequence is:

[0123] Function 1: Provide a basis for obtaining the saturated ion adsorption capacity; for the equilibrium ion concentrations and theoretical saturated adsorption capacities of multiple ion segmentation sequences, construct an equilibrium ion group and a theoretical adsorption group respectively, and then through the confidence interval screening method, the saturated ion adsorption capacity can be obtained. The saturated ion adsorption capacity is an important indicator for judging the resin adsorption capacity and the nickel ion adsorption state;

[0124] Function 2: Assist in selecting an appropriate prediction model, measure the nickel ion adsorption capacity in real time and compare it with the saturated ion adsorption capacity. If it is not saturated, draw a real-time adsorption deviation change curve by analyzing the adsorption deviation ratio, and divide the rapid adsorption period, diffusion control period and mixed control period. The division of these periods and the selection of the corresponding models are based on the accurate grasp of the equilibrium ion concentration. For example, in the rapid adsorption period and the diffusion control period, the adsorption mechanisms are different. By selecting an appropriate model to predict the saturated adsorption capacity based on the relevant analysis of the equilibrium ion concentration, the prediction accuracy can be improved.

[0125] Dynamically adjust the adsorption time based on the model to ensure the efficient progress of the production process, reduce the risk of nickel ion residue in the pre-electrowinning solution, and improve the qualified rate of high-purity cobalt products.

[0126] The technical solution of this embodiment is: obtain the historical nickel ion adsorption data, construct a resin adsorption kinetics model, and based on the resin adsorption kinetics model, perform statistical analysis on the ion segmentation sequences in the historical nickel ion adsorption data to determine the equilibrium ion concentration of the ion segmentation sequences; which is beneficial to optimizing production efficiency and resource utilization rate.

[0127] Example 6

[0128] As Figure 2 shown, a nickel ion adsorption monitoring method further includes the following steps:

[0129] Step 3: Obtain the equilibrium ion concentrations of multiple ion segmentation sequences, calculate the equilibrium adsorption capacity through the resin adsorption kinetics model, and screen the equilibrium adsorption capacity to obtain the saturated ion adsorption capacity;

[0130] Obtain the equilibrium ion concentration of the ion segmentation sequence and the adsorption time t when the equilibrium ion concentration is reached;

[0131] Through the formula: Obtain the equilibrium adsorption capacity within the adsorption time t , where Ce is the equilibrium ion concentration;

[0132] where C o represents the initial concentration of nickel ions, V and m respectively represent the total volume of the solution and the dry basis mass of the ion exchange resin, which are measured by professional technical personnel in the field;

[0133] Based on the equilibrium ion concentration, the theoretical saturated adsorption capacity was obtained by fitting and calculating through the pseudo-second-order kinetic model;

[0134] Obtaining the equilibrium adsorption amounts of multiple ion segmentation sequences and constructing a balanced ion set;

[0135] Obtain theoretical saturated adsorption amounts of multiple ion segmentation sequences and construct theoretical adsorption groups;

[0136] The confidence interval of the theoretical adsorption group is calculated by the confidence interval screening method, and the equilibrium adsorption amount of the balance ion group within the confidence interval of the theoretical adsorption group is screened;

[0137] Based on the screening, the equilibrium adsorption amount is obtained, marked as the saturated ion adsorption amount, and a saturated adsorption group is constructed;

[0138] It should be noted that the data of nickel ion adsorption on resin was processed by the confidence interval screening method, and the confidence interval of the theoretical adsorption amount was calculated based on the global mean and model error. The data with equilibrium adsorption amount falling within the interval were retained, and the outliers were eliminated;

[0139] By quantifying the uncertainty of model predictions, a saturated adsorption group was constructed to improve the robustness of the kinetic model.

[0140] Step 4: Real-time measurement of the nickel ion adsorption capacity and curve analysis, extraction of different periods of the curve, selection of different models for prediction and analysis of the saturated adsorption capacity, and obtaining the predicted saturated adsorption capacity;

[0141] During the monitoring period, based on the real-time measurement of the nickel ion concentration at the outlet of the nickel ion adsorption resin column, the monitoring adsorption amount during the monitoring time is calculated through the resin adsorption kinetic model;

[0142] The monitored adsorption amount is compared with the saturated ion adsorption amount in the saturated adsorption group. If the monitored adsorption amount is within the saturated ion adsorption amount in the saturated adsorption group, it is considered that the resin has reached adsorption equilibrium;

[0143] If the monitored adsorption amount is lower than the saturated ion adsorption amount in the saturated adsorption group, the monitoring time is divided into multiple fragments using the sliding window method, and the deviation ratio of the monitored adsorption amount at the start and end of each fragment is calculated to obtain the adsorption deviation ratio;

[0144] Based on the adsorption deviation ratios in multiple time segments, a real-time adsorption deviation change curve is drawn with time as the X-axis and the adsorption deviation ratio as the Y-axis;

[0145] Based on the changing state of the real-time adsorption deviation change curve, the real-time adsorption deviation change curve is divided into different periods, including: rapid adsorption period, diffusion control period, and mixing control period;

[0146] It should be noted that by calculating the absolute value of the slope of the real-time adsorption deviation change curve within different time periods, the real-time adsorption deviation change curve is divided into different change states;

[0147] Exemplarily, if the absolute value of the slope of the real-time adsorption deviation change curve in the first 1 / 3 time period is higher than twice the absolute value of the slope of the real-time adsorption deviation change curve in the last 1 / 3 time period, then the real-time adsorption deviation change curve in the first 1 / 3 time period is determined as the rapid adsorption period, the last 1 / 3 time period is the diffusion control period, and the remaining time period is the mixed control period, that is, the alternating period of the rapid adsorption period and the diffusion control period;

[0148] Based on different periods of the real-time adsorption deviation change curve, different prediction models are used to calculate the predicted saturated adsorption amounts in different periods;

[0149] Specifically, based on the adsorption deviation ratio in the rapid adsorption period, the pseudo-second-order kinetic model is used to predict the saturated adsorption amount;

[0150] Based on the adsorption deviation ratio in the diffusion control period, the intraparticle diffusion model is used to predict the saturated adsorption amount;

[0151] Based on the adsorption deviation ratio in the mixed control period, the pseudo-second-order kinetic model and the intraparticle diffusion model are respectively used to predict the saturated adsorption amount;

[0152] It should be noted that the pseudo-second-order kinetic model predicts the saturated adsorption amount from the perspective of chemical adsorption by considering the relationship between factors such as adsorption time and adsorption amount; the intraparticle diffusion model focuses on the diffusion of the adsorbate inside the adsorbent particles and predicts the saturated adsorption amount based on the change law of adsorption time and adsorption amount. The combination of the two models can more comprehensively and accurately reflect the adsorption situation in this stage and provide a more reliable basis for determining the saturated adsorption amount.

[0153] It should be noted that the functions of using different models for prediction are as follows:

[0154] Function 1: Quantification of the dynamic process. By using a mathematical model to describe the adsorption behavior of nickel ions on the resin, key parameters such as adsorption rate and equilibrium adsorption amount are quantified, providing a theoretical basis for real-time monitoring;

[0155] Function 2: Division of the adsorption stage. Based on model analysis, the adsorption process is divided into a rapid adsorption period, a diffusion control period, and a mixed control period, which is beneficial to solving the problem that traditional single models cannot accurately reflect the characteristics of different adsorption stages;

[0156] Function 3: Prediction of saturated adsorption. Combining historical data with real-time monitoring, the pseudo-second-order kinetic model and the intraparticle diffusion model are selected in segments.

[0157] Step 5. Based on the saturated adsorption capacities predicted by different models, use the resin adsorption kinetic model to determine the saturated adsorption time and adjust the estimated adsorption time;

[0158] Obtain the ion segmentation sequence corresponding to the saturated ion adsorption amount within the saturated adsorption group from historical data;

[0159] Based on the nickel ion concentration of the ion segmentation sequence, construct a historical adsorption deviation change curve, and use different prediction models to calculate the predicted saturated adsorption amounts in different historical periods;

[0160] Among them, the historical periods are the historical rapid adsorption period, the historical diffusion control period, and the historical mixed control period;

[0161] Calculate the relative errors between the predicted saturated adsorption amounts in multiple different historical periods and the saturated ion adsorption amounts, and construct a historical error distribution table as shown in Table 1;

[0162] Those skilled in the art can understand that since there are multiple cobalt solution purification production projects in the historical data, there are multiple historical adsorption deviation change curves, and there are also multiple relative errors between the predicted saturated adsorption amounts and the saturated ion adsorption amounts in different historical periods;

[0163] Table 1 Historical Error Distribution

[0164]

[0165] Based on the historical error distribution table, use the three - standard - deviation criterion to remove the outliers of the average error in each period;

[0166] Based on the historical error distribution table after removing the outliers, calculate the mean value of the relative root - mean - square error in each period;

[0167] Normalize the mean value of the root - mean - square error in each historical period, and calculate the proportion of the relative root - mean - square error in each period;

[0168] Obtain the predicted saturated adsorption amount in the rapid adsorption period, the predicted saturated adsorption amount in the diffusion control period, and the predicted saturated adsorption amount in the mixed control period calculated from the real - time adsorption deviation change curve;

[0169] Perform a weighted summation on the predicted saturated adsorption amount in the rapid adsorption period, the predicted saturated adsorption amount in the diffusion control period, and the predicted saturated adsorption amount in the mixed control period to obtain the comprehensive adsorption amount;

[0170] Use the proportion of the relative root - mean - square error corresponding to the predicted saturated adsorption amount in each historical period of the historical adsorption deviation change curve as the calculation weight of the comprehensive adsorption amount;

[0171] Based on the comprehensive adsorption amount, calculate the saturated adsorption time through the resin adsorption kinetic model;

[0172] Compare the saturation adsorption time with the preset expected adsorption time. If the saturation adsorption time is higher than the preset expected adsorption time, calculate the difference between the saturation adsorption time and the preset expected adsorption time;

[0173] Adjust the expected adsorption time based on the difference between the saturation adsorption time and the preset expected adsorption time;

[0174] If the saturation adsorption time is lower than the preset expected adsorption time, no processing is required;

[0175] It should be noted that the function of obtaining the comprehensive adsorption capacity is as follows:

[0176] Function 1: Determine the saturation adsorption time. The comprehensive adsorption capacity is obtained by weighted summing the predicted saturation adsorption capacities in the rapid adsorption period, diffusion control period, and mixed control period. Based on the comprehensive adsorption capacity, the resin adsorption kinetics model can more accurately calculate the saturation adsorption time, reducing the error caused by using a single model prediction or a fixed adsorption time, and making the control of the adsorption time more accurate;

[0177] Function 2: Optimize the adsorption time adjustment. Compare the calculated saturation adsorption time with the preset expected adsorption time. If the saturation adsorption time is higher than the expected value, the difference between the two can be calculated, and the expected adsorption time can be adjusted based on this difference. This process enables the adsorption time to be dynamically optimized according to the actual situation, reducing the possibility of over-adsorption or under-adsorption.

[0178] The technical solution of this embodiment is as follows: Obtain the equilibrium ion concentrations of multiple ion segment sequences, calculate the equilibrium adsorption capacity through the resin adsorption kinetics model, screen the equilibrium adsorption capacity to obtain the saturated ion adsorption capacity; measure the nickel ion adsorption capacity in real time and perform curve analysis, extract different periods of the curve, select the saturated adsorption capacities predicted by different models. Based on the saturated adsorption capacities predicted by different models, use the resin adsorption kinetics model to determine the saturation adsorption time and adjust the estimated adsorption time, enabling the adsorption time to be dynamically optimized according to the actual situation and reducing the possibility of over-adsorption or under-adsorption.

[0179] Embodiment Seven

[0180] As Figure 3 shown, a nickel ion adsorption monitoring system for implementing a nickel ion adsorption monitoring method includes the following modules:

[0181] Model construction module: used to obtain nickel ion historical adsorption data and construct a resin adsorption kinetics model;

[0182] Equilibrium analysis module: Based on the resin adsorption kinetic model, it is used to statistically analyze the ion segmentation sequence in the historical adsorption data of nickel ions and determine the equilibrium ion concentration of the ion segmentation sequence;

[0183] Saturation determination module: It is used to obtain the equilibrium ion concentration of multiple ion segmentation sequences, calculate the equilibrium adsorption capacity through the resin adsorption kinetic model, screen the equilibrium adsorption capacity, and obtain the saturated ion adsorption capacity;

[0184] Real-time prediction module: It is used to measure the nickel ion adsorption capacity in real time and perform curve analysis, extract different periods of the curve, select different models to predict and analyze the saturated adsorption capacity, and obtain the predicted saturated adsorption capacity;

[0185] Analysis and adjustment module: Based on the saturated adsorption capacity predicted by different models, use the resin adsorption kinetic model to determine the saturated adsorption time and adjust the estimated adsorption time.

[0186] The above has described an embodiment of the present invention in detail, but the content described is only a preferred embodiment of the present invention and cannot be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of the present invention application should still fall within the patent coverage scope of the present invention.

Claims

1. A method for preparing high-purity cobalt by deeply purifying copper and nickel ions in a cobalt solution, characterized in that, It includes the following steps: S1: Add cobalt powder to the cobalt solution containing Cu and Ni impurity ions, stir and mix, and then filter to obtain a filtrate. The Cu-containing filter residue in the filtrate is acid-leached and extracted to obtain a Cu-rich pure solution; S2: Pass the filtrate obtained in S1 through an ion exchange resin column, monitor the adsorption capacity of the ion exchange resin column for nickel ions, and regulate the adsorption time of the ion exchange resin column to obtain a Ni-rich pure solution; The regulation process of the adsorption time of the ion exchange resin column is as follows: Calculate the equilibrium adsorption capacity through the resin adsorption kinetics model and perform screening treatment to obtain the saturated ion adsorption capacity; Measure the nickel ion adsorption capacity in real time and perform curve analysis, extract different periods of the curve and perform prediction analysis to obtain the saturated adsorption capacities predicted by different models; Based on the saturated adsorption capacities predicted by different models, use the resin adsorption kinetics model to determine the saturated adsorption time and adjust the estimated adsorption time; The adjustment method for the estimated adsorption time is as follows: Perform weighted summation processing on the predicted saturated adsorption capacities in the rapid adsorption period, diffusion control period, and mixed control period calculated based on the real-time adsorption deviation change curve to obtain the comprehensive adsorption capacity; Take the proportion of the relative root mean square error in each historical period as the calculation weight of the comprehensive adsorption capacity; Based on the comprehensive adsorption capacity, calculate the saturated adsorption time through the resin adsorption kinetics model; If the saturated adsorption time is higher than the preset expected adsorption time, adjust the expected adsorption time; S3: Perform insoluble anode electrowinning on the solution obtained through the ion exchange resin column to obtain high-purity cobalt with a purity of 5N.

2. The method for preparing high-purity cobalt by deeply purifying copper and nickel ions in a cobalt solution according to claim 1, wherein, The cobalt solution is a cobalt sulfate solution or a cobalt chloride solution, the cobalt ion concentration is 50 - 140 g / L, the Cu concentration is less than 0.1 g / L, and the Ni concentration is less than 0.1 g / L.

3. A method for preparing high-purity cobalt by deeply purifying copper and nickel ions in a cobalt solution, as claimed in claim 1, wherein The particle size of the cobalt powder is 50 - 300 mesh, and the addition amount of the cobalt powder is 1.0 - 3.0 times the molar amount of Cu in the cobalt solution.

4. A method for preparing high-purity cobalt by deeply purifying copper and nickel ions in a cobalt solution according to claim 1, characterized in that, The ion exchange resin is D854 hydrogen-type cation exchange resin, control the inlet flow rate of the cobalt solution to be 0.5 - 5.0 BV / h, and adsorb at room temperature for 20 - 40 h.

5. A method for preparing high-purity cobalt by deeply purifying copper and nickel ions in a cobalt solution according to claim 1, characterized in that, The insoluble anode material is a titanium-coated iridium electrode, a titanium-coated ruthenium electrode, or a titanium-coated ruthenium-iridium electrode, and the cathode is a titanium plate.

6. The method for preparing high-purity cobalt by deeply purifying copper and nickel ions in a cobalt solution according to claim 1, characterized in that, The acquisition method of the saturated ion adsorption capacity is as follows: Obtain the equilibrium ion concentration of the ion segmented sequence and the adsorption time to reach the equilibrium ion concentration, and perform fitting calculation through the pseudo-second-order kinetics model to obtain the theoretical saturated adsorption capacity; Obtain the equilibrium adsorption capacities of multiple ion segmented sequences and construct an equilibrium ion group; Obtain the theoretical saturated adsorption capacities of multiple ion segmented sequences and construct a theoretical adsorption group; Through the confidence interval screening method, calculate the confidence interval of the theoretical adsorption group, perform screening treatment on the equilibrium ion group, and construct a saturated adsorption group.

7. A method for preparing high-purity cobalt by deeply purifying copper and nickel ions in a cobalt solution, characterized in that, The acquisition method of the predicted saturated adsorption capacity is as follows: Based on the nickel ion concentration measured in real time, calculate the monitored adsorption capacity during the monitoring time through the resin adsorption kinetics model; If the monitored adsorption capacity is lower than the saturated ion adsorption capacity in the saturated adsorption group, perform curve analysis on the monitored adsorption capacity, divide the curve into multiple different periods, and use different prediction models to calculate the saturated adsorption capacities predicted in different periods.

8. A method for preparing high-purity cobalt by deeply purifying copper and nickel ions in a cobalt solution, as claimed in claim 7, wherein The method of calculating using different prediction models is as follows: Construct a real-time adsorption deviation change curve, and divide the curve into: a rapid adsorption period, a diffusion control period, and a mixed control period; Obtain the monitoring time and the monitored adsorption amount corresponding to the real-time adsorption deviation change curve; Use the sliding window method to divide the monitoring time into multiple segment times, calculate the deviation ratio of the monitored adsorption amounts at the starting and ending times within each segment time, and obtain the adsorption deviation ratio; Based on the adsorption deviation ratio in the rapid adsorption period, use the pseudo-second-order kinetic model to predict the saturated adsorption amount; Based on the adsorption deviation ratio in the diffusion control period, use the intra-particle diffusion model to predict the saturated adsorption amount; Based on the adsorption deviation ratio in the mixed control period, use the pseudo-second-order kinetic model and the intra-particle diffusion model to predict the saturated adsorption amount.

9. A method for preparing high-purity cobalt by deeply purifying copper and nickel ions in a cobalt solution, as claimed in claim 1, wherein The method of obtaining the proportion of the relative root mean square error for each historical period is as follows: From the historical data, construct a historical adsorption deviation change curve; Based on the historical adsorption deviation change curve, calculate the predicted saturated adsorption amount in the historical rapid adsorption period, the predicted saturated adsorption amount in the historical diffusion control period, and the predicted saturated adsorption amount in the historical mixed control period; Calculate the mean value of the relative root mean square error corresponding to the predicted saturated adsorption amount in each historical period, and perform normalization processing to calculate the proportion of the relative root mean square error for each period.

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