Method for removing impurities from cobalt solutions

Abstract

A method for removing impurities from a cobalt solution is provided, comprising the steps of: packing a column with an adsorption resin, passing the cobalt solution through the column, and adsorbing cadmium ions from the cobalt solution onto the resin; or adding an adsorption resin to the cobalt solution for electrostatic adsorption, and adsorbing cadmium ions from the cobalt solution onto the resin; the cobalt solution is an acidic cobalt solution containing cadmium ions, and the adsorption resin is a thioureido- or isothioureido-containing adsorption resin. The cobalt solution is subjected to impurity removal using the adsorption resin with a specific structure. The impurity removal process is easy to operate and achieves a high cadmium removal rate.

Description

[Technical Field]

[0001] This application claims priority to Chinese Patent Application No. 202310091014.8, entitled "Method for Removing Impurities from Cobalt Solution," filed with the State Intellectual Property Office of the People's Republic of China on January 20, 2023, the entire contents of which are incorporated herein by reference.

[0002] FIELD OF THE INVENTION Embodiments of the present application relate to the field of technology for removing impurities from solutions, and more particularly to methods for removing impurities from cobalt solutions. [Background technology]

[0003] Cobalt is an important strategic metal widely used in aerospace, electrical machinery, machinery, chemical engineering, ceramics, batteries, and other fields. High-purity cobalt exhibits excellent semiconducting, magnetic, and conductive properties, making it an important material for preparing magnetic recording media, magnetic recording heads, optoelectronic devices, integrated circuits for magnetic sensors, and other components. High-purity cobalt with a purity of 5N or higher is primarily used in the manufacture of sputtering targets for the ultra-large-scale integrated circuit industry.

[0004] Currently, purification methods for removing impurities from cobalt sulfate solutions mainly involve chemical precipitation, ion exchange, and solvent extraction to remove metal impurities (such as copper, iron, zinc, aluminum, manganese, calcium, magnesium, and nickel) from the cobalt sulfate solution. The purified cobalt solution is then electrolyzed to obtain high-purity cobalt metal. During the purification and impurity removal process, cadmium, a highly biotoxic metal element with special chemical properties, is difficult to purify and separate. Current methods for removing cadmium from cobalt sulfate solutions mainly include cadmium precipitation by sulfurization and deep cadmium removal by N235 extraction. However, these methods involve complex operations and are expensive. In addition, some methods may introduce other impurity ions, making it difficult to reduce the cadmium ion concentration to the ppb level. Summary of the Invention [Problem to be solved by the invention]

[0005] In view of the above, an embodiment of the present application provides a method for removing impurities from a cobalt solution. The method uses an adsorption resin with a specific structure to remove cadmium ions from the solution. The impurity removal process is easy to operate and achieves a high cadmium removal rate. [Means for solving the problem]

[0006] In particular, in a first aspect of the present embodiment, there is provided a method for removing impurities from a cobalt solution, the method comprising the steps of: Packing a column with an adsorption resin, and passing a cobalt solution through the column to adsorb cadmium ions from the cobalt solution onto the resin; or adding an adsorption resin to the cobalt solution for static adsorption, and adsorbing cadmium ions from the cobalt solution onto the resin; and the cobalt solution is an acidic cobalt solution and contains the cadmium ions; A method is provided wherein the adsorption resin is a thioureido (-NH-C(=S)-NH2)- or isothioureido (-SC(=NH)NH2)-containing adsorption resin.

[0007] The adsorption resin used in this application is a thioureido (-NH-C(=S)-NH2)- or isothioureido (-SC(=NH)NH2)-containing macroporous adsorption resin. Macroporous adsorption resins are separation materials that combine the principles of adsorption and screening, and have a favorable macroporous mesh structure and a large specific surface area. Physical adsorption can be achieved using macroporous adsorption resins based on their large specific surface area, via van der Waals forces between the adsorbed molecules (adsorbates). In an embodiment of this application, cadmium impurity ions are removed from an acidic cobalt solution using a macroporous adsorption resin with a specific thioureido- or isothioureido-containing structure. Cadmium impurity ions can be selectively removed through a simple adsorption process. This cadmium removal method is simple and has a high cadmium removal rate. Furthermore, by using the macroporous adsorption resin having a specific thioureido- or isothioureido-containing structure of the present invention, it is possible to selectively adsorb cadmium even in a cadmium ion-containing acidic cobalt solution having a high cobalt ion concentration, and the concentration of cadmium impurity ions in the cobalt solution can be reduced to the ppb (parts per billion) level. This solves the problems of the prior art, such as insufficient separation of cadmium from an acidic cobalt solution containing cadmium ions and complicated operation processes.

[0008] In an embodiment of the present application, the adsorption resin is a thioureido- or isothioureido-containing macroporous adsorption resin of styrene-divinylbenzene copolymer.

[0009] By using a thioureido- or isothioureido-containing macroporous adsorption resin of styrene-divinylbenzene copolymer, cadmium ions can be sufficiently selectively removed from cobalt solutions, resulting in excellent cadmium removal efficiency.

[0010] In one embodiment of the present application, the adsorption resin is a spherical particle, and the specific surface area is 500 m 2 / g to 1500m 2 / g, and the average pore size is 0.3 mm to 1.5 mm. The specific surface area is the value per gram of dry resin. The adsorption resin has a suitable specific surface area and suitable average pore size, which makes it easy to adsorb and remove cadmium ions from cobalt solutions.

[0011] In one embodiment of the present application, the adsorption resin is a spherical particle, and the adsorption resin has a volume exchange capacity of 1.0 mmol / mL or more and a water content of 40% to 60%. The adsorption resin has a large volume exchange capacity and a suitable water content, which facilitates the adsorption and removal of cadmium ions from a cobalt solution.

[0012] In one embodiment of the present application, the acidic cobalt solution containing cadmium ions includes a cobalt sulfate solution containing cadmium ions, a cobalt chloride solution containing cadmium ions, a cobalt nitrate solution containing cadmium ions, or a cobalt acetate solution containing cadmium ions. For different types of acidic cobalt solutions containing cadmium ions, the use of thioureido- or isothioureido-containing macroporous adsorption resins can achieve good cadmium removal effects, thereby meeting the application needs of cadmium removal from various cobalt solutions.

[0013] In one embodiment of the present application, the cadmium ion-containing acidic cobalt solution has a cobalt ion concentration of 1 g / L to 100 g / L and a cadmium ion concentration of 5.0 g / L or less. The use of the thioureido- or isothioureido-containing macroporous adsorption resin in this embodiment can remove cadmium ions from acidic cobalt solutions with different concentrations of cobalt ions, different concentrations of cadmium ions, and different cobalt-cadmium relative concentrations, and can achieve good cadmium removal even from cobalt solutions with a high cobalt ion concentration.

[0014] In one embodiment of the present application, the pH of the effluent after passing through the column is 2.0 to 5.0, and the pH of the mixed solution obtained by adding the adsorption resin to the cobalt solution is 2.0 to 5.0. By controlling the pH of the effluent and the pH of the mixed solution within a suitable acidic range, selective adsorption of cadmium ions in the cobalt solution by the adsorption resin becomes easy.

[0015] In one embodiment of the present application, the contact time during which the cobalt solution passes through the column is controlled to be 1 hour or more. By appropriately controlling the contact time during which the cobalt solution passes through the column, cadmium ions can be more effectively adsorbed by the adsorption resin.

[0016] In one embodiment of the present application, the operating temperature during passage through the column is between 10°C and 30°C; The operating temperature of the static adsorption is 10° C. to 30° C. The adsorption process in the present embodiment can be carried out at ambient temperatures of 10° C. to 30° C., making the process highly operable and practicable.

[0017] In one embodiment of the present application, stirring or agitation is performed during the static adsorption, which can enhance the contact between the adsorption resin and the mixed solution, thereby promoting the adsorption of cadmium ions and improving the adsorption efficiency.

[0018] In one embodiment of the present application, the static adsorption time is 1 to 8 hours. By appropriately controlling the adsorption time, the complete adsorption of cadmium ions can be facilitated and the impurity removal effect can be improved.

[0019] In one embodiment of the present application, before using the adsorption resin to adsorb cadmium ions, the adsorption resin is first pretreated, and the pretreatment includes: soaking the adsorption resin in saturated saline for 18 to 20 hours and washing the adsorption resin with water until the effluent is no longer yellow; Next, immersing the adsorption resin in a dilute hydrochloric acid solution for 4 to 8 hours, and then washing the adsorption resin with water until the adsorption resin becomes approximately neutral; Finally, immersing the adsorption resin in a 2% to 4% by weight sodium hydroxide solution for 4 to 8 hours and washing the adsorption resin with water until the adsorption resin is neutral for use; Through the above-mentioned pretreatment, various impurities can be effectively removed from the adsorption resin, and the adsorption effect of the adsorption resin can be improved.

[0020] In one embodiment of the present application, the concentration ratio of cobalt ions to cadmium ions after the acidic cobalt solution containing cadmium ions is subjected to cadmium removal treatment using the adsorption resin is (10,000 to 3,000,000): 1. In some embodiments, the concentration ratio of cobalt ions to cadmium ions after the acidic cobalt solution containing cadmium ions is subjected to cadmium removal using the adsorption resin may be, for example, 10,000: 1, 20,000: 1, 50,000: 1, 80,000: 1, 100,000: 1, 200,000: 1, 500,000: 1, 800,000: 1, 1,000,000: 1, 1,500,000: 1, 2,000,000: 1, 2,500,000: 1, or 3,000,000: 1. By using the thioureido- or isothioureido-containing macroporous adsorption resin in the present embodiment, the relative concentration of cadmium ions in the acidic cobalt solution can be reduced to an extremely low level, which indicates that the adsorption resin has an extremely high selective adsorption effect for cadmium ions in the cobalt solution system.

[0021] In one embodiment of the present application, the cadmium ion concentration after the acidic cobalt solution containing cadmium ions is subjected to cadmium removal treatment using the adsorption resin is less than 10 ppb. In some embodiments, the cadmium ion concentration after the acidic cobalt solution containing cadmium ions is subjected to cadmium removal using the adsorption resin is 5 ppb or less. In some embodiments, the cadmium ion concentration after the acidic cobalt solution containing cadmium ions is subjected to cadmium removal using the adsorption resin is 2 ppb or less. In some embodiments, the cadmium ion concentration after the acidic cobalt solution containing cadmium ions is subjected to cadmium removal using the adsorption resin is 1 ppb or less. By using the thioureido- or isothioureido-containing macroporous adsorption resin in the embodiment of the present application, the concentration of cadmium ions in the acidic cobalt solution can be reduced to the ppb level, thereby effectively solving the prior art problems of insufficient cadmium separation from the acidic cobalt solution containing cadmium ions and complicated operation processes.

[0022] In one embodiment of the present application, the cadmium removal rate of the adsorption resin for the acidic cobalt solution containing cadmium ions is 99% or more. In some embodiments, the cadmium removal rate of the adsorption resin used to remove cadmium ions from a solution containing cadmium ions is 99.9% or more. The use of a thioureido- or isothioureido-containing macroporous adsorption resin in embodiments of the present application can achieve a high cadmium removal rate and good cadmium removal effect in the removal of cadmium ions from a cobalt solution.

[0023] In one embodiment of the present application, the cobalt solution includes an acidic cobalt electroplating solution for advanced process nodes or a battery-grade acidic cobalt solution. Cobalt has low resistivity and is less likely to diffuse into silicon wafers than copper. Using cobalt metal as an interconnect material can reduce electromigration and diffusion without the need for a high-resistivity barrier layer, facilitating the reduction of chip package size. Cobalt electroplating solutions are important raw materials for preparing cobalt metal interconnect structures, and the purity of the cobalt electroplating solution directly affects the performance of the cobalt metal interconnect structure. In an embodiment of the present application, the thioureido- or isothioureido-containing macroporous adsorbent resin is used to remove cadmium ions from the acidic cobalt electroplating solution required for advanced integrated circuit process nodes, purifying the acidic cobalt electroplating solution and increasing the purity of the cobalt solution. In this case, a high-purity, high-quality electroplated cobalt layer can be obtained through electroplating, thereby improving the performance of semiconductor devices. The battery-grade acidic cobalt solution may be, but is not limited to, a cobalt sulfate solution. Cathode materials are one of the key materials determining battery performance. Currently, commonly used lithium-ion cathode materials mainly include lithium cobalt oxide, lithium iron phosphate, lithium manganese oxide, and multi-element materials. Cobalt sulfate is an important raw material for preparing precursors of battery cathode materials. With increasing demands for battery safety performance, the impurity content of cobalt sulfate is increasingly restricted. By using the thioureido- or isothioureido-containing macroporous adsorption resin of the present application, cadmium ions are removed from the cobalt sulfate solution, which is the raw material for the precursor of the battery cathode material, and the purity of the cobalt sulfate solution is increased, thereby improving the properties of the cathode material and the electrochemical properties and safety performance of the battery.

[0024] In one embodiment of the present application, the method for removing impurities further comprises the step of regenerating the adsorption resin after the adsorption resin is saturated, The regenerating step includes: immersing the adsorption resin in a dilute hydrochloric acid solution for 4 to 8 hours and washing the adsorption resin until the adsorption resin is nearly neutral; Thereafter, the adsorption resin is immersed in a 2% to 4% by weight sodium hydroxide solution for 4 to 8 hours and washed until the adsorption resin is neutral for use; The dilute hydrochloric acid may be, for example, hydrochloric acid having a mass concentration of 5% to 10%. The adsorption resin to which cadmium ions have been adsorbed can be regenerated by using the above-mentioned regeneration method, and the adsorption resin can be reused.

[0025] In a second aspect of the present embodiment, there is provided the use of an adsorption resin in removing cadmium ions from a solution, comprising: the adsorption resin is a thioureido- or isothioureido-containing adsorption resin; The adsorption resin is used to remove cadmium ions from a solution containing the cadmium ions. In an embodiment of the present application, a macroporous adsorption resin having a specific thioureido- or isothioureido-containing structure is used to remove cadmium ions from a solution, and cadmium impurity ions can be selectively removed from a solution containing cadmium ions through a simple adsorption process.

[0026] In one embodiment of the present application, the adsorption resin is a thioureido- or isothioureido-containing macroporous adsorption resin of styrene-divinylbenzene copolymer, which can selectively and effectively remove cadmium impurity ions from a solution containing cadmium ions, thereby achieving an excellent cadmium removal effect.

[0027] In one embodiment of the present application, the adsorption resin is 500 ml 2 / g to 1500m 2The adsorption resin has a specific surface area of ​​0.3 mm to 1.5 mm / g and an average pore size of 0.3 mm to 1.5 mm. The specific surface area is measured per gram of dry resin. The adsorption resin has a suitable specific surface area and an average pore size, which facilitates the adsorption and removal of cadmium impurity ions from solution.

[0028] In one embodiment of the present application, the solution containing cadmium ions includes an acidic cobalt solution containing cadmium ions, a nickel sulfate solution containing cadmium ions, a ferric sulfate solution containing cadmium ions, a ferrous sulfate solution containing cadmium ions, a calcium chloride solution containing cadmium ions, a magnesium chloride solution containing cadmium ions, or a sodium chloride solution containing cadmium ions. By using a thioureido- or isothioureido-containing macroporous adsorption resin, a good cadmium removal effect can be achieved from the solution containing cadmium ions.

[0029] In one embodiment of the present application, the method of use comprises: Packing an adsorption resin into a column, passing the solution containing the cadmium ions through the column, and adsorbing the cadmium ions onto the resin; or For static adsorption, adding the adsorption resin to a solution containing the cadmium ions to adsorb the cadmium ions onto the resin. In the two adsorption methods described above, the cadmium ions in a solution containing cadmium ions are adsorbed by the adsorption function of the adsorption resin, and the cadmium is removed, resulting in a cadmium-free solution. The above-mentioned methods are simple and easy to implement.

[0030] In one embodiment of the present application, the pH of the effluent after passing through the column is 2.0 to 5.0, and the pH of the mixed solution obtained by adding the adsorption resin to the solution containing cadmium ions is 2.0 to 5.0. By controlling the pH of the effluent and the pH of the mixed solution within a suitable acidic range, it becomes easy to selectively adsorb cadmium ions in the solution containing cadmium ions onto the adsorption resin.

[0031] In one embodiment of the present application, the contact time during which the solution containing cadmium ions passes through the column is controlled to be 1 hour or more. By controlling the contact time so that the solution containing cadmium ions passes through the column, the cadmium ions can be more effectively adsorbed onto the adsorption resin.

[0032] In one embodiment of the present application, the operating temperature for passing through the column is 10° C. to 30° C., and the operating temperature for the static adsorption is 10° C. to 30° C. The adsorption process in this embodiment can be carried out at ambient temperatures of 10° C. to 30° C., making the process highly operable and practicable.

[0033] In one embodiment of the present application, stirring or agitation is performed during the static adsorption, which can increase the contact between the adsorption resin and the mixed solution, thereby promoting the adsorption of cadmium ions and improving the adsorption efficiency.

[0034] In one embodiment of the present application, the adsorbent resin is used to remove cadmium ions from acidic cobalt electroplating solutions in advanced process nodes, or to remove cadmium ions from battery-grade acidic cobalt solutions, or to remove micro or trace amounts of cadmium ions from nickel sulfate solutions, ferric sulfate solutions, ferrous sulfate solutions, calcium chloride solutions, magnesium chloride solutions, or sodium chloride solutions. The thioureido- or isothioureido-containing macroporous adsorbent resin of the present application can be used to remove cadmium ions from acidic cobalt electroplating solutions required for advanced integrated circuit process nodes, thereby increasing the purity of the cobalt solution. In this case, a high-purity, high-quality electroplated cobalt layer can be obtained via electroplating, thereby improving the performance of semiconductor devices. The use of a thioureido- or isothioureido-containing macroporous adsorption resin in accordance with an embodiment of the present application removes cadmium ions from a cobalt sulfate solution, which is a raw material for a battery cathode precursor, thereby increasing the purity of the cobalt sulfate solution, thereby improving the properties of the cathode material and further enhancing the electrochemical properties and safety of the battery. The use of a thioureido- or isothioureido-containing macroporous adsorption resin in accordance with an embodiment of the present application removes cadmium ions from the solution, thereby purifying the solution. "Micro amounts" refers to a cadmium ion content of less than one part in ten thousand and more than one part in a million. "Trace amounts" refers to a cadmium ion content of less than 1 ppm.

[0035] In a third aspect of the present embodiment, there is provided a cobalt solution obtained after impurities have been removed by using the method for removing impurities according to the first aspect of the present embodiment, or a cobalt solution obtained through the aforementioned use. The concentration of cadmium ions in the cobalt solution is less than 10 ppb. The cobalt solution may be an acid cobalt electroplating solution obtained after impurities removal in an advanced process node, or a battery-grade acid cobalt solution obtained after impurities removal, in particular, a cobalt sulfate solution, a cobalt chloride solution, a cobalt nitrate solution, a cobalt acetate solution, etc. DETAILED DESCRIPTION OF THE INVENTION

[0036] Hereinafter, the embodiments of the present application will be specifically described.

[0037] High-purity cobalt exhibits excellent semiconducting, magnetic, and conductive properties, making it an important material for preparing magnetic recording media, magnetic recording heads, optoelectronic devices, integrated circuits for magnetic sensors, and other components. The ultra-large-scale integrated circuit (ULCI) industry requires high-purity cobalt as a sputtering target, which requires high-purity cobalt sulfate solutions for its preparation. High-purity cobalt electroplating solutions are also required for electroplated cobalt interconnects. High-purity cobalt solutions are also required for the preparation of battery cathode materials. Currently, purification methods for removing impurities from cobalt solutions mainly include chemical precipitation, ion exchange, and solvent extraction, and primarily remove metal impurities (such as copper, iron, zinc, aluminum, manganese, calcium, magnesium, and nickel) from cobalt solutions. During the purification and impurity removal process, cadmium, a highly biotoxic metal element with unique chemical properties, makes its purification and separation difficult. At present, the methods for removing cadmium from cobalt sulfate solution mainly include cadmium precipitation by sulfurization, deep cadmium removal by N235 extraction, etc. However, these methods involve complicated operations and are costly, and in some cases, other impurity ions (e.g., chloride ions) may be further mixed in, making it extremely difficult to reduce the concentration of cadmium ions to the ppb level.

[0038] To solve the above problems, an embodiment of the present application provides a method for removing impurities from a cobalt solution. Cadmium ions are removed from the cobalt solution by using an adsorption resin with a specific structure. The impurity removal process is easy to operate and achieves a high cadmium removal rate.

[0039] In particular, one embodiment of the present application provides a method for removing impurities from a cobalt solution, the method comprising: Packing a column with an adsorption resin, passing a cobalt solution through the column, and adsorbing cadmium ions from the cobalt solution onto the resin; or adding an adsorption resin to the cobalt solution for static adsorption to adsorb cadmium ions from the cobalt solution onto the resin; and the cobalt solution is an acidic cobalt solution containing the cadmium ions, A method is provided in which the adsorption resin is a thioureido (-NH-C(=S)-NH2)- or isothioureido (-SC(=NH)NH2)-containing adsorption resin. The isothioureido (-SC(=NH)NH2) group is the enol isomer of the thioureido (-NH-C(=S)-NH2) group. It is understood that the thioureido (-NH-C(=S)-NH2) group may be bonded to the molecular chain of the adsorption resin by an N atom, for example, the thioureido group may be -CH2-NH-C(=S)-NH2 bonded to a carbon atom; the isothioureido (-SC(=NH)NH2) group may be bonded to the molecular chain of the adsorption resin by an S atom, for example, the isothioureido group may be -CH2-SC(=NH)NH2 bonded to a carbon atom. The thioureido group and the isothioureido group are polar groups. The adsorption resin is a chelating resin.

[0040] The adsorption resin used in this application is a thioureido (-NH-C(=S)-NH2)- or isothioureido (-SC(=NH)NH2)-containing macroporous adsorption resin. Macroporous adsorption resins are separation materials that combine the principles of adsorption and screening, and have a favorable macroporous mesh structure and a large specific surface area. Physical adsorption based on the large specific surface area can be achieved using macroporous adsorption resins due to the van der Waals forces between the macroporous adsorption resin and the adsorbed molecules (adsorbents). In an embodiment of this application, a macroporous adsorption resin with a specific thioureido- or isothioureido-containing structure is used to remove cadmium impurity ions from an acidic cobalt solution. Cadmium impurity ions can be selectively removed through a simple adsorption process. This cadmium removal method is simple and has a high cadmium removal rate. Furthermore, by using the macroporous adsorption resin having a specific thioureido- or isothioureido-containing structure of the present invention, selective adsorption of cadmium can be achieved even in a cadmium ion-containing acidic cobalt solution having a high cobalt ion concentration, and the concentration of cadmium impurity ions in the cobalt solution can be reduced to the ppb (parts per billion) level, thereby solving the problems of the prior art, such as insufficient separation of cadmium from an acidic cobalt solution containing cadmium ions and complicated operation processes.

[0041] In an embodiment of the present application, the adsorption resin is a thioureido- or isothioureido-containing macroporous adsorption resin of styrene-divinylbenzene copolymer. In an embodiment of the present application, the selective removal of cadmium from the cobalt solution is achieved by the synergistic effect of the thioureido or isothioureido groups and the styrene-divinylbenzene copolymer. In an embodiment of the present application, the thioureido- or isothioureido-containing macroporous adsorption resin of styrene-divinylbenzene copolymer may be prepared by self-preparation or may be obtained commercially. For example, the thioureido- or isothioureido-containing macroporous styrene-divinylbenzene copolymer adsorption resin may be, but is not limited to, the following commercially available brands: DOWEX™ XUS43600, Tulsion® CH-97, Purolite® S920, Purolite® MTS9140, LEWATIT® MonoPlus TP-214, and Suqing D405-II. The thioureido- or isothioureido-containing macroporous styrene-divinylbenzene copolymer adsorption resin can be used to selectively remove cadmium ions from cobalt solutions, achieving excellent cadmium removal.

[0042] In one embodiment of the present application, the adsorption resin is 500 ml 2 / g to 1500m 2 The adsorption resin has a specific surface area of ​​0.3 mm to 1.5 mm. The specific surface area is a value per gram of dry resin. The adsorption resin has a suitable specific surface area and a suitable average pore size, which facilitates the adsorption and removal of cadmium ions from a cobalt solution. In one embodiment of the present application, the adsorption resin may be spherical particles, and the adsorption resin may have a volume exchange capacity of 1.0 mmol / mL or more and a water content of 40% to 60%. The adsorption resin has a large volume exchange capacity and a suitable water content, which facilitates the adsorption and removal of cadmium ions from a cobalt solution.

[0043] In one embodiment of the present application, the acidic cobalt solution containing cadmium ions may include a cobalt sulfate solution containing cadmium ions, a cobalt chloride solution containing cadmium ions, a cobalt nitrate solution containing cadmium ions, or a cobalt acetate solution containing cadmium ions. The thioureido- or isothioureido-containing macroporous adsorption resin of the present application can achieve good cadmium adsorption effect for different types of acidic cobalt solutions containing cadmium ions, thereby meeting the application needs of cadmium removal from various cobalt solutions.

[0044] In one embodiment of the present application, in the acidic cobalt solution containing cadmium ions, the concentration of cobalt ions is 1 g / L to 100 g / L, and the concentration of cadmium ions is 5.0 g / L or less. In some embodiments, the concentration of cobalt ions may be, for example, 1 g / L, 10 g / L, 20 g / L, 30 g / L, 40 g / L, 50 g / L, 60 g / L, 70 g / L, 80 g / L, 90 g / L, or 100 g / L, among others. In some embodiments, the concentration of cadmium ions may be 0.01 g / L, 0.05 g / L, 0.5 g / L, 1.0 g / L, 2.0 g / L, 3.0 g / L, 4.0 g / L, or 5.0 g / L. In some embodiments, the concentration of cadmium ions may be 0.01 g / L to 1.0 g / L. In some embodiments, the cadmium ion concentration may be 1.0 g / L or less. In some embodiments, the cadmium ion concentration may be, for example, 0.01 g / L, 0.05 g / L, 0.1 g / L, 0.2 g / L, 0.3 g / L, 0.4 g / L, 0.5 g / L, 0.6 g / L, 0.7 g / L, 0.8 g / L, 0.9 g / L, or 1.0 g / L, among others. In some embodiments, the cadmium ion concentration may be less than 0.01 g / L. The use of thioureido- or isothioureido-containing macroporous adsorption resins according to embodiments of the present application can remove cadmium ions from acidic cobalt solutions having different concentrations of cobalt ions, different concentrations of cadmium ions, and different cobalt-cadmium relative concentrations, and can achieve good cadmium removal even from cobalt solutions containing high concentrations of cobalt ions.

[0045] In one embodiment of the present application, the method for removing impurities is removal of impurities through adsorption by passing through a column. In the operation method of adsorption by passing through a column in this embodiment, cadmium ions in a cobalt solution containing cadmium ions are adsorbed by an adsorption resin through dynamic adsorption, thereby removing cadmium and obtaining a cobalt solution from which cadmium has been removed. This operation method has a simple process and is easy to implement.

[0046] In this embodiment, the pH of the effluent after passing through the column is 2.0 to 5.0, and may be, for example, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, or 5.0. The pH of the effluent after passing through the column is controlled in the range of 2.0 to 5.0, i.e., the pH of the mixture of the cobalt solution containing cadmium ions and the adsorption resin is controlled in the range of 2.0 to 5.0. Controlling the pH of the effluent in an appropriate acidic range promotes selective adsorption of cadmium ions in the cobalt solution by the adsorption resin.

[0047] In this embodiment, the contact time of the cobalt solution passing through the column is controlled to be 1 hour or more. Specifically, the contact time of the cobalt solution passing through the column is controlled to be 1 to 12 hours, such as 1 hour, 2 hours, 3 hours, 5 hours, 8 hours, 10 hours, or 12 hours. By appropriately controlling the contact time when the cobalt solution passes through the column, cadmium ions can be more effectively adsorbed onto the adsorption resin, and higher adsorption efficiency can be achieved.

[0048] In this embodiment, the operating temperature for passing through the column is 10° C. to 30° C. In this embodiment, the adsorption process by passing through the column can be carried out at normal temperatures of 10° C. to 30° C., and the process is highly operable and feasible.

[0049] In another embodiment of the present application, the method for removing impurities is impurity removal via static adsorption. In the static adsorption method of this embodiment, cadmium ions in a cobalt solution containing cadmium ions are adsorbed based on the adsorption function of the adsorption resin, thereby removing cadmium and obtaining a cadmium-removed solution. This method has a simple process and is easy to implement.

[0050] In this embodiment, the pH of the mixed solution obtained by adding the adsorption resin to the cobalt solution is 2.0 to 5.0, and may be, for example, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, or 5.0. By controlling the pH of the mixed solution to an appropriate acidic range, selective adsorption of cadmium ions in the cobalt solution containing cadmium ions onto the adsorption resin becomes easy.

[0051] In this embodiment, the operating temperature of static adsorption is 10° C. to 30° C. The adsorption process in this embodiment can be carried out at ambient temperatures of 10° C. to 30° C., making the process highly operable and feasible.

[0052] In this embodiment, the static adsorption is performed by stirring or agitating, which can enhance the contact between the adsorption resin and the mixed solution, thereby promoting the adsorption of cadmium ions and improving the adsorption efficiency.

[0053] In this embodiment, the static adsorption time is 1 to 8 hours, and may be, for example, 1 hour, 2 hours, 3 hours, or 5 hours. A suitable adsorption time allows the adsorption resin to better adsorb cadmium ions, resulting in higher adsorption efficiency.

[0054] In one embodiment of the present application, the adsorption resin is first pretreated before adsorbing cadmium ions. The pretreatment includes soaking the adsorption resin in saturated saline for 18 to 20 hours and rinsing it with water until the discharged water is no longer yellow. Next, the adsorption resin is soaked in dilute hydrochloric acid for 4 to 8 hours and rinsing it with water until the adsorption resin is nearly neutral. Finally, the adsorption resin is soaked in 2 to 4 wt% sodium hydroxide for 4 to 8 hours and rinsing it with water until the adsorption resin is neutral for use. The dilute hydrochloric acid may be, for example, hydrochloric acid with a mass concentration of 5% to 10%. This pretreatment effectively removes various impurities from the adsorption resin and improves the adsorption effect of the adsorption resin.

[0055] In embodiments of the present application, after the acidic cobalt solution containing cadmium ions is subjected to a cadmium removal treatment using an adsorption resin, the concentration ratio of cobalt ions to cadmium ions is (10,000 to 3,000,000):1, resulting in a high cobalt-cadmium ratio. In some embodiments, by subjecting the acidic cobalt solution containing cadmium ions to a cadmium removal treatment using an adsorption resin, the concentration ratio of cobalt ions to cadmium ions may be, for example, 10,000:1, 20,000:1, 50,000:1, 80,000:1, 100,000:1, 200,000:1, 500,000:1, 800,000:1, 1,000,000:1, 1,500,000:1, 2,000,000:1, 2,500,000:1, or 3,000,000:1. By using the thioureido- or isothioureido-containing macroporous adsorption resin in the examples of this application, the relative concentration of cadmium ions in the acidic cobalt solution can be reduced to an extremely low level, which indicates that the adsorption resin has an extremely high selective adsorption effect for cadmium ions in the cobalt solution system.

[0056] In one embodiment of the present application, after cadmium removal from an acidic cobalt solution containing cadmium ions using the adsorption resin, the concentration of cadmium ions is less than 10 ppb. In some embodiments, after cadmium removal from an acidic cobalt solution containing cadmium ions using the adsorption resin, the concentration of cadmium ions is 5 ppb or less. In some embodiments, after cadmium removal from an acidic cobalt solution containing cadmium ions using the adsorption resin, the concentration of cadmium ions is 2 ppb or less. In some embodiments, after cadmium removal from an acidic cobalt solution containing cadmium ions using the adsorption resin, the concentration of cadmium ions is 1 ppb or less. The use of thioureido- or isothioureido-containing macroporous adsorption resins in embodiments of the present application can reduce the concentration of cadmium ions in an acidic cobalt solution to the ppb level, thereby effectively solving the problems of the prior art, such as incomplete cadmium separation from an acidic cobalt solution containing cadmium ions and complicated operating processes.

[0057] In embodiments of the present application, the cadmium removal rate of the adsorption resin used to remove cadmium ions from a solution containing cadmium ions is 99% or greater. In some embodiments, the cadmium removal rate of the adsorption resin used to remove cadmium ions from a solution containing cadmium ions is 99.9% or greater. By using the thioureido- or isothioureido-containing macroporous adsorption resin of embodiments of the present application to remove cadmium ions from a solution containing cadmium ions, a high cadmium removal rate and good cadmium removal effect can be achieved.

[0058] In embodiments of the present application, the cobalt solution may be an acid cobalt electroplating solution in advanced process nodes, or may be a battery-grade acid cobalt solution, or may be an acid cobalt solution in another application scenario.

[0059] In one embodiment of the present application, the cobalt solution is an acidic cobalt electroplating solution for advanced process nodes. Cobalt has low resistivity and is less likely to diffuse into silicon wafers than copper. The use of cobalt metal as an interconnect material can reduce electromigration, reduce diffusion without the need for a high-resistivity barrier layer, and facilitate the reduction of chip package size. The cobalt electroplating solution is an important raw material for preparing cobalt metal interconnect structures, and the purity of the cobalt electroplating solution directly affects the performance of the cobalt metal interconnect structure. In an embodiment of the present application, the thioureido- or isothioureido-containing macroporous adsorbent resin is used to remove cadmium ions from the acidic cobalt electroplating solution required for advanced process nodes of integrated circuits, purify the acidic cobalt electroplating solution, and improve the purity of the cobalt solution. In this case, a higher-purity, higher-quality electroplated cobalt layer can be obtained through electroplating, thereby improving the performance of semiconductor devices.

[0060] In another embodiment of the present application, the cobalt solution is a battery-grade acidic cobalt solution. The battery-grade acidic cobalt solution may be, but is not limited to, a cobalt sulfate solution. The cathode material is one of the key materials that determine battery performance. Currently, commonly used lithium-ion cathode materials mainly include lithium cobalt oxide, lithium iron phosphate, lithium manganese oxide, multi-element materials, etc. Cobalt sulfate is an important raw material for preparing the precursor of a battery cathode material. With increasing demands for battery safety performance, the content of impurities in cobalt sulfate is becoming increasingly strict. By using a thioureido- or isothioureido-containing macroporous adsorption resin in an embodiment of the present application, cadmium ions are removed from the cobalt sulfate solution, which is the raw material for the precursor of the battery cathode material, and the purity of the cobalt sulfate solution is improved, thereby enhancing the properties of the cathode material and further improving the electrochemical and safety characteristics of the battery.

[0061] In one embodiment of the present application, the method for removing impurities further includes the step of regenerating the adsorption resin after it is saturated by the following method: immersing the adsorption resin in a dilute hydrochloric acid solution for 4 to 8 hours and washing the adsorption resin until it is nearly neutral, and then immersing the adsorption resin in a 2 wt% to 4 wt% sodium hydroxide solution for 4 to 8 hours and washing the adsorption resin until it is neutral for use. The dilute hydrochloric acid may be, for example, hydrochloric acid having a mass concentration of 5% to 10%. The adsorption resin with adsorbed cadmium ions is regenerated using the above-mentioned regeneration method, allowing the adsorption resin to be reused.

[0062] One embodiment of the present application further provides a use of an adsorption resin for removing cadmium ions from a solution, wherein the adsorption resin is a thioureido- or isothioureido-containing macroporous adsorption resin, and the adsorption resin is used for selectively removing cadmium ions from a solution containing cadmium ions. In this embodiment, cadmium ions are removed from a solution by using a macroporous adsorption resin with a specific thioureido- or isothioureido-containing structure, and cadmium impurity ions can be selectively removed from a solution containing cadmium ions through a simple adsorption operation. The cadmium removal process is easy to operate and achieves a high cadmium removal rate.

[0063] In the use of the adsorption resin in removing cadmium impurity ions from a solution in the embodiment of the present application, it can be understood that the relevant description of the adsorption resin is referred to the above description, and the details will not be described again here.

[0064] In one embodiment of the present application, the solution containing cadmium ions includes an acidic cobalt solution containing cadmium ions, a nickel sulfate solution containing cadmium ions, a ferric sulfate solution containing cadmium ions, a ferrous sulfate solution containing cadmium ions, a calcium chloride solution containing cadmium ions, a magnesium chloride solution containing cadmium ions, or a sodium chloride solution containing cadmium ions. By using a thioureido- or isothioureido-containing macroporous adsorption resin for a solution containing cadmium impurity ions, a good cadmium removal effect can be achieved.

[0065] In one embodiment of the present application, the method of use may include filling a column with an adsorption resin and passing a solution containing cadmium ions through the column to adsorb the cadmium ions onto the resin, or adding an adsorption resin to a solution containing cadmium ions for static adsorption to adsorb the cadmium ions onto the resin. In these two adsorption methods, the cadmium ions in the solution containing cadmium ions are adsorbed based on the adsorption function of the adsorption resin, thereby removing cadmium and obtaining a cadmium-free solution. The operation methods have simple processes and are easy to implement.

[0066] In an embodiment of the present application, the pH of the effluent after passing through the column is 2.0 to 5.0, and the pH of the mixed solution obtained by adding the adsorption resin to the solution containing cadmium ions is 2.0 to 5.0, specifically, for example, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, or 5.0. By controlling the pH of the effluent and the pH of the mixed solution within a suitable acidic range, it becomes easy to selectively adsorb cadmium ions in the solution containing cadmium ions onto the adsorption resin.

[0067] In one embodiment of the present application, the contact time during which the solution containing cadmium ions passes through the column is controlled to be 1 hour or more. Specifically, the contact time during which the cobalt solution passes through the column is controlled to be 1 hour, 2 hours, 3 hours, etc. By appropriately controlling the contact time during which the solution containing cadmium ions passes through the column, the cadmium ions can be effectively adsorbed by the adsorption resin.

[0068] It can be understood that in the use of the adsorption resin in removing cadmium impurity ions from a solution in the embodiment of the present application, the relevant explanations of the operation for adsorption by passing through a column and the operation for static adsorption are referred to the above description, and the details will not be described again here.

[0069] In embodiments of the present application, the sorbent resins are used in removing cadmium ions from acidic cobalt electroplating solutions in advanced process nodes, or from battery-grade acidic cobalt solutions, or to remove micro- or trace amounts of cadmium ions from nickel sulfate solutions, ferric sulfate solutions, ferrous sulfate solutions, calcium chloride solutions, magnesium chloride solutions, or sodium chloride solutions. The thioureido- or isothioureido-containing macroporous sorbent resins of the present application can be used to remove cadmium ions from acidic cobalt electroplating solutions required for advanced integrated circuit process nodes, improving the purity of the cobalt solution. In this case, higher purity and higher quality electroplated cobalt layers can be obtained via electroplating, thereby improving the performance of semiconductor devices. The use of a thioureido- or isothioureido-containing macroporous adsorption resin in accordance with an embodiment of the present application removes cadmium ions from a cobalt sulfate solution, which is a raw material for a precursor of a battery cathode material, improving the purity of the cobalt sulfate solution, thereby improving the properties of the cathode material and further improving the electrochemical and safety characteristics of the battery. The use of a thioureido- or isothioureido-containing macroporous adsorption resin in accordance with an embodiment of the present application removes cadmium ions from the solution, thereby purifying the solution. Microamounts refer to cadmium ion contents of less than one part in ten thousand to more than one part in a million. Trace amounts refer to cadmium ion contents of less than 1 ppm.

[0070] The present embodiment further provides a cobalt solution obtained after impurity removal using the aforementioned impurity removal method according to the present embodiment, or a cobalt solution obtained by the aforementioned use. The cobalt solution may be an acid cobalt electroplating solution obtained after impurity removal in an advanced process node, a battery-grade acid cobalt solution obtained after impurity removal, or an acid cobalt solution in another application scenario, specifically, a cobalt sulfate solution, a cobalt chloride solution, a cobalt nitrate solution, a cobalt acetate solution, or the like. The concentration of cadmium ions in the cobalt solution is less than 10 ppb. In some embodiments, the concentration of cadmium ions is 5 ppb or less. In some embodiments, the concentration of cadmium ions is 2 ppb or less. In some embodiments, the concentration of cadmium ions is 1 ppb or less. In the cobalt solution, the concentration ratio of cobalt ions to cadmium ions may be (10,000-3,000,000):1. In some embodiments, the concentration ratio of cobalt ions to cadmium ions in the cobalt solution can be, for example, 10,000:1, 20,000:1, 50,000:1, 80,000:1, 100,000:1, 200,000:1, 500,000:1, 800,000:1, 1,000,000:1, 1,500,000:1, 2,000,000:1, 2,500,000:1, or 3,000,000:1, among others. By using the thioureido- or isothioureido-containing macroporous adsorption resins of the present application, cadmium ions can be suitably removed from the cobalt solution, and the cobalt solution can be purified.

[0071] Hereinafter, the embodiments of the present application will be further described using several embodiments.

[0072] Example 1 A method for removing cadmium impurity ions from a cobalt sulfate solution comprises the following steps: Step 1: Prepare 1000 mL of cobalt sulfate solution. The concentration of cobalt ions is 80 g / L and the concentration of cadmium ions is 0.2 g / L. Step 2: Pretreating the adsorption resin. Here, the adsorption resin is a weakly acidic thioureido- or isothioureido-containing macroporous adsorption resin of styrene-divinylbenzene copolymer. The pretreatment process is as follows: First, the adsorption resin to be treated is immersed in saturated saline solution with a volume approximately twice the volume of the adsorption resin for 18 to 20 hours, and then washed with clean water until the discharge water is no longer yellow. Next, the adsorption resin is immersed in a 5 wt% hydrochloric acid solution for 4 to 8 hours, and then washed with clean water until the adsorption resin is close to neutral. Finally, the adsorption resin is immersed in a 2% to 4% sodium hydroxide solution for 4 to 8 hours, and then washed with clean water until the adsorption resin is neutral enough for use.

[0073] Step 3: The adsorption resin pretreated in Step 2 is mixed with the cobalt sulfate solution in a volume ratio of 1:10 to obtain a mixed solution. The pH of the mixed solution is 2.0 to 5.0, and the mixed solution is stirred at room temperature for 2 hours to perform static adsorption, yielding a purified cobalt sulfate solution.

[0074] The purified cobalt sulfate solution obtained in step 3 is evaluated. The cadmium ion concentration is 0.98 ppb, and the cadmium removal rate reaches 99.9%.

[0075] Example 2 A method for removing cadmium impurity ions from a cobalt sulfate solution comprises the following steps: Step 1: Prepare 1000 mL of cobalt sulfate solution. The concentration of cobalt ions is 100 g / L, and the concentration of cadmium ions is 0.48 g / L. Step 2: Pretreating the adsorption resin. The adsorption resin is a weakly acidic thioureido- or isothioureido-containing macroporous adsorption resin of styrene-divinylbenzene copolymer. The pretreatment process is the same as in Example 1. Step 3: 100 mL of the pretreated adsorption resin was packed into a column and subjected to dynamic adsorption with cobalt sulfate solution for 1 hour. The pH of the effluent was between 3.0 and 5.0, and the total adsorption duration was 10 hours.

[0076] The purified cobalt sulfate solution obtained in step 3 is evaluated. The cadmium ion concentration is 1.6 ppb, and the cadmium removal rate reaches 99.9%.

[0077] Example 3 A method for removing cadmium impurity ions from a cobalt sulfate solution comprises the following steps: Step 1: Prepare 1000 mL of cobalt sulfate solution. The concentration of cobalt ions is 50 g / L and the concentration of cadmium ions is 0.06 g / L. Step 2: Pretreating the adsorption resin. The adsorption resin is a weakly acidic thioureido- or isothioureido-containing macroporous adsorption resin of styrene-divinylbenzene copolymer. The pretreatment process is the same as in Example 1. Step 3: Mix the pretreated adsorption resin from Step 2 with the cobalt sulfate solution in a volume ratio of 1:5 to obtain a mixed solution. The pH of the mixed solution is 3.0 to 5.0, and the mixed solution is stirred at room temperature for 3 hours to perform static adsorption, yielding a purified cobalt sulfate solution.

[0078] The purified cobalt sulfate solution obtained in step 3 is evaluated. The concentration of cadmium ions is 0.72 ppb, and the cadmium removal rate reaches 99.9%.

[0079] Example 4 A method for removing cadmium impurity ions from a cobalt sulfate solution comprises the following steps: Step 1: Prepare 5000 mL of cobalt sulfate solution. The concentration of cobalt ions is 80 g / L and the concentration of cadmium ions is 0.5 g / L. Step 2: Pretreating the adsorption resin. The adsorption resin is a weakly acidic thioureido- or isothioureido-containing macroporous adsorption resin of styrene-divinylbenzene copolymer. The pretreatment process is the same as in Example 1. Step 3: 100 mL of the pretreated adsorption resin in Step 2 was packed into a column, and dynamic adsorption was performed on the cobalt sulfate solution for a contact time of 2 hours. The effluent was collected every hour. The pH value of the effluent was between 3.0 and 5.0, and the total adsorption time was 100 hours.

[0080] The purified cobalt sulfate solution obtained in step 3 is evaluated. The concentration of cadmium ions is 1.0 ppb, and the cadmium removal rate reaches 99.9%.

[0081] (Comparative Example 1) A method for removing cadmium impurity ions from a cobalt sulfate solution comprises the following steps: Step 1: Prepare 1000 mL of cobalt sulfate solution. The concentration of cobalt ions is 30 g / L and the concentration of cadmium ions is 0.18 g / L. Step 2: Pretreating the adsorption resin. The pretreatment procedure is the same as in Example 1. The adsorption resin is a macroporous styrene-divinylbenzene copolymer adsorption resin with iminodiacetic acid functional groups, such as Hangzhou Zhengguang resin D851. Step 3: Mix the pretreated adsorption resin from Step 2 with the cobalt sulfate solution in a volume ratio of 1:6 to obtain a mixed solution. The pH of the mixed solution is 2.0 to 5.0. The mixed solution is stirred at room temperature and adsorption is carried out for 2 hours to obtain a purified cobalt sulfate solution.

[0082] The purified cobalt sulfate solution obtained in step 3 is evaluated. The cadmium ion concentration is 135 ppm, and the cadmium removal rate is 25%.

[0083] (Comparative Example 2) A method for removing cadmium impurity ions from a cobalt sulfate solution comprises the following steps: Step 1: Prepare 5000 mL of cobalt sulfate solution. The concentration of cobalt ions is 80 g / L and the concentration of cadmium ions is 0.2 g / L. Step 2: Pretreating the Strongly Acidic Resin The pretreatment procedure is the same as in Example 1. The resin is a typical 001x7 (732) strongly acidic styrene cation exchange resin, which has sulfonic acid groups in a styrene-divinylbenzene copolymer. Step 3: 100 mL of the pretreated strong acid resin was packed into a column and subjected to dynamic adsorption with the cobalt sulfate solution for a contact time of 2 hours. The pH of the effluent was between 3.0 and 5.0, and the total adsorption time was 25 hours.

[0084] The purified cobalt sulfate solution obtained in step 3 is evaluated. The cadmium ion concentration is 0.15 g / L, and the cadmium removal rate is 25%.

[0085] As can be seen from Examples 1 to 4 and Comparative Examples 1 and 2, in the present application, cadmium ions are removed from acidic cobalt solutions using a thioureido- or isothioureido-containing macroporous adsorption resin of styrene-divinylbenzene copolymer. Through a simple adsorption process, cadmium ions can be selectively removed from cobalt solutions containing cadmium ions, with a high cadmium removal rate. Even in cobalt solutions with high cobalt ion concentrations, the cadmium ion concentration can be reduced to the ppb level. However, the resins of Comparative Examples 1 and 2 have poor selective cadmium removal performance.

[0086] It should be understood that the terms "first," "second," and various numerals used herein are merely used for distinction purposes to facilitate explanation and are not intended to limit the scope of the present application.

[0087] In this application, "and / or" represents an associative relationship between related objects and indicates that three relationships may exist. For example, A and / or B may represent the presence of only A, the presence of both A and B, and the presence of only B, where A and B may be singular or plural. The character " / " generally indicates an "or" relationship between related objects.

[0088] As used herein, "at least one" means one or more, and "plurality" means two or more. "At least one of the following items" or similar expressions means any combination of those items, including any combination of a single item or multiple items. For example, "at least one of a, b, or c" or "at least one of a, b, and c" refers to a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c may be singular or plural.

[0089] It should be understood that the sequence numbers of the above processes do not refer to the order of implementation in various embodiments of the present application. Some or all of the steps may be implemented in parallel or sequentially. The order of implementation of the processes should be determined based on the functions and internal logic of the processes, and should not be construed as any limitation on the implementation process of the embodiments of the present application.

Claims

1. 1. A method for removing impurities from a cobalt solution, comprising: Packing a column with an adsorption resin, and passing a cobalt solution through the column to adsorb cadmium ions from the cobalt solution onto the resin; or adding an adsorption resin to the cobalt solution for static adsorption, and adsorbing cadmium ions from the cobalt solution onto the resin; and the cobalt solution is an acidic cobalt solution and contains the cadmium ions; The method wherein the adsorption resin is a thioureido- or isothioureido-containing adsorption resin.

2. 10. The method of claim 1, wherein the adsorption resin is a thioureido- or isothioureido-containing macroporous adsorption resin of a styrene-divinylbenzene copolymer.

3. The adsorption resin is a spherical particle, and the specific surface area is 500 m 2 / g to 1500m 2 3. The method of claim 1, wherein the average pore size is from 0.3 mm to 1.5 mm.

4. The method according to any one of claims 1 to 3, wherein the adsorption resin has a volume exchange capacity of 1.0 mmol / mL or more and a water content of 40% to 60%.

5. 5. The method of claim 1, wherein the acidic cobalt solution containing cadmium ions comprises a cobalt sulfate solution containing cadmium ions, a cobalt chloride solution containing cadmium ions, a cobalt nitrate solution containing cadmium ions, or a cobalt acetate solution containing cadmium ions.

6. 6. The method according to claim 1, wherein in the acidic cobalt solution containing cadmium ions, the concentration of cobalt ions is 1 g / L to 100 g / L and the concentration of cadmium ions is 5.0 g / L or less.

7. 7. The method according to claim 1, wherein the pH of the effluent after passing through the column is 2.0 to 5.0, and the pH of the mixed solution obtained by adding the adsorption resin to the cobalt solution is 2.0 to 5.

0.

8. 8. The method according to claim 1, wherein the contact time of the cobalt solution passing through the column is controlled to be at least one hour.

9. The operating temperature during passage through the column is between 10°C and 30°C; 9. The method according to any one of claims 1 to 8, wherein the operating temperature of the static adsorption is from 10°C to 30°C.

10. 10. The method according to claim 1, wherein a stirring or agitation operation is carried out during the static adsorption.

11. Before using the adsorption resin to adsorb cadmium ions, the adsorption resin is first pretreated, and the pretreatment includes: soaking the adsorption resin in saturated saline for 18 to 20 hours and washing the adsorption resin with water until the effluent is no longer yellow; Next, immersing the adsorption resin in a dilute hydrochloric acid solution for 4 to 8 hours, and then washing the adsorption resin with water until the adsorption resin becomes approximately neutral; Finally, immersing the adsorption resin in a 2% to 4% by weight sodium hydroxide solution for 4 to 8 hours and washing the adsorption resin with water until the adsorption resin is neutral for use; 11. The method according to claim 1, comprising:

12. 12. The method according to claim 1, wherein a concentration ratio of cobalt ions to cadmium ions after subjecting the acidic cobalt solution containing cadmium ions to a cadmium removal treatment using the adsorption resin is (10,000 to 3,000,000):

1.

13. 13. The method according to claim 1, wherein the cadmium ion concentration after the acidic cobalt solution containing cadmium ions is subjected to a cadmium removal treatment using the adsorption resin is less than 10 ppb.

14. 14. The method according to claim 1, wherein the cadmium removal rate of the adsorption resin for the acidic cobalt solution containing cadmium ions is 99% or more.

15. 15. The method of any one of claims 1 to 14, wherein the cobalt solution comprises an acid cobalt electroplating solution in an advanced process node or a battery grade acid cobalt solution.

16. Further, after the adsorption resin is saturated, a step of regenerating the adsorption resin is included. The regenerating step includes: immersing the adsorption resin in a dilute hydrochloric acid solution for 4 to 8 hours and washing the adsorption resin until the adsorption resin is nearly neutral; Thereafter, the adsorption resin is immersed in a 2% to 4% by weight sodium hydroxide solution for 4 to 8 hours and washed until the adsorption resin is neutral for use; 16. The method according to any one of claims 1 to 15, comprising:

17. 1. Use of an adsorption resin in removing cadmium ions from a solution, comprising: the adsorption resin is a thioureido- or isothioureido-containing adsorption resin; The adsorption resin is used to remove cadmium ions from a solution containing cadmium ions.

18. 18. The use according to claim 17, wherein the adsorption resin is a thioureido- or isothioureido-containing macroporous adsorption resin of styrene-divinylbenzene copolymer.

19. The adsorption resin is 500 m 2 / g to 1500m 2 19. The use according to claim 17 or 18, wherein the specific surface area is 0.3 mm to 1.5 mm / g and the average pore size is 0.3 mm to 1.5 mm.

20. 20. The use according to any one of claims 17 to 19, wherein the solution containing cadmium ions comprises an acidic cobalt solution containing cadmium ions, a nickel sulfate solution containing cadmium ions, a ferric sulfate solution containing cadmium ions, a ferrous sulfate solution containing cadmium ions, a calcium chloride solution containing cadmium ions, a magnesium chloride solution containing cadmium ions, or a sodium chloride solution containing cadmium ions.

21. The method of use comprises: Packing an adsorption resin into a column, passing the solution containing the cadmium ions through the column, and adsorbing the cadmium ions onto the resin; or For static adsorption, adding the adsorption resin to a solution containing the cadmium ions to adsorb the cadmium ions onto the resin.

21. The use according to any one of claims 17 to 20, wherein

22. The use according to claim 21, wherein the pH of the effluent after passing through the column is 2.0 to 5.0, and the pH of the mixed solution obtained by adding the adsorption resin to the solution containing cadmium ions is 2.0 to 5.

0.

23. 23. The use according to claim 21 or 22, wherein the contact time during which the solution containing cadmium ions passes through the column is controlled to be at least 1 hour.

24. 24. The use according to any one of claims 21 to 23, wherein the operating temperature for passing through the column is between 10°C and 30°C, and the operating temperature for static adsorption is between 10°C and 30°C.

25. 25. The use according to any one of claims 21 to 24, wherein a stirring or agitation operation is carried out during the static adsorption.

26. 26. The use of any one of claims 17 to 25, wherein the sorbent resin is used to remove cadmium ions from acid cobalt electroplating solutions in advanced process nodes, or is used to remove cadmium ions from battery grade acid cobalt solutions, or is used to remove micro or trace amounts of cadmium ions from nickel sulfate solutions, ferric sulfate solutions, ferrous sulfate solutions, calcium chloride solutions, magnesium chloride solutions, or sodium chloride solutions.

27. A cobalt solution obtained after impurities have been removed by using the method for removing impurities according to any one of claims 1 to 16, or a cobalt solution obtained through the use according to any one of claims 17 to 26, A cobalt solution, wherein the concentration of cadmium ions in the cobalt solution is less than 10 ppb.

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