Preparation process of 6N high-purity nickel

Abstract

The invention relates to the technical field of nickel solution impurity removal, in particular to a preparation process of 6N high-purity nickel. The preparation process of the 6N high-purity nickel comprises the following preparation steps: (1) adding a metal extractant microcapsule into a nickel chloride coarse solution, adjusting the pH value, stirring at 20-40 DEG C for 0.5-1 hour, and filtering to obtain a nickel chloride primary treatment solution; (2) adjusting the pH value of the nickel chloride primary treatment liquid obtained in the step (1) again, enabling the nickel chloride primary treatment liquid to pass through a functionalized hierarchical pore adsorption chelating resin column at 20-40 DEG C, and controlling the flow rate to obtain a high-purity nickel chloride solution; and (3) filling the high-purity nickel chloride solution obtained in the step (2) into an electrolytic bath, and carrying out direct-current electrolysis to obtain 6N high-purity nickel on a negative plate. According to the preparation process, various impurity ions in the nickel chloride solution can be effectively removed, and the 6N high-purity nickel meeting the standard is obtained.

Description

Technical Field

[0001] The invention relates to the technical field of high-purity nickel preparation, and in particular to a preparation process of 6N high-purity nickel. Background Art

[0002] Sputtering targets have a wide range of applications, mainly in the electronics and information industry, glass coating field, wear-resistant materials, high-temperature corrosion resistance, high-end decorative products and other industries. High chemical purity is the basis of the quality of sputtering targets. High-purity sputtering targets can significantly reduce the impact of impurities on the film layer and ensure that the film layer has excellent physical and chemical properties. This requires that the metal solution used to make the sputtering target must meet the requirements of the sputtering target. At present, the methods for removing other metal ion impurities in metal solutions are mainly chemical precipitation and solvent extraction. The chemical precipitation method generally relies on the addition of specified agents and calcium, magnesium, etc. to form a precipitate and then separate and remove it. This method has a good impurity removal effect, but other impurity ions will be introduced during the impurity removal process, which is not conducive to the subsequent use of metal solutions for sputtering target production, and the target metal in the metal solution will be lost when the precipitated slag is separated. The solvent extraction method has the advantages of high selectivity, high recovery rate, simple process and continuous operation. Commonly used extractants include P507, C272 and N235. However, there are problems such as the extractant structure is easily destroyed, the extraction effect is not ideal, and some metal ions cannot be effectively removed.

[0003] Patent CN 114058845 A discloses a method for combined extraction of P204 and N235 in nickel chloride solution. The extraction method of the invention comprises the following steps: first adjusting the pH of the nickel chloride solution to 3.5-4; mixing and saponifying a certain proportion of P204 and sulfonated kerosene, adding the obtained saponified organic phase to the nickel chloride solution for extraction to obtain a first raffinate; then mixing and acidifying a certain proportion of N235, isooctyl alcohol and sulfonated kerosene, adding the obtained acidified organic phase to the first raffinate for extraction to obtain a second raffinate. Although this method has a good removal effect on a variety of impurity metal ions and can avoid the problem of the performance of the N235 extractant being destroyed due to "zinc poisoning", the extractant used is relatively large, and the extraction temperature needs to be controlled at 40-50°C, the operation is not simple enough, and the cost is relatively high.

[0004] In summary, there are still many problems in the existing methods of purifying metal salt solutions for sputtering targets. In order to solve the above technical problems, a method for purifying nickel solutions using an extraction method is developed. While effectively removing a variety of impurity ions, it can also simplify operations and reduce production costs, which is of great significance to process production and social development. Summary of the invention

[0005] In order to solve the above-mentioned technical problems, the present invention provides a preparation process of 6N high-purity nickel, which can effectively remove various impurity ions in the nickel chloride solution to obtain a high-purity nickel chloride solution, and then obtain 6N high-purity nickel with extremely low impurity content by electrolysis. The operation is simple and the production cost is reduced to a certain extent.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] The present invention provides a preparation process of 6N high-purity nickel, comprising the following preparation steps:

[0008] (1) adding metal extractant microcapsules to a crude nickel chloride solution, adjusting the pH, stirring at 20-40° C. for 0.5-1 h, and filtering to obtain a nickel chloride primary treatment solution;

[0009] (2) adjusting the pH of the nickel chloride primary treatment solution of step (1) again, passing it through a functionalized multi-stage pore adsorption chelating resin column at 20-40° C., controlling the flow rate, and obtaining a high-purity nickel chloride solution;

[0010] (3) The high-purity nickel chloride solution of step (2) is loaded into an electrolytic cell and subjected to direct current electrolysis to obtain 6N high-purity nickel on the cathode plate.

[0011] In some embodiments, the concentration of each metal ion in the crude nickel chloride solution is: nickel ion concentration ≤250g / L, cobalt ion concentration ≤4g / L, copper ion concentration ≤1.5g / L, iron ion concentration ≤1g / L, zinc ion concentration ≤1g / L, chromium ion concentration ≤1g / L, manganese ion concentration ≤1g / L, magnesium ion concentration ≤1g / L, and lead ion concentration ≤1g / L.

[0012] In some embodiments, the metal extractant microcapsules are used in an amount of 0.1-4.5 wt % of the crude nickel chloride solution.

[0013] In some embodiments, the pH in step (1) is adjusted to 3-4.5.

[0014] In some embodiments, the pore size of the filtration membrane is ≤20 μm.

[0015] In some embodiments, the pH in step (2) is adjusted to 2-4.

[0016] In some embodiments, the amount of the functionalized multi-level pore adsorption chelating resin in the functionalized multi-level pore adsorption chelating resin column is 1-10 wt % of the crude nickel chloride solution.

[0017] In some embodiments, the temperature of the high-purity nickel chloride solution during direct current electrolysis is ≥40°C, the center distance between the anode plate and the cathode plate in the electrolytic cell is 10-20 cm, and the current is 80-120 A / m 2 .

[0018] Preferably, the temperature of the high-purity nickel chloride solution during direct current electrolysis is 55°C, the center distance between the anode plate and the cathode plate in the electrolytic cell is 15 cm, and the current is 100 A / m 2 .

[0019] In the present invention, the usage amount of the metal extractant microcapsule and the functionalized multi-level porous adsorption chelating resin can be selected according to the concentration of different impurity ions in the crude nickel chloride solution.

[0020] In some embodiments, the method for preparing the functionalized multi-level porous adsorption chelating resin comprises the following preparation steps:

[0021] S1. Styrene, divinylbenzene and vinyl acetic acid were mixed uniformly, an initiator was added thereto, and the mixture was stirred until the initiator was completely dissolved, and then poured into pure water, and the mixture was reacted under stirring and heating conditions for 6-10h, and then separated, washed and dried to obtain a white solid;

[0022] S2. At room temperature, the white solid obtained in step S1 is added to C2H4Cl2, stirred and swollen for 10-14 hours, and then p-dichlorobenzyl and anhydrous tin tetrachloride are added thereto in sequence, stirred for 25-40 minutes, reacted at 75-85°C for 20-24 hours, separated, washed, and dried to obtain a multi-level porous adsorption resin;

[0023] S3. Add the multi-level porous adsorption resin and coupling agent obtained in step S2 into toluene and mix evenly, then add the functional monomer, heat to 100-120°C and react for 1-4h, then cool to room temperature, separate, wash and dry to obtain a functionalized multi-level porous adsorption chelating resin.

[0024] In some embodiments, the molar ratio of styrene, divinylbenzene and vinyl acetic acid is 1:(0.01-0.02):(0.05-0.15).

[0025] In some embodiments, the heating temperature in step (1) is 85-95°C.

[0026] Preferably, the heating temperature in step (1) is 90°C.

[0027] In some embodiments, the mass ratio of the white solid, p-benzyl dichloride and anhydrous tin tetrachloride in step (2) is 1:(0.9-1.1):(0.9-1.1).

[0028] Preferably, in step (2), the mass ratio of the white solid, p-benzyl dichloride and anhydrous tin tetrachloride is 1:1.05:1.05.

[0029] In some embodiments, the preparation steps of the functional monomer are:

[0030] Mix hydroxylamine hydrochloride, DL-aminocaprolactam and toluene evenly, react at 85-95° C. for 2-4 hours with stirring, separate and dry to obtain a functional monomer.

[0031] In some embodiments, the molar ratio of hydroxylamine hydrochloride to DL-aminocaprolactam is (1-1.3):1.

[0032] Preferably, the molar ratio of hydroxylamine hydrochloride to DL-aminocaprolactam is 1.15:1.

[0033] In some embodiments, the amount of the functional monomer in step (3) is 10-20 wt % of the multi-level porous adsorption resin.

[0034] Preferably, the amount of the functional monomer used in step (3) is 15 wt % of the multi-level porous adsorption resin.

[0035] In some embodiments, the flow rate is 5-10 L / h.

[0036] In some embodiments, the method for preparing the metal extractant microcapsules comprises the following preparation steps:

[0037] (1) Ethyl acrylate, methacrylamide, 2-acrylamido-2-methylpropanesulfonic acid sodium salt, a crosslinking agent, and an initiator are uniformly mixed, and the emulsifier mixture is added dropwise under stirring conditions, ultrasonicated, and irradiated with ultraviolet light for 10-20 minutes under stirring conditions, and then washed with pure water, separated, and dried to obtain hollow microcapsules;

[0038] (2) evacuating the hollow microcapsules obtained in step (1), adding a metal chelating agent, ultrasonically treating for 5-10 hours, filtering, and washing to obtain metal extractant microcapsules;

[0039] In some embodiments, the emulsifier mixture is obtained by adding emulsifier and talcum powder into pure water.

[0040] Preferably, the emulsifier is one or more of sodium ethylenediamine ethanesulfonate, sodium dodecyl diphenyl ether disulfonate, and dodecylbenzene sulfonate; and the amount of the emulsifier added is 2-4.5wt% of pure water.

[0041] In some embodiments, the emulsifier mixture contains 2-5 wt % talc.

[0042] Preferably, the emulsifier mixture contains 3 wt% talc;

[0043] Further preferably, the fineness of the talc powder is 1250-2500 mesh.

[0044] The structural formula of the metal chelator is:

[0045]

[0046] In some embodiments, the preparation steps of the metal chelator are:

[0047] (1) dissolving dibutanolamine in anhydrous ethanol, adding carbon disulfide, reacting for 5-8 hours at 0-5° C. in a nitrogen atmosphere, adjusting the pH to neutral with an aqueous sodium hydroxide solution, and rotary evaporating to obtain sodium di(4-hydroxybutyl)dithiocarbamate;

[0048] (2) Add 4-[bis(β-chloroethyl)amino]benzaldehyde, sodium di(4-hydroxybutyl)dithiocarbamate obtained in step (1) and potassium iodide to anhydrous ethanol, heat to reflux, remove anhydrous ethanol under reduced pressure, add the obtained solid to pure water and stir, extract and combine the organic phases, dry the water in the organic phases, concentrate, let stand for 10-20 hours, separate, and obtain a metal chelating agent.

[0049] The metal extractant microcapsules of the present invention can also be made into a structure similar to a resin column to extract the crude nickel chloride solution.

[0050] In the present invention, a crude nickel chloride solution is first purified by metal extractant microcapsules, and then purified by functionalized multi-level pore adsorption chelating resin for secondary purification, and the obtained high-purity nickel chloride solution is electrolyzed to obtain 6N high-purity nickel with extremely low impurity content. The metal extractant microcapsules and functionalized multi-level pore adsorption chelating resin used in the present invention have good adsorption capacity for various metal ions. During the purification process, the metal extractant microcapsules and functionalized multi-level pore adsorption chelating resin can have a low adsorption amount for nickel and maintain high adsorption capacity for other impurity metal ions other than nickel, especially cobalt ions and copper ions, by regulating the pH of the nickel chloride solution at 20-40° C., so that they can be better separated from nickel to obtain a high-purity nickel chloride solution, which is beneficial to improving the purity of nickel. In addition, after the metal extractant microcapsules of the present invention adsorb the solution, the microcapsules can be recovered by filtration, and the metal ions can be eluted from the microcapsules by a cleaning technology. The cleaned metal extractant microcapsules can be reused, and the functionalized multi-level porous adsorption chelating resin can also be reused after cleaning, which can greatly reduce production costs and improve resource utilization.

[0051] The metal extractant microcapsules used in the present invention are obtained by polymerizing a certain proportion of ethyl acrylate, methacrylamide, and 2-acrylamide-2-methylpropanesulfonic acid sodium salt to form hollow microcapsules through process control, and then loading a metal chelating agent in the hollow structure of the microcapsules through ultrasound. The metal extractant microcapsules have strong adsorption capacity for different metal ions and can be recycled, which can greatly reduce production costs and improve resource utilization. The metal chelating agent used in the microcapsules contains more hydroxyl groups, which can improve the performance of the metal chelating agent to a certain extent. The hydroxybutyl groups in the structure are symmetrically distributed, and the symmetry of the metal chelating agent molecules is higher, and it is easier to combine with metal ions to form symmetrical chelate rings, thereby improving the stability of the chelate. However, in the preparation process of microcapsules, the problem of unstable system after the oil phase and the water phase are mixed may occur. In the present invention, one or more of sodium ethylenediamine ethanesulfonate, sodium dodecyl diphenyl ether disulfonate, and dodecylbenzene sulfonate are selected as emulsifiers, and talcum powder with a certain fineness is added to improve the dispersibility of oil phase droplets in the water phase. The talcum powder can be evenly and stably dispersed in the emulsion, which can not only form a protective film with a screen structure, but also selectively restrict the movement of the oil phase in the mixed system, which is beneficial to promoting the formation of microcapsules and the uniformity of particle size, thereby improving the subsequent encapsulation rate of the microcapsules for metal chelating agents; in addition, the emulsifier and talcum powder are combined with the surface of talcum powder particles in the form of adsorption or chemical bonds, so that the surface of the particles changes from hydrophobic to hydrophilic, thereby improving the compatibility of talcum powder particles with the water phase, and facilitating the formation of microcapsules and the improvement of mechanical properties.

[0052] In addition, the functionalized multi-level porous adsorption chelating resin used in the present invention is prepared by synthesizing a carboxylated resin using styrene, divinylbenzene and vinylacetic acid as raw materials, and then introducing a hydroxamic acid functional monomer generated by a chemical reaction between hydroxylamine hydrochloride and DL-aminocaprolactam into the carboxylated resin. The functionalized multi-level porous adsorption chelating resin has a hydroxamic acid functional group and an acylamino functional group, can chelate metal ions well, and the hydrophobic group in the hydroxamic acid can effectively reduce the interfacial tension between the resin and the heavy metal ions, thereby improving the adsorption performance of the chelating resin for heavy metal ions.

[0053] Compared with the prior art, the present invention has the following beneficial effects:

[0054] 1. In the present invention, the nickel chloride crude solution is first purified by metal extractant microcapsules, and then purified by functionalized multi-level pore adsorption chelating resin for secondary purification, and the obtained high-purity nickel chloride solution is electrolyzed to obtain 6N high-purity nickel with extremely low impurity content. Different metal ions can be removed differently by adjusting the pH of the solution, and various impurity removal needs can be met. The metal extractant microcapsules and functionalized multi-level pore adsorption chelating resin used can be used repeatedly, which greatly reduces production costs and improves resource utilization.

[0055] 2. The metal extractant microcapsules prepared in the present invention have a strong adsorption capacity for different metal ions. The structure contains more hydroxyl groups, which can improve the performance of the metal chelator to a certain extent. The hydroxybutyl groups in the structure are symmetrically distributed, and the metal chelator molecules have a higher symmetry, which makes it easier to combine with metal ions to form a symmetrical chelate ring, thereby improving the stability of the chelate.

[0056] 3. The functionalized multi-level porous adsorption chelating resin used in the present invention has hydroxamic acid functional groups and acylamino functional groups, which can chelate metal ions well, and the hydrophobic group in the hydroxamic acid can effectively reduce the interfacial tension between the resin and the heavy metal ions, thereby improving the adsorption performance of the chelating resin for heavy metal ions. DETAILED DESCRIPTION

[0057] Now describe in detail various exemplary embodiments of the present invention, this detailed description should not be considered as limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present invention. It should be understood that the terms described in the present invention are only for describing a particular embodiment, and are not used to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper limit and the lower limit of the range is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the range.

[0058] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. Various modifications and variations may be made to the specific embodiments of the present invention specification without departing from the scope or spirit of the present invention, which will be apparent to those skilled in the art. Other embodiments obtained from the present invention specification will be apparent to the technician. The present application specification and examples are exemplary only.

[0059] The words “include,” “including,” “have,” or “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0060] The initiator used in Preparation Example 1 of the present invention is photosensitizer 651; the initiator used in Preparation Example 2 is initiator TPO; the coupling agent used is N,N-carbonyldiimidazole; the pore size of the filter membrane used is 10 μm; and the fineness of the talc used is 2000 mesh.

[0061] The concentrations of the metal ions in the crude nickel chloride solution used in the embodiment of the present invention are: nickel ion concentration is 200 g / L, cobalt ion concentration is 2.5 g / L, copper ion concentration is 0.5 g / L, iron ion concentration is 0.1 g / L, zinc ion concentration is 0.05 g / L, chromium ion concentration is 0.05 g / L, manganese ion concentration is 0.5 g / L, magnesium ion concentration is 0.5 g / L, and lead ion concentration is 0.5 g / L.

[0062] Preparation Example 1

[0063] The preparation method of metal extractant microcapsules comprises the following preparation steps:

[0064] (1) 0.1 mol of ethyl acrylate, 0.2 mol of methacrylamide, 0.175 mol of 2-acrylamido-2-methylpropanesulfonic acid sodium salt, 11.40 g of a crosslinking agent, and 3.04 g of an initiator were uniformly mixed, 326 mL of an emulsifier mixture was added dropwise under a stirring condition of 150 r / min, ultrasonicated at 40 kHz for 15 min, irradiated with a 2000 W ultraviolet lamp at a distance of 15 cm for 10 min under a stirring condition of 150 r / min, washed with pure water three times, filtered, and vacuum dried to obtain hollow microcapsules;

[0065] (2) 39 g of the hollow microcapsules obtained in step (1) were evacuated, 20 g of a metal chelating agent was added, ultrasonic treatment was performed at 20 kHz for 8 h, filtration was performed, and the microcapsules were washed with pure water for 3 times to obtain metal extractant microcapsules.

[0066] Preparation of the cross-linking agent used: 1,4-butanediol dimethacrylate and hexanediol dimethacrylate in a mass ratio of 28:1 were mixed evenly to obtain a cross-linking agent;

[0067] The preparation steps of the emulsifier mixture used are as follows: 2 g of sodium ethylenediamine ethanesulfonate, 1.5 g of sodium dodecyl diphenyl ether disulfonate and 3.105 g of talc are added into 100 g of pure water and stirred evenly to obtain an emulsifier mixture;

[0068] Preparation of metal chelating agents used:

[0069] (1) Dissolve 1 mol of dibutanolamine in 500 mL of anhydrous ethanol, add 1.1 mol of carbon disulfide, react for 6 h at 0° C. in a nitrogen atmosphere, adjust the pH to neutral with a 2 mol / L sodium hydroxide aqueous solution, and perform rotary evaporation to obtain sodium di(4-hydroxybutyl)dithiocarbamate;

[0070] (2) 0.1 mol of 4-[bis(β-chloroethyl)amino]benzaldehyde, 0.235 mol of sodium di(4-hydroxybutyl)dithiocarbamate obtained in step (1) and 4.19 mmol of potassium iodide were added to 500 mL of anhydrous ethanol, and the mixture was heated under reflux at 90° C. for 25 h. The anhydrous ethanol was removed under reduced pressure, and the obtained solid was added to 500 mL of pure water and stirred. The mixture was then extracted three times with 250 mL of dichloromethane, and the organic phases were combined. 15 g of sodium sulfate was added to dry the water in the organic phase, and the mixture was concentrated to 50 mL. The mixture was allowed to stand for 20 h and filtered to obtain a metal chelating agent.

[0071] Preparation Example 2

[0072] The preparation method of the functionalized multi-level porous adsorption chelating resin comprises the following preparation steps:

[0073] S1. 1 mol of styrene, 0.015 mol of divinylbenzene and 0.1 mol of vinyl acetic acid were mixed uniformly, 0.04 mol of initiator was added thereto, and the mixture was stirred at a stirring speed of 200 r / min until the initiator was completely dissolved, and then poured into 250 mL of pure water, and reacted at 200 r / min and 90°C for 12 h, filtered, washed with pure water 3 times, and dried at 65°C to constant weight to obtain a white solid;

[0074] S2. At room temperature, 60 g of the white solid obtained in step S1 was added to 500 mL of C2H4Cl2, stirred and swollen for 12 h, and then 63 g of p-dichlorobenzyl and 63 g of anhydrous tin tetrachloride were added thereto in sequence, stirred for 35 min, reacted at 80 ° C for 22 h, filtered, washed with pure water 3 times, and dried at 65 ° C to constant weight to obtain a multi-level porous adsorption resin;

[0075] S3. Add 50g of the multi-level porous adsorption resin obtained in step S2 and 14g of the coupling agent into 200mL of toluene and mix evenly, then add 7.5g of the functional monomer, heat to 110°C and react for 2.5h, then cool to room temperature, filter, wash with anhydrous ethanol and pure water for 3 times respectively, and dry at 65°C to constant weight to obtain a functionalized multi-level porous adsorption chelating resin.

[0076] Preparation of the functional monomer used: 1.15 mol of hydroxylamine hydrochloride, 1 mol of DL-aminocaprolactam and 500 mL of toluene were mixed evenly, reacted at a stirring speed of 150 r / min and 90° C. for 3 h, filtered, and dried at 60° C. to constant weight to obtain a functional monomer.

[0077] Preparation Example 3

[0078] The preparation method of the metal extractant microcapsules is the same as that of Preparation Example 1, except that no talc is added to the 326 mL of the emulsifier mixture.

[0079] Example 1

[0080] A preparation process for 6N high-purity nickel comprises the following preparation steps:

[0081] (1) adding 40 g of metal extractant microcapsules to 2 kg of nickel chloride crude solution, adjusting the pH to 4.5, stirring at 20° C. for 0.5 h, and filtering to obtain a nickel chloride primary treatment solution;

[0082] (2) adjusting the pH of the nickel chloride primary treatment solution of step (1) to 4 again, passing it through a functionalized multi-stage pore adsorption chelating resin column at 20° C., controlling the flow rate to 5 L / h, to obtain a high-purity nickel chloride solution;

[0083] (3) The high-purity nickel chloride solution of step (2) is loaded into an electrolytic cell and subjected to direct current electrolysis to obtain 6N high-purity nickel on the cathode plate.

[0084] The metal extractant microcapsules used were obtained from Preparation Example 1;

[0085] Preparation of functionalized multi-stage porous adsorption chelating resin column: 100 g of the functionalized multi-stage porous adsorption chelating resin of Preparation Example 2 was filled into a glass adsorption column with an inner diameter of 10 mm and a height of 300 mm to obtain a functionalized multi-stage porous adsorption chelating resin column.

[0086] Example 2

[0087] A preparation process for 6N high-purity nickel comprises the following preparation steps:

[0088] (1) adding 40 g of metal extractant microcapsules to 2 kg of a crude nickel chloride solution, adjusting the pH to 3, stirring at 40° C. for 1 h, and filtering to obtain a nickel chloride primary treatment solution;

[0089] (2) adjusting the pH of the nickel chloride primary treatment solution of step (1) to 2 again, passing it through a functionalized multi-stage pore adsorption chelating resin column at 40° C., controlling the flow rate to 10 L / h, to obtain a high-purity nickel chloride solution;

[0090] (3) The high-purity nickel chloride solution of step (2) is loaded into an electrolytic cell and subjected to direct current electrolysis to obtain 6N high-purity nickel on the cathode plate.

[0091] The metal extractant microcapsules used were obtained from Preparation Example 1;

[0092] Preparation of functionalized multi-stage porous adsorption chelating resin column: 100 g of the functionalized multi-stage porous adsorption chelating resin of Preparation Example 2 was filled into a glass adsorption column with an inner diameter of 10 mm and a height of 300 mm to obtain a functionalized multi-stage porous adsorption chelating resin column.

[0093] Example 3

[0094] A preparation process for 6N high-purity nickel comprises the following preparation steps:

[0095] (1) adding 40 g of metal extractant microcapsules to 2 kg of a crude nickel chloride solution, adjusting the pH to 4, stirring at 30° C. for 0.5 h, and filtering to obtain a nickel chloride primary treatment solution;

[0096] (2) adjusting the pH of the nickel chloride primary treatment solution of step (1) to 3.5 again, passing it through a functionalized multi-stage pore adsorption chelating resin column at 30° C., controlling the flow rate to 7 L / h, to obtain a high-purity nickel chloride solution;

[0097] (3) The high-purity nickel chloride solution of step (2) is loaded into an electrolytic cell and subjected to direct current electrolysis to obtain 6N high-purity nickel on the cathode plate.

[0098] The metal extractant microcapsules used were obtained from Preparation Example 1;

[0099] Preparation of functionalized multi-stage porous adsorption chelating resin column: 100 g of the functionalized multi-stage porous adsorption chelating resin of Preparation Example 2 was filled into a glass adsorption column with an inner diameter of 10 mm and a height of 300 mm to obtain a functionalized multi-stage porous adsorption chelating resin column.

[0100] Example 4

[0101] A preparation process for 6N high-purity nickel, the specific implementation method is the same as that of Example 3, except that the pH in step (1) and step (2) is adjusted to 5.

[0102] Example 5

[0103] A preparation process of 6N high-purity nickel, the specific implementation method is the same as that of Example 3, except that the pH in step (1) is adjusted to 6.

[0104] Example 6

[0105] A preparation process for 6N high-purity nickel, the specific implementation method is the same as that of Example 3, except that the pH in step (1) and step (2) is adjusted to 5.5.

[0106] Example 7

[0107] A preparation process for 6N high-purity nickel, the specific implementation method is the same as that of Example 3, except that the metal extractant microcapsules used are obtained from Preparation Example 3.

[0108] The specific operation of the direct current electrolysis of the present invention is: a ruthenium-iridium-titanium anode plate and a titanium cathode plate are loaded into an electrolytic cell, and an ion diaphragm bag is installed on the anode plate, and then a high-purity nickel chloride solution at a temperature of 55° C. in each embodiment is put into the electrolytic cell, wherein the inter-electrode spacing is 15 cm, and the current density is 100 A / m 2 , direct current electrolysis is carried out to obtain ultra-pure nickel on the cathode plate.

[0109] Performance Testing

[0110] 1. Encapsulation efficiency of metal extractant microcapsules

[0111] Weigh 5g of the metal extractant microcapsules obtained in Preparation Examples 1 and 3 respectively, grind them in a mortar for 10min, add 10mL of dichloromethane, ultrasonicate at 40KHz for 15min, and centrifuge to obtain a supernatant and a solid, repeat this extraction process 5 times, and dry the solid finally obtained in a vacuum oven to constant weight, weigh it and record it as M, and calculate it according to the following formula: Encapsulation efficiency (%) = 100% * (1-M / 5); where 5 is the mass of the metal extractant microcapsules. The specific test results are shown in Table 1.

[0112] Table 1

[0113] serial number Preparation Example 1 Preparation Example 3 Encapsulation rate (%) 85.2 78.8

[0114] It can be seen from Table 1 that, compared with Preparation Example 3, an appropriate amount of talc is added in Preparation Example 1, which can improve the encapsulation rate of the hollow microcapsules for the metal chelating agent, thereby improving the utilization rate of raw materials and saving costs.

[0115] 2. Pore size ratio, specific surface area and pore volume of chelating resin

[0116] The pore size ratio, specific surface area and pore volume of the chelating resin in Preparation Example 2 were measured using ASAP2020 according to the BET method. Specific test data are shown in Table 2.

[0117] Table 2

[0118]

[0119] As can be seen from Table 2, the functionalized multi-level pore adsorption chelating resin prepared in Preparation Example 2 has relatively uniform distribution of micropores, mesopores and macropores, moderate particle size, large specific surface area and pore volume, and it can be seen that it has excellent adsorption capacity.

[0120] 3. Adsorption performance

[0121] The concentration of metal ions in the high-purity nickel chloride solution obtained in each embodiment is tested. Among them, the copper ion concentration is determined according to the sodium diethyldithiocarbamate spectrophotometry in the national standard GB / T 7474-87; the lead ion concentration is determined according to the dithizone spectrophotometry in the national standard GB / T 7470-87; the nickel ion concentration is determined according to the dimethylglyoxime spectrophotometry in the national standard GB 11910-89; the zinc ion concentration is determined according to the dithizone spectrophotometry in the national standard GB 7472-87; the iron ion is determined according to the o-phenanthroline spectrophotometry in the national standard HJ / T 345-2007; the cobalt ion is determined according to the flame atomic absorption spectrophotometry in the national standard HJ 957-2018; the magnesium ion concentration is determined according to the ion chromatography in the national standard HJ 812-2016; the chromium ion concentration is determined according to the national standard HJ The concentration of manganese ions was determined by flame atomic absorption spectrophotometry in accordance with the national standard HJ / T 344-2007. The specific test results are shown in Table 3.

[0122] Table 3

[0123]

[0124]

[0125] As shown in Table 3, the concentration of each impurity ion in the high-purity nickel chloride solution obtained in Examples 1-6 is relatively low, and the adsorption amount of nickel ions by the metal extractant microcapsules and the functionalized multi-level pore adsorption chelating resin during the adsorption process is reduced compared to the adsorption amount of nickel ions by the common extraction method used in other patents. The nickel chloride solution obtained in Example 3 has the highest purity. Compared with Example 3, the pH of the solution in step (1) and step (2) is changed in Examples 4-6, respectively, which will cause the adsorption capacity of the metal extractant microcapsules and the functionalized multi-level pore adsorption chelating resin to different metal ions to change to a certain extent, so that their adsorption capacity for nickel ions, cobalt ions, copper ions, iron ions, zinc ions, chromium ions, manganese ions, magnesium ions and lead ions in the solution also changes; talcum powder is not added during the preparation process of the metal extractant microcapsules used in Example 7, which affects the molding of the microcapsules and the encapsulation rate of the metal chelating agent, so that its adsorption effect on impurity metal ions is reduced.

[0126] 3. Impurity element content of 6N high purity nickel

[0127] Based on the above test data, the 6N high-purity nickel obtained in Example 3 was tested for impurity elements using GD-MS (Thermo Fisher Scientific, Germany, model LH-S-046), with the testing temperature of the equipment being 18-28° C. and the relative humidity being 30-70%. The specific test results are shown in Table 3.

[0128] Impurity Elements Content (ppm) cobalt <0.05 copper <0.05 iron 0.12 Zinc <0.05 chromium 0.02 manganese <0.005 magnesium <0.005 lead 0.04 aluminum 0.06 calcium <0.05 silver <0.01

[0129] It can be seen from Table 3 that the 6N high-purity nickel obtained in Example 3 has a low content of impurity elements and a high quality.

[0130] The above is only a preferred embodiment of the present invention and does not constitute any form of limitation to the present application. Although the present application is disclosed as above in the preferred embodiment, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution.

Claims

1. A process for preparing 6N high-purity nickel, characterized in that: The method comprises the following preparation steps: (1) adding metal extractant microcapsules to a crude nickel chloride solution, adjusting the pH, stirring at 20-40° C. for 0.5-1 h, and filtering to obtain a nickel chloride primary treatment solution; (2) adjusting the pH of the nickel chloride primary treatment solution of step (1) again, passing it through a functionalized multi-stage pore adsorption chelating resin column at 20-40° C., controlling the flow rate, and obtaining a high-purity nickel chloride solution. ; (3) The high-purity nickel chloride solution of step (2) is loaded into an electrolytic cell and subjected to direct current electrolysis to obtain 6N high-purity nickel on the cathode plate.

2. The preparation process of 6N high purity nickel according to claim 1, characterized in that: The concentrations of the metal ions in the crude nickel chloride solution are: nickel ion concentration ≤250 g / L, cobalt ion concentration ≤4 g / L, copper ion concentration ≤1.5 g / L, iron ion concentration ≤1 g / L, zinc ion concentration ≤1 g / L, chromium ion concentration ≤1 g / L, manganese ion concentration ≤1 g / L, magnesium ion concentration ≤1 g / L, and lead ion concentration ≤1 g / L.

3. The preparation process of 6N high purity nickel according to claim 1, characterized in that: The usage amount of the metal extractant microcapsule is 0.1-4.5wt% of the crude nickel chloride solution.

4. The preparation process of 6N high purity nickel according to claim 1, characterized in that: In the step (1), the pH is adjusted to 3-4.

5.

5. The preparation process of 6N high purity nickel according to claim 1, characterized in that: The pore size of the filtering membrane is ≤20 μm.

6. The process for preparing 6N high purity nickel according to claim 1, characterized in that: In the step (2), the pH is adjusted to 2-4.

7. The process for preparing 6N high purity nickel according to claim 1, characterized in that: The amount of the functionalized multi-level pore adsorption chelating resin in the functionalized multi-level pore adsorption chelating resin column is 1-10 wt % of the crude nickel chloride solution.

8. The process for preparing 6N high purity nickel according to claim 7, characterized in that: The preparation method of the functionalized multi-level porous adsorption chelating resin comprises the following preparation steps: S1. Styrene, divinylbenzene and vinyl acetic acid were mixed uniformly, an initiator was added thereto, and the mixture was stirred until the initiator was completely dissolved, and then poured into pure water, and the mixture was reacted under stirring and heating conditions for 6-10h, and then separated, washed and dried to obtain a white solid; S2. At room temperature, the white solid obtained in step S1 is added to C2H4Cl2, stirred and swollen for 10-14 hours, and then p-dichlorobenzyl and anhydrous tin tetrachloride are added thereto in sequence, stirred for 25-40 minutes, reacted at 75-85°C for 20-24 hours, separated, washed, and dried to obtain a multi-level porous adsorption resin; S3. Add the multi-level porous adsorption resin and coupling agent obtained in step S2 into toluene and mix evenly, then add the functional monomer, heat to 100-120°C and react for 1-4h, then cool to room temperature, separate, wash and dry to obtain a functionalized multi-level porous adsorption chelating resin.

9. The process for preparing 6N high purity nickel according to claim 1, characterized in that: The flow rate is 5-10 L / h.

10. The process for preparing 6N high purity nickel according to claim 1, characterized in that: The preparation method of the metal extractant microcapsule comprises the following preparation steps: (1) Ethyl acrylate, methacrylamide, 2-acrylamido-2-methylpropanesulfonic acid sodium salt, a crosslinking agent, and an initiator are uniformly mixed, and the emulsifier mixture is added dropwise under stirring conditions, ultrasonicated, and irradiated with ultraviolet light for 10-20 minutes under stirring conditions, and then washed with pure water, separated, and dried to obtain hollow microcapsules; (2) evacuating the hollow microcapsules obtained in step (1), adding a metal chelating agent, ultrasonically treating for 5-10 hours, filtering, and washing to obtain metal extractant microcapsules; The emulsifier mixture contains 2-5wt% talc.

Images