Preparation method of 6N5 high-purity nickel

Abstract

The invention relates to the technical field of preparation of high-purity nickel, in particular to a preparation method of 6N5 high-purity nickel, which comprises the following steps: solution preparation, solution purification, precision filtration, electrodeposition refining and ionic membrane electrolytic refining. Various impurities in the nickel raw material are effectively removed through solution purification treatment including solution preparation through dissolution, extraction and micron-sized ion exchange impurity removal, and the high purity of the nickel nitrate solution is further ensured in combination with the subsequent precision filtration step. The temperature of the electrolyte is optimized to a temperature range more suitable for nickel ion precipitation, the precipitation amount of nickel ions is increased, and the precipitation probability of other impurity ions is greatly reduced, so that the purity of cathode nickel is improved. An insoluble electrode plate and an ion diaphragm bag are adopted in the electrodeposition refining process, the electrolysis environment is optimized, and 6N high-purity nickel can be efficiently separated out through a negative plate. On the basis, the 6N high-purity nickel is used as an anode plate in the ionic membrane electrolytic refining step, deep purification is performed by using the ionic membrane electrolysis technology again, and finally, the high-purity nickel with the purity as high as 6N5 is successfully obtained on a cathode plate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high-purity nickel preparation, and particularly relates to a preparation method of 6N5 high-purity nickel. BACKGROUND

[0002] Nickel, with a relative atomic mass of 58.69, is a metal that is hard and ductile and has ferromagnetism, can be highly polished and is resistant to corrosion, has a melting point of 1453 DEG C, a boiling point of 2732 DEG C, and a density of 8.902 g / cm 3 High-purity nickel refers to nickel with a purity of 4N or more, that is, the content of nickel is greater than 99.99%, and high-purity nickel contains very little impurities. Because high-purity nickel is hard, ductile and has excellent processing performance, it is widely used in sputtering targets and ion plating, wire for electronic industry, high-purity reagents, high-performance alloys and other fields. In recent years, with the development of high-tech industries, the application field of high-purity nickel is increasingly wide. High-purity nickel is generally prepared from traditional smelting processes to obtain intermediate products such as nickel nitrate or nickel chloride, and then the high-purity nickel is extracted from the intermediate products to form metal. Electrolytic reduction or hydrogen reduction is the main method for preparing high-purity nickel.

[0003] The electrolytic refining method is the most important method for preparing high-purity nickel. The electrolytic nickel obtained by the traditional smelting process and the aqueous solution of nickel chloride are used as the anode and the electrolyte, respectively, and the third-stage amine is used as the extractant in the purification of the electrolyte. If only the metal components are considered, the 4N grade nickel with an impurity content of 10-20 ppm can be easily obtained by refining the electrolytic nickel.

[0004] The traditional electrolysis technology cannot effectively remove Co, Pb, Fe and other impurities, so that the impurity content of the obtained high-purity nickel is high, and high-purity nickel with a purity of more than 6N cannot be obtained. Chinese patent CN1489642A discloses a method for preparing high-purity nickel. When using a nickel-containing solution as an electrolyte for electrolysis, the anode electrolyte is adjusted to pH=2-5, and an oxidizing agent is added to the anode electrolyte to precipitate iron, cobalt, copper and other impurities in the form of hydroxides, or the impurities are removed by pre-electrolysis, or Ni foil is added to remove the impurities by displacement reaction. Regardless of whether one or more than two of these methods is used to remove impurities, a filter is further used to remove impurities, and the solution after removing the impurities is used as the cathode electrolyte for electrolysis. This technology can effectively manufacture high-purity nickel with a purity of more than 5N from nickel raw materials containing a large amount of impurities. However, the process is relatively complicated, and the high-purity nickel produced finally has a purity of only 5N, which cannot reach a purity of more than 6N. SUMMARY

[0005] In view of the problem that the impurity content of high-purity nickel is high and cannot reach a purity of more than 6N in the prior art, the present application provides a preparation method of 6N5 high-purity nickel.

[0006] To achieve the above object, the technical scheme of the present application is as follows:

[0007] A preparation method of 6N5 high-purity nickel comprises the following steps:

[0008] S1, dissolving liquid preparation: reacting nickel raw material with nitric acid to obtain a nickel nitrate solution;

[0009] S2, solution purification: first extracting the nickel nitrate solution obtained in S1 by using an extractant, and then removing impurities by using a micron-level ion exchange membrane;

[0010] S3, precision filtration: performing precision filtration on the purified nickel nitrate solution in S2 to obtain a high-purity nickel nitrate solution;

[0011] S4, electrodeposition refining: pouring the high-purity nickel nitrate solution obtained in S3 into an electrodeposition tank, using an insoluble electrode plate as an anode plate, a titanium plate as a cathode plate, and installing an ion diaphragm bag on the anode plate; performing electrolysis by using direct current, the temperature of the nickel nitrate electrolyte being 30-80℃, and obtaining 6N high-purity nickel on the cathode plate;

[0012] S5, ion membrane electrolysis refining: pouring the high-purity nickel nitrate solution obtained in S3 into an ion membrane electrolysis tank, using the 6N high-purity nickel obtained in S4 as an anode plate, a titanium plate as a cathode plate, and installing an ion diaphragm bag on the anode plate; performing electrolysis by using direct current, the temperature of the nickel nitrate electrolyte being 30-80℃, and obtaining 6N5 high-purity nickel on the cathode plate.

[0013] Further, in S1, the nickel raw material is 3N8 electro-nickel.

[0014] Further, in S1, the concentration of nickel ions in the nickel nitrate solution is 100-200g / L, and the pH value of the solution is 2-4.

[0015] Further, the inter-electrode distance in the electrodeposition tank and the ion membrane electrolysis tank is 10-20cm.

[0016] Further, in the electrolysis process, the current density of the direct current is 80-120A / m 2 .

[0017] Further, in S2, the extractant is C272 extractant.

[0018] In the solution purification link, the C272 extractant is first used to remove Fe, Zn, Cu, Pb, Co, Mg, Ca impurities in ionic form in electrolysis, and then the micron-level ion exchange membrane is used to remove Pb impurities in the solution.

[0019] In the electrodeposition refining and ion membrane electrolysis refining links, the ion diaphragm bag installed on the anode plate can prevent the impurities generated at the anode from being released to the cathode in the electrolysis process.

[0020] In the case of the same content of electrolyte impurities, the ion exchange membrane electrolytic refining is adopted, the selective permeation of the ion exchange membrane is utilized to prevent the small part of cation impurities in the electrolyte from being removed by the purification process and being free to the cathode, and meanwhile, under the process condition of controlling the electrolyte temperature between 30-80 DEG C, the nickel ion precipitation amount at the cathode can be effectively promoted, the electrochemical reaction is more inclined to the precipitation of elemental nickel ion under the same current, the current effectively acts on the precipitation of nickel ion, and the precipitation probability of other impurity ions is greatly reduced, so that the purpose that the impurities in the solution cannot be precipitated at the cathode is achieved, and the 6N5 high-purity nickel product with higher purity is obtained.

[0021] Compared with the prior art, the beneficial effects of the present application are:

[0022] The present application provides a preparation method of 6N5 high-purity nickel, which effectively removes various impurities in the nickel raw material through solution purification treatment of dissolving liquid preparation, extraction and micron-level ion exchange impurity removal, and further ensures the high purity of the nickel nitrate solution by combining with the subsequent precision filtration step. The electrolyte temperature is optimized to a temperature range more suitable for the precipitation of nickel ions, the precipitation amount of nickel ions is increased, and the precipitation probability of other impurity ions is greatly reduced, thereby improving the purity of the cathode nickel. In the electrodeposition refining process, insoluble electrode plates and ion diaphragm bags are used to optimize the electrolysis environment, so that the cathode plate can efficiently precipitate 6N high-purity nickel. On this basis, the ion exchange membrane electrolytic refining step uses 6N high-purity nickel as the anode plate, and the ion exchange membrane electrolysis technology is used again for deep purification, so that high-purity nickel with a purity of up to 6N5 is successfully obtained on the cathode plate, which meets the stringent requirements of high-end fields for the purity of nickel materials, and the preparation process is reasonable and operable, and has high industrial application value. BRIEF DESCRIPTION OF DRAWINGS

[0023] The embodiments of the present application will be further described below with reference to the accompanying drawings, in which:

[0024] Figure 1 A process flow diagram of the preparation method of 6N5 high-purity nickel is shown. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application will be further described in detail below with reference to the accompanying drawings through specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0026] Example 1

[0027] A preparation method of 6N5 high-purity nickel, comprising the following steps:

[0028] S1, dissolving solution: 3N8 electro-nickel is reacted with nitric acid to obtain a nickel nitrate solution, the concentration of nickel ions in the nickel nitrate solution is 100 g / L, and the pH value of the solution is 2;

[0029] S2, solution purification: the nickel nitrate solution obtained in S1 is first extracted by using an extractant C272, and then impurities are removed by using a micron-level ion exchange membrane;

[0030] S3, precision filtration: the nickel nitrate solution purified in S2 is subjected to precision filtration to obtain a high-purity nickel nitrate solution;

[0031] S4, electrodeposition refining: the high-purity nickel nitrate solution obtained in S3 is poured into an electrodeposition tank, an insoluble electrode plate is used as an anode plate, a titanium plate is used as a cathode plate, an ion diaphragm bag is additionally arranged on the anode plate, and the inter-electrode distance is 10 cm; direct current is used for electrolysis, the temperature of the nickel nitrate electrolyte is 30 ℃, and the current density of the direct current is 80 A / m 2 6N high-purity nickel is obtained on the cathode plate;

[0032] S5, ion membrane electrolysis refining: the high-purity nickel nitrate solution obtained in S3 is poured into an ion membrane electrolysis tank, the 6N high-purity nickel obtained in S4 is used as an anode plate, a titanium plate is used as a cathode plate, an ion diaphragm bag is additionally arranged on the anode plate, and the inter-electrode distance is 10 cm; direct current is used for electrolysis, the temperature of the nickel nitrate electrolyte is 30 ℃, and the current density of the direct current is 80 A / m 2 6N5 high-purity nickel is obtained on the cathode plate. The 6N5 high-purity nickel obtained on the cathode plate is subjected to GD-MS element analysis, and the results are shown in Table 1.

[0033] Table 1

[0034]

[0035] Example 2

[0036] A method for preparing 6N5 high-purity nickel, comprising the following steps:

[0037] S1, dissolving solution: 3N8 electro-nickel is reacted with nitric acid to obtain a nickel nitrate solution, the concentration of nickel ions in the nickel nitrate solution is 150 g / L, and the pH value of the solution is 3;

[0038] S2, solution purification: the nickel nitrate solution obtained in S1 is first extracted by using an extractant C272, and then impurities are removed by using a micron-level ion exchange membrane;

[0039] S3, precision filtration: the nickel nitrate solution purified in S2 is subjected to precision filtration to obtain a high-purity nickel nitrate solution;

[0040] S4, electrowinning refining: pouring the high-purity nickel nitrate solution obtained in S3 into an electrowinning tank, using an insoluble electrode plate as an anode plate, a titanium plate as a cathode plate, and installing an ion diaphragm bag on the anode plate, with an inter-electrode distance of 15 cm; electrolyzing by direct current, with the temperature of the nickel nitrate electrolyte being 50℃ and the current density of the direct current being 100 A / m 2 obtaining 6N high-purity nickel on the cathode plate;

[0041] S5, ion membrane electrolysis refining: pouring the high-purity nickel nitrate solution obtained in S3 into an ion membrane electrolysis tank, using the 6N high-purity nickel obtained in S4 as an anode plate, a titanium plate as a cathode plate, and installing an ion diaphragm bag on the anode plate, with an inter-electrode distance of 15 cm; electrolyzing by direct current, with the temperature of the nickel nitrate electrolyte being 50℃ and the current density of the direct current being 100 A / m 2 obtaining 6N5 high-purity nickel on the cathode plate. The 6N5 high-purity nickel obtained on the cathode plate was subjected to GD-MS element analysis, and the results are shown in Table 2.

[0042] Table 2

[0043]

[0044]

[0045] Example 3

[0046] A method for preparing 6N5 high-purity nickel, comprising the following steps:

[0047] S1, dissolving and preparing solution: reacting 3N8 electro-nickel with nitric acid to obtain a nickel nitrate solution, with the concentration of nickel ions in the nickel nitrate solution being 200 g / L and the pH value of the solution being 4;

[0048] S2, solution purification: first extracting the nickel nitrate solution obtained in S1 by using an extractant C272, and then removing impurities by using a micron-level ion exchange membrane;

[0049] S3, precision filtration: precision filtering the nickel nitrate solution purified in S2 to obtain a high-purity nickel nitrate solution;

[0050] S4, electrowinning refining: pouring the high-purity nickel nitrate solution obtained in S3 into an electrowinning tank, using an insoluble electrode plate as an anode plate, a titanium plate as a cathode plate, and installing an ion diaphragm bag on the anode plate, with an inter-electrode distance of 20 cm; electrolyzing by direct current, with the temperature of the nickel nitrate electrolyte being 80℃ and the current density of the direct current being 120 A / m 2 obtaining 6N high-purity nickel on the cathode plate;

[0051] S5, ion membrane electrolytic refining: pouring the high-purity nickel nitrate solution obtained in S3 into an ion membrane electrolytic cell, using the 6N high-purity nickel obtained in S4 as an anode plate, a titanium plate as a cathode plate, and an ion diaphragm bag on the anode plate, with an inter-electrode distance of 20 cm; using direct current for electrolysis, with the temperature of the nickel nitrate electrolyte being 80℃, and the current density of the direct current being 120 A / m 2 The 6N5 high-purity nickel was obtained on the cathode plate. The 6N5 high-purity nickel obtained on the cathode plate was subjected to GD-MS element analysis, and the results are shown in Table 3.

[0052] Table 3

[0053]

[0054] Comparative Example 1

[0055] The difference between this comparative example and Example 1 is that the temperature of the nickel nitrate electrolyte during electrodeposition refining and ion membrane electrolytic refining is 15℃. The high-purity nickel obtained on the cathode plate was subjected to GD-MS element analysis, and the results are shown in Table 4.

[0056] Table 4

[0057]

[0058]

[0059] Comparative Example 2

[0060] The difference between this comparative example and Example 1 is that the temperature of the nickel nitrate electrolyte during electrodeposition refining and ion membrane electrolytic refining is 95℃. The high-purity nickel obtained on the cathode plate was subjected to GD-MS element analysis, and the results are shown in Table 5.

[0061] Table 5

[0062]

[0063] Comparative Example 3

[0064] The difference between this comparative example and Example 1 is that the current density of the direct current during electrodeposition refining and ion membrane electrolytic refining is 60 A / m 2 . The high-purity nickel obtained on the cathode plate was subjected to GD-MS element analysis, and the results are shown in Table 6.

[0065] Table 6

[0066]

[0067] Comparative Example 4

[0068] The difference between this comparative example and Example 1 is that the current density of the direct current during electrodeposition refining and ion membrane electrolytic refining is 150 A / m 2The high-purity nickel obtained on the cathode plate was subjected to GD-MS elemental analysis, and the results are shown in Table 7.

[0069] Table 7

[0070]

[0071]

[0072] Comparative Example 5

[0073] The difference between this comparative example and Example 1 is that the inter-electrode distance is 25 cm during electrodeposition refining and ion membrane electrolytic refining. The 6N5 high-purity nickel obtained on the cathode plate was subjected to GD-MS elemental analysis, and the results are shown in Table 8.

[0074] Table 8

[0075]

[0076] The application provides a preparation method of 6N5 high-purity nickel. Through solution purification treatment of dissolving solution preparation, extraction and micron-level ion exchange impurity removal, various impurities in the nickel raw material are effectively removed, and the high purity of the nickel nitrate solution is further ensured through the subsequent precise filtration step. The electrolyte temperature is optimized to a temperature range more suitable for nickel ion deposition, which improves the deposition amount of nickel ions and greatly reduces the deposition probability of other impurity ions, thereby improving the purity of the cathode nickel. In the electrodeposition refining process, insoluble electrode plates and ion membrane bags are used to optimize the electrolysis environment, so that the cathode plate can efficiently deposit 6N high-purity nickel. On this basis, the ion membrane electrolytic refining step uses 6N high-purity nickel as the anode plate, and the ion membrane electrolysis technology is used again for deep purification, and finally high-purity nickel with a purity of up to 6N5 is successfully obtained on the cathode plate, which meets the stringent requirements of high-end fields for the purity of nickel materials, and the preparation process is reasonable and operable, and has high industrial application value.

[0077] Some exemplary embodiments of the application are described above, and it can be understood that the above-described embodiments are only used to explain the application and do not constitute a limitation on the protection scope of the application. The features in these embodiments can be recombined in a suitable manner, and the schemes obtained thereby are still within the protection scope required by the application. Based on the above-described embodiments, all other embodiments obtained by those skilled in the art without creative labor, i.e., all modifications, equivalent replacements and improvements, etc. made within the spirit and principles of the present application, are within the protection scope required by the application.

Claims

1. A method for preparing 6N5 high-purity nickel, characterized in that: The following steps are involved: S1, dissolving and preparing liquid: reacting nickel raw material with nitric acid to obtain nickel nitrate solution; S2, solution purification: the nickel nitrate solution obtained in S1 is first extracted with an extractant, and then passed through a micron-sized ion exchange membrane to remove impurities; S3, precision filtration: the nickel nitrate solution purified in S2 is subjected to precision filtration to obtain a high-purity nickel nitrate solution; S4, electrowinning refining: pour the high-purity nickel nitrate solution obtained in S3 into the electrowinning tank, use an insoluble electrode plate as the anode plate, a titanium plate as the cathode plate, and install an ion diaphragm bag on the anode plate; Electrolysis is carried out using direct current, the temperature of the nickel nitrate electrolyte is 30-80°C, and 6N high-purity nickel is obtained on the cathode plate; S5, ion membrane electrolytic refining: Pour the high-purity nickel nitrate solution obtained in S3 into the ion membrane electrolytic cell, use the 6N high-purity nickel obtained in S4 as the anode plate, the titanium plate as the cathode plate, and install an ion membrane bag on the anode plate; Direct current is used for electrolysis, the temperature of the nickel nitrate electrolyte is 30-80°C, and 6N5 high-purity nickel is obtained on the cathode plate.

2. The method for preparing 6N5 high-purity nickel according to claim 1, wherein: In S1, the nickel raw material is 3N8 electrolytic nickel.

3. The method for preparing 6N5 high-purity nickel according to claim 1, wherein: In S1, the concentration of nickel ions in the nickel nitrate solution is 100-200 g / L, and the pH value of the solution is 2-4.

4. The method for preparing 6N5 high-purity nickel according to claim 1, wherein: The inter-electrode distances in the electrolytic cell and the ion membrane electrolytic cell are both 10-20 cm.

5. The method for preparing 6N5 high-purity nickel according to claim 1, wherein: During the electrolysis process, the current density of direct current is 80-120A / m 2 .

6. The method for preparing 6N5 high-purity nickel according to claim 1, wherein: In S2, the extractant is C272 extractant.

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