A process for the production of nickel products by electrolysis

Abstract

This invention relates to a method for preparing nickel products by electrolysis, comprising the following steps: Step 1: Preparing a cathode and an anode, wherein the anode is a pure nickel plate, and the cathode includes a conductive plate and a mask attached to the conductive plate. The mask is made of a non-conductive material and has N-sided through holes of a predetermined size, each corner of which is rounded, and N≥3; Step 2: Preparing an electrolyte, which includes nickel salts; the order of Step 1 and Step 2 is not important; Step 3: Inserting the cathode and anode into the electrolyte, adjusting the distance between the cathode and anode, controlling the current density, maintaining the electrolysis temperature, and allowing the electrolyte to undergo an electrolytic reaction; Step 4: After the electrolytic reaction is completed, removing the cathode, peeling off the mask, rinsing the surface of the prepared nickel product with pure water to remove the electrolyte, and then drying it. The prepared nickel product has a regular shape and no sharp edges.

Description

Technical Field

[0001] This invention relates to a method for preparing nickel products, specifically a method for preparing nickel products by electrolysis. Background Technology

[0002] Nickel is a silvery-white metal with a melting point of 1453℃ and a boiling point of 2732℃. Electrolytic nickel possesses excellent properties such as high mechanical strength, good ductility, refractory nature, and resistance to oxidation in air. Stainless steel and various alloys made from nickel are widely used in military aircraft, tanks, ships, radar, missiles, spacecraft, nuclear reactors, and in civilian industries such as structural steel, acid-resistant steel, and heat-resistant steel, as well as in ceramic pigments, permanent magnet materials, and electronic remote control applications. However, current nickel products prepared through electroplating processes are mostly nickel buckles, round nickel plates, or irregularly shaped nickel blocks, which have the following technical drawbacks:

[0003] Firstly, traditional nickel buckles are small in size and have low stacking density, making them prone to sliding and scattering during bulk transportation. Furthermore, their sharp edges and corners can easily cause packaging damage or personal injury, resulting in a transportation loss rate that is generally between 3% and 5%.

[0004] Secondly, irregularly shaped nickel blocks, during the electrolytic refining process, result in uneven current distribution, leading to a large number of surface particles (particle diameter ≥ 0.5 mm), which affects product purity (usually ≤ 99.95%) and electrochemical performance, and causes large fluctuations in dissolution rate during subsequent use.

[0005] Third, existing nickel products lack standardized design in shape, have chaotic size specifications, are difficult to position during subsequent processing, and are prone to cracking due to stress concentration at the edges and corners, resulting in a processing qualification rate of only 85% to 90%.

[0006] Fourth, some blocky nickel products have not optimized the four corners structure, which makes them prone to chipping at the corners due to collisions during transportation. This leads to uneven bonding of the anode and cathode during electrolysis, further reducing production efficiency.

[0007] Fifth, traditional nickel products (such as nickel plates and irregular nickel blocks) often need to be cut and shaped. During the cutting process, nickel shavings and nickel dross (solid debris similar to "cement slag") will be generated. These waste residues are easy to fall into the electroplating solution, causing pollution to the electroplating solution and affecting the quality of the coating. Moreover, cleaning the waste residues requires stopping the machine, which reduces production efficiency.

[0008] Sixth, the sharp edges of traditional nickel products can easily cut the electroplating strips used in the electroplating process (such as titanium strips and nickel strips), causing the electroplating strips to break and leak. This not only increases the cost of consumables, but also causes problems such as electroplating solution pollution and electrolysis malfunction.

[0009] Seventh, irregularly shaped or sharp-edged nickel products are prone to getting stuck in the electroplating tank, cathode frame or other workpieces, causing positioning deviation, affecting the uniformity of electrolysis, and even requiring manual intervention to clean, reducing production continuity.

[0010] Although some existing technologies mention block-shaped nickel products, such as the Chinese invention patent application CN202310986291.5 (publication number CN116949514A) which discloses "A method for producing electroplating-specific nickel using metallized anode plates", this patent does not optimize the edge structure of nickel products by arc grinding and only limits a single size specification. It cannot adapt to different electrolytic cell capacities, processing equipment parameters and application scenarios. It still has problems such as damage from transportation collisions, insufficient electrolysis efficiency, poor adaptability to multiple scenarios, waste residue pollution, damage to electroplating belts, and easy jamming. It cannot meet the comprehensive requirements of industrial production for the safety, stability, processing convenience, specification diversity and clean production of nickel products. Summary of the Invention

[0011] The technical problem to be solved by the present invention is to provide a method for preparing nickel products by electrolysis, which is based on the current state of the prior art. The nickel products prepared by this method are N-sided with rounded corners.

[0012] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: A method for preparing nickel products by electrolysis includes the following steps:

[0013] Step 1: Prepare the cathode and anode. The anode is a pure nickel plate. The cathode includes a conductive plate and a mask attached to the conductive plate. The mask is made of a non-conductive material and has N-sided through holes of a set size. Each corner of the N-sided through hole is rounded, and N≥3.

[0014] Step 2: Prepare the electrolyte, which includes nickel salt;

[0015] The order of steps one and two above is not important;

[0016] Step 3: Insert the cathode and anode into the electrolyte, adjust the distance between the cathode and anode, control the current density, maintain the electrolysis temperature, and the electrolyte will undergo an electrolysis reaction (the electrolyte can undergo an electrolysis reaction under stirring, circulation, or static conditions).

[0017] Step 4: After the electrolysis reaction is complete, remove the cathode, peel off the mask, rinse the electrolyte on the surface of the prepared nickel product with pure water, and then dry it.

[0018] Preferably, in step one, the cathode fabrication process includes the following steps:

[0019] (1) Pre-treat the conductive plate;

[0020] (2) First, cut N-sided through holes with rounded corners on the mask, and then attach the mask to the surface of the conductive plate; or, first attach the mask to the surface of the conductive plate, and then cut N-sided through holes with rounded corners on the mask. The mask can be attached to the surface of the conductive plate using existing thermoforming bonding technology.

[0021] Preferably, in step (1), the pretreatment method is to sequentially perform alkaline washing to remove oil, dilute acid activation, pure water rinsing, and drying on the conductive plate to avoid impurities on the conductive plate affecting the tightness of the mask on the conductive plate, resulting in bubbles, voids, and wrinkles at the bonding interface between the two.

[0022] Alkaline washing for degreasing involves using a 30–80 g / L NaOH solution at 50–70°C to remove oil, fingerprints, and impurities from the conductive plate surface. Dilute acid activation involves activating the conductive plate with 5%–10% dilute sulfuric acid for 60–180 seconds, until the conductive plate surface is evenly wetted, free of water residue, and shows a metallic luster, in order to remove the oxide scale from the conductive plate and improve the adhesion of the mask.

[0023] N-sided through holes can be formed by die-cutting. Preferably, in step (2), laser cutting is used to form the N-sided through holes. The laser power is 10-30 W, the cutting speed is 50-150 mm / s, the cutting accuracy is ±5 μm, and the edges of the N-sided through holes are smooth and burr-free, with a corner radius deviation of ≤0.2 mm. This cutting process results in smooth cuts, no burrs, no carbonization, no scorch edges, and no damage to the mask.

[0024] Preferably, in step one, the mask is one of polyimide (PI) film, polyester (PET) film, polyvinylidene fluoride (PVDF) film, perfluoroalkoxy (PFA) film, polyethersulfone (PES) film, or fluorinated ethylene propylene (FEP) film.

[0025] Preferably, in step one, the thickness of the mask is 25–50 μm, which results in high edge precision of the prepared nickel product.

[0026] Preferably, in step one, N=4, the quadrilateral nickel blocks have the highest stacking density, the smallest gaps, and the highest transportation efficiency; the shape is regular, the electrolysis is uniform; the packaging, boxing, and palletizing are the most stable; automated loading and unloading are the easiest; and the production, die-cutting, and mask making costs are the lowest.

[0027] Preferably, in step two, the electrolyte comprises 250–350 g / L NiSO4·7H2O, 40–80 g / L NiCl2·6H2O, 30–50 g / L H3BO3, with the remainder being deionized water.

[0028] Preferably, in step three, the pH of the electrolyte is controlled to be 3-5 during the electrolysis reaction, so that nickel ions are deposited stably, without hydrolysis, without the generation of nickel hydroxide impurities, and without the coating becoming brittle.

[0029] The electrolyte temperature is 45-55 ℃. The electrolyte has good conductivity, a dense nickel layer, low internal stress, and does not burn or granulate.

[0030] With a current density of 300–500 A / m², the deposition rate is moderate, resulting in finely crystallized, highly pure nickel layers with a smooth surface that will not burn or become porous.

[0031] Preferably, in step three, the cathode and anode are arranged in parallel and opposite directions, with a distance of 8 to 16 cm between them. If the distance is too small, it will cause excessive local current, burning, and granulation. Also, if the distance is too small, the electrolyte flow will be obstructed. If the distance is too large, it will result in low efficiency and slow deposition. Furthermore, if the distance is too large, the electrolytic cell needs to be expanded synchronously.

[0032] Compared with the prior art, the advantages of the present invention are:

[0033] 1. This invention comprises a cathode consisting of a conductive plate and a mask, with the mask having N-sided through-holes, each corner of which is rounded. These N-sided through-holes allow for selective control of nickel product growth, resulting in nickel products whose dimensions match the N-sided through-holes. This ensures the nickel products have regular and standard shapes without sharp edges. Nickel products with this structure significantly improve stacking stability, achieving a stacking density of 6.5–7.0 g / cm³, more than 30% higher than traditional nickel buckles. During bulk transportation, there is no slippage or scattering, increasing single-box loading capacity by 40% and reducing logistics costs by 15%–20%. The nickel products of this invention completely eliminate sharp edges, reducing packaging (such as kraft paper bags and plastic films) breakage rates from the traditional 15%–20% to below 1%. Simultaneously, it eliminates the risk of scratches during handling, reducing the annual workplace injury rate to below 0.1‰ and the transportation loss rate to below 0.5%.

[0034] 2. The regularly shaped and standardized nickel products of this invention ensure uniform distribution of electric field lines during electrolysis, reducing surface granulation by 80%, maintaining product purity above 99.99%, and achieving more precise control over impurity content. Key impurity elements such as Fe and Cu are ≤20ppm, meeting the high purity requirements of nickel raw materials for high-end electronic components. The parallelism of the upper and lower surfaces and the perpendicularity of the sides ensure uniform anode-cathode spacing during electrolysis (spacing deviation ≤0.5mm), current density fluctuation ≤5%, and avoids excessive dissolution caused by current concentration at corners during electrolysis, thus improving the overall uniformity of nickel dissolution. 0%, improving electrochemical dissolution activity, shortening single-batch electrolysis time by 3-5 hours, and significantly improving production efficiency; reducing residual amount after dissolution by 40%, increasing raw material utilization rate to over 98%, and reducing resource waste; the one-piece molding design without cutting avoids cutting waste falling into the electroplating solution, eliminating the need for frequent shutdowns to clean waste, improving production continuity by 25%, and increasing daily output of a single unit by over 300 kg; completely solving the problem of traditional nickel products cutting the electroplating strip, extending the service life of the electroplating strip by more than 3 times, while avoiding electroplating solution pollution and working condition disorder caused by electroplating strip damage, and greatly improving production stability.

[0035] 3. This invention can cut through holes to the appropriate size according to the required nickel product size. The process is simple and multiple specifications are suitable for different packaging sizes (such as 20kg / box, 50kg / box). Small specifications can be stacked into standard cubes with a porosity of ≤5%. Large specifications have flat sides for easy fixing with lifting straps, reducing the risk of slippage during lifting by 95%. It is suitable for different logistics scenarios such as road, rail, and sea transportation.

[0036] As can be seen from the above, the present invention solves the technical problems of unsafe transportation, uneven electrolysis, high processing difficulty, limited specifications, pollution from cutting waste, easy damage to electroplating strips, and easy jamming in electroplating tanks in traditional nickel products. Attached Figure Description

[0037] Figure 1 This is a partial structural schematic diagram of the mask according to Embodiment 1 of the present invention;

[0038] Figure 2 This is a schematic diagram of the structure of some nickel products produced in Embodiment 1 of the present invention. Detailed Implementation

[0039] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] In the description of this invention, it should be understood that, unless otherwise stated, "a plurality of" means two or more, and the terms "upper," "lower," "left," "right," "top," "bottom," "front," "rear," etc., indicate the orientation or positional relationship based on the direction or positional relationship shown in the drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0041] In the description of this invention patent, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an adhesive connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention patent based on the specific circumstances.

[0042] Example 1

[0043] The method for preparing nickel products by electrolysis in this embodiment includes the following steps:

[0044] Step 1: Prepare the cathode and anode. The anode is a pure nickel plate with a purity of 99.99%. The cathode includes a conductive plate and a mask attached to the conductive plate. The conductive plate is made of 304 stainless steel, and the mask is a PET film with a thickness of 25μm and a size of 100mm × 100mm. The mask has N-sided through holes of a set size, with an N-sided through hole size of 50×50mm. Each corner of the N-sided through hole is rounded with a radius of 2mm, and N=4. The conductive area of ​​the conductive plate is exposed through the N-sided through holes.

[0045] Step 2: Prepare the electrolyte, which consists of 300 g / L NiSO4·7H2O, 60 g / L NiCl2·6H2O, 37.5 g / L boric acid, and the remainder is deionized water. After stirring all components of the electrolyte evenly, filter to remove impurities, and then adjust the pH value to 3.0. The pH adjuster is sulfuric acid and ammonia water, depending on the pH value.

[0046] The order of steps one and two above is not important;

[0047] Step 3: Insert the cathode and anode into the electrolyte, setting them parallel and opposite to each other. Adjust the distance between the cathode and anode to 8 cm. Electrolyze the electrolyte for 8 hours with stirring. During the reaction, control the electrolyte pH to 3.0, the DC current density to 300 A / m², maintain the electrolysis temperature at 45 ℃, and the electrolyte circulation rate at 5 L / min. Use an air pump to introduce clean air (compressed air) into the electrolyte to ensure uniform stirring. During the electrolysis reaction, nickel ions selectively reduce and grow only in the area constrained by the N-sided through-hole, forming a one-piece square-shaped ground-corner nickel block.

[0048] Step 4: After the electrolysis reaction is complete, remove the cathode, peel off the mask, rinse the surface of the prepared nickel product with pure water to remove the electrolyte, and then dry it at 65°C.

[0049] In step one, the cathode fabrication process includes the following steps:

[0050] (1) Pre-treat the conductive plate. The pre-treatment method is to perform alkaline washing to remove oil, dilute acid activation, pure water rinsing, and drying at 65°C in sequence. The alkaline washing to remove oil is to use a 65g / L NaOH solution at 60°C to remove oil stains, fingerprints, and impurities from the surface of the conductive plate. The dilute acid activation is to activate the conductive plate with 8% dilute sulfuric acid for 130 seconds until the surface of the conductive plate is evenly wetted, without water residue, and with a metallic luster, so as to remove the oxide scale of the conductive plate and improve the adhesion of the mask.

[0051] (2) First, cut N-sided through holes with rounded corners on the mask, and then attach the mask to the surface of the conductive plate; or, first attach the mask to the surface of the conductive plate, and then cut N-sided through holes with rounded corners on the mask. It is necessary to ensure that there are no bubbles, voids and wrinkles at the bonding interface between the mask and the conductive plate.

[0052] In this step, an N-sided through hole is formed using laser cutting technology. The laser power is 10 W, the cutting speed is 50 mm / s, the cutting accuracy is ±5 μm, the edge of the N-sided through hole is smooth and burr-free, and the corner radius deviation is ≤0.2 mm.

[0053] The final nickel product obtained in this embodiment has dimensions of 50 mm × 50 mm × 10 mm, an arc radius of 2 mm, a parallelism of 0.2 mm, a side perpendicularity of 0.2 mm, a stacking density of approximately 7.661 g / cm³, a pure nickel density of 8.908 g / cm³, a space utilization rate of 86.00%, a purity of 99.999%, and impurities including Ca 4.33ppm, Cu 0.77ppm, Fe 2.51ppm, Pb 2.32ppm, Mn 0.45ppm, and Zn 0.53ppm, meeting the requirements for use in high-end electronic components such as lithium battery cathode materials, semiconductor electroplating anodes, and alloy raw materials.

[0054] Example 2

[0055] The method for preparing nickel products by electrolysis in this embodiment includes the following steps:

[0056] Step 1: Prepare the cathode and anode. The anode is a pure nickel plate with a purity of 99.99%. The cathode includes a conductive plate and a mask attached to the conductive plate. The conductive plate is made of 304 stainless steel. The mask is a PET film with a thickness of 25μm and a size of 180mm × 150mm. The mask has N-sided through holes of a set size, with an N-sided through hole size of 150×100mm. Each corner of the N-sided through hole is rounded with an arc radius of 5mm. N=4.

[0057] Step 2: Prepare the electrolyte, which consists of 300 g / L NiSO4·7H2O, 60 g / L NiCl2·6H2O, 37.5 g / L boric acid, and the remainder is deionized water. After stirring all components of the electrolyte evenly, filter to remove impurities, and then adjust the pH value to 4.0. The pH adjuster is sulfuric acid and ammonia water, depending on the pH value.

[0058] The order of steps one and two above is not important;

[0059] Step 3: Insert the cathode and anode into the electrolyte, setting them parallel and opposite to each other. Adjust the distance between the cathode and anode to 12 cm. Electrolyze the electrolyte for 9 hours with stirring. During the reaction, control the electrolyte pH to 4.0, the DC current density to 400 A / m², maintain the electrolysis temperature at 50 ℃, and the electrolyte circulation rate at 5 L / min. Use an air pump to introduce clean air (compressed air) into the electrolyte to ensure uniform stirring. During the electrolysis reaction, nickel ions selectively reduce and grow only in the area constrained by the N-sided through-hole, forming a one-piece quadrilateral ground-corner nickel block.

[0060] Step 4: After the electrolysis reaction is complete, remove the cathode, peel off the mask, rinse the surface of the prepared nickel product with pure water to remove the electrolyte, and then dry it at 65°C.

[0061] The method for preparing the cathode in this embodiment is the same as that in Embodiment 1. The only difference is that the parameters for laser cutting the N-sided through hole in this embodiment are different from those in Embodiment 1. In this embodiment, the laser power is 20 W and the cutting speed is 100 mm / s.

[0062] The final nickel product obtained in this embodiment has dimensions of 150 mm × 100 mm × 30 mm, an arc radius of 5 mm, a parallelism of 0.3 mm, a side perpendicularity of 0.3 mm, a stacking density of 7.358 g / cm³, a pure nickel density of 8.908 g / cm³, a space utilization rate of 82.60%, a purity of 99.999%, and impurities including Ca 4.32 ppm, Cu 0.47 ppm, Fe 1.53 ppm, Pb 2.2 ppm, Mn 0.35 ppm, and Zn 0.45 ppm.

[0063] Example 3

[0064] The method for preparing nickel products by electrolysis in this embodiment includes the following steps:

[0065] Step 1: Prepare the cathode and anode. The anode is a pure nickel plate with a purity of 99.99%. The cathode includes a conductive plate and a mask attached to the conductive plate. The conductive plate is made of 304 stainless steel. The mask is a PET film with a thickness of 25μm and a size of 350mm × 250mm. The mask has N-sided through holes of a set size, with an N-sided through hole size of 300×200mm. Each corner of the N-sided through hole is rounded with an arc radius of 8mm. N=4.

[0066] Step 2: Prepare the electrolyte, which consists of 300 g / L NiSO4·7H2O, 60 g / L NiCl2·6H2O, 37.5 g / L boric acid, and the remainder is deionized water. After stirring all components of the electrolyte evenly, filter to remove impurities, and then adjust the pH value to 5.0. The pH adjuster is sulfuric acid and ammonia water, depending on the pH value.

[0067] The order of steps one and two above is not important;

[0068] Step 3: Insert the cathode and anode into the electrolyte, setting them parallel and opposite to each other. Adjust the distance between the cathode and anode to 16 cm. Electrolyze the electrolyte for 8 hours with stirring. During the reaction, control the electrolyte pH to 5.0, the DC current density to 500 A / m², maintain the electrolysis temperature at 55 ℃, and the electrolyte circulation rate at 5 L / min. Use an air pump to introduce clean air (compressed air) into the electrolyte to ensure uniform stirring. During the electrolysis reaction, nickel ions selectively reduce and grow only in the area constrained by the N-sided through-hole, forming a one-piece quadrilateral ground-corner nickel block.

[0069] Step 4: After the electrolysis reaction is complete, remove the cathode, peel off the mask, rinse the surface of the prepared nickel product with pure water to remove the electrolyte, and then dry it at 65°C.

[0070] The method for preparing the cathode in this embodiment is the same as that in Embodiment 1. The only difference is that the parameters for laser cutting the N-sided through hole in this embodiment are different from those in Embodiment 1. In this embodiment, the laser power is 30 W and the cutting speed is 150 mm / s.

[0071] The final nickel product obtained in this embodiment has dimensions of 300 mm × 200 mm × 50 mm, an arc radius of 8 mm, a parallelism of 0.3 mm, a side perpendicularity of 0.3 mm, a stacking density of 7.465 g / cm³, a pure nickel density of 8.908 g / cm³, a space utilization rate of 83.80%, a purity of 99.999%, and impurities including Ca 4.35ppm, Cu 0.57ppm, Fe 2.52ppm, Pb 2.55ppm, Mn 0.35ppm, and Zn 0.15ppm. It is suitable for 50 kg / box packaging.

[0072] Example 4

[0073] Step 1: Prepare the cathode and anode. The anode is a pure nickel plate with a purity of 99.99%. The cathode includes a conductive plate and a mask attached to the conductive plate. The conductive plate is made of 304 stainless steel, and the mask is a PET film with a thickness of 25μm and a size of 100mm × 100mm. The mask has N-sided through holes of a set size. The N-sided through holes are regular pentagons with a circumcircle diameter of 50mm and an arc radius of 2mm at each corner. N=5. The conductive area of ​​the conductive plate is exposed through the N-sided through holes.

[0074] Step 2: Prepare the electrolyte, which consists of 300 g / L NiSO4·7H2O, 60 g / L NiCl2·6H2O, 37.5 g / L boric acid, and the remainder is deionized water. After stirring all components of the electrolyte evenly, filter to remove impurities, and then adjust the pH value to 3.0.

[0075] The order of steps one and two above is not important;

[0076] Step 3: Insert the cathode and anode into the electrolyte, setting them parallel and opposite to each other. Adjust the distance between the cathode and anode to 8 cm. Electrolyze the electrolyte for 8 hours with stirring. During the reaction, control the electrolyte pH to 3.0, the DC current density to 300 A / m², maintain the electrolysis temperature at 45 ℃, and the electrolyte circulation rate at 5 L / min. Use an air pump to introduce clean air (compressed air) into the electrolyte to ensure uniform stirring. During the electrolysis reaction, nickel ions selectively reduce and grow only in the area constrained by the N-sided through-hole, forming a one-piece pentagonal ground-angle nickel block.

[0077] Step 4: After the electrolysis reaction is complete, remove the cathode, peel off the mask, rinse the surface of the prepared nickel product with pure water to remove the electrolyte, and then dry it at 65°C.

[0078] The method for preparing the cathode in this embodiment is the same as that in Embodiment 1. The only difference is that the N parameter for laser cutting the N-sided through hole in this embodiment is different from that in Embodiment 1. In this embodiment, N is 5.

[0079] The final nickel product obtained in this embodiment is a regular pentagonal rounded corner nickel block with an outer circle diameter of 50 mm, a thickness of 12 mm, an arc radius of 3 mm, a parallelism of 0.3 mm, a side perpendicularity of 0.3 mm, good stacking stability, a stacking density of 5.861 g / cm³, a pure nickel density of 8.908 g / cm³, a space utilization rate of 65.79%, a purity of 99.999%, and impurities including Ca 4.44 ppm, Cu 0.79 ppm, Fe 2.52 ppm, Pb 2.34 ppm, Mn 0.55 ppm, and Zn 0.54 ppm.

[0080] The conductive plates in the above embodiments can also be made of other materials, such as steel / carbon steel, copper, copper alloys (brass, phosphor bronze) or non-metallic materials (plastic, ceramic) after surface chemical copper plating.

[0081] The above description is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing nickel products by electrolysis, characterized in that: Includes the following steps: Step 1: Prepare the cathode and anode. The anode is a pure nickel plate. The cathode includes a conductive plate and a mask attached to the conductive plate. The mask is made of a non-conductive material and has N-sided through holes of a set size. Each corner of the N-sided through hole is rounded, and N≥3. Step 2: Prepare the electrolyte, which includes nickel salt; The order of steps one and two above is not important; Step 3: Insert the cathode and anode into the electrolyte, adjust the distance between the cathode and anode, control the current density, maintain the electrolysis temperature, and the electrolyte will undergo an electrolysis reaction; Step 4: After the electrolysis reaction is complete, remove the cathode and strip the nickel product.

2. The method for preparing nickel products by electrolysis according to claim 1, characterized in that: In step one, the cathode fabrication process includes the following steps: (1) Pre-treat the conductive plate; (2) First, cut N-sided through holes with rounded corners on the mask, and then attach the mask to the surface of the conductive plate; or, first attach the mask to the surface of the conductive plate, and then cut N-sided through holes with rounded corners on the mask.

3. The method for preparing nickel products by electrolysis according to claim 2, characterized in that: In step (1), the pretreatment method is to sequentially perform alkaline washing to remove oil, dilute acid activation, pure water rinsing, and drying on the conductive plate.

4. The method for preparing nickel products by electrolysis according to claim 2, characterized in that: In step (2), an N-sided through hole is formed by laser cutting process. The laser power is 10 to 30 W, the cutting speed is 50 to 150 mm / s, the cutting accuracy is ±5 μm, the edge of the N-sided through hole is smooth and burr-free, and the rounded corner deviation is ≤0.2 mm.

5. The method for preparing nickel products by electrolysis according to any one of claims 1 to 4, characterized in that: In step one, the mask is one of polyimide film, polyester film, polyvinylidene fluoride film, perfluoroalkoxy film, polyethersulfone film or fluorinated ethylene propylene film.

6. The method for preparing nickel products by electrolysis according to any one of claims 1 to 4, characterized in that: In step one, the thickness of the mask is 25~50μm.

7. The method for preparing nickel products by electrolysis according to any one of claims 1 to 4, characterized in that: In step one, N=4.

8. The method for preparing nickel products by electrolysis according to any one of claims 1 to 4, characterized in that: In step two, the electrolyte comprises NiSO4·7H2O 250-350 g / L, NiCl2·6H2O 40-80 g / L, H3BO3 30-50 g / L, and the balance is deionized water.

9. The method for preparing nickel products by electrolysis according to any one of claims 1 to 4, characterized in that: In step three, the electrolyte pH is controlled at 3–5, the temperature at 45–55 °C, and the current density at 300–500 A / m² during the electrolysis reaction.

10. The method for preparing nickel products by electrolysis according to any one of claims 1 to 4, characterized in that: In step three, the cathode and anode are arranged in parallel and opposite directions, with a distance of 8 to 16 cm between them.

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