CN113174613B - Preparation method of sulfur-free nickel button - Google Patents

Abstract

The invention discloses a preparation method of a sulfur-free nickel button, and belongs to the field of hydrometallurgy. The invention grows the base button in the first-stage electrolyte with sulfur-containing additive, and then grows the finished nickel button in the second-stage electrolyte without sulfur. The internal stress of the electrolyte is reduced by the brightening agent and the leveling agent in one section of electrolyte, so that the internal stress of the grown base buckle is low, the nickel buckle is ensured not to tilt, and the surface is smooth and flat; the second-stage electrolyte does not contain sulfur-containing additives, so that sulfur is not contained in the nickel simple substance deposited by the cathode, the sulfur content in the nickel button is diluted, the nickel button is prevented from tilting and falling off in the growth process, the surface is smooth and flat, the nickel button is easy to separate from the polar plate, and the nickel button has good application prospect.

Description

A kind of preparation method of sulfur-free nickel buckle

technical field

The invention relates to a preparation method of a sulfur-free nickel button, which belongs to the field of hydrometallurgy.

Background technique

Nickel buckle is an anodic material for electroplating nickel. Because of its oblate button-shaped appearance, it has good fluidity, not only has a high filling density in the anode titanium basket, but also does not appear "tower bridge"phenomenon; the anode area is stable and uniform, and there will be no anode "empty" The "hole" phenomenon is very beneficial to electroplating production, and it is also convenient for mechanical automation to add; in the electroplating process, it has the characteristics of high passivation current density and small passivation area, so nickel buttons are widely used in wire cutting, electronics, crystallizer, Electroforming and other industries. Nickel buckles are divided into sulfur-containing nickel buckles and sulfur-free nickel buckles. The sulfur-free nickel buckles require less than 0.0008% sulfur content and are mainly used in the field of corrosion-resistant electroplating. The direct electrolytic production of sulfur-free nickel buttons in the mixed electrolyte of nickel sulfate and nickel chloride without additives will produce tensile stress. Nickel buttons with high tensile stress tend to have a layered structure, and the edges of the buttons are in a curled state. During the growth process It is easy to fall off the plate. The additives with stress adjustment function are mostly sulfur-containing compounds, which will react with nickel at the cathode to form Ni _x S _y when added to the electrolyte, causing the sulfur content of nickel to exceed the standard.

Contents of the invention

In order to overcome the problem that the nickel buckle caused by high tensile stress in the current production of sulfur-free nickel buckle is easy to present a layered structure, the edge of the buckle is in a curled state, and it is easy to fall off from the plate during the growth process, and a sulfur-free nickel buckle is provided. The preparation method is to suppress the tensile stress of the electrolyte for the flat growth of the nickel buckle on the pole plate, and at the same time ensure that the sulfur content of the nickel buckle meets the requirements.

The preparation method of the sulfur-free nickel button of the present invention is to first electrolytically grow a base button with a certain thickness in a first-stage electrolyte solution containing a sulfur stress regulator with a low current, and then grow a button in a second-stage electrolyte solution without additives. A sulfur-free nickel buckle with a smooth, bright appearance, easy peeling, and a sulfur content of less than 0.0008% is obtained. Concretely include the following process steps:

(1) Heat and dissolve the leveling agent in deionized water, cool to room temperature without solid precipitation, add Class I brightener and Class II brightener respectively, stir and dissolve, and obtain the base buckle additive solution. The leveling agent is at least one of methacrylate and 2,6-pyridinedicarboxylic acid; the class I brightener is at least one of sodium saccharin, sodium benzenesulfonate, and sodium styrene sulfonate; the class II brightener The agent is at least one of 1,4-butynediol, ethoxylated propynyl alcohol, and coumarin.

(2) Add the base button additive solution to the basic electrolyte to obtain a section of electrolyte; heat a section of electrolyte to 60~70°C, put the cathode plate and metal nickel anode dedicated for nickel buttons into the electrolytic cell for electrolysis: The current density is controlled at 110~240A/m ² , and it is taken out after 4~24 hours of electrolysis to obtain a long base-buttoned plate.

In the basic nickel electrolyte, the concentration of each component is nickel sulfate 80~120g/L, nickel chloride 26~95g/L, sodium sulfate 10~30g/L, sodium chloride 10~30g/L, pH=4.5~5.0 . In the first stage of electrolyte, the concentration of leveling agent is 10~260mg/L, the concentration of class I brightener is 30~400mg/L, and the concentration of class II brightener is 5~75mg/L.

(3) Put the pole plate with the base button into the second-stage electrolyte (basic nickel electrolyte), control the electrolysis current density at 240A/m ² ~560A/m ² , and the electrolysis time is 144~240 hours; the nickel button After the electrolysis is completed, take out the nickel buckle plate and vibrate to make the nickel buckle separate from the template, and obtain the finished sulfur-free nickel buckle.

The base buckle prepared above (nickel buckle obtained by one-stage electrolysis. Due to the short period of electrolysis and the low current, the buckle grown is very small, and the nickel buckle obtained by one-stage electrolysis acts like a template, so it is called the base buckle). 0.17~0.57g, the weight of the finished nickel buckle is 18g~30g. Sulfur-free nickel button has dense crystals, smooth surface, and regular button shape. The mass percent content of sulfur element in the nickel buckle is less than 0.0008%.

The internal stress of the nickel coating was detected by the strip cathode method. The results show that the internal stress of the nickel coating obtained by electrolysis in the first-stage electrolyte is -0.3~0.5kg/mm ² , and the internal stress of the nickel coating obtained by adding the second-stage electrolyte is -0.3~0.5kg/mm ² . It shows that the internal stress of the electrolytic nickel buckle in the second-stage electrolyte is not enough to deform the base buckle. )

Compared with the prior art, the present invention has the following advantages: the tensile stress of the nickel buckle produced in the electrolyte without additives is too large, and the electrolysis is divided into two steps for the production of sulfur-free nickel buckle: the first step is to grow the base in a section of electrolyte Buckle, a section of electrolyte contains brightener and leveling agent to reduce the internal stress of the electrolyte, so that the internal stress of the grown base buckle is low, and at the same time it has a smooth and flat surface. Due to the short period of electrolysis, the low current grows a small buckle , the base button obtained by the first-stage electrolysis plays a role similar to the template; the second step continues to grow the finished button in the second-stage electrolyte, because the second-stage electrolyte does not contain sulfur-containing additives, so the nickel element deposited by the cathode does not Contain sulfur, thereby diluting the sulfur content in the nickel buckle. At the same time, because the base buckle has a certain thickness and mechanical strength, it is used as a template to continue to grow in the second-stage electrolyte with high stress, and the internal stress of the second-stage nickel buckle is insufficient. In order to deform the base buckle, the finished nickel buckle finally has a smooth appearance.

Detailed ways

The preparation of the sulfur-free nickel button of the present invention will be further described through specific examples below.

Example 1

(1) Prepare the basic nickel electrolyte in the electrolytic cell according to nickel sulfate 90g/L, nickel chloride 40g/L, sodium chloride 20g/L, and sodium sulfate 20g/L, pH=4.5;

(2) Stir and dissolve 2,6-pyridinedicarboxylic acid in hot water at 60°C, cool to room temperature without solid precipitation, add sodium saccharin, sodium benzenesulfinate, sodium styrenesulfonate, and 1,4-butyne diol and stirred to dissolve to obtain sulfur-containing nickel button additive aqueous solution. The amount of each component in the sulfur-containing nickel button additive aqueous solution is according to its concentration in the first stage of electrolyte: sodium saccharin 90mg/L, sodium benzenesulfonate 85mg/L, sodium styrenesulfonate 85mg/L, 1,4-butyne Metering of diol 10mg/L and 2,6-pyridinedicarboxylic acid 15mg/L;

(3) Add the additive aqueous solution to the basic nickel electrolyte to obtain a section of electrolyte, heat the solution to 60°C, put the special cathode plate for nickel buckle and metal nickel anode into the electrolysis cell for electrolysis, the electrolysis conditions are: first The current density of the section is controlled at 110A/m ² , and it is taken out after 8 hours of electrolysis to obtain a long base-buttoned plate;

(4) Put the long base plate into the second-stage electrolyte (basic electrolyte), control the electrolysis current density at 240A/m ² , and the electrolysis time is 240 hours. After the nickel buckle electrolysis is completed, take out the nickel buckle plate and vibrate to make the nickel buckle detach from the template. The weight of the base button is 0.17g, and the weight of the finished nickel button is 11.3g. The crystal is dense, the surface is smooth, and the shape is a regular button. The nickel buckle detects a sulfur content of 0.0005%.

Example 2

(1) Prepare the basic nickel electrolyte in the electrolytic cell according to nickel sulfate 90g/L, nickel chloride 50g/L, sodium chloride 30g/L, and sodium sulfate 10g/L, pH=4.9;

(2) Stir and dissolve 2,6-pyridinedicarboxylic acid in hot water at 80°C, cool to room temperature without solid precipitation, add sodium saccharin, sodium benzenesulfonate, and coumarin, stir and dissolve respectively, and obtain sulfur-containing nickel button additive aqueous solution. The amount of each component in the sulfur-containing nickel button additive aqueous solution is according to its concentration in the first stage of electrolyte: sodium saccharin 90mg/L, sodium benzenesulfonate 90mg/L, sodium styrenesulfonate 30mg/L, coumarin 5mg/L , 2,6-pyridinedicarboxylic acid 5mg/L metering;

(3) Add the additive aqueous solution to the basic nickel electrolyte to obtain a section of electrolyte, heat the solution to 65°C, and then put the cathode plate for nickel buckle and metal nickel anode into the electrolytic cell for electrolysis. The electrolysis conditions are: The current density of the first section is controlled at 110A/m ² , and it is taken out after 12 hours of electrolysis. Obtain a long base buckle plate;

(4) Put the long base plate into the second-stage electrolyte (basic nickel electrolyte), control the electrolysis current density at 440A/m ² , and perform electrolysis for 144 hours. After the nickel buckle electrolysis is completed, take out the nickel buckle plate and vibrate to make the nickel buckle detach from the template. The weight of the base button is 0.26g, and the weight of the finished nickel button is 12.1g. The crystal is dense, the surface is smooth, and the shape is a regular button. The sulfur content detected by the nickel buckle is 0.0006%.

Example 3

(1) Prepare the basic nickel electrolyte in the electrolytic cell according to nickel sulfate 80g/L, nickel chloride 58g/L, sodium chloride 10g/L, and sodium sulfate 30g/L, pH=4.8;

(2) Stir and dissolve 2,6-pyridinedicarboxylic acid in hot water at 70°C, cool to room temperature without solid precipitation, add sodium saccharin, sodium benzenesulfonate, sodium styrenesulfonate, and ethoxylated propyne Alcohol and methacrylate are stirred and dissolved to obtain an aqueous solution of sulfur-containing nickel button additive. The amount of each component in the sulfur-containing nickel button additive aqueous solution is according to its concentration in the first stage of electrolyte: sodium saccharin 66mg/L, sodium benzenesulfonate 35mg/L, sodium styrenesulfonate 50mg/L, ethoxylated propyne Alcohol 5mg/L, methacrylate 70mg/L, 2,6-pyridinedicarboxylic acid 10mg/L;

(3) Add the additive aqueous solution to the basic nickel electrolyte to obtain a section of electrolyte, heat the solution to 65°C, put the special cathode plate for nickel buckle and metal nickel anode into the electrolytic cell for electrolysis, the electrolysis conditions are: first The current density of the section is controlled at 110A/m ² , and it is taken out after 24 hours of electrolysis, so that the base plate is grown;

(4) Put the long base plate into the second-stage electrolyte (basic nickel electrolyte), control the electrolysis current density at 440A/m ² , and the electrolysis time is 168 hours. After the nickel buckle electrolysis is completed, take out the nickel buckle plate and vibrate to make the nickel buckle detach from the template. The weight of the base button is 0.51g, and the weight of the finished nickel button is 14.2g. The crystal is dense, the surface is smooth, and the shape is a regular button. The sulfur content detected by the nickel buckle is 0.0008%.

Example 4

(1) Prepare the basic nickel electrolyte in the electrolytic cell according to nickel sulfate 115g/L, nickel chloride 30g/L, sodium chloride 30g/L, and sodium sulfate 15g/L, pH=5.0;

(2) Stir and dissolve 2,6-pyridinedicarboxylic acid in hot water at 60°C, cool to room temperature without solid precipitation, add sodium saccharin, sodium benzenesulfonate, sodium styrenesulfonate, coumarin, methyl The acrylate is stirred and dissolved to obtain an aqueous solution of the sulfur-containing nickel button additive. In the sulfur-containing nickel button additive aqueous solution, the consumption of each component is according to its concentration sodium saccharin 80mg/L in the first stage of electrolyte, sodium benzenesulfonate 80mg/L, sodium styrenesulfonate 50mg/L, coumarin 15mg/L L, methacrylate 70mg/L, 2,6-pyridinedicarboxylic acid 10mg/L calculation;

(3) Add the additive aqueous solution to the basic nickel electrolyte to obtain a section of electrolyte, heat the solution to 65°C, put the special cathode plate for nickel buckle and metal nickel anode into the electrolytic cell for electrolysis, the electrolysis conditions are: first The current density of the section is controlled at 180A/m ² , and it is taken out after 8 hours of electrolysis to obtain a base plate.

(4) Put the long base plate into the second-stage electrolyte (basic nickel electrolyte), control the electrolysis current density at 540A/m ² , and the electrolysis time is 168 hours. After the nickel buckle electrolysis is completed, take out the nickel buckle plate and vibrate to make the nickel buckle detach from the template. The weight of the base button is 0.28g, and the weight of the finished nickel button is 17.2g. The crystal is dense, the surface is smooth, and the shape is a regular button. The sulfur content detected by the nickel buckle is 0.0007%.

Example 5

(1) Prepare the basic nickel electrolyte in the electrolytic cell according to nickel sulfate 110g/L, nickel chloride 95g/L, sodium chloride 10g/L, and sodium sulfate 15g/L, pH=5.0;

(2) Stir and dissolve 2,6-pyridinedicarboxylic acid in hot water at 65°C, cool to room temperature without solid precipitation, add sodium saccharin, sodium benzenesulfonate and 1,4-butynediol respectively, stir and dissolve, and obtain Aqueous solution of sulfur nickel button additive. The amount of each component in the sulfur-containing nickel button additive aqueous solution is according to its concentration in the first stage of electrolyte: sodium saccharin 95mg/L, sodium benzenesulfonate 95mg/L, 1,4-butynediol 15mg/L, ethoxy Propyrynol 5mg/L, 2,6-pyridinedicarboxylic acid 15mg/L;

(3) Add the additive aqueous solution to the basic nickel electrolyte to obtain a section of electrolyte, heat the solution to 65°C, put the special cathode plate for nickel buckle and metal nickel anode into the electrolytic cell for electrolysis, the electrolysis conditions are: first The current density of the section is controlled at 240A/m ² , and it is taken out after 4 hours of electrolysis, so that the base plate is grown;

(4) Put the long base plate into the second-stage electrolyte (basic nickel electrolyte), control the electrolysis current density at 560A/m ² , and the electrolysis time is 192 hours. After the nickel buckle electrolysis is completed, take out the nickel buckle plate and vibrate to make the nickel buckle detach from the template. The weight of the base button is 0.19g, and the weight of the finished nickel button is 20.2g. The crystal is dense, the surface is smooth, and the shape is a regular button. The nickel buckle detects a sulfur content of 0.0005%.

Example 6

(1) Prepare the basic nickel electrolyte in the electrolytic cell according to nickel sulfate 110g/L, nickel chloride 95g/L, sodium chloride 15g/L, and sodium sulfate 10g/L, pH=5.0;

(2) Stir and dissolve 2,6-pyridinedicarboxylic acid in hot water at 65°C, cool to room temperature without solid precipitation, add sodium saccharin, sodium benzenesulfonate, sodium styrenesulfonate, and 1,4-butyne Diol is stirred and dissolved to obtain an aqueous solution of sulfur-containing nickel button additive. The amount of each component in the sulfur-containing nickel button additive aqueous solution is according to its concentration in the first stage of electrolyte: sodium saccharin 74mg/L, sodium benzenesulfonate 75mg/L, sodium styrenesulfonate 35mg/L, 1,4-butyne Diol 15mg/L, 2,6-pyridinedicarboxylic acid 15mg/L calculation;

(3) Add the additive aqueous solution to the basic nickel electrolyte to obtain a section of electrolyte, heat the solution to 70°C, put the special cathode plate for nickel buckle and metal nickel anode into the electrolysis cell for electrolysis, the electrolysis conditions are: first The current density of the section is controlled at 240A/m ² , and it is taken out after 6 hours of electrolysis, so that a base-buttoned plate can be grown;

(4) Put the long base plate into the second-stage electrolyte (basic nickel electrolyte), control the electrolysis current density at 440A/m ² , and the electrolysis time is 192 hours. After the nickel buckle electrolysis is completed, take out the nickel buckle plate and vibrate to make the nickel buckle detach from the template. The weight of the base button is 0.28g, and the weight of the finished nickel button is 16g. The crystal is dense, the surface is smooth, and the shape is a regular button. The sulfur content detected by the nickel buckle is 0.0006%.

Claims (6)

1. a preparation method of sulfur-free nickel buckle, comprising the following processing steps: (1) Heat and dissolve the leveling agent in deionized water, cool to room temperature without solid precipitation, add Class 1 brightener and Class 2 brightener respectively and stir to dissolve to obtain the base buckle additive solution; (2) Add the base button additive solution to the basic electrolyte to obtain a section of electrolyte; heat a section of electrolyte to 60~70°C, put the cathode plate and metal nickel anode dedicated for nickel buttons into the electrolytic cell for electrolysis: The current density is controlled at 110~240A/m ² , and it is taken out after 4~24 hours of electrolysis to obtain long base-buttoned plates; (3) Put the pole plate with the base buckle into the basic nickel electrolyte, and electrolyze it for 144~240 hours at a current density of 240A/m ² ~560A/m ² ; after the electrolysis of the nickel buckle is completed, take out the nickel buckle plate and vibrate The nickel buckle is separated from the formwork to obtain a finished sulfur-free nickel buckle. 2. A method for preparing a sulfur-free nickel button as claimed in claim 1, wherein the leveling agent is at least one of methacrylate and 2,6-pyridinedicarboxylic acid. 3. A kind of preparation method of sulfur-free nickel button as claimed in claim 1, is characterized in that: a class of brightening agent is at least one in sodium saccharin, sodium benzenesulfonate, sodium styrenesulfonate. 4. A kind of preparation method of sulfur-free nickel buckle as claimed in claim 1, is characterized in that: the second class brightener is 1,4-butynediol, ethoxylated propynyl alcohol, coumarin at least one. 5. A kind of preparation method of sulfur-free nickel buckle as claimed in claim 1, is characterized in that: in basic nickel electrolyte, each component concentration is nickel sulfate 80～120g/L, nickel chloride 26～95g/L , sodium sulfate 10~30g/L, sodium chloride 10~30g/L, pH=4.5~5.0. 6. A method for preparing sulfur-free nickel buckles as claimed in claim 1, characterized in that: in the first stage of electrolyte, the concentration of the leveling agent is 10-260 mg/L, and the concentration of the first-class brightener is 30-400 mg/L , the concentration of the second class brightener is 5~75mg/L.