阅读说明：本技术 一种化学镀镍浸锌盐溶液的分析方法 (Analysis method of chemical nickel-plating zinc-dipping salt solution ) 是由 熊劲松 黎小莲 赵家林 于 2020-12-10 设计创作，主要内容包括：本发明公开了一种化学镀镍浸锌盐溶液的分析方法,包括：氧化锌分析、氢氧化钠分析和酒石酸钾钠分析；其中,氧化锌分析包括：取化学镀镍浸锌盐溶液,在pH为5.4的溶液中,以二甲酚橙作指示剂,用EDTA为络合剂进行滴定；氢氧化钠分析包括：取化学镀镍浸锌盐溶液,用氯化钡沉淀碳酸盐,以酚酞作指示剂,用盐酸进行滴定；酒石酸钾钠分析包括：取化学镀镍浸锌盐溶液,加入氨水,用乙酸铅进行滴定。本发明的分析方法可实现化学镀镍浸锌盐溶液中氧化锌、氢氧化钠和酒石酸钾钠的分析,准确度高,解决了现有化学镀镍生产中浸锌盐溶液难于分析的技术难题。(The invention discloses an analysis method of chemical nickel and zinc plating solution, comprising the following steps: zinc oxide analysis, sodium hydroxide analysis and potassium sodium tartrate analysis; wherein, the zinc oxide analysis comprises: taking a chemical nickel-plating zinc-dipping salt solution, and titrating in a solution with pH of 5.4 by using xylenol orange as an indicator and EDTA as a complexing agent; sodium hydroxide analysis included: taking chemical nickel plating zinc dipping salt solution, precipitating carbonate by barium chloride, taking phenolphthalein as an indicator, and titrating by hydrochloric acid; sodium potassium tartrate analysis included: taking the chemical nickel plating zinc dipping salt solution, adding ammonia water, and titrating by lead acetate. The analysis method of the invention can realize the analysis of zinc oxide, sodium hydroxide and potassium sodium tartrate in the chemical nickel plating zincate solution, has high accuracy and solves the technical problem that the zincate solution is difficult to analyze in the existing chemical nickel plating production.)

1. An analytical method for electroless nickel and zincate solutions, comprising: zinc oxide analysis, sodium hydroxide analysis and potassium sodium tartrate analysis; wherein the content of the first and second substances,

the zinc oxide analysis comprises: taking a chemical nickel-plating zinc-dipping salt solution, and titrating in a solution with pH of 5.4 by using xylenol orange as an indicator and EDTA as a complexing agent;

the sodium hydroxide analysis comprises: taking chemical nickel plating zinc dipping salt solution, precipitating carbonate by barium chloride, taking phenolphthalein as an indicator, and titrating by hydrochloric acid;

the potassium sodium tartrate analysis comprises: taking the chemical nickel plating zinc dipping salt solution, adding ammonia water, and titrating by lead acetate.

2. The analytical method according to claim 1, wherein the zinc oxide analysis specifically comprises:

taking a chemical nickel plating zinc dipping salt solution, and neutralizing with an acid solution until white precipitate is generated;

after precipitation, adding a buffer solution with pH of 5.4, ammonium bifluoride and a xylenol orange indicator;

titrating with EDTA standard solution until the solution changes from purple to yellow as an end point.

3. The analytical method of claim 2,

the acid solution is a dilute hydrochloric acid solution;

the buffer solution is hexamethylenetetramine-hydrochloric acid buffer solution;

the xylenol orange indicator is a mixture of xylenol orange and potassium nitrate.

4. The analytical method of any one of claims 1 to 3, wherein the zinc oxide is present in an amount of:

ρ_(ZnO)＝C₁V₁·M_ZnO/V

in the formula (I), the compound is shown in the specification,

ρ_(ZnO)the content of zinc oxide is given in g/l;

C₁the molar volume of EDTA is expressed in mol/l;

V₁volume in ml of EDTA consumed;

M_ZnOtaking 81.4g/mol as the molar mass of ZnO;

v is the volume of the chemical nickel and zinc plating solution taken, and the unit is ml.

5. The analytical method according to claim 1, wherein the sodium hydroxide analysis specifically comprises:

adding barium chloride solution into the chemical nickel plating zinc dipping salt solution, shaking up, and precipitating carbonate in the chemical nickel plating zinc dipping salt solution;

add phenolphthalein indicator and titrate with hydrochloric acid standard solution until the red color disappears as the end point.

6. The assay of claim 1 or 5, wherein the sodium hydroxide is present in an amount of:

ρ_(NaOH)＝C₂V₂·M_NaOH/V

in the formula (I), the compound is shown in the specification,

ρ_(NaOH)is the content of sodium hydroxide, and the unit is g/l;

C₂is the molar volume of hydrochloric acid and has the unit of mol/l;

V₂the volume of consumed hydrochloric acid is ml;

M_NaOHtaking 40g/mol as the molar mass of NaOH;

v is the volume of the chemical nickel and zinc plating solution taken, and the unit is ml.

7. The assay method according to claim 1, wherein the potassium sodium tartrate assay specifically comprises:

taking a chemical nickel plating and zinc dipping salt solution, and adding water and ammonia water;

titration with lead acetate was carried out until a white precipitate was obtained as an end point.

8. The analytical method of claims 1 and 7, wherein the potassium sodium tartrate is present in an amount of:

ρ_{(KNaC4H4O6.4H2O)}＝1000V₃T/V

in the formula (I), the compound is shown in the specification,

ρ_{(KNaC4H4O6.4H2O)}is potassium tartrateThe content of sodium is g/l;

V₃the volume of consumed lead acetate is in ml;

t is titer, and the unit is g/ml;

v is the volume of the chemical nickel and zinc plating solution taken, and the unit is ml.

Technical Field

The invention relates to the technical field of solution component analysis, in particular to an analysis method of a chemical nickel and zinc plating solution.

Background

Electroless plating is a surface processing method in which a reducing agent in a system is oxidized by some chemical method to release free electrons, and metal ions are reduced to metal atoms and deposited on the surface of a substrate to form a plating layer without passing an external current.

The main process characteristics of chemical plating comprise:

1. uniform plating layer thickness, wherein the chemical plating has the great characteristics of uniform plating layer thickness and good uniform plating capability, so that the chemical plating is caused by an electroplating process; the electroplating layer of the electroplating process can cause uneven plating thickness due to uneven current distribution, the plating thickness of the electroplating process on the whole part is sometimes greatly different, particularly for parts with complex shapes, and the thicker part of the plating layer is mainly at the corner of the part and the part close to the anode; but is poorly or even non-plated on the inner surface or at locations remote from the anode. The use of chemical plating can avoid the defect of electroplating, when the chemical plating is carried out, the surface of the part only needs to be contacted with the plating solution, and substances consumed in the plating solution are supplemented in time, so that the plating thickness of each part of the substrate can be ensured to be approximately equal, and the plating can be carried out even if the groove, the gap and the blind hole are formed.

2. The chemical plating layer can be deposited on the surfaces of various materials, such as steel nickel-based alloy, zinc-based alloy, aluminum alloy, semiconductors and the like, and can also be plated on the surfaces of glass, ceramics and plastics, so that the performance of the base material is improved.

The electroplating can not carry out full-surface plating on the surfaces of workpieces with complex shapes, in particular to plating of difficult-to-plate metals such as aluminum alloy and the like; the chemical nickel plating of the aluminum alloy needs to be performed with a zincing treatment, but at present, no good method exists for analyzing the solution of the nickel plating zincate.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides an analysis method of chemical nickel plating and zincification salt solution.

The invention discloses an analysis method of chemical nickel and zinc plating solution, comprising the following steps: zinc oxide analysis, sodium hydroxide analysis and potassium sodium tartrate analysis; wherein the content of the first and second substances,

the zinc oxide analysis comprises: taking a chemical nickel-plating zinc-dipping salt solution, and titrating in a solution with pH of 5.4 by using xylenol orange as an indicator and EDTA as a complexing agent;

the sodium hydroxide analysis comprises: taking chemical nickel plating zinc dipping salt solution, precipitating carbonate by barium chloride, taking phenolphthalein as an indicator, and titrating by hydrochloric acid;

the potassium sodium tartrate analysis comprises: taking the chemical nickel plating zinc dipping salt solution, adding ammonia water, and titrating by lead acetate.

As a further improvement of the present invention, the zinc oxide analysis specifically includes:

taking a chemical nickel plating zinc dipping salt solution, and neutralizing with an acid solution until white precipitate is generated;

after precipitation, adding a buffer solution with pH of 5.4, ammonium bifluoride and a xylenol orange indicator;

titrating with EDTA standard solution until the solution changes from purple to yellow as an end point.

As a further improvement of the present invention,

the acid solution is a dilute hydrochloric acid solution;

the buffer solution is hexamethylenetetramine-hydrochloric acid buffer solution;

the xylenol orange indicator is a mixture of xylenol orange and potassium nitrate.

As a further improvement of the invention, the content of the zinc oxide is:

ρ_(ZnO)＝C₁V₁·M_ZnO/V

in the formula (I), the compound is shown in the specification,

ρ_(ZnO)the content of zinc oxide is given in g/l;

C₁the molar volume of EDTA is expressed in mol/l;

V₁volume in ml of EDTA consumed;

M_ZnOtaking 81.4g/mol as the molar mass of ZnO;

v is the volume of the chemical nickel and zinc plating solution taken, and the unit is ml.

As a further improvement of the present invention, the sodium hydroxide analysis specifically includes:

adding barium chloride solution into the chemical nickel plating zinc dipping salt solution, shaking up, and precipitating carbonate in the chemical nickel plating zinc dipping salt solution;

add phenolphthalein indicator and titrate with hydrochloric acid standard solution until the red color disappears as the end point.

As a further improvement of the invention, the content of the sodium hydroxide is as follows:

ρ_(NaOH)＝C₂V₂·M_NaOH/V

in the formula (I), the compound is shown in the specification,

ρ_(NaOH)is the content of sodium hydroxide, and the unit is g/l;

C₂is the molar volume of hydrochloric acid and has the unit of mol/l;

V₂the volume of consumed hydrochloric acid is ml;

M_NaOHtaking 40g/mol as the molar mass of NaOH;

v is the volume of the chemical nickel and zinc plating solution taken, and the unit is ml.

As a further improvement of the present invention, the sodium potassium tartrate analysis specifically includes:

taking a chemical nickel plating and zinc dipping salt solution, and adding water and ammonia water;

titration with lead acetate was carried out until a white precipitate was obtained as an end point.

As a further improvement of the invention, the content of the potassium sodium tartrate is as follows:

ρ_{(KNaC4H4O6.4H2O)}＝1000V₃T/V

in the formula (I), the compound is shown in the specification,

ρ_{(KNaC4H4O6.4H2O)}the content of potassium sodium tartrate is shown as the unit of g/l;

V₃the volume of consumed lead acetate is in ml;

t is titer, and the unit is g/ml;

v is the volume of the chemical nickel and zinc plating solution taken, and the unit is ml.

Compared with the prior art, the invention has the beneficial effects that:

the analysis method of the invention can realize the analysis of zinc oxide, sodium hydroxide and potassium sodium tartrate in the chemical nickel plating zincate solution, has high accuracy and solves the technical problem that the zincate solution is difficult to analyze in the existing chemical nickel plating production.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

The invention is described in further detail below:

the invention provides an analysis method of chemical nickel and zinc plating salt solution of aluminum alloy, which comprises the following steps: zinc oxide analysis, sodium hydroxide analysis and potassium sodium tartrate analysis; wherein the content of the first and second substances,

the zinc oxide analysis of the present invention comprises: taking the chemical nickel plating zinc dipping salt solution, and titrating in a solution with pH of 5.4 by using xylenol orange as an indicator and EDTA as a complexing agent.

The method specifically comprises the following steps: taking chemical nickel plating zinc dipping salt solution, and neutralizing with 1:4 hydrochloric acid until white precipitate is generated; after the precipitation, a buffer solution (hexamethylenetetramine-hydrochloric acid buffer solution) with a pH of 5.4, ammonium bifluoride and a xylenol orange indicator are added; finally, titrating by using EDTA standard solution until the solution changes from purple to yellow as an end point; wherein, the content of zinc oxide is:

ρ_(ZnO)＝C₁V₁·M_ZnO/V

in the formula (I), the compound is shown in the specification,

ρ_(ZnO)the content of zinc oxide is given in g/l;

C₁the molar volume of EDTA is expressed in mol/l;

V₁volume in ml of EDTA consumed;

M_ZnOtaking 81.4g/mol as the molar mass of ZnO;

v is the volume of the chemical nickel and zinc plating solution taken, and the unit is ml.

As an example of the zinc oxide analysis, the analysis method includes: sucking 5ml of the plating solution into a 250ml conical flask by using a 5ml pipette, adding 10ml of water, and neutralizing by using 1:4 hydrochloric acid until a white precipitate appears; then, 20ml of a buffer solution with a pH of 5.4 was added (the buffer solution was prepared by weighing 40g of hexamethylenetetramine and diluting to 100ml with 10ml of concentrated hydrochloric acid), 1g of ammonium bifluoride was added, shaking was carried out, about 0.2g of a xylenol orange indicator was added (the xylenol orange indicator was prepared by weighing 1g of xylenol orange and 100g of potassium nitrate and mixing and grinding them uniformly), and the mixture was titrated with 0.05mo1/l of EDTA standard solution until the solution turned from purple to yellow. Wherein, the content of zinc oxide is:

ρ_(ZnO)＝C₁V₁·81.4/5

the sodium hydroxide analysis of the present invention comprises: taking the chemical nickel plating zinc dipping salt solution, precipitating carbonate by barium chloride to eliminate the interference of carbonate ions, taking phenolphthalein as an indicator, and titrating by using a hydrochloric acid standard solution until the red color disappears as a terminal point.

Wherein, the principle of sodium hydroxide analysis is as follows: titrating sodium hydroxide in the chemical nickel plating and zinc dipping salt solution analysis method by using a hydrochloric acid standard solution, adding barium chloride to precipitate carbonate by using phenolphthalein as an indicator, converting sodium zincate in the plating solution into zinc hydroxide precipitate when the titration is finished, wherein the zinc hydroxide corresponds to zinc oxide used in the preparation of the plating solution:

ZnO+2NaOH＝Na₂ZnO₂+H₂O

titrating with hydrochloric acid until the phenolphthalein indicator changes color,

Na₂ZnO₂+2HCl＝Zn(OH)₂+2NaCl

when preparing a plating solution, 2mol of sodium hydroxide is consumed by lmol zinc oxide, and 2mol of hydrochloric acid is consumed by 1mol of sodium zincate when phenolphthalein is titrated to be discolored by hydrochloric acid; thus, with phenolphthalein as the indicator, titration with hydrochloric acid, divalent zinc in the bath does not interfere with the determination of sodium hydroxide.

Wherein, the content of the sodium hydroxide is as follows:

ρ_(NaOH)＝C₂V₂·M_NaOH/V

in the formula (I), the compound is shown in the specification,

ρ_(NaOH)is the content of sodium hydroxide, and the unit is g/l;

C₂is the molar volume of hydrochloric acid, monoThe site is mol/l;

V₂the volume of consumed hydrochloric acid is ml;

M_NaOHtaking 40g/mol as the molar mass of NaOH;

v is the volume of the chemical nickel and zinc plating solution taken, and the unit is ml.

As an example of the sodium hydroxide analysis, the analysis method includes: sucking 1ml of the aluminum alloy chemical nickel and zinc plating solution into a 250ml conical flask, adding 50ml of water, adding 10ml of barium chloride solution (10% aqueous solution), shaking up, adding 2-3 drops of phenolphthalein indicator (1g of phenolphthalein is dissolved in 80ml of ethanol, and after dissolution, adding water to dilute to 100ml), and titrating with 0.1mo1/l hydrochloric acid standard solution until the red disappears.

The content of sodium hydroxide is:

ρ_(NaOH)＝C₂V₂·40

the potassium sodium tartrate analysis of the invention comprises: taking the chemical nickel plating zinc dipping salt solution, adding ammonia water, and titrating by using lead acetate until white precipitate is obtained as a terminal point.

Wherein, the analysis of potassium sodium tartrate uses lead acetate to react with potassium sodium tartrate to produce white precipitate, the precipitate is dissolved in ammonia water, and the excessive lead acetate and hydroxide in the solution generate white end point.

The content of potassium sodium tartrate is as follows:

ρ_{(KNaC4H4O6.4H2O)}＝1000V₃T/V

in the formula (I), the compound is shown in the specification,

ρ_{(KNaC4H4O6.4H2O)}the content of potassium sodium tartrate is shown as the unit of g/l;

V₃the volume of consumed lead acetate is in ml;

t is titer, and the unit is g/ml;

v is the volume of the chemical nickel and zinc plating solution taken, and the unit is ml.

As an example of potassium sodium tartrate analysis, the analysis method comprises: sucking 5ml of the aluminum alloy electroless nickel and zinc plating solution into a 250ml conical flask, adding 50ml of water and 20ml of ammonia water, and titrating the solution by adding 0.05mo1/l lead acetate until a white precipitate is obtained.

Examples

Example 1:

taking No. 1 tank liquor of the company A for zinc oxide analysis:

sucking 5ml of the aluminum alloy electroless nickel and zinc plating solution into a 250ml conical flask, adding 10ml of water, neutralizing with 1:4 hydrochloric acid until a white precipitate appears, adding a buffer solution (20ml, adding 1g of ammonium bifluoride, shaking up and adding about 0.2g of xylenol orange indicator, and titrating with 0.05mo1/l of EDTA standard solution until the solution turns yellow from purple.

The content of zinc oxide is:

ρ_(ZnO)＝C₁V₁·81.4/5

the results after 3 analytical tests are shown in table 1:

TABLE 1

The tank liquor No. 1 from the company A is taken for sodium hydroxide analysis:

sucking 1ml of the aluminum alloy chemical nickel and zinc plating solution into a 250ml conical flask, adding 50ml of water, adding 10ml of barium chloride solution (10% aqueous solution), shaking up, adding 2-3 drops of phenolphthalein indicator (1g of phenolphthalein is dissolved in 80ml of ethanol, and after dissolution, adding water to dilute to 100ml), and titrating with a hydrochloric acid standard solution until the red color disappears.

The content of sodium hydroxide is:

ρ_(NaOH)＝C₂V₂·40

the results after 3 analytical tests are shown in table 2:

TABLE 2

Taking No. 1 tank liquor of the company A for potassium sodium tartrate analysis:

sucking 5ml of the aluminum alloy electroless nickel and zinc plating solution into a 250ml conical flask, adding 50ml of water and 20ml of ammonia water, and adding 0.05mo1/l lead acetate to titrate until white precipitate is formed.

The results after 3 analytical tests are shown in table 3:

TABLE 3

Example 2:

taking No. 1 tank liquor of B company for zinc oxide analysis:

sucking 5ml of the aluminum alloy electroless nickel and zinc plating solution into a 250ml conical flask, adding 10ml of water, neutralizing with 1:4 hydrochloric acid until a white precipitate appears, adding a buffer solution (20ml, adding 1g of ammonium bifluoride, shaking up and adding about 0.2g of xylenol orange indicator, and titrating with 0.05mo1/l of EDTA standard solution until the solution turns yellow from purple.

The content of zinc oxide is:

ρ_(ZnO)＝C₁V₁·81.4/5

the results after 3 analytical tests are shown in table 4:

TABLE 4

The tank liquor No. 1 from the company B is taken for sodium hydroxide analysis:

sucking 1ml of the aluminum alloy chemical nickel and zinc plating solution into a 250ml conical flask, adding 50ml of water, adding 10ml of barium chloride solution (10% aqueous solution), shaking up, adding 2-3 drops of phenolphthalein indicator (1g of phenolphthalein is dissolved in 80ml of ethanol, and after dissolution, adding water to dilute to 100ml), and titrating with a hydrochloric acid standard solution until the red color disappears.

The content of sodium hydroxide is:

ρ_(NaOH)＝C₂V₂·40

the results after 3 analytical tests are shown in table 5:

TABLE 5

Taking No. 1 tank liquor of B company for potassium sodium tartrate analysis:

sucking 5ml of the aluminum alloy electroless nickel and zinc plating solution into a 250ml conical flask, adding 50ml of water and 20ml of ammonia water, and adding 0.05mo1/l lead acetate to titrate until white precipitate is formed.

The results after 3 analytical tests are shown in table 6:

TABLE 6

The invention has the advantages that:

the analysis method of the invention can realize the analysis of zinc oxide, sodium hydroxide and potassium sodium tartrate in the chemical nickel plating zincate solution, has high accuracy and solves the technical problem that the zincate solution is difficult to analyze in the existing chemical nickel plating production.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.