Chemical deplating solution and deplating method suitable for removing tin-nickel coating on surface of brass

A tin-nickel coating and stripping solution technology, applied in stripping solution and its stripping field, can solve the problems of water, soil, natural ecological pollution, affecting workers' physical and mental health, difficult industrialized production, etc. It is beneficial to the large-scale production operation of the factory and the effect of accelerating the dissolution

Inactive Publication Date: 2010-07-14
HEFEI UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Often contain cyanide, chromic acid, hydrofluoric acid, etc. in these processes about brass substrate elemental coating, these deplating solutions often contain very high toxicity, cause working environment bad, have a strong impact on the physical and mental health of workers, and also affect the water area , soil, and natural ecology produce a lot of pollution
And, the method for copper substrate deplating coating that has been reported at present also generally exists overcorrosion strong, high cost, defects such as difficult suitability for industrialized production, so it is necessary to develop a kind of novel deplating of tin-nickel alloy coating on brass surface Liquid and its deplating method

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] Chemical stripping solution of the present invention is used for stripping the method for stripping the tin-nickel coating on the brass surface, and the steps are:

[0026] 1. Surface treatment: immerse the waste material coated with tin-nickel coating on the brass substrate in lye at 80°C for 3 minutes;

[0027] The lye is an aqueous solution, which contains: NaOH: 8g / L, Na 2 CO 3 : 50g / L, Na 3 PO 4 12H 2 O: 56g / L, NaSiO 3 : 10g / L;

[0028] 2. Washing with water: wash and dry the waste after finishing alkali washing, and set aside;

[0029] 3. Deplating: Immerse the dried waste into 250mL compound acid / L (1L contains 36-38% hydrochloric acid 65mL, 65-68% nitric acid 195mL), 30g citric acid / L, 0.10g benzotriazepine Deplating is carried out in a deplating solution with the balance of azole / L, and the balance is water; the deplating condition is that the temperature is 50°C; the process of deplating is continuously stirred, and the deplating time is 6 minutes;

[...

Embodiment 2

[0032] Chemical stripping solution of the present invention is used for stripping the method for stripping the tin-nickel coating on the brass surface, and the steps are:

[0033] 1. Surface treatment: immerse the waste material coated with tin-nickel coating on the brass substrate in 90°C lye for 2 minutes;

[0034] The lye is an aqueous solution, which contains: NaOH: 10g / L, Na 2 CO 3 : 55g / L, Na 3 PO 4 12H 2 O: 60g / L, NaSiO 3 : 5g / L;

[0035] 2. Washing with water: wash and dry the waste after finishing alkali washing, and set aside;

[0036] 3. Deplating: Dip the dried tin-nickel plating waste into 300mL compound acid / L (1L contains 36-38% hydrochloric acid 75mL, 65-68% nitric acid 225mL), 20g citric acid / L, 0.30g benzene and triazole / L, and the balance is deplating solution of water for deplating; the deplating condition is, the temperature is 40 ° C; the process of deplating is constantly stirred, and the deplating time is 6 minutes;

[0037] 4. Take out the wast...

Embodiment 3

[0039] Chemical stripping solution of the present invention is used for stripping the method for stripping the tin-nickel coating on the brass surface, and the steps are:

[0040] 1. Surface treatment: immerse the waste material coated with tin-nickel coating on the brass substrate in 90°C lye for 2 minutes;

[0041] The lye is an aqueous solution, which contains: NaOH: 12g / L, Na 2 CO 3 : 60g / L, Na 3 PO 4 12H 2 O: 56g / L, NaSiO 3 : 5g / L;

[0042]2. Washing with water: wash and dry the waste after finishing alkali washing, and set aside;

[0043] 3. Deplating: Immerse the dried tin-nickel plating waste into 400mL compound acid / L (including 100mL / L hydrochloric acid and 300mL / L nitric acid), 15g citric acid / L, 0.40g benzotriazole / L, Deplating is carried out in the deplating solution with the balance of water; the deplating condition is, the temperature is 30°C; the process of deplating is continuously stirred, and the deplating time is 10 minutes;

[0044] 4. Take out the...

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PUM

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Abstract

The invention discloses a deplating solution and a deplating method thereof for tin-nickel coating (commonly called plated scrap) on the surface of brass. The deplating solution comprises oxidizer, accelerator, complexing agent and inhibitor, and the deplating solution is prepared by adding water to the reagents, stirring, dissolving, then putting in a water bath and slowly heating. The oxidizer adopts 65-68% nitric acid, the accelerator adopts 36-38% hydrochloric acid, the complexing agent adopts citric acid and the inhibitor adopts benzotriazole. After being deplated by the deplating solution of the invention, the surface of the brass is bright, the color of the substrate is basically unchanged, and the brass has no pinholes and small corrosion amount.

Description

technical field [0001] The invention relates to a deplating solution and a deplating method thereof, in particular to a chemical deplating solution and a deplating method suitable for stripping the tin-nickel coating on the surface of brass. Background technique [0002] The recycling and utilization of scraps of copper and copper alloy products with tin-nickel plating on the surface have received great attention in countries all over the world. In order to recycle defective or waste products with metallization on the surface, it is necessary to remove the metal composite coating, that is, deplating. Regarding the deplating process of the coating, chemical or electrochemical stripping methods can be used. Electrochemical stripping solution has simple composition, weak corrosion to the substrate, and can be recycled for some metals, which is beneficial to environmental protection, but it needs to provide power supply and stripping tank, and sometimes special hangers are requ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C23F1/16C23F1/30
Inventor 胡献国蔡文举徐玉福
Owner HEFEI UNIV OF TECH
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