Electrolytic regeneration method of acidic etching waste solution

A technology for acidic etching waste liquid and electrolytic regeneration, which is applied in the field of electrolytic regeneration of acidic etching waste liquid for printed circuit boards. The effect of high reliability

Inactive Publication Date: 2009-09-16
GUANGZHOU RES INST OF NON FERROUS METALS
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The potential distribution is uneven, the possibility of chlorine gas precipitation is high, the graphite anode is continuously worn out, the cell voltage rises, and the cooling energy consumption of the electrolyte is high

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0016] For copper containing 140g / L (Cu + 10g / L), chlorine 242g / L, hydrogen 2.0g / L acidic etching waste liquid for electrolytic regeneration, the inhibitor ammonium chloride concentration is 0.3mol / L. Mix the etching waste liquid with water at a volume ratio of 1:4 to form a catholyte, containing 28 g / L of copper. The electrolyzer operates at a DC voltage of 3.5V with a current density of 1000A / m 2 . After passing the photoelectric colorimetric test, the anolyte and catholyte are mixed evenly at a volume ratio of 4.5:1.

[0017] Most of the copper powder is concentrated in the bottom of the cathode chamber, which is rose red. Chemical analysis showed that the copper powder was 99.2% pure. The electric efficiency of copper powder precipitation is 86%. Tested by starch potassium iodide test paper, no chlorine gas is precipitated, and the regeneration efficiency of copper ions is 99%.

[0018] This regeneration solution contains copper 120g / L (Cu + 0.5g / L), chlorine 240g / L...

Embodiment 2

[0020] For copper containing 120g / L (Cu + 8g / L), chlorine 180g / L, hydrogen 1.2g / L, and acidic etching waste liquid containing ammonium radical 17g / L for electrolytic regeneration. Mix the etching waste liquid with water at a volume ratio of 1:4 to form the catholyte, containing 24 g / L of copper. The electrolyzer operates at a DC voltage of 4.0V with a current density of 750A / m 2 . After passing the photoelectric colorimetric test, the anolyte and catholyte are mixed evenly at a volume ratio of 3.7:1.

[0021] Most of the copper powder is concentrated at the bottom of the cathode chamber, and the color is rose red. Chemical analysis showed that the copper powder was 99.5% pure. The electric efficiency of copper powder precipitation is 85%. Tested by starch potassium iodide test paper, no chlorine gas is precipitated, and the regeneration efficiency of copper ions is 98%.

[0022] This regeneration solution contains copper 100g / L (Cu + 0g / L), chlorine 178g / L, hydrogen 1.0...

Embodiment 3

[0024] For copper containing 130g / L (Cu + 8.5g / L), chlorine 210g / L, and hydrogen 1.4g / L acidic etching waste liquid for electrolytic regeneration, and the concentration of inhibitor triethanolamine is 0.1mol / L. Mix the etching waste liquid with water at a volume ratio of 1:4.3 to form a catholyte, containing 30 g / L of copper. The electrolyzer operates at a DC voltage of 4.5V with a current density of 1000A / m 2 . After passing the photoelectric colorimetric test, the anolyte and catholyte are mixed evenly at a volume ratio of 2.4:1.

[0025] Most of the copper powder is concentrated at the bottom of the cathode chamber, and the color is rose red. Chemical analysis showed that the copper powder was 99.2% pure. The electric efficiency of copper powder precipitation is 86%. Tested by starch potassium iodide test paper, no chlorine gas is precipitated, and the regeneration efficiency of copper ions is 97%.

[0026] This regeneration solution contains copper 100g / L (Cu + 0.5g...

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Abstract

An electrolytic regeneration method of acidic etching waste solution is characterized in that the acidic etching waste solution is used as anolyte added or not added with an inhibitor with concentration of 0.05-0.5mol/L and acidic etching waste solution with mass concentration of diluted copper of 15-40g/L is used as catholyte; electrolysis is carried out for 3-8h under the conditions of 3-6V DC electrolyzing voltage and 500-2000A/m<2> current density, after electrolysis, metal copper powder is obtained in a cathode chamber; the anolyte and catholyte are mixed into acidic etching regeneration solution according to the volume ratio of 2-5:1. The method of the invention has the following advantages: the electric efficiency of copper ion regeneration is not less than 97%, the electric efficiency of copper powder precipitation is not less than 85% and the purity of the copper powder is higher than 99%; the copper powder can not damage ion films and the method has high reliability. No chlorine is precipitated during electrolytic regeneration and hydrochloric acid is unnecessary to be added, therefore, the method of the invention is environment-friendly.

Description

technical field [0001] The invention relates to a regeneration method for acidic copper-containing waste liquid, in particular to an electrolytic regeneration method for acidic etching waste liquid of printed circuit boards. Background technique [0002] In the process of manufacturing printed circuit boards using the subtractive method, circuit patterns are formed by chemical etching. When the copper concentration or the cuprous ion concentration of the etching solution increases to a certain value, the etching solution cannot stably and quickly bite the copper foil, and at this time it becomes an acidic waste liquid. The mass concentration of copper in typical etching waste liquid is 120-160g / L, chlorine is 180-245g / L, and hydrogen is 1-4g / L. Acidic etching waste liquid is a hazardous waste, and there are many risks in the process of storage, transportation and recycling. Therefore, the economical, efficient and environmentally friendly electrolytic regeneration of acidic...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C23F1/46C23F1/18C25C5/02
Inventor 蒋玉思张建华黄奇书肖方明程华月
Owner GUANGZHOU RES INST OF NON FERROUS METALS
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