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Titanium Anodes for Copper Recovery from Etching Solution

1. Application field: The PCB industry produces a large amount of micro etching solution, etching solution, copper nitrate, and other copper containing different concentrations in the production process

2. Current density: (200-400) A/m2

3. Service life: 12-24 months

4. Process flow:

A. Micro etching solution (Cu2SO4+H2O2) oxygen breaking electrolytic cell (decomposition of H2O2) for copper electroplating

B. Alkaline etching solution extraction process for copper sulfate+copper sulfate electrowinning

C. Acid etching solution ion membrane electrolysis (electrowinning copper) tail gas treatment (absorbing chlorine gas)

5. Electrochemical performance and life testing (refer to standard HG/T2471-2007 Q/CLTN-2012)

6. Product usage background and introduction:

In the production process of the PCB industry, a large amount of micro etching solution, etching solution, copper nitrate and other metals with different concentrations are generated, which have high recovery value. In addition, there will also be a small amount of copper heavy metals in the discharged wastewater. If environmental protection treatment cannot be carried out reasonably, it will cause serious resource waste on the one hand, and on the other hand, heavy metals will seep into the soil and water sources after discharge, which will cause serious pollution and harm to the natural environment and our own health that we rely on for survival.

1) Microetching solution

Microetching solution includes sodium persulfate/sulfuric acid system and hydrogen peroxide/sulfuric acid system, which have been widely used in surface treatment processes of PCB in recent years, such as copper deposition (PTH) process, electroplating process, inner layer pre-treatment, green oil pre-treatment, OSP treatment and other production lines. Direct electrolysis can damage the anode coating.

2) Etching solution

During the etching process of electronic circuit boards (PCBs), the copper content in the etching solution gradually increases. To achieve the best etching effect, each liter of etching solution needs to contain 120 to 180 grams of copper and corresponding amounts of etching salt (NH4CI) and ammonia solution (NH3). The etching solution regeneration cycle system can be divided into acidic and alkaline systems, which can be further divided into extraction method and direct electrolysis method. A large amount of used etching solution that originally needed to be discharged can be reduced and regenerated into reusable etching solution. Thereby reducing the discharge of production waste liquid, reusing it to reduce production costs, and extracting high-purity electrolytic copper metal.