In the copper foil production process, one of the first stages is to dissolve high-grade (recycled) copper in Sulfuric Acid (H2S04)(1). This solution will pump through filters to produce the desired copper electrolyte solution and remove impurities. The last stage is a storage tank. This is where they keep the solution before its fed to the actual plating process to create copper foil(2).
On the side of this storage tank, in a recirculated bypass, they constantly monitor both concentrations (Cu + H2SO4). This is a critical measurement in the production process of copper foil. When the solution meets all chemical and quality standards, the solution is pumped into large plating tanks. The tanks contain partially immersed titanium drums to create a thin film of very pure copper. These are also referred to as electroplating (ED) machines(3).