Electrolytic copper foil production method in the process of copper dissolution

1, principle: the processed copper material is added to the copper tank, the larger the surface area of the copper material, the better, there should be a small gap between the copper material, to increase the reaction area. After adding a certain amount of pure water and sulfuric acid, through the compressed air oxidation reaction, the formation of copper sulfate solution. Its chemical reaction formula is: 2Cu+2H2SO4+O2=2CuSO4+2H2O. The reaction is solid - liquid, solid - gas, liquid - gas multiphase reaction. The reaction rate is related to the total surface area of copper material in the tank, and the larger the surface area is, the faster the reaction rate is. The second is related to the air volume, the increase of air volume, the reaction speed is also accelerated.

2, foil raw material requirements: the thinner the copper foil thickness, the higher the quality grade, the lower the impurity content in the electrolyte. In order to ensure the quality of copper foil, the purity of copper must be greater than 99.9%.

Equipment and principle of making foil:

1, cathode roller: with the improvement of customer requirements and the development of technology, the diameter of cathode roller from the original 1m, 1.5m increased to 2.2m, 2.7m, width of 1400mm~1500mm, the material is now mostly pure titanium. The cathode roller has good corrosion resistance, and its surface quality directly affects the surface quality and visual effect of raw foil, so the roughness of roller surface Ra<0.3μm. < p="">

2, anode seat: insoluble anode, the current use of material, one is lead-antimony alloy (or lead-silver alloy), the other is titanium. With the prolongation of the service time of the former, the alloy corrosion becomes more and more, resulting in the increase of the electrode distance, the increase of the tank voltage and the increase of power consumption; At the same time, because the corrosion is not very uniform, it also affects the consistency of pole distance, so that the uniformity of copper foil is poor. The latter consists of a titanium matrix and coating. The coating is a mixture of iridium (56%) and tantalum (44%). The anode has good corrosion resistance and the voltage of the groove basically does not rise within a certain limit, so the thickness uniformity of the foil is good, but the one-time investment is large. Even if the coating is damaged and thin, it can be repaired by recoating.

3, raw foil manufacturing: the use of copper sulfate as electrolyte, its main components are Cu2+ and H+. Under direct current, the cation moves to the cathode and the anion moves to the anode. Two electrons of Cu2+ were obtained on the cathode and reduced to Cu, which crystallized on the cathode roll to form raw foil. After the electrolytic process, the content of Cu2+ decreases and that of H2SO4 increases. The electrolyte returned to the copper bath to adjust, so that the electrolyte Cu2+ increased and H2SO4 content decreased. The contents of Cu2+ and H2SO4 in the electrolyte are balanced by electrolysis and copper dissolution.