Effect of process conditions on the preparation of copper powders by electro-deposition

Copper powders were prepared by electro-deposition with an inert anode. The effects of Cu²⁺ mass concentration, H₂SO₄ mass concentration, current density, electrolyte temperature and scraping interval on the median particle diameter of copper powders were investigated. The results show that high quality copper powders with a normal particle size distribution and dendritic micromorphologies were obtained under the optimum conditions of the Cu²⁺ mass concentration of 15 g·L^-1, the H₂SO₄ mass concentration of 140g·L^-1, the current density of 1 800 A· m^-2, the electrolyte temperature of 35℃, the scraping interval of 30 min, the circulation rate of 14 L·h^-1 and the interpolar distance of 4.5 cm. It is advantageous to the decrease in cell voltage to increase the Cu²⁺ mass concentration, H₂SO₄ mass concentration and electrolyte temperature. The increases of Cu²⁺ mass concentration, electrolyte temperature and scraping interval help improving the current efficiency. A higher current density, a higher H₂SO₄ mass concentration and a lower Cu²⁺ mass concentration are beneficial to obtain copper powders with small particle size.