Supercritical Hydrothermal Preparation of Copper and Copper Oxide Nanoparticles from Acidic Etching Waste Solution

Stable copper and copper oxide nanoparticles are prepared by supercritical hydrothermal synthesis using acidic etching waste solution as the raw material. The effect of different alkali additions on the preparation of copper oxide nanoparticles is investigated, and verification test of the effect of impurity removal is conducted. The control mechanism of copper oxide morphology is obtained, and the effect of corrosion on the purity of final products is analyzed. The results show that under optimized parameters, copper and copper oxide nanoparticles prepared from acidic etching waste liquid have average particle sizes of 82 nm and 52 nm, respectively, with purities of 99.41% and 99.2%, after the removal of impurities. The technological process for the pre-treatment of acidic etching waste is established, and the synthesis process of high-purity nano copper and nano-copper oxide using acidic etching waste as precursor is developed. Finally, the technical economy is accounted based on a pilot-scale continuous plant with a treatment capacity of 480 L/h.