Abstract

Ultrafine copper powder was prepared from CuO-H_2O slurry with hydrazine, a reductant, under 70°C. The influence of various reaction parameters such as temperature, reaction time, molar ratio of N_2H_4, PvP and NaOH to Cu in aqueous solution had been studied on the morphology and powder phase of Cu powders obtained. The production ratio of Cu from CuO was increased with the ratio of N_2H_4/Cu and the temperature. When the ratio of N_2H_4/Cu was higher than 2.5 and the temperature was higher than 60°C, CuO was completely reduced into Cu within 40 min. The crystalline size of Cu obtained became fine as the temperature increase, whereas the aggregation degree of particles was increased with the reaction time. The morphology of Cu powder depended on that of the precursor of CuO and processing conditions. The average particle size was about 0.5µm.

• Keywords: Preparation;Copper powder;Copper oxide;Slurry;Wet-reduction;