Synthesis of Cobalt Powder by Reduction of Cobalt Oxide with Ethanol

Abstract

In this study, ethanol (C2H5OH) was used as a reducing agent for Co powder synthesis from Co3O4. It aimed to investigate the effects of temperature (700-900 K), reaction time (0-60 min), and gas flow rate on the reaction behavior of Co3O4 in ethanol flow. Mass measurement, x-ray diffraction, and scanning electron microscopy techniques were used to characterize the products. Single-phase Co powders with mean particle sizes of 0.51 mu m and 0.70 mu m were obtained within similar to 10 min at 800 K and 900 K, respectively. Above 800 K, external mass transfer controlled the reduction process (Q(a) = 0.52 kJ/mole). Below 800 K, the process (Q(a) = 20.17 kJ/mole) was partly controlled by external mass transfer and partly by intrinsic chemical reaction kinetics. Significant C uptake was observed at 700 K and 750 K within 60 min. The reactions were discussed in the light of thermodynamic results, which predicted Co formation from Co3O4 and C2H5OH.