Abstract: The ultrafine spheric Co powder with good dispersity was prepared with Co(OH)₂ being the raw material and glycol being the solvent and reductant.The effect of the quantity of NaOH on the reaction speed,the effect of the quantity of Co(OH)2 per unit volume of glycol and the quantity of additive on the particle-size and particle-appearance of the Co powder were examined.SEM,XRD,BET and the laser particle-size analyzer were used to examine the particle appearance,the crystal structure,the surface area and the particle-size distribution.The results showed that the Co powders reduced by polyol were spheric,most being cubic closest packing,few being hexagonal closert packing;when the conditions were Co(OH)₂ 150 g/L,NaOH 40 g/L and surface active agent glycot 30 g/L,the particle-size distribution of Co powder was narrow with an average dimeter of 0.88 μm,the surface area was 2.705 m2/g,and the Co content was over 99.5%.

Key words: glycol, ultrafine powder, Co powder, reduction