| 摘要 |
A process for the production of powdered metallic cobalt in- cluding ultra fine metallic cobalt by reduction of cobaltous ammo- nium sulphate solutions. A soluble silver salt, preferably silver sul- phate or silver nitrate, is added in an amount to provide a soluble silver to cobalt weight ratio in the range of 1 g to 10 g silver: 1 kg cobalt, an organic dispersant such as bone glue or polyacrylic acid, or mixture thereof, is added in an amount of 0.01 to 2.5% of the weight of the cobalt, an ammonia to cobalt mole ratio in the range of about 1.5:1 to 3.0:1, preferably about 2.0:1 is established, and the solution is heated to a temperature in the range of 150 to 250 .degree.C, preferably about 180.degree.C, with agitation under a hydrogen pr es- sure of 3000 to 4000 kPa for an induction period and a reduction period sufficient to reduce cobaltous sulphate to cobalt metal pow- der. The ultra fine cobalt powder is submicron in size, is nodular, and has a surface area in excess of 2.0 M2/g. The particle size and surface area are essential to allow for lower sintering tempera- tures to achieve the required sintered product density.
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