Abstract:A precursor of cobaltous dihydroxycarbonate was firstly prepared by precipitation reaction of cobalt sulfate solution and ammonium carbonate solution, and then a hydrothermal process for the precursor was conducted to obtain the spherical cobalt carbonate with low sulfur content. The experimental results show that the feeding method, final pH value of the precipitation reaction slurry and the concentration of the cobalt sulfate solution have obvious effects on the sulfur content, morphology and particle size distribution of the precursor. The sulfur content of the precursor is 0.0115 wt.% under the optimized conditions. The hydrothermal treatment with temperatures of 125-150 °C can transform the precursor of cobaltous dihydroxycarbonate into spherical cobalt carbonate and decrease the sulfur content to 0.0030 wt.% in the obtained product.

Key words: cobalt sulfate solution; cobaltous dihydroxycarbonate; ammonium carbonate; spherical cobalt carbonate; hydrothermal treatment