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 ...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 p H 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℃can transform the precursor of cobaltous dihydroxycarbonate into spherical cobalt carbonate and decrease the sulfur content to 0.0030 wt.%in the obtained product.展开更多
Spherical cobalt carbonate with high tap density, good crystallization and uniform particle size was prepared by controlled chemical crystal method using cobalt chloride and ammonium bicarbonate as cobalt source and p...Spherical cobalt carbonate with high tap density, good crystallization and uniform particle size was prepared by controlled chemical crystal method using cobalt chloride and ammonium bicarbonate as cobalt source and precipitator. The effects of pH value and reaction time on crystallization and physical properties of cobalt carbonate were studied. The results show that the key factors influencing the preparation process of spherical cobalt carbonate with high tap density and good crystallization are how to control pH value (7.25±0.05) and keep some reaction time (about 10 h). Co4O3 was prepared by sintering spherical morphology CoCO3 samples at varied temperatures. The results show that as the decomposition temperature increases, the as-obtained Co4O3 products with porous structure transform into polyhedral structure with glazed surface, and simultaneously the cobalt content and tap density increase. However, the specific surface area shows a trend of decrease.展开更多
基金Project(51874372)supported by the National Natural Science Foundation of China
文摘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 p H 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℃can transform the precursor of cobaltous dihydroxycarbonate into spherical cobalt carbonate and decrease the sulfur content to 0.0030 wt.%in the obtained product.
文摘Spherical cobalt carbonate with high tap density, good crystallization and uniform particle size was prepared by controlled chemical crystal method using cobalt chloride and ammonium bicarbonate as cobalt source and precipitator. The effects of pH value and reaction time on crystallization and physical properties of cobalt carbonate were studied. The results show that the key factors influencing the preparation process of spherical cobalt carbonate with high tap density and good crystallization are how to control pH value (7.25±0.05) and keep some reaction time (about 10 h). Co4O3 was prepared by sintering spherical morphology CoCO3 samples at varied temperatures. The results show that as the decomposition temperature increases, the as-obtained Co4O3 products with porous structure transform into polyhedral structure with glazed surface, and simultaneously the cobalt content and tap density increase. However, the specific surface area shows a trend of decrease.
