Preparation of basic nickel carbonate particles in solution system of Ni(Ⅱ)-NH3-CO32--H2O
来源期刊：中国有色金属学报(英文版)2004年第5期
论文作者：郭学益 黄凯 张多默
文章页码：1006 - 1012
Key words：thermodynamic equilibrium; nickel ammonia complex; basic nickel carbonate; precipitation
Abstract: Based on the principles of simultaneous equilibrium and mass balance, a series of thermodynamic equilibrium equations of Ni(Ⅱ)-NH3-CO32--H2O system at ambient temperature were deduced theoretically and the thermodynamic diagrams of lg［Ni］T versus pH at different solution compositions were drawn, which was quite effective to explain the formation mechanism of precipitation particles with different microscopic shapes. When pH of the solution is below 7.0, free nickel ions are dominant and when the precipitant is added, the fast coagulation will take place leading to the loose flocculation particles. While pH is above 7.0, because of the coordination of nickel ion with ammonia, the precipitation proceeds slowly accompanying with the release of Ni2+ from the multi-coordinated Ni(NH3)n2+(n=1, 2, …, 6), which easily leads to the formation of the dense spherical particles.
