碳酸镍沉淀过程的研究以及介孔氧化镍的制备  

Study on the precipitation process of nickel carbonate and synthesis of mesoporous nickel oxide

作　　者：刘昉[1] 张昭[1] 

机构地区：[1]四川大学化工学院,四川成都610065

出　　处：《电子元件与材料》2008年第8期72-73,共2页Electronic Components And Materials

基　　金：国家自然科学基金资助项目(No.50474071)

摘　　要：碳酸镍和氧化镍是重要的无机精细化学品,在化学、冶金、电子和能源等领域有广泛的应用。首先从碳酸镍沉淀过程的热力学分析出发,研究阴离子(SO42-,Cl–)对碳酸镍沉淀过程的影响。活度系数反映了电解质溶液中阳、阴离子之间和离子与溶剂之间微观作用程度的大小。笔者采用Meissner半经验模型计算了碳酸镍在不同条件下水溶液中的活度系数,并进一步估算了碳酸镍在其中的溶解度大小。估算结果表明,与氯化钠溶液体系相比,碳酸镍在硫酸钠溶液体系中的活度系数较小,因而溶解度较大。为了提高计算置信度,还采用了Bromley模型和Pitzer模型对相应体系的活度系数进行估算,计算结果与Meissner半经验模型的结果非常接近。实验测量了各溶液的表面张力和溶液在碳酸镍表面的润湿角。结果表明,碳酸镍在硫酸钠溶液体系中的固–液界面张力较大,微小晶粒在硫酸钠溶液体系中的溶解度也较大。以上结果表明,碳酸镍在硫酸钠溶液体系中较难析出结晶,在氯化钠溶液体系中则相对容易些。Nickel carbonate and nickel oxide are important inorganic fine chemicals, widely used in chemical, metallurgical, electronic and energy sources industries. The research was beginning with studying the effects of anions on precipitation process of nickel carbonate. Activity coefficient shows the effect size of the microcosmic effects between ions and solvent. Meissner＇s semi empirical model was applied to calculate the average activity coefficients of nickel carbonate in different electrolyte solutions at different conditions. And the conditional solubility of nickel carbonate was also calculated. The calculated results show that activity coefficients of NiCO3 in sodium sulphate solutions are less than that in sodium chloride solutions, and the solubilities in sodium sulphate solutions are larger. To improve the confidence of the calculations, Bromley＇s and Pitzer＇s models were also applied to calculate activity coefficients. The calculation results of Bromley＇s and Pitzer＇s models are very close to Meissner＇s results. And then experiments were carried out to measure the surface tensions, and contact angles of solutions on NiCO3 surface. According to the experiment results, the solid-liquid interface tension between NiCO3 and sodium sulphate solution is larger than that between NiCO3 and sodium chloride solution. And the tiny crystal NiCO3 has larger solubility in sodium sulphate solutions, which indicates that crystallization of NiCO3 in sodium sulphate solution is more difficult than in sodium chloride solution. The influence of SO4^2- and Cl^- on precipitation and crystallization process of NiCO3 was also studied based on crystal dynamics. The supersaturations at different initial concentration of reaction system were compared. Diffusion coefficients of ions were described by Glasstone＇s model. The diffusion coefficients of Ni^2＋ and CO3^2- in chloride solutions are larger than those in sulphate solutions. In sulphate solutions, the diffusion coefficients and supersaturation are both less,

关 键 词：无机非金属材料 碳酸镍 理论分析 工艺研究 计算机模拟 介孔氧化镍 

分 类 号：TQ110.6[化学工程—无机化工]