您目前所在的位置:首页 - 期刊简介 - 详细页面

铁道科学与工程学报

JOURNAL OF RAILWAY SCIENCE AND ENGINEERING

Vol. 15    No. 4    August 2005

[PDF Download]    [Flash Online]

    

Thermodynamic analysis on preparation of fibrous NiO precursor powders with oxalate precipitation process
ZHAN Jing(湛 菁), ZHANG Chuan-fu(张传福),
 LI Tie-jing(李铁晶), WU Jian-hui(邬建辉)

School of Metallurgical Science and Engineering, Central South University, 
Changsha 410083, China

Abstract: According to the principles of simultaneous equilibrium and mass balance, a series of thermodynamic equilibrium equations of Ni(Ⅱ)-C2O2-4-NH3-NH+4-H2O system at ambient temperature are deduced theoretically and the logarithm concentration versus pH value(lg[Ni2+T—pH) diagrams at different solution compositions are drawn. The results show that when pH is above 8.0, nickel ions coordinate with ammonia, the precipitation proceeds slowly accompanying with the release of nickel ions from the multi-coordinated Ni(NH3)2+n(n=1, 2, …, 6) and the morphology of NiO powder precursor is fibrous; when pH is below 8.0, nickel ion directly reacts with C2O2-4 and the morphology of NiO powder precursor is of cubic-shape. Some experiments were made to confirm the relation between the total concentration of nickel ion and pH. It is shown that the thermodynamic mathematical model is correct and the calculated values are basically accurate.

 

Key words: thermodynamic analysis; NiO precursor powder; fibrous shape; cubic-shape

ISSN 1672-7029
CN 43-1423/U

主管:中华人民共和国教育部 主办:中南大学 中国铁道学会 承办:中南大学
湘ICP备09001153号 版权所有:《铁道科学与工程学报》编辑部
------------------------------------------------------------------------------------------
地 址:湖南省长沙市韶山南路22号 邮编:410075
电 话:0731-82655133,82656174   传真:0731-82655133   电子邮箱:jrse@mail.csu.edu.cn