六水合氯化钴脱水过程分析

Analysis on dehydration of cobalt chloride hexahydrate

六水合氯化钴是制备钴酸锂电池用四氧化三钴粉末的主要原料,不同结晶水含量的氯化钴制得的四氧化三钴其粒度及分散性存在差异,以二水合氯化钴为原料,通过高温水解反应可以得到粒度细小、分布均匀的四氧化三钴粉末。通过热重差热分析(TG-DTA)测定了六水合氯化钴的脱水过程,研究并分析了脱水过程中干燥温度以及料层厚度对脱水的影响,为研究以六水合氯化钴为原料通过高温水解反应制备四氧化三钴提供理论依据。结果表明:温度高、料层薄均可提高六水合氯化钴的脱水速率;在120℃下干燥230 min可以脱除4个结晶水,变成二水合氯化钴,干燥360 min可脱除5个结晶水,变成一水合氯化钴;当温度升高到220℃并且累积干燥时间达到21 h时,六水合氯化钴可脱除全部结晶水。

Cobalt Chloride Hexahydrate （CoCl2 . 6H2O ） is a main raw material for preparing cobalt oxide （Co3O4 ） powder used for lithium cobalt oxide battery. Granularity and dispersion of Co3O4 powder were not the same when crystal water contents of CoCl2 were different. Powders with small size and uniform distribution could be obtained with CoCl2 . 2H2O as raw material by high temperature hydrolysis method. Dehydration process of CoCl2 . 6H2O was determined by TG - DTA. In addition, effects of drying temperature and thickness of feed layer on dehydration in the dehydration process were studied and analyzed , which provided the theoretical foundation for preparation of Co3O4 with CoCl2. 6H2O as raw material by high temperature hydrolysis reaction. Results indicated that higher temperature and thinner feed layer both could increase dehydration speed of CoCl2. 6H2O; four crystal waters were dehydrated from CoCl2 . 6H2O and it turned to CoCl2 . 2H2O at 120 ℃ for 230 rain;another one crystal water was dehydrated and it turned to CoCl2 .H2O at the same temperature for 360 min;If the temperature increased to 220 ℃ for 21 h, all crystal waters could be dehydrated.