摘要
分别以CoCO_(3)、CoC_(2)O_(4)·2H_(2)O、Co_(3)O_(4)(T)和Co_(3)O_(4)(C)_(4)种钴化合物为原料,在不同温度下进行氢还原法制备钴粉实验,通过XRD进行物相分析,探究还原温度及原料对钴粉晶型的影响。研究表明:上述4种原料在相同温度下进行氢还原实验,所得还原钴粉的晶型组成明显不同;通过控制还原温度和原料,存在定向制备指定晶型组成钴粉的可能;氢还原制备钴粉时,往往是多项反应共同影响产物晶型组成,CoCO_(3)可进行“直接还原反应”和“分解-还原反应”,CoC_(2)O_(4)·2H_(2)O存在“直接还原反应”、“脱水-分解反应”和“脱水分解反应”,Co_(3)O_(4)(T)和Co_(3)O_(4)(C)仅有“直接还原反应”,但亦可细分为“CoO还原反应”和“Co2O_(3)还原反应”。
The effects of reduction temperature and raw materials on the crystal form of cobalt powder were stud‐ied through controlled variable experiments,and the corresponding internal mechanism was explored.Four cobalt compounds,CoCO_(3)、CoC_(2)O_(4)·2H_(2)O、Co_(3)O_(4)(T)and Co_(3)O_(4)(C),were used as raw materials,and the hydrogen reduc‐tion method was used to prepare cobalt powder at different temperatures.The raw materials were evenly placed in a stainless steel boat,and then placed in a sliding rail tube furnace,and the furnace tube was purged with argon for a period of time to exhaust the air.After that,hydrogen gas was continuously passed in,and the temperature was raised to the reaction temperature at a fixed rate and kept for a period of time.After the reaction,continue to pass hydrogen gas and cool down in the furnace to room temperature,to obtain the sample.The phase analysis of the product was carried out by XRD,and then the data was processed and edited by Origin software.These data were finally used for result analysis and conclusion output.With the increase of reaction temperature,the proportion of FCC-Co in the product increases significantly.However,the components of the reduction products of different raw materials at the same temperature are different,and the corresponding temperature-component curves are also different.For example,at 480℃,the content of FCC-Co in three groups of reduction products all exceed 90%,of which the content of Co_(3)O_(4)(T)reduction product is the highest at 96.0%,and the content of FCC-Co in the corre‐sponding products of CoC_(2)O_(4)·2H_(2)O and Co_(3)O_(4)(C)are 94.8%and 93.3%,respectively.However,the FCC-Co content in the CoCO_(3)reduction product is only 70%at this time.The above-mentioned four kinds of raw materials are subjected to hydrogen reduction experiments under the same process,and the crystal composition of the obtained reduced cobalt powder is obviously different.By controlling the temperature and raw material,it is possi‐ble to directionally prepare cobalt powder with a specified crystal form composition.When cobalt powder is pre‐pared by hydrogen reduction,multiple reactions often affect the crystal composition of the product.CoCO_(3)can undergo“direct reduction reaction”and“decomposition-reduction reaction”,and CoC_(2)O_(4)·2H_(2)O has“direct reduc‐tion reaction”,“dehydration-decomposition reaction”and“dehydration decomposition reaction”,Co_(3)O_(4)(T)and Co_(3)O_(4)(C)only have“direct reduction reaction”,but they can also be subdivided into“CoO reduction reaction”and“Co2O_(3)reduction reaction”.
作者
朱治军
王朝安
曲鹏
ZHU Zhijun;WANG Chao′an;QU Peng(School of Physics and Materials Science,Nanchang University,Nanchang 330000,China;Anhui Hanrui New Material Co.,Ltd.,Chuzhou 239000,China)
出处
《粉末冶金工业》
CAS
北大核心
2022年第6期77-81,共5页
Powder Metallurgy Industry
关键词
钴粉
氢还原
FCC-Co
相变
晶型
crystal form
hydrogen reduction
FCC-Co
phase transition
