The reduction mechanism of Nickel Oxide with Graphite
강태욱Tai Ouk Kang, 이강인Kang In Lee, 윤종규Jong Kyu Yoon
Abstract
The reduction of Nickel oxide powder mixed with the graphite in solid state has been studied in the temperature range of 820-920℃ by Thermogravimetric method under the flowing CO₂ and N₂ gas. The reduction rate shows rapid increase suddenly after initial slow rate in CO₂ gas flowing system. This rapid increase of reduction rate has been explained in terms of cyclic reduction due to the generation of CO gas and autocatalytic effect of the product Ni powder. The similar pattern of the reduction rate in less than stoichiometric carbon content in the N₂ gas flowing system has been observed in the later part of the reduction. The mechanism of the anomalous reaction rate has been also explained in terms of reaction contact area and the cyclic reduction of CO generation. The activation energy of the N₂ gas flowing system has been determined to be about 55±5 ㎉/mole.