NiOおよびNiO-MgO固溶体ペレットのCOガス還元に関する研究
1977 年 93 巻 1073 号 p. 500-506
詳細
1977 年 93 巻 1073 号 p. 500-506
The reduction of right cylindrical pellet of NiO and (Nix Mgr-x) O with CO gas has been studied in terms of kinetic consideration. The experimental data were analysed by the methods based on the unreacted core shrinking model. The observation through scanning electron microscope indicates that number and size of pores or grain form depend upon the reduction temperature. The values of rate parameters Kg' for the NiO pellet are in good agreement with those derived from naphthalene sublimation method. The temperature dependence of effective diffusion coefficient Ds for NiO will be expressed as follows; In Ds (NiO) =-7.59/R.T103+0.87
The equation is also in good agreement with the equation Ds=DCO-CO2 εvζ. In case of NiO-MgO pellets, the appearance of reduced layer is different from that of NiO, but the values Ds seems to show similar temperature dependence to the above mentioned. The activation energy for the reduction reaction in case of NiO is about 9.63 kcal/mole. whereas in NiO-MgO system the activation energy is about 70-80 kcal/mole.
