The reduction kinetics are based on an adsorption-autocatalytic reaction. Reduction enthalpy and temperature are linked by a linear relationship. The calculated activation energy is about 75 kJ•mol-1. Carbide formation occurs only when all oxygen is removed.
The apparent activation energy at the beg, inning of the reaction is 121kj/m0l WO3 and increases during further progress t0 205 kJ•mol-1 WO3, due to the fact that the reaction becomes diffusion-controlled (diffusion of oxygen to the particle surface).
The assumed reaction mechanism is as follows: direct reaction of WO3 and C at contact zones and. For the main portion, sublimation of W03 to the carbon particles, reduction at the surface of the carbon particles, and desorption of CO and CO2.
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