The kinetics and mechanism of the reduction of olivine by H2 have been studied at H2 partial pressures between 0.046 and 0.14 atm and temperatures from 1070 to 1370 K. For Fa93 (Fe1.86-Mg0.14SiO4), the reaction order with respect to H2 is 0.8 and the activation energy is 205 kJ/mol for conversions up to 40%. For Fa100 (Fe2SiO4), the reaction order is 0.5 and the activation energy is 260 kJ/mol. The apparent kinetic parameters do not change significantly as conversion increases from about 15 to 60%. Mg2+ is less reducible than Fe2+, and its presence slows the reaction. The solid products of the reaction are metallic iron and vitreous silica. The products form a nonporous layer around an unreacted core. Permeation of H2 through this layer is important in determining the rate of reaction.
ASJC Scopus subject areas
- Chemical Engineering(all)
- Industrial and Manufacturing Engineering