Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1652749 | Materials Letters | 2007 | 4 Pages |
A powder mixture of NiO and graphite was heated in a single mode-microwave (MW) applicator at 2.45 GHz for carbo-thermal reduction of NiO. The specimen was placed in the wave guide at maximum positions of either electric (E) field or magnetic (H) field and kept at a constant temperature.A tendency was observed that the reduction rate at 600 °C was larger in the H-field than in the E-field. Considering the fact that NiO can be heated only in the E-field, while graphite can be heated in both fields, graphite particles in the powder mixture might be selectively heated in the H-field. Hence, it is postulated that a microscopic temperature gradient is formed more in the H-field, which caused the gas convection, then the mass transfer and the gas–solid reaction is enhanced, so the enhanced reduction kinetics resulted, eventually.