Abstract
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.
Original language | English |
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Pages (from-to) | 2096-2099 |
Number of pages | 4 |
Journal | Materials Letters |
Volume | 61 |
Issue number | 10 |
DOIs | |
Publication status | Published - 2007 Apr 1 |
Keywords
- Carbo-thermal reduction
- Electric field
- Kinetics
- Magnetic field
- Microwave
- Nickel oxide
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering