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Processing of Refractory Ores in a Microwave Induced “Cold” Plasma

Published online by Cambridge University Press:  25 February 2011

D.E. Bullard
Affiliation:
Both at Arizona Materials Laboratory, Department of Materials Science and Engineering, University of Arizona, Tucson, Arizona 85721
D.C. Lynch
Affiliation:
Both at Arizona Materials Laboratory, Department of Materials Science and Engineering, University of Arizona, Tucson, Arizona 85721
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Abstract

A Microwave Induced Plasma has been used to investigate the processing of metallurgically significant refractory oxides in a non-equilibrium or “cold” plasma. The main emphasis of this work has centered on the reduction of TiO2 in a hydrogen plasma. The plasma was maintained using microwave energy (2.45 GHz) in a single mode resonant cavity. The reaction was monitored for volatile species with a quadrupole mass spectrometer, while the extent of reaction was determined by an external standard X-Ray diffraction technique. The effect of process variables (absorbed power by the plasma, chamber pressure, and time) on the extent of reaction was investigated. Hydrogen reduction in a plasma has produced up to 60% conversion of TiO2 to Ti2O3 in 11 minutes with the sample on a grounded support rod, while only an 8% conversion is observed for a sample on an insulated support rod. Sample temperatures were below 735 K for most plasma conditions, based upon thermodynamic considerations.

Type
Research Article
Copyright
Copyright © Materials Research Society 1992

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